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Monitoring our EnvironmentDischarges and Monitoring in the United Kingdom
Annual Report 2009
Quantity SI unit and abbreviation
Absorbed dose Gray (Gy)
Dose equivalent Sievert (Sv)
Radioactivity Becquerel (Bq)
Factor Prefix and abbreviation Factor Prefix and abbreviation
1018 exa (E) 10-3 milli (m)
1015 peta (P) 10-6 micro (µ)
1012 tera (T) 10-9 nano (n)
109 giga (G) 10-12 pico (p)
106 mega (M) 10-15 femto (f)
103 kilo (k) 10-18 atto (a)
The tonne (metric ton) has the official abbreviation 't'.However, in this report 'te' has been used to avoid confusion with the British ton.
SI Units
Multiples and submultiples of SI units
Introduction Page
Sellafield Ltd 5
Environmental reporting by Sellafield Ltd 5
Regulation of non-radioactive discharges
and disposals 5
Regulation of radioactive discharges and disposals 6
Critical group and collective doses 7
Critical group doses 7
Critical group dose limits and constraints 7
Collective doses 8
Monitoring of environmental radioactivity
and dose assessment 8
Analytical measurements, limits of detection
and rounding of data 9
Protection of the environment 10
Natural radioactivity 10
References 11
SellafieldSummary 14
Operations at Sellafield 14
Radioactive discharges and disposals 15
Liquid discharges via the pipeline 15
Liquid discharges via the Factory Sewer 17
Aerial discharges 17
Solid wastes 21
Monitoring of the environment for radioactivity 21
Marine pathways 21
Foodstuffs 21
Indicators 23
Seawater and sediments 23
External pathways 23
Beach monitoring 25
Airborne and terrestrial pathways 26
Airborne 26
Foodstuffs and water 28
Indicators 31
Groundwater 31
Direct radiation 31
Radiological impact of operations at Sellafield 33
Critical group doses 33
Marine pathways 33
Airborne and terrestrial pathways 37
Direct radiation 42Collective doses 42
Non-radioactive discharges and disposals 43Disposals made under the terms of Waste Disposal
or Waste Management Licences 43Ozone depleting substances and fluorinated
greenhouse gases 43
Carbon dioxide and other greenhouse gases 43
Off-site disposals of solid waste 44
Page
Non-radiological monitoring of the environment 44
Air sampling 44
Water sampling 45
Monitoring of Sellafield’s landfill sites 45
Environmental impact of non-radioactive discharges 45
References 46
CapenhurstSummary 48
Operations at Capenhurst 48
Radioactive discharges and disposals 48
Liquid discharges into the Rivacre Brook 48
Aerial discharges 48
Solid wastes 50
Monitoring of the environment for radioactivity 50
Aquatic pathways 50
Airborne and terrestrial pathways 50
Direct radiation 50
Radiological impact of operations at Capenhurst 52
Critical group doses 52
Aquatic pathways 52
Airborne and terrestrial pathways 52
Direct radiation 52
Collective doses 52
Non-radioactive discharges and disposals 52
Discharges made under the terms of Prescribed Process authorisations 52
Discharges made under the terms of consents 53
Ozone depleting substances 53
Off-site disposals of solid waste 53
References 53
AppendixValues for individual dose per unit intake and collective dose per unit discharge
Individual doses 55
Collective doses 58
References 60
GlossaryGlossary of terms and abbreviations 62
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IntroductionDischarges and Monitoring in the United Kingdom
Annual Report 2009
Sellafield Ltd
1. Sellafield Ltd is the company responsible for safelydelivering decommissioning, reprocessing, nuclearwaste management and fuel manufacturing activitieson behalf of the Nuclear Decommissioning Authority.The company has sites at Sellafield in Cumbria andCapenhurst in Cheshire as well as an extensiveengineering design capability based at Risley inWarrington. Now under the ownership of NuclearManagement partners, Sellafield Ltd has the largestconcentration of nuclear expertise in Europe, with over50 years of experience. The strategy and focus ofSellafield Ltd is to deliver accelerated nuclear clean-upprogrammes, safely and cost-effectively.
2 Sellafield Ltd (established in April 2007) was previouslyoperating as British Nuclear Group Sellafield Ltd.British Nuclear Group Sellafield Ltd was establishedfollowing the restructuring of its parent company BNFLin response to the formation of the NuclearDecommissioning Authority (NDA). The NDA is thepublic body tasked by Her Majesty's Government withtaking strategic responsibility for the decommissioningof civil public sector nuclear sites in the UK. InNovember 2008, Nuclear Management Partnersbecame the Parent Body Organisation after a 2 yearcompetitive process by the NDA to secure a newParent Body Organisation for Sellafield Ltd. The NDAhas contracted the operation of the Sellafield andCapenhurst sites to Sellafield Ltd and of the Low LevelWaste Repository (LLWR) to LLW Repository Ltd andwill award subsequent contracts on a competitivetender basis.
Environmental reporting by Sellafield Ltd
3 Before 2004, BNFL produced a single environmentalannual report that contained information on all of theCompany's UK sites. From 2004, following theformation of the NDA and the restructuring of BNFL,individual site management companies tookresponsibility for producing their own environmentalannual reports.
4 This 2009 report has been produced by Sellafield Ltdand covers the Sellafield Ltd sites in Cumbria(Sellafield) and Cheshire (Capenhurst). It providesdetailed information on radioactive discharges anddisposals, monitoring of the environment andradiological impact, and also includes information onnon-radioactive discharges and disposals. It may benoted that the report provides a summary of thecomprehensive data that are available for inspectionby members of the public on the Public Registersmaintained by the Environment Agency. This report isalso available on the Sellafield Ltd website(http://www.sellafieldsites.com).
5 Wherever practicable, this report continues to present annual discharge and disposal data over five years forall radionuclides specified in Radioactive SubstancesAct (RSA) authorisations; the results of environmentalmonitoring for the report year; information on trends;and radiological impact in terms of critical group andcollective doses. Any non-compliance with numericallimits is reported.
6 For non-radioactive discharges, it would beimpracticable to report the discharges of all chemicalspecies and performance against every condition in allauthorisations and consents, even more so for a five-year period (many consent conditions relate toconcentrations in individual samples). Accordingly,discharges and disposals are normally reported forjust the year of the report and other quantitativeconditions, such as temperature and pH, are usuallyonly reported where non-compliances have occurred.Information relating to longer-term trends is includedwhere it is of particular interest. Discharges arereported as annual 'loads', which are more practicableto report than effluent concentrations, the form inwhich limits are often defined, although any non-compliances with such limits are reported.
7 All current authorisations and consents, as well aswaste disposal and waste management licences,issued specifically to each site, are available forinspection on the Public Registers referred to inparagraph 4.
Regulation of non-radioactive discharges anddisposals
8 The regulation of non-radioactive discharges anddisposals is, with the exception of dischargesregulated by consents issued by the relevant sewageundertaker (see paragraph 9), the responsibility of theEnvironment Agency and local authorities whoregulate discharges in accordance with the provisionsof the Environmental Protection Act 1990 (EPA 1990),the Control of Pollution Act 1974, the WaterResources Act 1991 as amended by the EnvironmentAct 1995 and the Pollution Prevention and Control Act1999.
9 Discharges to controlled waters of sewage or tradeeffluent, from processes not subject to EPA 1990authorisation, are regulated through a system ofconsents under the Water Resources Act in Englandand Wales. Where discharges of trade effluent aremade to public sewers, they must be subject to aconsent issued by the relevant sewage undertaker asrequired by the Water Industry Act 1991 in Englandand Wales. In granting consents, the regulatoryagencies or sewage undertakers take account ofStatutory Water Quality Objectives. Consents place
5
limits on either total quantities discharged (loads) orinstantaneous concentrations.
10 Disposals of non-radioactive wastes are regulatedthrough EPA 1990 and the Hazardous WasteRegulations 2005. Where wastes are transferred toanother organisation for treatment or disposal, there isa legal Duty of Care on producers, carriers anddisposers to ensure that waste is only disposed ofunder the terms of a Waste Management Licence.Where non-hazardous and inert waste is transferred, it is accompanied by a transfer note which includes afull written description of the waste. Where hazardouswaste is transferred in accordance with HazardousWaste Regulations 2005; it is accompanied by aconsignment note. Landfill disposals are subject tothe Landfill Regulations which implement therequirements of the Landfill Directive and placeadditional requirements on both landfill site operatorsand waste consignors.
Regulation of radioactive discharges and disposals
11 The control of radioactive wastes is subject to theprovisions of Radioactive Substances Act 1993.Under this Act, operators are permitted to dischargeand dispose of radioactive waste only in accordancewith Certificates of Authorisation issued by theEnvironment Agency in England and Wales.
12 It is the policy of these agencies to reviewauthorisations regularly. In establishing dischargelimits for authorisations, they take into account theradiation protection principles presented in the latestrelevant Government White Paper (table 1)1. Theseprinciples are based on Government policy and the
advice of the Health Protection Agency as discussedbelow in the context of critical group dose limits andconstraints (paragraphs 22-25) and collective doses(paragraphs 26-29). Those parts of the Euratom BasicSafety Standards Directive (BSS) 1996 relating todose limits (paragraph 25) were incorporated into UKlaw in the Radioactive Substances (Basic SafetyStandards) Directive 2000 issued by the appropriateministers to the Environment Agency. Otherprovisions of the BSS Directive were implementedthrough the Ionising Radiation Regulations 1999.
13 All discharges of radioactivity are subject to therequirement to use Best Practicable Means (BPM) tolimit the amount of radioactivity discharged. To enablethe Environment Agency to monitor the application ofBPM, Quarterly Notification Levels (QNLs) apply atsome sites to discharges of certain radionuclides.Exceeding a QNL requires the operator to submit awritten justification of the BPM used to limitdischarges.
14 The Food Standards Agency, which reports to healthministers, was formed on 1 April 2000. Itsresponsibilities include food safety implications ofdischarges of radioactive waste, in support of which itundertakes a substantial radiological surveillanceprogramme both for marine and terrestrial samples. It has taken on the role, formerly exercised by theMinistry of Agriculture Fisheries and Foods (MAFF), asstatutory consultee to the Environment Agency inmatters relating to radioactive dischargeauthorisations. The Nuclear Installations Inspectorate(NII) has a similar role as statutory consultee becauseit regulates the accumulation of radioactive waste onlicensed sites and the exposure of the general publicto direct radiation from those sites.
6
1000 µSv Limits the overall exposure to the general public from man-made controlled sources of radiation (excluding medicaluses), including the effects of past and current discharges andsumming across all relevant exposure pathways.
500 µSv A ‘site constraint’ to limit the aggregate exposure froma number of sources with contiguous boundaries at a singlelocation.
300 µSv A ‘dose constraint’ used as the principal criterion in determiningapplications for discharge authorisations from new facilities. Itapplies to the sum of all relevant exposures resulting from theoperation of a single new source only.
20 µSv Threshold for optimisation below which the regulators will notseek further reduction in public exposures, provided they aresatisfied that ‘Best Practicable Means’ are being applied tosafeguard the public.
The previous flexibility to average exposure overmore than one year is no longer considerednecessary, and this limit is now a cap on annualexposure.
Applies irrespective of whether different sources onthe site are owned or operated by the same ordifferent organisations.
Existing facilities may seek a higher dose constraintin certain circumstances. In most cases this shouldnot be necessary and, in any case, the dose limitand the ALARA principle continue to apply.
The introduction of this concept is consistent withthe current practice of the Health and SafetyExecutive.
Annual dose Applicability Comments
Table 1. Summary of radiation protection principles in the Government’s review of radioactive waste management policy (1995)1
15 The nuclear regulators employed by the EnvironmentAgency regularly pay inspection visits to nuclear sitesto critically review operations against radiologicalprotection standards and the application of BPM.Thus the authorisation process is one of continualreview (see also paragraph 12). This process not onlyreviews operations, effluent control and treatmentarrangements, on-site sampling and analyticalmethods, but also the results of environmentalmonitoring, habits surveys and advances in themethodology for assessing radiological impacts.
16 Thus the authorisation and inspection processembraces important aspects of radiation protectionby:
• controlling, monitoring and recording dischargesto the environment in accordance with BPM;
• monitoring of the environment to establishresultant radionuclide concentrations;
• carrying out appropriate research, investigationsand assessments to determine pathways for thetransport of radioactivity through theenvironment;
• assessing radiation doses to the public;
• predictive assessment of radiation doses to thepublic arising from future discharges to theenvironment.
17 The Company is involved in all these activities withrespect to discharges from its sites. Under the termsof the discharge authorisations, there is a statutoryobligation to carry out defined monitoringprogrammes, both for discharges and forenvironmental radioactivity, the latter being known asStatutory Environmental Monitoring Programmes(SEMPs). In addition, the NII requires the assessmentof doses to members of the public from directradiation.
18 At the Ministerial meeting of the OSPAR Commissionat Sintra in Portugal in 1998 (see Glossary), the UKGovernment agreed to a commitment to reduceconcentrations of radioactive and hazardoussubstances in the marine environment so that, by2020, discharges will be reduced to levels at whichthe resulting concentrations additional to historic levelsare close to zero. Following Defra's (see Glossary)publication in July 2009 of the UK Strategy forRadioactive Discharges2, the Company is continuingto work with Government and regulators to achievethe objectives agreed at Sintra.
Critical group and collective doses
Critical group doses
19 A key concept for assessment of dose to the public isthe 'critical group'. This represents those members ofthe public who are most exposed to radiation due tooperations at a given site3,4. The dose to members ofa critical group is assessed as the mean of the sumsof committed effective doses from intakes ofradionuclides during the year and their effective dosesfrom external irradiation (see paragraph 34). Thesesums are for convenience termed Effective Doses (seeGlossary). Effective doses are calculated bycombining dose per unit intake data (see Appendix)with estimates of annual radionuclide intake byingestion and inhalation, taking into account allrelevant pathways, such as consumption of specificfoods at high rates and inhalation during occupancy ofcertain areas5,6.
20 In determining the critical group appropriate to aparticular site, it is recognised that the relative dosesfrom different pathways will depend on the habits ofparticular groups of individuals. Such doses shouldbe summed as required to obtain the critical groupdose. Thus a high rate consumer of seafoods mayreceive only a minor exposure via pathways such asmilk consumption or proximity to the site perimeter.For another group, consumption of locally producedmeat and milk may combine to result in an elevatedexposure. Accordingly, it is common practice todefine exposure groups in terms of a dominantpathway or habit (e.g. seafood consumers, boatdwellers, anglers, inhalation pathways etc). Forsimplicity, these may at times be referred to in thisreport as 'critical groups', although strictly speakingthe Radiation Protection Division of the HealthProtection Agency (formerly the National RadiologicalProtection Board, NRPB)4 defines only the mostexposed group at any given time as the critical group.
21 This report focuses mainly on doses to members ofcritical groups; the small groups of people that aremost exposed to radiation from nuclear facilities. Thedoses received by the rest of the population, fromoperations at Sellafield Ltd sites, will be very muchless than those received by critical groups.
Critical group dose limits and constraints
22 UK dose limits and constraints, which are applicableto controlled releases of radioactivity, are based on the'1990 Recommendations' of the InternationalCommission on Radiological Protection (ICRP)3 inwhich it reviewed the quantities used in radiologicalprotection, the biological effects of radiation relevantto radiological protection, the conceptual frameworkof radiological protection and recommendations on
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dose limitation. Under these recommendations, theprimary dose quantity was redefined as effective dose(see paragraph 19 and the Glossary), taking intoaccount 'weighting factors' which reflect the sensitivityof different body organs to induction of cancerfollowing exposure to radiation. For members of thepublic, the ICRP recommended an annual limit oneffective dose of 1000 µSv.
23 The '1990 Recommendations' also placed emphasison the optimisation of radiological protection (seeparagraph 29) and on the concept of source-relatedrestrictions on individual dose, relating to theoptimisation process, termed 'dose constraints'. Adose constraint is an upper bound on the annual doseto the overall critical group, summed over all exposurepathways, from the planned operation of a controlledsource3. Dose constraints may introduce additionalrestrictions within the overall dose limit.
24 In 1993, the NRPB published guidance based onICRP's '1990 Recommendations' and recommendedthat for proposed new controlled sources, themaximum dose constraint should be 300 µSv peryear4. Constraints lower than this could be set wheresuch doses are readily achievable. Existing facilitiesare expected to operate within the appropriateconstraints but where it is not possible to comply withthe recommended dose constraint, the HealthProtection Agency advise that the operating regime bereviewed with the regulatory body to ensure thatdoses are 'as low as reasonably achievable'.Exposures arising from past controlled releases shouldbe included in any comparison with the 1000 µSvdose limit but not in comparison with the doseconstraint of 300 µSv. Health Protection Agencyadvice includes the caveat that doses should in anycase be below the 1000 µSv limit on annual dose.
25 The 1000 µSv dose limit was incorporated into theEuratom Basic Standards Directive 1996 andimplemented in UK law through RadioactiveSubstances (Basic Safety Standards) Direction 2000(paragraph 12). Ministers have directed theEnvironment Agency, when discharging their dutiesunder RSA 1993, to ensure that the Directive limit onannual dose to the public is not exceeded, and that amaximum source constraint of 300 µSv and a siteconstraint of 500 µSv are applied for authorisingradioactive discharges. The annual dose limit of 1000µSv should be compared with the sum of doses fromthe sites, from discharges from all other sources, andfrom any historical accumulation of radionuclides inthe environment from past discharges.
Collective doses
26 In addition to estimating doses to critical groups,doses to populations as a whole can be estimated7.This involves the concept of 'collective dose': the
summation of all individual radiation doses received bya population over some defined period of time. Sinceradionuclides persist in the environment, subject toprocesses of dilution, dispersion, radioactive decay,and ingrowth of daughter products, the public willcontinue to receive radiation doses (generally at adecreasing rate) for some time after a discharge ismade. Calculating the collective dose thereforeinvolves predicting the behaviour of radionuclides overextended periods following the discharge.
27 In practice, collective doses are often dominated bythe summation of a large number of exceedingly smalldoses received by individuals who are remote, in bothspace and time, from the point of discharge.Consequently, the calculation of collective dose reliesheavily on the use of theoretical models that predictthe dispersion of radionuclides over large geographicalareas and long timescales. The unit for collectivedose is the man Sievert (man Sv) which emphasisesthat the value quoted is the sum of doses received bya number of individuals.
28 The time and geographical area over which acollective dose is integrated is necessarily stated withthe estimated value. Current Health ProtectionAgency advice emphasises a 500 year integrationperiod8 and this is used throughout this report. Dosesare generally calculated to the populations of UK,Europe (including the UK) and the world. Detailedinformation is given in the Appendix.
29 Collective doses play an important role in theoptimisation of radiological protection using theALARA (As Low As Reasonably Achievable) principle.This is recognised by the Health Protection Agency4
as being a useful technique for aiding decisionsbetween different options for radiological protection.Its advice gives monetary values for unit collectivedoses, which allows the cost of collective doses to becompared with the capital and operating costs ofpreventing those doses from arising.
Monitoring of environmental radioactivity and doseassessment
30 The structure of the Statutory EnvironmentalMonitoring Programmes (paragraph 17) reflects theemphasis placed on assessing radiation doses to thepublic in the areas local to Sellafield Ltd’s sites. Theessential considerations are to:
• take account of the most important pathways bywhich radiation exposure of the public mayoccur;
• conduct appropriate sampling and analysis todetermine radionuclide concentrations orradiation levels relevant to those pathways;
8
• combine the monitoring results with data onfoodstuff consumption and other habits, and withdata on the biokinetic behaviour of radionuclides,to yield estimates of radiation dose to the public.
31 It should be noted that these dose estimates, beingbased on environmental concentrations, will includecontributions from radionuclides discharged in earlieryears. They will therefore differ from those doseestimates in technical submissions to authorisationreviews which relate to projected doses at expectedfuture levels of discharge and at proposed dischargelimits.
32 Data identifying critical groups and their habits bypathway have been provided by the Food StandardsAgency, Environment Agency and the Centre forEnvironment, Fisheries and Aquaculture Science(CEFAS), or their predecessors, based on publishedsurvey work9,10,11. Site-specific habits data used indose assessments may relate to single years or tofive-year averages as appropriate. Generalised foodconsumption rates for use in radiological doseassessments (particularly for terrestrial pathways) havebeen reviewed by the Health Protection Agency andrevised guidelines issued in 200312. Whereappropriate, such generalised advice may besupplemented by other Health Protection Agencyadvice13, or by information from local habits surveys.
33 In assessing doses, the Company takes account ofresearch studies carried out both nationally andinternationally, and also sponsors environmentalresearch focusing specifically on the behaviour ofradionuclides released from its sites. In addition,throughout this report the guidance of the HealthProtection Agency, its predecessor NRPB13 and themost recent dose coefficients in ICRP Publication 7214
are adopted where available and appropriate. For thespecific calculation of the dose from krypton-85,where the Health Protection Agency does not provideadvice, a cloud immersion dose is calculated from therecommendations of the ICRP3,15. In general, defaultvalues recommended by the ICRP for eachradionuclide are assumed for the purpose of dosecalculations unless specific studies indicate that analternative is appropriate as discussed in theAppendix.
34 In accordance with regulatory guidance16, radiationdose rates in air ('air kerma') are generally measured inprimary units of µGy h-1. In order to express this as aneffective dose rate, µSv h-1, a conversion factor of0.86 µSv per µGy is appropriate in most cases16. Thisreflects the differing energy deposition of ionisingradiation in differing media: in this case air and tissue.By expressing the radiation dose rate in µSv h-1 andmaking allowance for background dose rates9,10,17,18, adirect estimate of the dose to man can be obtained.
35 Independent environmental monitoring programmesand dose assessments in the areas both local toSellafield Ltd's sites and further afield are carried outand reported by government agencies and othergroups9,10,19-22.
36 Collective doses have been calculated, using a 500year integration period (paragraph 28), based on themost recent EU methodology23-25. This approach isconsistent with the dosimetric basis used to calculatecritical group doses, as assessed by both SellafieldLtd and independently by the Food StandardsAgency9. A summary of collective dose per unitrelease factors is included in the Appendix.
Analytical measurements, limits of detection and
rounding of data
37 All measurements of radioactive discharges,concentrations of radionuclides in the environmentand radiation dose rates are subject, as with any othertype of measurement, to uncertainties arising from themeasurement process itself. These may becomeimportant when the quantities involved are very smallcompared with the measurement uncertainty, and theresult is then quoted as a 'limit of detection' (i.e. witha '<' sign). This value is chosen to give a high degreeof confidence that the actual result is less than thatvalue.
38 Results from the Company's environmental monitoringprogrammes are reported here as the arithmeticmeans of measurements taken throughout the year.The concentrations of many radionuclides in theenvironment are now sufficiently low that mostmeasurements are reported as limit of detectionvalues, as explained above. They continue to beincluded in the monitoring and analysis programmesfor reassurance that new pathways involving, forexample, remobilised historical materials, have notarisen. Dose calculations either conservatively usesuch 'limit of detection' values, or use more realisticestimates of concentrations derived usingenvironmental models.
39 For clarity of presentation (and after calculations havebeen completed) discharges, concentration and doserate data are normally rounded to two significantfigures, or just one where the numbers are very small.Dashes are shown in tables to indicate where datahave not been collected.
40 It should also be noted that measurements of 'totalalpha' and 'total beta' activity do not necessarilyequate to the sum of individually measuredradionuclides. This is because of differing countingefficiencies and the presence of naturally occurringradionuclides.
9
Protection of the environment
41 In its 1990 Recommendations3, the ICRP consideredthat 'the standard of environmental control needed toprotect man to the degree presently thought desirablewill ensure that other species are not put at risk.' Thisview is defensible in most situations, particularly wherecritical groups are exposed in the areas of highestenvironmental concentrations, close to the point ofdischarge, through a variety of pathways. However,ICRP acknowledges that the protection of theenvironment needs to be considered in the widersense, and has work underway which is addressingthis matter. It was recognised in the MinisterialStatement of the OSPAR Convention at Sintra (1998),that the protection of biota for the preservation ofbiodiversity and bioresources is necessary in its ownright. Sellafield Ltd is contributing to a number ofinitiatives intended to develop criteria for theprotection of the environment. In addition, SellafieldLtd is carrying out assessments of exposure againstthe guidelines given in national and internationalpublications26,27,28 and, on the basis of work to date,there is no reason to believe that radioactivedischarges from Sellafield Ltd are harming theenvironment.
Natural radioactivity
42 To put into context the data presented in this report, itis important to recognise that natural radioactivity isthe dominant source of radiation exposure to thepopulation as a whole, including individuals living closeto nuclear establishments. In addition, thewidespread radioactive fallout from the testing ofnuclear weapons and from the Chernobyl disastermake small contributions to overall doses. Thesubject has been reviewed comprehensively by theHealth Protection Agency17,18 and others29.
43 Individual doses from natural radioactivity in the UKrange broadly from 1000 µSv to 100,000 µSv peryear17. The upper end of the range stems from homeswith particularly high indoor levels of radon and itsdecay products. Dose limits set for the industry donot apply to natural background radiation, such asthat from radon. Nevertheless, it may be noted, forcomparative purposes only, that these upper figuressubstantially exceed the dose limits to the public (andindeed the workforce) applicable to the operation ofnuclear establishments (see paragraphs 12, 25, andtable 1). The Health Protection Agency recommends
10
Radon 50%
Medical 15%
Internal 9.5%
Occupational 0.2%Fallout 0.2%
Artificial 16%Natural 84%
Disposals <0.1%Products <0.1%
Gamma 13%
Cosmic 12%
Figure 1. Sources of annual average radiation dose to the UK population17
Reproduced by kind permission of the HPA.
that measures be taken to reduce levels of radon inhomes if the average annual indoor activityconcentrations exceed 200 Bq m-3 and suggests thata radon-222 concentration of 20 Bq m-3 correspondsto an annual dose of 1200 µSv from the short-liveddecay products of the gas17.
44 The measurements in this report relate toenvironmental radioactivity that is mainly attributable todischarges from Company sites. However, naturalradioactivity makes an appreciable contribution to thereported values in some instances. Where it ispracticable to do so, the appropriate correction ismade and noted. Thus, gamma dose rates quoted inthis report are total dose rates including naturalterrestrial background and cosmic ray contributions.For dose assessment purposes, the naturalcontributions are deducted.
45 A comparison of annually averaged doses toindividuals in the UK population from all sources ofradioactivity is presented in table 2 and figure 1.Typically, natural background accounts for some 84%of the total dose and medical uses of radiation for afurther 15%. On this basis, the annual average doseis around 2700 µSv, of which 2230 µSv is derivedfrom natural sources (mainly cosmic rays, rocks andsoils, radon gas and foodstuffs - see table 2), 410 µSvfrom medical exposures, 6 µSv from occupationalexposure, 6 µSv from nuclear weapons fallout, 0.9 µSv from discharges and disposals, includingthose from the nuclear industry, and 0.1 µSv fromconsumer products17. In areas of higher naturalbackground radiation (e.g. Cornwall), the averagedose may exceed 7000 µSv per year18.
Acknowledgements
This report was prepared by Sellafield Ltd’sEnvironmental Monitoring and Assessments Groupassisted by Westlakes Scientific Consulting Ltd. anddesigned by Wilson & Cooke Ltd. The contributions ofstaff at Sellafield Ltd, who collected the environmentalsamples and measured environmental dose rates, areacknowledged. The VT Nuclear ServicesEnvironmental Laboratories at Westlakes Science Park,Cumbria, analysed the Sellafield samples.
The Capenhurst chapter was written by the QEH&SDepartment at Sellafield Ltd Capenhurst. Urenco UKLtd at Capenhurst collected the environmentalsamples and measured environmental dose rates.Samples are analysed at the Urenco UK Ltdlaboratories and external laboratories are used by theEnvironment Agency.
Members of the public who co-operated with the staffcollecting samples and making measurements at allsites are especially thanked.
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11
Annual dose (µSv)Source
Average Range
Cosmic radiation 330 200 - 400
Terrestrial gamma radiation 350 100 - 1000
Irradiation from internal radionuclides 250 100 - 1000
Exposure to radon and progeny 1200 300 - 100,000
Exposure to thoron and progeny 100 50 - 500
Total 2230 1000 -100,000
Table 2. Summary of doses to the UK population from
natural sources17
Reproduced (with minor presentational changes) by kind permission of the HPA.
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19 McKay W A and Stephens B A (1990). A survey
of fish and shellfish radioactivity levels in
Cumbrian near-shore waters, 1989. AEA-EE-0041, Harwell.
20 McKay W A and Walker M I (1990). Plutonium
and americium behaviour in Cumbrian near-
shore waters. J. Environ. Radioactivity 12: 49-77.
21 Walker M I and McKay W A (1991). Radionuclide
distributions in seawater around the Sellafield
pipeline. Est. Coast. Shelf Sci. 32: 385-393.
22 Isle of Man Government Laboratory (2005).Radioactivity monitoring on the Isle of Man,
2004.
23 Mayall A, Cabianca T, Attwood C A, Fayers C A,Smith J G, Penfold J, Steadman D, Martin G,Morris T P and Simmonds J R (1997). PC CREAM 97: Installing and using the PC
system for assessing the radiological impact of
routine discharges. NRPB Report SR296/EUR17791 (Luxembourg: European Commission,DGXI).
24 Simmonds J R, Lawson G and Mayall A (1995).Methodology for assessing the radiological
consequences of routine releases of
radionuclides to the environment. EUR-15760(Luxembourg: European Commission, DGXIII).
25 Bexon A (2002). PC CREAM 98: Technicalnote. Daughter radionuclides in DORIS and
MARINE ASSESSOR.
http://www.nrpb.org/publications/software/sr296/technical_support.htm
26 Environment Agency (2001). Impact assessment
of ionising radiation on wildlife. R&DPublication 128.
27 International Atomic Energy Agency (1999).Protection of the environment from the effects
of ionizing radiation. A report for discussion.
IAEA-TECDOC-1091.
28 Copplestone D, Wood M, Bielby S, Jones S R,Vives J and Beresford N A (2003). Habitats
regulations for Stage 3 assessments:
radioactive substances authorisations.
Environment Agency R&D Technical Report P3-101/SP1A, 104 pp.
29 Saunders P (1990). Radiation and You. Banson.
12
13
SellafieldDischarges and Monitoring in the United Kingdom
Annual Report 2009
Summary
1 There was only one instance in 2009 of non-compliance with numerical limits in authorisationsregulating discharges and disposals of radioactivewastes at Sellafield. This was an aerial discharge ofantimony-125 of 11 GBq compared to a limit of 6.9 GBq caused by increased reprocessing of fuelwith higher burn-up (coupled with relatively low fuelcooling). An increased limit of 30 GBq was agreedwith the Environment Agency and accepted by theEuropean Commission before the limit was breached.
2 Radioactive discharges (aerial and liquid) weregenerally similar to those in 2008 and, apart fromantimony-125, all well below the authorised limits.
3 The estimated dose in 2009 due to discharges to seafrom Sellafield to members of the critical group, whoconsume fish and shellfish from the local area, wasabout 130 µSv. Taking into account doses due tobeach occupancy and aerial pathways, the total doseto this group was about 160 µSv. Doses due to directradiation from plant on site were estimated as beingup to 1.4 µSv to the most exposed members of thepublic who live nearby, who may, in addition, havereceived up to 12 µSv from aerial discharge pathways.These doses are summarised in table 1.
4 There were two instances in 2009 of non-compliancewith numerical limits in PPC authorisations and theEnvironmental Permit. These were exceedances in thevolume of discharges from the site’s laundry andsewage treatment plant. The former was caused by aleaking valve and the latter was caused by water froma burst main entering the sewage treatment plant.Both leaks were investigated and repaired.
Operations at Sellafield
5 Sellafield is one of the most complex nuclear sites inthe world, home to the Thorp and Magnoxreprocessing plants, the Sellafield MOX plant and awide range of waste management and effluenttreatment facilities. As reprocessing runs down theemphasis is shifting to remediation, decommissioningand clean up of the historical legacy.
6 During reprocessing operations, some effluentscontaining a small fraction of the radioactivity originallypresent in the used fuel are discharged to the sea andatmosphere, or disposed of as solid wastes to theLow Level Waste Repository (LLWR) near Drigg.Discharges of radioactivity to sea have declinedsignificantly since the 1970s as a result ofconsiderable investments and improvements ineffluent treatment plants that have been described in previous reports in this series.
7 Since 1990, a number of plants that encapsulate solidintermediate-level radioactive waste in stainless steeldrums have been and continue to be brought on line.
8 Sellafield also operates the Waste Vitrification Plantwhich converts both historical and current arisings ofliquid high-level waste into a form of glass. The moltenglass is allowed to solidify inside stainless steelcontainers, which are then placed in a speciallydesigned, self-cooling storage facility.
9 The Solvent Treatment Plant (STP), which wascommissioned in 2002 and is now fully operational,treats arisings of solvent as well as historical solventwastes currently stored at Sellafield.
14
Pathway 2008 2009Position in text(paragraph no.)
Marine critical groupseafood consumption 160 130 55, 56aerial pathways 0.50 2.7 56external radiation from beach occupancy 31 32 60
Total dose to marine critical group 190 160 55, 56
Terrestrial critical groupinhalation (adults) 0.60 0.71 64immersion (adults) 0.61 0.64 68external radiation from beach occupancy (all ages) 0.77 1.1 67terrestrial foodstuff consumption (infants) 20 11 63, 64
(of which milk) 16 7.8 63marine foodstuff consumption (adults) 1.7 2.0 67
All discharge pathways (infants) 20 12 69
direct radiation 1.7 1.4 70
Total dose to terrestrial critical group (infants) 22 13 69, 70
Table 1. Summary of critical group doses from operations at Sellafield (µSv)
10 The Sellafield MOX (Mixed Oxide) Fuel Plant (SMP)manufactures reactor fuel, based upon the recycle ofplutonium.
11 Magnox reprocessing throughput in 2009 was slightlyhigher than that in 2008 (544 te compared to 441 te)but lower than in previous years due to a number ofplanned outages and reprocessing constraints due tothe Antimony-125 aerial discharge limit.Decommissioning work on older Magnox plantscontinued throughout the year.
12 Thorp reprocessing throughput in 2009 was higherthan that in 2008 (196 te compared to 104 te) butlower than in previous years.
Radioactive discharges and disposals
13 Sellafield discharges are regulated by a RadioactiveSubstances Act (1993) multi-media authorisationcovering all the discharge and disposal routes under asingle Certificate of Authorisation. Additionalrequirements are specified by the Environment Agencyin a supplementary document, the 'Compilation ofEnvironment Agency Requirements' (CEAR). Thisincludes the Statutory Environmental MonitoringProgramme and the required format for dischargereports.
14 A review of the Monitoring Programme wasundertaken in 2005, and has led to an overallreduction in the types of samples collected andradionuclides analysed. The aim of these changes isto avoid unnecessary duplication with monitoringundertaken by Environment Agency and FoodStandards Agency, particularly where limited samplenumbers are available. Monitoring of importantexposure pathways and indicators has been retained,or in a few instances extended, for reasons of publicreassurance.
15 The results of the Sellafield Ltd environmentalmonitoring programme for 2009 (black text in tables)are presented within this report alongsidesupplementary data, for foodstuffs and radionuclidespertinent to dose calculations, published by the FoodStandards Agency (grey text in tables).
16 A number of inter-site transfer authorisations cover thetransfer of radioactive waste between Sellafield andthe LLWR.
Liquid discharges via the pipeline
17 Radioactive liquid effluents arise from fuelreprocessing and storage operations; on-sitedecommissioning operations, and Sellafield Ltd andUKAEA laboratories. Liquors from the reprocessing
plants that contain the highest levels of activity arerouted directly to storage pending incorporation intosolid glass form in the Waste Vitrification Plant; theyare not therefore discharged from the site.
18 Where practicable, the medium active waste streamsfrom reprocessing are routed via the Medium ActiveEvaporator, or the Salt Evaporator, to interim decaystorage pending treatment in the Enhanced ActinideRemoval Plant (EARP) prior to discharge. Where this isnot possible, the effluents are routed directly to EARPor other plants for treatment prior to discharge.
19 The remaining low-level liquid effluents are dischargedto sea, after monitoring, via the Sellafield pipeline. The main sources of such effluents are:
• Storage pond water from the old Magnoxdecanning plants and the Fuel Handling Plant(FHP). This water is treated in the Site Ion-Exchange Effluent Plant (SIXEP) to remove radioactive contaminants, principally caesium-137 and strontium-90.
• Storage pond water from the oxide fuelreprocessing plant, Thorp.
• EARP Bulk discharges, consisting of treatedMagnox effluents and some effluents from Thorp;and 'EARP Concentrate' discharges, consisting oftreated batches of effluent from interim storageand other concentrates.
• Thorp dissolver off-gas scrubber liquors followingtreatment to remove carbon-14 as solid waste.
• Remaining process liquors are routed to theSegregated Effluent Treatment Plant (SETP) whereeffluent is adjusted for pH and held forconfirmation of its composition prior to discharge.Three discharge tanks are in operation, permittingflexible effluent management and the extendedretention of effluent if required.
• Minor waste streams, such as surface drainagewater and laundry effluent.
20 The authorisation includes Site Limits for liquideffluents with Annual Limits and Quarterly NotificationLevels for 'total alpha' and 'total beta' activity as wellas for individual radionuclides. In addition, theauthorisation has limits on individual plants. For thisreport, only performance against the Site Limits isconsidered. To comply with the authorisation, samplesfrom each waste stream are analysed either daily(Thorp Receipt and Storage, SIXEP, laundry, surfacedrainage water) or prior to discharge (SETP, EARPBulks and Concentrates, Thorp carbon-14 removalfacility) for 'total alpha', 'total beta' and (SETP andEARP only) tributylphosphate. More detailed analyses
15
16
Annual discharge (TBq) Authorised Radionuclide
2005 2006 2007 2008 2009 Limit (TBq)b
Tritium 1,600 1,100 600 780 1,500 20,000Carbon-14 5.0 11 4.7 7.2 8.2 21Sulphur-35 0.08 0.06 0.05 0.05 c
Manganese-54 0.01 0.007 0.007 0.009 c
Iron-55 0.02 0.03 0.02 0.03 c
Cobalt-60 0.70 0.14 0.05 0.07 0.08 3.6Nickel-63 0.90 1.9 0.41 0.80 c
Zinc-65 0.02 0.02 0.02 0.02 0.02Strontium-89 1.1 0.50 0.45 0.23 c
Strontium-90 13 5.0 5.0 1.7 2.9 48Zirconium-95 0.09 0.09 0.07 0.07 0.11
3.8Niobium-95 0.07 0.07 0.05 0.05 0.08Technetium-99 7.0 6.0 4.9 2.4 3.1 10Ruthenium-103 0.12 0.13 0.11 0.09 c
Ruthenium-106 1.8 3.5 1.5 1.4 3.2 63Silver-110m 0.07 0.07 0.07 0.08 c
Antinimony-125 12 8.0 5.1 3.1 3.8Iodine-129 0.30 0.20 0.10 0.20 0.25 2Caesium-134 0.16 0.15 0.14 0.12 0.14 1.6Caesium-137 6.0 6.0 7.0 5.1 4.3 34Cerium-144 0.54 0.60 0.40 0.40 0.50 4Promethium-147 0.30 0.17 0.06 d c
Europium-152 0.17 0.11 0.13 0.11 0.07Europium-154 0.11 0.08 0.09 0.10 0.06Europium-155 0.12 0.06 0.07 0.10 0.09Neptunium-237 0.05 0.05 0.04 0.04 0.05 1Plutonium-alpha 0.20 0.15 0.11 0.11 0.12 0.7Plutonium-241 5.0 3.6 2.8 2.4 2.9 25Americium-241 0.03 0.05 0.02 0.03 0.05 0.3Curium-242 0.004 0.002 0.001 0.001 c
Curium-243+244 0.004 0.002 0.003 0.003 0.005 0.05
Total alphaa 0.25 0.21 0.12 0.13 0.15 1Total betaa 43 29 25 14 18 220
Uranium (kg) 370 440 300 280 410 2,000
Table 2. Radioactive discharges to the Irish Sea via the pipeline, 2005 – 2009
a. ‘Total alpha’ and ‘total beta’ are control measures relating to specified analytical determinations. They do not reproduce precisely the contributions from allindividual isotopes.
b. Current discharge authorisation dates from 01/10/2004.c. Not measured in 2009.d. Not measured in 2008.
a. Current discharge authorisation dates from 01/10/2004.
Annual discharge (GBq) AuthorisedRadionuclide
2005 2006 2007 2008 2009 Limit (GBq)a
Total alpha 0.12 0.06 0.06 0.08 0.05 0.30Total beta 0.29 0.58 0.68 0.55 1.1 6.1Tritium 14 21 11 16 9.8 68
Table 3. Radioactive discharges to the Irish Sea via the Factory Sewer, 2005 – 2009
for a wide range of radionuclides, including all thoselisted in the schedule to the authorisation, are carriedout monthly or quarterly bulks of daily samples.
21 Trends in liquid effluent discharges from the Sellafieldpipeline for radionuclides that contribute to largestproportions of the marine critical group dose areillustrated in figures 1a-e. Table 2 presents data ondischarges over the last five years and provides abasis for comparison with current authorised limits. All discharges during 2009 were within those limits.
22 The discharges of the actinides (and hence of 'totalalpha') in 2009 were similar to 2008 and remainedlower than in 2005-6.
Liquid discharges via the Factory Sewer
23 The Factory Sewer discharges into the confluence ofthe Rivers Calder and Ehen. The primary source of theeffluent is treated sewage and surface water drainagefrom non-radioactive areas of the Sellafield site to thenorth of the River Calder. This water may contain traceamounts of radioactivity and therefore discharges are
included in the RSA 1993 authorisation for theSellafield site. Total quantities of radioactivitydischarged over the last five years and currentauthorised limits are shown in table 3.
Aerial discharges
24 Aerial effluents are discharged from a number ofstacks (chimneys) on the Sellafield site. They mainlyconsist of ventilation air from the process plants. Their radioactive constituents comprise noble gases(e.g. krypton), other gases and vapours (e.g.hydrogen, water vapour, iodine and carbon dioxide)and suspended particulates. Most release points aremonitored continuously and fitted with appropriateabatement equipment, such as high efficiencyparticulate air filters or scrubbers.
25 The authorisation has annual Site Limits and individualStack Limits. The individual stack discharges aresummed to produce the Site discharge. In this report,only performance against the Site Limits is presented(see table 4).
17
Figure 1a. Tc-99 discharge from marine pipeline and concentration in lobster
0
50
100
150
200 16000
14000
12000
10000
8000
6000
4000
2000
0
Year
Con
cent
ratio
n (B
q/kg
)
Dis
char
ge (T
Bq)
Discharge
Concentration in lobster
90 91 92 93 94 95 96 97 02 03 04 05 06 07 08 0998 99 00 01
Figure 1b. Pu-alpha discharge from marine pipeline and concentration in winkles
Year
Con
cent
ratio
n (B
q/kg
)
Dis
char
ge (T
Bq)
Discharge
Concentration in winkles
0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
0
5
10
15
20
25
30
90 91 92 93 94 95 96 97 02 03 04 05 06 07 08 0998 99 00 01
18
Figure 1c. Am-241 discharge from marine pipeline and concentration in winkles
Year
Con
cent
ratio
n (B
q/kg
)
Dis
char
ge (T
Bq)
Discharge
Concentration in winkles
0
0.2
0.4
0.6
0.8
1.0
0
5
10
15
20
25
30
35
40
90 91 92 93 94 95 96 97 02 03 04 05 06 07 08 0998 99 00 01
Figure 1d. Pu-alpha discharge from marine pipeline and concentration in mussels
Year
Con
cent
ratio
n (B
q/kg
)
Dis
char
ge (T
Bq)
Discharge
Concentration in mussels
0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
0
2
4
6
8
10
12
14
16
18
93 94 95 96 97 02 03 04 05 06 07 08 0998 99 00 01
Figure 1e. Am-241 discharge from marine pipeline and concentration in mussels
Year
Con
cent
ratio
n (B
q/kg
)
Dis
char
ge (T
Bq)
Discharge
Concentration in mussels
00.10.2
0.30.40.50.60.7
0.80.91.0
0
5
10
15
20
25
30
93 94 95 96 97 02 03 04 05 06 07 08 0998 99 00 01
Radioactivity disposed (GBq)d
Radionuclide2005 2006 2007 2008 2009
Tritium 2.3 2.1 3.4 21 12 1,400Carbon-14 0.30 0.30 0.15 0.20 0.27 50Cobalt-60a 6.9 11 2.3 110 40 2,000Iodine-129 0.03 0.08 0.17 0.08 0.06 0.22Othersb 950 700 480 590 620 15,000
Radium-226 + Thorium-232 0.03 0.02 0.02 0.04 0.15 30Uranium 22 4.6 4.5 3.9 6.3 300Other alpha emittersc 43 92 31 30 24 300
Volume (m3 y-1)d 4,900 6,000 4,000 4,000 3,600 34,000
Table 5. Disposals of solid radioactive waste to LLWR from Sellafield, 2004 - 2009
a. The cobalt-60 figure is included in ‘others’ as well as shown separately.b. Defined in the current authorisation as:
i. iron-55 and beta emitting radionuclides with half lives greater than three months (excluding carbon-14, iodine-129 and tritium).ii. not more than 2TBq may be cobalt-60.
c. Alpha emitting radionuclides with half-lives greater than three months (excluding uranium, radium-226 and thorium-232).d. These volumes represent the volume of waste and its primary containment. Figures are for waste produced by Sellafield Ltd. only. From 1 April 2008 this
includes the Windscale site.e. Includes waste consigned by other customers for treatment at Sellafield. Current discharge authorisation dates from 01/10/2004.
AuthorisedLimit
(GBq)e
a. Current discharge authorisation dates from 01/10/2004.b. Corrected for contribution from Miscellaneous and other outlets in 2005.c. Site limit changed April 2008 to 6.9GBq.d. Site limit introduced in April 2008 as part of Windscale integration.
Radionuclide2005 2006 2007 2008 2009
Annual discharge (TBq)
Tritium 93 200 83 140 190 1,100Carbon-14 0.9 0.71 0.36 0.69 0.38 3.3Krypton-85 50,000 23,000 14,000 26,000 42,000 440,000
Annual discharge (GBq)
Strontium-90 0.05 0.05 0.04 0.04 0.04 0.71Ruthenium-106 1.5 1.6 1.3 1.4 0.97 28Antimony-125 0.38 1.5 0.71 3.6 11 6.9c
Iodine-129 15 6.7 4.8 5.7 7.6 70Iodine-131 1.0 0.66 0.56 0.63 0.69 55Caesium-137 0.61 0.59 0.17 0.13 0.12 5.8Radon-222 - - - 32 43 500d
Plutonium alpha 0.03 0.03 0.03 0.02 0.03 0.19Plutonium-241 0.33 0.22 0.28 0.26 0.36 3Americium-241+ Curium-242 0.03 0.03 0.02 0.02 0.02 0.12
Total alphab 0.09 0.11 0.14 0.11 0.10 0.88Total betac 1.7 2.0 2.1 1.5 1.4 42
Table 4. Total airborne radioactive discharges, 2004 - 2009
AuthorisedLimita
(all sources)
26 Discharges of radioactivity to the atmosphere alsotake place from "Other Outlets and MiscellaneousOutlets". These are largely associated with the re-suspension of radioactivity from open fuel storageponds and other places. As in previous years,releases in 2009 were calculated by a methodologyagreed with the Environment Agency using data onactivity concentrations in air at the site perimeter.
27 Discharges for the years 2005 to 2009 aresummarised in table 4. The discharges of tritium andcarbon-14 generally reflect the reprocessingthroughput (paragraphs 11 and 12). Recordedantimony-125 discharges increased in 2008 as aresult of increased reprocessing of fuel with higherburn-up (coupled with relatively low fuel cooling) andchanges in the sampling arrangements. Most of theremaining radionuclides are associated with particulate
19
Species Location
Mean radionuclide concentration (Bq kg-1 wet weight)
Total Total 14C a 60Co 90Sr 99Tc 106Ru 125Sb 129I 134Cs 137Cs Pu(α) 241Am U(α)alpha beta
Porphyra
umbilicalis St Bees-Selker 12 130 63 0.28 0.40 13 9.2 0.76 <1.0 <0.08 2.0 3.7 5.7 0.31
Fucus Nethertown 21 300 61 1.4 0.44 1,300 2.2 1.3 7.1 <0.11 5.3 11 5.0 4.4
vesiculosus Drigg Barnscar 33 320 80 2.2 0.43 1,900 1.9 1.3 5.1 <0.10 4.1 16 8.2 6.7
Walney Island 12 240 27 0.38 0.46 910 <0.80 0.51 <1.7 <0.07 3.3 4.6 1.3 3.9
Isle of Whithorn 8.5 180 18 0.13 0.32 280 <0.50 0.23 <1.5 <0.06 1.7 1.8 1.2 1.6
20
Species LocationMean radionuclide concentration (Bq kg-1 wet weight)
14Ca 60Co 99Tc 106Ru 137Cs Pu(α) 241Am
Plaice Sellafield coastal area 170 0.06 7.0 <0.25 3.9 0.03 0.04
Sellafield offshore area 170 0.05 15 <0.23 3.7 0.02 0.05
Sellafield areab 170 0.05 8.9 <0.25 3.9 0.03 0.04
Whitehaven landed 110 0.04 2.0 <0.23 4.1 0.04 0.06
Cod Sellafield coastal area 110 - <0.36 <0.26 7.1 <0.01 <0.01
Sellafield offshore area 110 - <0.34 <0.26 6.8 <0.01 <0.01
Sellafield areab 110 - <0.35 <0.26 7.0 <0.01 <0.01
Whitehaven landed 60 - <0.35 <0.29 8.1 <0.01 <0.01
Species Location
Mean radionuclide concentration (Bq kg-1 wet weight)
Total Total 14C a 60Co 90Sr 99Tc 106Ru 110mAg 125Sb 129I 137Cs 237Np Pu(α) 238Pu 241Pu 241Am Cm(α) U(α)alpha beta
Molluscs
winkles Sellafieldcoastal area 28 120 200 1.8 1.6 80 15 0.21 1.0 - 4.7 - 8.4 - - 47 14 - 1.3
mussels Sellafieldcoastal area 34 67 240 1.2 0.69 120 14 - 1.7 <0.12 1.6 0.02 6.1 1.1 5.0 40 13 <0.05 1.5
RavenglassGarth mussel bed 29 81 180 1.6 0.36 450 6.4 - 1.4 <0.10 1.3 0.03 6.1 1.1 5.1 38 13 <0.03 2.2
Crustaceans
crabs Sellafieldcoastal area - - 140 0.52 <0.23 8.5 <1.9 0.13 0.40 - 1.3 - 0.42 - - - 1.2 - 0.12
lobsters Sellafieldcoastal area - - 130 0.21 - 220 - 0.14 - <0.10 1.8 - 0.21 - - - 2.2 - 0.04
Nephrops Sellafieldcoastal area - - - - - 80 - - - - - - - - - - 1.1 - -
Table 6. Radioactivity in fish, 2009
a. 14C data includes background.b. Combined average for Sellafield coastal and offshore areas, this is consistent with the St Bees-Selker location reported in previous reports.
Table 8. Radioactivity in seaweed, 2009
Table 7. Radioactivity in molluscs and crustaceans, 2009
a. 14C data includes background.
a. 14C data includes background.
239 +240Pu
21
material and their annual discharges are not directlyrelated to annual reprocessing rates. Radon-222 wasadded to the aerial discharge data set in 2008following the integration of the Windscale site intoSellafield Ltd.
Solid wastes
28 Solid low level radioactive waste arises on theSellafield site from process operations anddecommissioning. Arisings of process wastes havebeen reduced in recent years to a fairly constant level,so that fluctuations in total arisings now mainly reflectdecommissioning operations. The wastes are sent tothe LLWR under the terms of an inter-site transferauthorisation which also covers use of the WasteMonitoring and Compaction (WAMAC) facility atSellafield. This facility reduces the volume of wastebeing sent for disposal at the LLWR. It also offers acompaction service to other generators of low levelradioactive waste across the UK. Therefore, the inter-site transfer authorisation (and Limit) also includesallowances for the transfer of non-Sellafield Ltd wastefrom WAMAC to the LLWR. The annual radionuclidecontent of waste produced by Sellafield Ltd only andsent to the LLWR under the terms of the inter-sitetransfer authorisation are presented in table 5.
29 Contaminated soil arising at Sellafield fromconstruction and excavation is disposed of on-site attwo authorised locations. The Calder FloodplainLandfill Extension - Segregated Area received 2,370 m3 in 2009. No waste was consigned to theSouth Landfill Site in 2009. These disposals areincluded in the Site's multi-media authorisation (see paragraph 74). The terms include an activity limitof 37 kBq kg-1 (dry weight) for total alpha + total beta,above which soil has to be disposed of at the LLWRas low level radioactive waste.
Monitoring of the environment for radioactivity
30 The main pathways identified by Sellafield Ltd, theEnvironment Agency and Food Standards Agency asrelevant to calculating critical group doses attributableto radioactive discharges from Sellafield are:
• Internal exposure from the high rate consumptionof seafoods (particularly crustacea and shellfish)and of local agricultural produce (particularly milk).
• External gamma radiation from exposed intertidalsediments, particularly the silts and muds ofestuaries and harbours.
• Inhalation of, and exposure to, airborneradioactivity.
The habits and consumption rates relating to eachpathway are kept under regular review1,6,9. The Statutory Environmental Monitoring Programme,as supplemented by data from the EA and FSAmonitoring programmes, reflects these pathways. Inaddition to pathways of radiation exposure, themonitoring programme also includes the analysis of‘indicators’. These are usually biological materialswhich accumulate radioactivity and therefore are morelikely to produce positive analytical results and providetrends in environmental concentrations; examples aregrass and seaweed. Doses from direct radiation, asdistinct from discharges, are discussed under aseparate heading (Paragraph 52 and 53).
31 Concentrations of radioactivity in the marineenvironment reflect discharges from the Sellafieldpipelines, whereas radioactivity in the terrestrialenvironment generally reflects discharges toatmosphere. Some overlap does occur, however, withsea to land transfer processes2,3 and on tidallyinundated pastures4. Concentrations of caesium-137,plutonium and americium-241 in most environmentalmaterials are predominantly as a consequence ofhistorical discharges.
Marine pathways
32 The extent of the marine environmental monitoringprogramme is illustrated in figure 2. Samples areregularly collected from the Cumbrian coast with morelimited sampling in south-west Scotland. The preciselocations are reviewed periodically. In certain cases,additional samples are obtained through commercialsuppliers, representing foodstuffs available for generalconsumption.
Foodstuffs
33 The concentrations of radionuclides in the edible partsof fish, molluscs and crustaceans from the Sellafieldarea and further afield are presented in tables 6 and 7.Temporal trends are shown in figures 1a-e alongsidethe discharges from the sea pipeline. Trends in theseafoods generally reflect the annual discharges fromthe pipeline and as such were generally similar tothose in recent years. For lobster caught offshore fromSellafield there is a lag of up to 2 years betweendischarges and Tc-99 concentrations, possiblyreflecting their diet of smaller molluscs andinvertebrates. Am-241 concentrations in winkles andmussels and Pu-alpha concentrations in mussels havealso declined but not as rapidly as dischargesbecause molluscs filter feed on marine bacteria andalgae that have accumulated radionuclides overseveral years.
22
Figure 2. Marine environmental monitoring around Sellafield
N
Key:
Coastal radiation surveys
Radiation survey
Silt
Sand
Shore seawater
Coastal biota samples
Seaweed
Mussels
Winkles
Nephrops
Off-shore samples
Fish ( ★ Indicates crabs and lobsters also taken as available)
Kilometres
0 10 20
BorgueDundrennan Silloth
Allonby
Maryport
Workington
Harrington
Whitehaven
St Bees
NethertownBraystones
Sellafield
Seascale
Drigg
Ravenglass
Selker
SilecroftMillom
HaveriggAskham
WalneyIsland
Barrow-in-Furness
Ramsey
Laxey
Isle Of Whithorn
Whithorn
★
★
SellafieldCoastal Area
(N)
SellafieldCoastal Area
(S) Flookburgh
23
Mean radionuclide concentration (Bq in one litre of seawater)
Location Total Total 3H 14C 90Sr 99Tc 129I 137Cs 237Np Pu(α) 241Pu 241Am U(α)alpha beta
St Bees filtrate <2.8 8.8 9.2 <0.53 0.04 <0.03 <0.04 0.09 0.0007 0.004 0.08 <0.002 0.08
solid 0.23 <0.18 - - 0.01 - - 0.03 0.00007 0.04 0.23 0.07 0.002
Sellafield filtrate <2.7 8.6 14 <0.54 0.05 0.05 <0.04 0.11 0.0006 0.005 0.06 <0.001 0.07
solid 0.33 0.16 - - 0.01 - - 0.04 0.0001 0.08 0.46 0.11 0.003
Seascale filtrate <2.7 8.5 7.9 <0.54 0.03 0.04 <0.03 0.09 0.0006 0.005 0.06 0.002 0.08
solid 0.53 0.35 - - 0.02 - - 0.07 0.0002 0.14 0.78 0.23 0.005
Drigg filtrate <2.9 9.7 9.1 <0.63 0.05 <0.03 <0.04 0.09 0.0006 0.006 0.06 0.002 0.07
solid 0.34 0.18 - - 0.01 - - 0.04 0.00008 0.07 0.39 0.12 0.003
Table 9. Radioactivity in coastal samples of seawater from the Irish Sea, 2009
Mean radionuclide concentration (Bq kg-1 dry weight)
Location Total Total 60Co 90Sr 99Tc 106Ru 125Sb 134Cs 137Cs Pu(α) 241Am U(α)alpha beta
Sand St Bees 790 400 1.6 - - <5.0 - <0.50 62 - - -
Braystones 580 330 1.4 - - <4.9 - <0.50 58 - - -
Sellafield 520 370 1.3 - - <5.1 <2.5 <0.56 47 - - -
Seascale Neb 580 390 1.2 - - <5.0 - <0.54 29 - - -
Drigg Barnscar 490 430 1.3 - - <3.9 - <0.47 26 - - -
Silt Ravenglass Ford 1,300 550 3.5 67 15 15 - <1.5 90 240 340 39
Ravenglass Salmon Garth 630 460 1.6 3.0 7.1 <11 - <1.2 39 80 360 24
Ravenglass Opp Raven Villa 1,400 580 4.8 27 21 <23 - <1.5 110 270 480 40
Eskmeals 1,500 1,100 6.1 37 29 23 7.2 <1.3 180 360 490 55
Newbiggin Marsh 1,900 1,100 7.2 71 44 33 <11 <1.9 280 480 680 58
Muncaster Rd Bridge 2,100 1,300 6.2 71 49 100 6.8 <1.6 330 610 940 61
Whitehaven Outer harbour (south) 610 370 1.1 <0.58 <2.2 <4.5 <2.7 <0.45 90 110 130 25
River Calder 410 430 <0.78 0.73 2.3 <8.1 - <0.95 55 45 40 32
Waberthwaite 1,900 1,500 5.4 80 29 83 6.1 <1.6 210 390 590 45
Table 10. Radioactivity in silts and sands from the West Cumbrian Coast, 2009
34 Data for carbon-14 presented in tables 6 and 7 arenot corrected for the levels which are presentnaturally5. However, background corrected values forcarbon-14 in fish, molluscs and crustacea have beenused in the assessment of radiation doses to criticalgroups (paragraph 54). For these marine foodstuffs,natural concentrations of carbon-14 have been takenfrom data published by the Environment Agency andFood Standards Agency1.
Indicators
35 Seaweeds are useful marine indicators (see paragraph30). Fucus vesiculosus is collected because itaccumulates many radionuclides (particularlytechnetium-99) and is sensitive to fluctuations in theirconcentrations in seawater. Thus, the reduction intechnicium-99 discharges from 2002 onwards wassoon reflected in the levels in this species (table 8).
Seawater and sediments
36 Sellafield Ltd routinely collects samples of seawaterfrom the shore at locations close to Sellafield.Concentrations of radioactivity in seawater (table 9)were generally similar to those of recent years.
37 Concentrations of radioactivity in sediments (table 10)were generally similar to those of recent years but withslight variation in actinides and strontium-90 at somesites. Redistribution of sub-surface sediments mayhave led to small fluctuations in radionuclideconcentrations.
External pathways
38 Gamma dose rate surveys are carried out in the areasmost often frequented by members of the public (table 11). Particular attention is paid to areas wheresilt or mud accumulates, such as in harbours or
24
Number of Mean dose rateArea of survey Description Nature of ground observations (µGy h-1)a
Whitehaven Harbour (north) outer harbour mud/silt 11 0.13
Whitehaven Harbour (south) outer harbour soft mud 11 0.13
St Bees (beach) beach sand 2 0.10
St Bees (groynes) groynes pebbles/rocks 2 0.16
St Bees promenade and car park concrete / grass 2 0.13
St Bees Seamill Lane car park car park 2 0.12
Coulderton grassed areas/beach bungalows grass banks 2 0.12
Nethertown beach pebbles/shingle 2 0.13
Nethertown car park concrete / grass 2 0.11
Nethertown grassed area/beach bungalows grass banks 2 0.14
Braystones beach pebbles/shingle 2 0.15
Braystones grassed areas/beach bungalows grass banks 2 0.15
Sellafield beach beach 2 0.16
Sellafield Pipeline 3 sand 12 0.13
Sellafield Pipeline 4 sand 12 0.12
Seascale beach north of pipeline sand 12 0.11
Seascale beach south of pipeline rocks/sand 12 0.12
Drigg Barn Scar mussel beds / silt / rocks 2 0.14
Drigg beach beach sand 12 0.12
Ravenglass Raven Villa saltmarsh 2 0.18
Ravenglass River Mite ford 2 0.13
Ravenglass small boat area firm silt / pebbles 2 0.14
Ravenglass Salmon Garth mussel beds 2 0.12
Ravenglass Salmon Garth (saltmarsh) sand / firm silt 2 0.15
Factory sewer outfall rocks / boulders / sand / shingle 12 0.14
Eskmeals Viaduct saltmarsh saltmarsh 2 0.15
Newbiggin saltmarsh saltmarsh 12 0.21
Muncaster road bridge riverbank grass 2 0.16
Hall Waberthwaite saltmarsh saltmarsh turf 2 0.18
Table 11. Mean gamma dose rates measured in air in intertidal and other coastal areas of Cumbria, 2009
a. Figures include contributions from natural background, typically 0.05 µGy h-1 over sandy areas and 0.07 µGy h-1 over silt.
Area of surveyNumber Mean dose rate
of locations (µSv h-1)a
North 4 0.01
East 5 0.07
South 3 0.01
West 4 0.04
River Ehen 2 0.01
River Calder 12 0.17
River Calder critical group 1 0.03
Mean annual average - 0.09
Table 12a. Mean gamma dose rates measured in air at
Sellafield site perimeter, 2009
a. Figures exclude contribution from natural background (approximately 0.06 µSv h-1).
Location Mean dose rate (µGy h-1)a
Calderbridge 0.09
Beckermet 0.08
Seascale 0.08
Ravenglass 0.08
Brow Top 0.08
Braystones 0.09
St Bees 0.10
Whitehaven 0.09
Gosforth 0.08
Cleator 0.08
Table 12b. Mean gamma dose rates measured in air in the
vicinity of Sellafield, 2009
a. Figures exclude contribution from natural background (approximately 0.07 µSv h-1).
25
Table 13a. Large area beach monitoring coverage and finds summary 2008
Monitoring area Area covered (ha)Finds Recovered Find Rate (finds per hectare)
Particles Stones Particles Stones
Allonby 19.59 1 0 0.051 0Workington 25.56 1 0 0.039 0Whitehaven 1.74 0 0 0 0St Bees 38.85 3 0 0.077 0Nethertown 1.89 0 0 0 0Braystones 34.68 4 0 0.115 0Sellafield 149.53 98 182 0.655 1.217Seascale 60.90 8 3 0.131 0.049Drigg 39.17 2 0 0.051 0
All 371.90 117 185 0.315 0.497
Table 13b. Large area beach monitoring coverage and finds summary 2009
Monitoring area Area covered (ha)Finds Recovered Find Rate (finds per hectare)
Particles Stones Particles Stones
St Bees 58.67 4 0 0.068 0Braystones 46.70 31 0 0.664 0Sellafield 69.18 78 53 1.127 0.766Seascale 87.06 12 0 0.138 0Drigg 9.28 0 0 0 0Silecroft 13.91 0 0 0 0
All 284.81 125 53 0.439 0.186
estuaries, where dose rates tend to be higherbecause of the presence of finely-divided sediments.Several measurements are made in each area allowingtemporal and geographical trends to be observed.Gamma dose rate surveys are also conducted aroundthe site perimeter and the surrounding district (seetables 12a and b and paragraph 52-53). Dose ratesfell steadily until 1993/1994 and have subsequentlystayed fairly constant.
39 Beta-gamma ground level monitoring is undertakenjust above the surface on local beaches to ascertainthe general levels of contamination and to removeitems of higher than normal activity if necessary. In addition to the routine monitoring programme, extramonitoring is carried out in the event of exceptionallyhigh tides or severe storms. During 2009, 163 man-hours of effort were spent monitoring 243 km ofcoastline. Monitoring was concentrated on recenttide-lines and wind-blown debris in near-shore areas. No items were found with higher than normal activity.
Beach monitoring
40 In 2003, a radioactive particle containing strontium-90activity was found during a routine beach monitoringsurvey. The unusual nature of the particle prompted areview of beach monitoring and, as a result, trials of alarge area monitoring technique were agreed with theEnvironment Agency (EA). The trial was undertaken by
a contractor on behalf of Sellafield Ltd (SL) using theirGroundhog™ monitoring system and provedsuccessful in finding a number of radioactive items onSellafield and Braystones beach. Following the trial,SL and the EA agreed a programme of large areabeach monitoring. This was specified as a reportingrequirement by the EA in their “Compilation ofEnvironment Agency Requirements” (CEAR)document.
41 The CEAR required SL to monitor 250 hectares ofbeach in each of the 2008/09 and 2009/10 financialyears. Tables 13a and b show which beaches weremonitored during the 2008 and 2009 calendar yearsin addition to the number of finds recovered andassociated find rates.
42 The current monitoring programme is determined bytaking account of the find rates (both particles andstones) and the occupancy information for eachbeach. The programme is reviewed annually and itsscope and extent are agreed with the EnvironmentAgency. Stakeholder views are also considered duringthe review process. Comparing the find rate between2008 and 2009, there is a clear reduction in thenumber of radioactive stones recovered throughoutthe monitoring programme. Additionally, during thefirst six months of 2009, the particle find rate alsodecreased compared to the previous year. However, inAugust 2009, the Groundhog™ Synergy detection
Table 14b. Radioactivity in air in the vicinity of Sellafield, 2009: Residential locations
RadionuclideMean radionuclide concentration (mBq m-3)
Beckermet Braystones Brow Top Calderbridge Cleator Gosforth Ravenglass Seascale St Bees Whitehaven
Total alpha 0.03 0.03 0.04 0.04 0.04 0.04 0.05 0.05 0.03 0.04Total beta 0.14 0.11 0.19 0.17 0.15 0.16 0.19 0.19 0.16 0.20Strontium-90 <0.002 <0.002 <0.002 <0.002 <0.001 <0.002 <0.002 <0.001 <0.001 <0.001Ruthenium-106 <0.04 <0.04 <0.04 <0.05 <0.04 <0.05 <0.04 <0.04 <0.04 <0.04Antimony-125 <0.02 <0.01 <0.02 <0.02 <0.01 <0.01 <0.01 <0.01 <0.01 <0.01Caesium-134 <0.005 <0.005 <0.004 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005 <0.005Caesium-137 <0.008 <0.005 <0.007 <0.009 <0.004 <0.005 <0.004 <0.005 <0.004 <0.004Plutonium alpha <0.0002 <0.0002 <0.0003 <0.0002 <0.0001 <0.0002 <0.0003 0.001 <0.0003 <0.0004Plutonium-241 <0.02 <0.02 <0.03 <0.02 <0.02 <0.02 <0.03 <0.02 <0.02 <0.03Americium-241 0.0002 0.0003 0.0002 0.0001 <0.0001 <0.0001 0.0003 0.003 <0.0002 0.0007Uranium-234 <0.0002 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0003 <0.0001 <0.0003Uranium-235 <0.00002 <0.00002 <0.00002 <0.00002 <0.00002 <0.00002 <0.00007 <0.00005 <0.00002 <0.00004Uranium-236 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0001 <0.0003 <0.0001 <0.0003Uranium-238 0.0002 0.0001 0.00009 0.0001 0.0001 0.00009 0.00008 0.0002 0.0001 0.0002
RadionuclideMean radionuclide concentration (mBq m-3)
Calder Gate Met Station North Gate West Ring Road South Side
Total alpha 0.04 0.03 0.03 0.03 0.04Total beta 0.23 0.26 0.29 0.19 0.23Strontium-90 0.004 0.006 0.01 <0.003 <0.002Ruthenium-106 <0.04 <0.04 <0.05 <0.05 <0.04Antimony-125 <0.02 0.02 0.03 0.02 <0.01Caesium-134 <0.005 <0.005 <0.005 <0.006 <0.005Caesium-137 0.03 0.05 0.14 0.02 <0.008Plutonium alpha 0.0005 0.0006 0.001 0.0006 0.0003Plutonium-241 <0.02 <0.02 <0.02 <0.02 <0.02Americium-241 0.0006 0.0006 0.001 0.0006 0.0006Uranium-234 <0.0004 0.0009 <0.0007 <0.0005 <0.0008Uranium-235 <0.00002 <0.00003 <0.00003 <0.00002 0.00004Uranium-236 <0.0001 <0.0002 <0.0001 <0.0001 <0.0002Uranium-238 0.0004 0.001 0.0009 0.0006 0.0008
Table 14a. Radioactivity in air in the vicinity of Sellafield, 2009: Site perimeter locations
26
system was introduced capable of detecting lowenergy gamma activity more effectively. The newGroundhog™ Synergy system included the originalGroundhog™ Evolution 2 setup plus 8 FIDLER (FieldInstrument for the Detection of Low-Energy Radiation)detectors. The introduction of Synergy resulted in anincreased find rate for the remainder of 2009.
43 The Health Protection Agency has advised theEnvironment Agency on the particle risks associatedwith using the beaches around Sellafield. The currentadvice is reproduced below.
“The information now available does not warrant achange from the advice given in 2007. No specialprecautionary actions are required at this time to limitaccess to or use of the beaches. However, monitoringand retrieval should be continued- with emphasis onfrequented areas.”
The HPA continues to keep the beach monitoring dataunder review. A full interpretation of the results is givenin the annual beach monitoring report 2009/10, whichis available from www.sellafieldsites.com. Moreinformation on the detection equipment, currentmonitoring programme and analytical results can alsobe found on the website.
Airborne and terrestrial pathways
44 The extent of the terrestrial environmental monitoringprogramme is illustrated in figure 3.
Airborne
45 High flow rate air sampling equipment, located closeto the site perimeter (table 14a) and in nearby centresof population (table 14b), is used to sample airborne
27
N
0 5
Kilometres
Milk
High Volume Air Samplers
Lake water
River water
Tap water
Grass
Spring water
Vegetables (potatoes)
Key:
Note:
Gamma dose rates are measured at the site perimeter and at the 10 district HVAS locations.
Bootle
Millom
River Esk
River MiteRiver Irt
Holmrook
A595
A595
Seascale
Drigg
Ravenglass
Sellafield
WastwaterGosforth
Calderbridge
Brow TopBeckermet
Braystones
Egremont
St. BeesCleator
Whitehaven
WorkingtonCockermouth
Aspatria
Ennerdale Water
Figure 3. Terrestrial environmental monitoring around Sellafield
28
Locationc
Mean radionuclide concentration (Bq l-1)
Total Total 3H 14CTotala 14CNet
b 90Sr 106Ru 125Sb 129I 131I 137Csalpha beta
Farm Ad <0.13 40 <3.5 17 2.0 0.16 <0.35 <0.09 <0.01 <0.04 0.24Farm B <0.13 39 <3.4 17 <0.65 0.13 <0.37 <0.10 <0.01 <0.04 0.27Farm C <0.13 40 <3.3 17 <0.65 0.07 <0.37 <0.09 <0.02 <0.04 0.17
Table 15. Radioactivity in milk from farms near Sellafield, 2009
a. Including natural background.b. Excluding natural background.c. Farms A to C are within the 0-4 km zone previously reported.d. Milk from farm A has been used in the radiological assessment.
SpeciesMean radionuclide concentration (Bq kg-1 wet weight)c
(Average) 3H 14CTotala 14CNet
b 60Co 90Sr 99Tc 106Ru 125Sb 129I 137Csd 238Pu 241Pu 241Am
Bovine Muscle <7.0 28 - <0.10 0.02 <0.02 <0.90 <0.20 <0.04 0.90 <0.0002 0.0002 <0.07 <0.0003Bovine Kidney <8.0 49 18 <0.20 0.60 <0.03 <2.0 <0.80 - 0.58 0.0002 0.0002 <0.12 <0.0004Bovine Liver <9.0 30 - <0.20 0.38 <0.03 <0.60 <0.40 <0.06 0.54 0.0002 0.0030 <0.07 0.002Eggs - General <3.0 33 - <0.10 0.04 - <1.7 <0.40 <0.03 0.09 <0.0001 <0.0001 <0.05 0.0002Ovine Muscle <6.0 23 - <0.15 0.03 <0.02 <1.2 <0.40 <0.03 1.1 <0.0003 <0.0003 <0.08 <0.0005Ovine Kidney/Liver <7.5 35 4.0 <0.25 0.22 <0.02 <1.5 <0.45 <0.03 0.80 0.0005 0.002 <0.10 0.002Ducke <7.0 97 25 <0.10 0.03 - <0.90 <0.40 <0.03 0.31 <0.0001 0.0003 - 0.0003Rabbit 42 30 3.3 <0.14 0.15 <0.24 <1.5 <0.43 <0.01 19 <0.0008 0.005 <0.27 0.001Pheasants <5.0 27 - <0.20 0.01 <0.03 <1.2 <0.20 <0.03 0.42 <0.0001 <0.0003 <0.10 <0.0004Deer Muscle <5.0 22 - <0.30 <0.02 <0.03 <0.46 <0.60 <0.03 0.93 <0.0002 <0.0003 <0.07 <0.0003
Table 16. Radioactivity in animal produce from farms near Sellafield, 2009
239 +240Pu
a. Including natural background.b. Excluding natural background (values taken from RIFE-14). Measured concentrations that are smaller than background value are indicated by a hyphen.c. Values shown in grey are from measurements performed by the Food Standards Agency.d. Cs-Total reported by the FSA has been assumed to be dominated by 137Cs, hence dose factors for that radionuclide have been used in the radiological
exposure assessment.e. Data from 2007.
particulates for radiochemical analysis. Levels off-sitewere generally below the limit of detection, with mostpositive values reflecting sea to land transfer fromhistorical marine discharges.
46 Atmospheric krypton-85 measured fortnightly at theMet station on the edge of Sellafield site ranged from3.6 to 324 Bq m-3 and averaged 67.5 Bq m-3. This isequivalent to an immersion dose of <1 µSv a-1 for allage groups (table 29). Significant variation inatmospheric krypton-85 was observed due todiscontinuities in reprocessing operations on Sellafieldsite combined with the variability in meteorologicalconditions.
Foodstuffs and water
47 Milk consumption remains the main contributor to thecritical group dose from terrestrial foodstuffs.Locations sampled include local farms (in the range 0 to 4 km from the Sellafield site). The averageconcentrations of radioactivity in milk are summarisedin table 15. The figures include the residual effects ofweapons testing and the 1986 Chernobyl reactoraccident. Data for carbon-14 includes the contribution
from natural background. However, estimates ofeffective dose (paragraph 63) have been made bysubtracting natural background levels of carbon-14.For milk and other terrestrial foodstuffs, vegetation andsoil, a background level of 240 Bq carbon-14 per kgcarbon is used. The milk results for 2009 are generallysimilar to those observed for previous years, withmany analyses at the limit of detection.
48 For terrestrial foodstuffs, other than milk, the results ofthe Sellafield environmental monitoring programme for2009 are presented in tables 16 and 17 (black text)alongside supplementary data published by the FoodsStandards Agency (grey text)6. The Sellafield Ltdsamples were mainly collected from within 4 km of theSellafield site as they became available throughout theyear. Direct comparison with the results of earlier yearsis difficult due to the relatively small numbers ofsamples and their locations. Data for carbon-14 arepresented as total and net (background subtracted)values. For terrestrial foodstuffs no longer monitoredby Sellafield Ltd, natural carbon-14 backgroundconcentrations have been taken from data publishedby the Environment Agency and Food Standards Agency1. Continued page 31
29
Mean radionuclide concentration (Bq l-1)Location
Total Total3H 90Sr 99Tc 137Cs Pu(α)
Am+alpha beta Cm
River water: River Calder at Sellafield <0.02 0.15 <3.8 0.02 <0.03 <0.006 <0.002 <0.0005River Calder at Calderbridge <0.02 <0.12 <3.8 0.006 <0.03 <0.005 <0.002 <0.0008
River Ehen upstream of of factory sewer outfall <0.02 0.17 <4.9 0.005 <0.03 <0.006 <0.002 <0.0008
River Ehen at Sellafield station <0.02 0.16 <3.9 0.005 <0.03 <0.005 <0.003 <0.0004
Lake water: Ennerdale water <0.01 <0.12 <4.3 0.002 - <0.004 <0.0009 <0.001Wastwater <0.02 <0.09 <4.6 0.004 - <0.006 <0.001 <0.001
Tap water: Tap water - Calderbridge <0.02 <0.07 <4.2 0.003 - <0.005 <0.001 <0.002Tap water - Sellafield Site <0.03 <0.08 <3.6 <0.003 - <0.004 <0.001 <0.001Tap water - Ravenglass <0.02 <0.09 <4.1 <0.004 - <0.005 <0.001 <0.001Tap water - Seascale <0.02 <0.10 <4.1 <0.003 - <0.006 <0.001 <0.001Tap water - Whitehaven <0.02 <0.07 <2.6 0.004 - <0.006 <0.001 <0.001
Spring water: Sellafield beach (South)a - 11 830 0.05 2.1 1.1 0.03 0.10Sellafield beacha - - 53 - 0.15 - - -
Table 18. Radioactivity in local waters, 2009
a Results corrected for seawater content.
SpeciesMean radionuclide concentration (Bq kg-1 wet weight)c
3H 14CTotala 14CNet
b 60Co 90Sr 99Tc 106Ru 125Sb 129I 137Cse,f 238Pu 241Pu 241Am
Potatoes 6.4 14 <0.50d <0.30 0.03 - <0.30 <0.45 <0.01 0.07 - - - -Cabbage <4.0 4.0 - <0.10 0.11 - <1.6 <0.30 <0.02 0.03 <0.0002 <0.0002 <0.07 <0.0003Cauliflower <4.0 3.0 - <0.10 0.07 - <0.60 <0.30 <0.02 0.06 <0.0001 <0.0001 <0.06 <0.0002Broccoli <5.0 8.0 - <0.10 0.12 - <0.60 <0.40 <0.02 0.11 0.0001 0.0003 <0.06 <0.0002Carrots <4.0 6.0 - <0.10 0.15 - <1.3 <0.40 <0.03 0.10 - - - -Swede <5.0 9.0 1.0e <0.20 0.17 - <1.5 <0.40 <0.04 0.08 - - - -Onions <4.0 6.0 - <0.10 0.10 - <1.1 <0.30 <0.02 0.05 - - - -Beans,Runner <5.0 11 - <0.20 0.13 - <1.2 <0.35 <0.03 0.11 <0.0002 0.001 <0.05 0.002Mushrooms <6.0 10 5.0e <0.20 0.60 - <0.50 <0.40 <0.04 0.26 0.002 0.01 <0.07 0.02Honeyg <7.0 78 - <0.20 0.04 - <1.4 <0.70 <0.02 3.7 <0.0001 0.0002 <0.16 <0.0004Blackcurrants <4.0 24 14e <0.20 0.11 - <1.4 <0.30 <0.06 0.10 0.0001 0.0007 <0.05 0.002Apples <4.5 9.0 - <0.15 0.09 <0.02 <1.2 <0.30 <0.02 0.11 <0.0001 0.0004 <0.07 0.001Strawberries 10 8.0 - <0.30 0.06 - <1.6 <0.40 <0.03 0.04 <0.0001 0.0001 <0.05 0.0007Blackberries 11 16 6.0e <0.20 1.2 - <1.6 <0.50 <0.04 0.41 0.0003 0.001 <0.06 0.0009Elderberries <5.0 19 9.0e <0.20 0.36 - <1.3 <0.50 <0.03 0.26 0.001 0.004 <0.07 0.009
Table 17. Radioactivity in fruit and vegetable produce collected near Sellafield, 2009
239 +240Pu
a. Including natural background.b. Excluding natural background. Measured concentrations that are smaller than background values are indicated by a hyphen.c. Values shown in grey are from measurements performed by the Food Standards Agency.d. Natural background calculated assuming 240 Bq natural 14C per kg carbon.e. Natural background concentrations taken from RIFE-14.f. Cs-Total reported by the FSA has been assumed to be dominated by 137Cs, hence dose factors for that radionuclide have been used in the radiological
exposure assessment.g. 2008 data.
30
49 Water samples are collected from the River Calderand River Ehen, lakes and domestic supplies. Theresults (table 18) are all very low and rarely above thelimits of detection except for strontium-90 which isgenerally present in rain water and surface water atlevels typical of those throughout the UK1.
Indicators
50 Grass and soil sampling are included in the monitoringprogramme as they provide time trend data onenvironmental concentrations of radioactivity. Grasssamples (table 19) are collected quarterly from fivelocations on the Sellafield site and from one at theRavenglass Estuary. Soil samples (5 cm cores) arecollected annually from the same locations (table 20).
Groundwater
51 The statutory monitoring programme includes theroutine monitoring of groundwater from 16 boreholesaround the perimeter of the site so that any significantmigration of radioactivity in groundwater will bedetected. These boreholes are shown in figure 4. The routine results in 2009 (table 21) were similar tothose reported in recent years. Most other resultswere near or below limits of detection, except fortritium and technetium-99 in boreholes 6986P1 and4025P1 which are in the vicinity of the main gate atthe southwest of the site. Old waste disposaltrenches, which were used before disposal operationscommenced at the LLWR, are believed to be thesource of the tritium in these boreholes and also ofthat monitored in groundwater up-welling on theSellafield beach. A redundant sea discharge storage tank is believed to be the source of thetechnetium-99. These concentrations are in line withgroundwater modelling that predicted peak
concentrations of 0.1 MBq m-3 technetium-99between 2000 and 2010. More detailed informationon groundwater monitoring at the Sellafield sites canbe found at www.sellafieldsite.com/land.
Direct radiation
52 Some of the older Magnox buildings, including theCalder reactors, have lower levels of radiationshielding than the modern buildings, such as Thorp.Consequently, it is possible to measure radiation doserates above natural background at the site perimeterfence. These dose rates were largely due to directradiation from the unshielded heat exchangers on theCalder reactors and therefore dependent upon theamount of power being produced by the reactors(until they were shut down in March 2003). Theperimeter radiation levels are still affected by radiationfrom contamination within the heat exchangers but ata much lower level.
53 Gamma dose rates are monitored continuously andanalysed quarterly using thermoluminescent detectors(TLDs) at 30 locations around the site perimeter (table 12a) and at a further 10 locations in thesurrounding district (table 12b). Dose rates at the siteperimeter averaged 0.15 µSv h-1, significantly lowerthan when the Calder Hall reactors were fullyoperational. Dose rates in the surrounding districtaveraged 0.09 µSv h-1. These are total dose rates,which include contributions from natural terrestrialbackground and cosmic rays. For dose assessmentpurposes the natural contributions are deducted.
Table 19. Radioactivity in grass at Sellafield, 2009
Mean radionuclide concentration (Bq kg-1 wet weight)
Location Total Total 3H 14CTotala 14CNet
b 90Sr 99Tc 106Ru 125Sb 129I 134Cs 137Cs Pu(α) 241Amalpha beta
Calder Gate 2.5 110 18 32 4.9 2.1 0.8 <0.89 3.7 <0.02 <0.11 3.9 0.07 0.14
Met Station 2.3 140 12 25 <0.95 11 2.1 <0.92 <0.53 <0.02 <0.10 5.3 0.10 0.07
North Gate 1.7 160 55 33 5.5 20 1.4 <1.2 2.7 <0.02 <0.11 51 0.23 0.13
South Side 4.0 130 8.2 34 <1.4 1.2 1.8 <1.2 <0.33 <0.02 <0.14 0.89 0.14 0.22
West Ring Road 7.4 140 23 27 <1.4 2.2 1.5 <1.1 1.1 <0.02 <0.13 5.3 0.61 0.59
Ravenglass 5.5 120 2.9 28 <1.5 0.56 4.3 <1.1 <0.29 <0.02 <0.12 0.74 0.31 0.53
a. 14C data includes background.b. Excluding natural background calculated assuming 240 Bq natural 14C per kg carbon.
31
Table 21. Radioactivity in groundwater at Sellafield, 2009
Boreholenumber
Mean radionuclide concentration (Bq m-3)
Total alpha Total beta 3H 90Sr 99Tc 137Cs
708P1733P11239P12028PP12564P1738P1739P14683P14684P12796P1801P11241P14688P14025P14996P16986P1
<63<62
-<56<63<65<53
---
<70-
<65<59<68<59
<32----
<30<32
---
870-
<3115,000
2006,300
<110360
-140<96<100<100
-<98
-<96
-<98<110<100<120
8,800<6,200<3,400<3,600<4,000<6,100<5,400<4,300<5,500<2,700<3,900<4,70017,00017,0007,000
2,100,000
<310520
<270<290<280590
<260<240<280<260<280<250<250<270<280370
<21<22<25<2124
<30<26<1339
<19<21<25<27<25<2178
Table 20. Radioactivity in soil at Sellafield, 2009
Mean radionuclide concentration (Bq kg-1 wet weight)
Location Total Total 3H 14CTotala 14CNet
b 90Sr 99Tc 106Ru 125Sb 129I 134Cs 137Cs Pu(α) 241Am U(α)alpha beta
Calder Gate 520 370 4.5 7.2 2.3 3.5 <2.2 <20 <5.3 <17 <2.2 72 16 8.2 40
Met Station 660 710 5.1 5.6 0.60 16 <2.2 <12 <4.0 <19 <1.3 270 92 27 38
North Gate 710 700 8.9 7.3 3.0 31 <2.2 <17 <5.1 <18 <1.7 340 180 29 53
South Side 580 370 2.6 13 <0.60 7.5 <2.2 <22 <5.6 <28 <2.6 79 13 6.7 53
West Ring Road 690 710 1.5 5.6 <0.20 11 <2.2 <22 <5.3 <16 <2.3 110 38 22 63
Ravenglass 1,100 1,000 <1.8 17 3.0 2.6 17 <14 <5.5 <31 <1.1 1,700 400 540 60
a. 14C data includes background.b. Excluding natural background calculated assuming 240 Bq natural 14C per kg carbon.
32
Figure 4. Groundwater and radiological environmental monitoring at Sellafield
MetStation
West Ring Road
River Ehenupstream ofpipe-bridge
Pipeline
North Gate
Separation
Area
River Calder(Calderbridge)
River Calderdownstream
of site
River Ehenupstream of
Factory Sewer outfall
CalderGate
South Side
River water samples
Air samples
Borehole samples
Soil and grass samples
739P1
738P1733P1
1239P1708P1
6986P12796P14683P1
4025P1
801P1
1248PP12564P1
4996P1
4684P1
2028PP1
1241P1
4688P1
Radiological impact of operations at Sellafield
Critical group doses
54 Critical group doses have been calculated followingthe Principles for Total Retrospective DoseAssessment7, which is consistent with last year’sreport. In 2005 several changes were made to thedose calculation methodology in order to make theSellafield Ltd. dose calculations more consistent withthese principles, the methodology for which ispresented in the National Dose Assessment WorkingGroup (NDAWG) Paper 11-038. These changes inmethodology include:
• Milk dose is based on the mean concentration ata nearby farm with the highest individual result (paragraph 63).
• The age groups considered for terrestrial criticalgroup dose now includes pre-natal (foetal) dose,which has been calculated as an extension to theadult dose assessment using relevant dosecoefficients.
• Dose per unit intake factors for ingestion andinhalation have been taken from the latest valuespublished by the Environment Agency and FoodStandards Agency. These factors differ from thoseused in previous reports because they include thepresence of short-lived daughter radionuclidesassumed to be in equilibrium with their parent atthe time of ingestion, inhalation etc. Furthermore,the Environment Agency and Food StandardsAgency methodology does not use a Cumbrianspecific dose per unit intake factor fortechnetium-99 in lobster, which was used inprevious assessments.
• Doses from inhaled and ingested tritium havebeen assessed using the more conservative dosefactor for organically bound tritium, rather thanthat for tritiated water, which was used in previousreports.
Marine pathways
55 Using habits surveys, the Food Standards Agency hasidentified the marine critical group for seafoodconsumption as a small number of people in theCumbrian coastal community who are high-rateconsumers of fish and shellfish obtained from theSellafield area between St Bees and Selker.Consumption and occupancy rates are kept underregular review and are published annually1. In thisreport, the consumption and occupancy rates used bySellafield Ltd for dose assessment purposes (table 22)are taken from the most recent data provided by FoodStandards Agency for the five years 2005-20099 withupdated consumption rates for crustaceans andmolluscs and occupancy rates from 20096. In reportspublished prior to 2005 the consumption of ‘othermolluscs’ was equally divided between limpets,mussels and cockles. Since 2005, for consistencywith the Food Standards Agency, they are all ascribedto mussels1. For the dose assessment, “Other fish”reported by the FSA are assumed to be plaice.
56 Table 23 shows dose to the critical group ofconsumers of seafood (caught locally between St Bees and Selker). The estimated critical group dosewas about 130 µSv compared to 161 µSv in 2008.The group may also receive doses from otherpathways, such as inhalation and consumption ofagricultural produce. An assessment has shown thatthese would increase the dose by only about 3 µSv.The doses from the consumption of molluscs are likelyto be overestimated because no account has been
33
Table 22. Seafood consumption rates for people associated with marine discharges (2005-2009 average data)
Consumption rates (kg y-1)
Seafood Critical group Consumers associated with Typical fish eating public(Sellafield fishing community) a Whitehaven fishery b (Whitehaven) b
Fish: cod 18.8 20 7.5plaice 21.9 20 7.5
Crustaceans: crabs 9.8 - -lobsters 5.1 - -Nephrops 3.8 9.7 -
Molluscs: winkles 17.9 - -mussels 14.3 - -
a. CEFAS, 2010. Radiological Habits Survey: Sellafield Review, 2009.b. RIFE-14.
34
Figure 5a. Dose to marine critical group from Tc-99 in lobster and consumption rate
Year
Dos
e (µ
Sv)
Con
sum
ptio
n ra
te (k
g/ye
ar)
0
1
2
3
4
5
6
7
8
0
5
10
15
20
25
Consumption rate
Dose
90 91 92 93 94 95 96 97 02 03 04 05 06 07 08 0998 99 00 01
Figure 5b. Dose to marine critical group from Pu-alpha in winkles and consumption rate
Year
0
24
68
10
1214
1618
20
0
5
10
15
20
25
30
35
40
45
Consumption rate
Dose
Dos
e (µ
Sv)
Con
sum
ptio
n ra
te (k
g/ye
ar)
90 91 92 93 94 95 96 97 02 03 04 05 06 07 08 0998 99 00 01
Radionuclide Cod Plaice Lobster Crab Nephrops Winkles MusselsTotal for
radionuclide
Carbon-14a 0.95 1.9 0.30 0.64 - 1.8 1.8 7.4Cobalt-60 - 0.004 0.004 0.02 - 0.11 0.06 0.20Strontium-90 - - - 0.07 - 0.89 0.31 1.3Technetium-99 0.004 0.12 0.72 0.05 0.19 0.92 1.1 3.1Ruthenium-106 0.03 0.04 - 0.13 - 1.9 1.4 3.5Silver-110m - - 0.002 0.004 - 0.01 - 0.02Antimony-125 - - - 0.004 - 0.02 0.03 0.05Iodine-129 - - 0.06 - - - 0.19 0.25Caesium-137 1.7 1.1 0.12 0.17 - 1.1 0.30 4.5Curium-alpha - - - - - - 0.11 0.11Neptunium-237 - - - - - - 0.03 0.03Plutonium-alpha 0.05 0.16 0.27 1.0 - 15 22 38Plutonium-241 - - - - - 1.6 2.7 4.3Americium-241 0.04 0.18 2.2 2.4 0.84 20 37 63
Total for species 2.8 3.5 3.7 4.5 1.0 43 67126
Total for group 126
Table 23. Summary of doses associated with marine discharges in 2009 (µSv): Critical group consumers of seafoodsb
(Sellafield fishing community)
a. Based on Sellafield area data for fish (table 6) and Sellafield coastal area data for crustaceans and molluscs (Table 7).b. Calculated using background corrected activity concentrations.
35
Figure 5d. Dose to marine critical group from Pu-alpha in mussels and consumption rate
Year
0
2
4
6
8
10
12
14
16
18
0
5
10
15
20
25
30
35
40
45
Consumption rate
Dose
Dos
e (µ
Sv)
Con
sum
ptio
n ra
te (k
g/ye
ar)
93 94 95 96 97 02 03 04 05 06 07 08 0998 99 00 01
Figure 5e. Dose to marine critical group from Am-241 in mussels and consumption rate
Year
Consumption rate
Dose
0
2
4
6
8
10
12
14
16
18
0
20
10
30
40
50
60
Dos
e (µ
Sv)
Con
sum
ptio
n ra
te (k
g/ye
ar)
93 94 95 96 97 02 03 04 05 06 07 08 0998 99 00 01
Figure 5c. Dose to marine critical group from Am-241 in winkles and consumption rate
Year
0
24
68
10
1214
1618
20
0
5
10
15
20
25
30
35
Consumption rate
Dose
Dos
e (µ
Sv)
Con
sum
ptio
n ra
te (k
g/ye
ar)
90 91 92 93 94 95 96 97 02 03 04 05 06 07 08 0998 99 00 01
36
taken of the effects of food preparation procedures,such as the soaking of winkles to eliminate their gutcontents which contain most of the actinideradioactivity (adsorbed onto silt particles). Doses totypical fish-eating members of the public were asusual very low (2.1 µSv). Doses to consumersassociated with the Whitehaven fishery (6.1 µSv) werelower than those of last year (11 µSv).
57 Figure 5 shows doses to the marine critical groupfrom seafoods (for nuclides contributing the highestproportions of dose) against the consumption rate ofthese foods. Consumption of lobster has steadily risenduring the last two decades. Dose from Tc-99 hasgenerally declined since 1997, despite this increasedconsumption because discharges, and henceconcentrations in lobster, have declined. Consumptionof winkles has increased steadily since 2000. This hasresulted in an increased dose from Pu-alpha and Am-241, despite stable discharges of theseradionuclides and concentrations in winkles.Consumption of mussels has increased steadily sincethe mid-1990s. This has resulted in an increased doseup to 2006 from Pu-alpha and Am-241, despite stable
discharges and concentrations of these radionuclidesin mussels. Since 2006/7 the dose has fallen sharplydue to a combination of reduced consumption andreduced Pu-alpha concentration in mussels.
58 Figure 6 shows the contribution of individual nuclidesto the marine critical group's dose. Over the last 15 years the main contributors to marine dose havebeen Am-241, Pu-alpha and Tc-99. The decrease indose in the last 5 years has largely been caused by areduction in Tc-99 dose resulting from decreased Tc-99 discharges.
59 Figure 7 shows the contribution of individual foodstuffsto the marine critical group's dose. Over the last 15years the main contributors to marine dose have beenfrom mussels, winkles and lobster. Variations in theproportion of dose from each food reflect changes inboth consumption rate and radionuclideconcentrations.
60 The Food Standards Agency and the EnvironmentAgency1 continue to keep under review the amount oftime spent by members of the public on inter-tidal
Figure 6. Marine critical group dose per nuclide
Others
Am-241
Pu-241
Pu-alpha
Tc-99
C-14
Year
Dos
e (µ
Sv)
0
50
100
150
200
250
94 95 96 97 02 03 04 05 06 07 08 0998 99 00 01
Figure 7. Critical group dose from seafoods
Year
Dos
e (µ
Sv)
Cod
Plaice
Nephrops
Mussels
Winkles
Crab
Lobster
0
50
100
150
200
250
97 02 03 04 05 06 07 08 0998 99 00 01
37
areas of the coastline bordering the north-east IrishSea and more inland locations. In particular, it wasconsidered that members of the critical group receivedan external contribution to their radiation exposurefrom spending up to 820 hours each year on localbeaches (i.e. Parton to Eskmeals). This additionaldose was estimated to be 32 µSv using averagedhabit data for 2005-2009.
61 The Health Protection Agency17 (HPA) continues tokeep under review the numbers and radionuclidecontent of particles that are detected by monitoring onbeaches near the Sellafield site. However, acting onthe information supplied by the EA during 2009, theHPA considered no special precautionary actions tobe necessary regarding access to, or use of, thesebeaches.
Airborne and terrestrial pathways
62 For some years Sellafield Ltd has used consumptionrates obtained from the approach used by the HealthProtection Agency (HPA)10, whereby several doseassessments are carried out to establish whichfoodstuffs contribute the maximum dose at highercritical group consumption rates. Using this process,the two food groups identified as making the highestcontribution to dose are assigned critical group(higher) consumption rates (milk and green vegetablesin 2007; milk and apples in 2008, milk and domesticfruit in 2009). The remainder are assigned nationalmean consumption rates. The consumption ratesused for 2009 are summarised in table 24. In additionto changes in food consumption rates, Sellafield Ltdhas adopted the generic advice of the HPA onparameters relating to external radiation pathways(table 25)11,12. In previous years the dose fromterrestrial foodstuffs has been based only on the foodssampled by Sellafield Ltd and Foods StandardsAgency in that year. In the dose assessment reportedhere, where 2009 data was not collected, the mostrecent data available was used (e.g. 2008 honey).
63 Milk dose is based on the mean concentration at anearby farm with the highest individual result. Thisaccounts for the possibility that any farm close to asite can act as the sole source of supply of milk tohigh-rate consumers. Based on the averageconcentrations of radioactivity in milk from Farm Areported in table 15 (excluding ruthenium-106 andiodine-131), the estimated annual dose to infants whodrink milk obtained only from local farms would havebeen 7.8 µSv and the corresponding doses to adults,children and foetus about 2.6, 4.0 and 2.7 µSvrespectively (table 26). The doses from ruthenium-106in all terrestrial foodstuffs and iodine-131 in milk,shown in table 26, are assessed using standardmodelling techniques11,13,14 (as used by the HealthProtection Agency and others) which are based on
knowledge of the transfer of these radionuclidesthrough the food chain. This is considered to be morerealistic than using the limits of detection from theradiochemical analysis.
64 Based on the average concentrations reported intables 14a, 14b, 16 and 17 for radioactivity in air, andin terrestrial foodstuffs other than milk, infants wouldhave received an estimated dose of about 3.0 µSv (4.2, 3.9 and 3.1 µSv for adults, children andfoetus) from these other foodstuffs and frominhalation. Detailed data are provided in tables 26 and27. Doses assessed as being less than 0.001 microSvhave been presented as “<0.001”.
Foodstuff a Consumption rate (kg y-1) i, j
Adult Child Infant
milk 240 240 320beef 15 15 3beef liver 5.5 3 1mutton 8 4 0.8poultryb 10 5.5 2gamec 6 4 0.8fish (cod + plaice) 15 3 0.75leafy vegetablesd 15 6 3.5potatoes 50 45 10root vegetablese 10 6 5legumesf 20 8 3domestic fruitg 75 50 35wild fruith 7 3 1mushrooms 3 1.5 0.6honey 2.5 2 2eggs 8.5 6.5 5
Table 24. Consumption rates of critical group consumers
associated with aerial discharges
a. Based on HPA/FSA recommendations.b. Duck from 2007.c. Rabbits, pheasants and venison.d. Cabbage, cauliflower and broccoli.e. Carrots, swede and onions.f. Runner beans.g. Apples, blackcurrents and strawberries.h. Blackberries and elderberries.i. Consumption rates for foetal exposure taken to be same as those of
adults.j. Milk and domestic fruit as high rate consumers.
a. Foetal dose is calculated from the adult dose multiplied by the ratio ofthe foetus to the adult dose conversion factors (following NRPB, 2005).
Adult Child Infant
Occupancy (%) 100 100 100Time indoors (%) 50 90 90Building shielding factor 0.2 0.2 0.2Breathing rate (m3 a-1) 9860 5600 1900
Table 25. Parameters for calculation of plume immersion
and inhalation dosesa
38
Figure 9. Critical group dose from terrestrial foods
Year
Dos
e (µ
Sv)
0
1
2
3
4
5
6Other
Potatoes
Milk
97 02 03 04 05 06 07 08 0998 99 00 01
Figure 8. Terrestrial (Infant) critical group dose per nuclide
Year
Dos
e (µ
Sv)
Others
Cs-137
I-131
I-129
Ru-106
Tc-99
Sr-90
C-140
10
20
30
40
50
60
97 02 03 04 05 06 07 08 0998 99 00 01
65 Table 27 and figure 8 show that over the last 15 years,the main radionuclides contributing to doses fromconsumption and inhalation are strontium-90,ruthenium-106, iodine-129, iodence-131 andcaesium-137 (all dominated by consumption). Dosesfrom strontium-90 and caesium-137 are dominated bypre-1980 discharges, the testing of nuclear weaponsin the 1960s, and (for caesium-137) the Chernobylaccident in 1986. The relative proportions of nuclidesin recent years can largely be explained by changes inreprocessing rates and improvements in the analyticallimits of detection achievable.
66 Figure 9 shows the contribution of individual foodstuffsto the terrestrial critical group's dose. Over the last 15 years terrestrial dose has been dominated by milkand potato consumption.
67 Members of the terrestrial critical group also receiveda dose of up to 3.1 µSv, arising from liquid effluentdischarges. This dose contained an externalcomponent (1.1 µSv) from radioactivity deposited onlocal beaches, based on data published by theEnvironment Agency and Food Standards Agency,
and an internal component (2.0, 0.39, 0.16 and 1.3, µSv respectively to adults, children, infants andfoetuses) from an assumed consumption of locallycaught fish (table 28).
68 In addition to exposure from the consumption of localproduce, the critical group also receives exposure fromimmersion in a plume containing krypton-85 dischargedfrom the reprocessing plants. The doses in 2009 toadults, children, infants and foetuses living near toSellafield would have been respectively 0.64, 0.45,0.45 and 0.64 µSv using modelling and dosimetrypublished by the EU and the ICRP 13,14 (table 29).
69 The doses to the terrestrial critical group aresummarised in table 29. If all the above pathways areconsidered to be additive, the highest dose to infantsin 2009 was about 12 µSv. Doses to adults, childrenand foetuses were slightly lower. The changes to thedose assessment methodology (paragraph 54), andthe inclusion of an external dose that is quoted as aless than value by the Food Standards Agency, are
Continued page 42
39
Radionuclide
Total tritiumCarbon-14b
Cobalt-60Strontium-90Technetium-99Ruthenium-106c
Antimony-125Iodine-129Iodine-131c
Caesium-134Caesium-137Plutonium alphaPlutonium-241Americium-241
Total
Milk
Adult Child Infant Foetus
0.04 0.05 0.13 0.050.28 0.38 1.0 0.38
- - - -1.2 2.5 4.8 1.8- - - -
<0.001 <0.001 <0.001 <0.0010.02 0.05 0.18 0.010.26 0.46 0.70 0.11
0.008 0.02 0.08 0.008- - - -
0.75 0.58 0.92 0.33- - - -- - - -- - - -
2.6 4.0 7.8 2.7
Beef
Adult Child Infant Foetus
0.004 0.006 0.003 0.007- - - -
0.005 0.02 0.008 0.0030.009 0.02 0.006 0.01
<0.001 <0.001 <0.001 <0.001<0.001 <0.001 <0.001 <0.0010.003 0.006 0.004 0.0010.07 0.11 0.03 0.03
- - - -- - - -
0.18 0.14 0.03 0.080.001 0.002 <0.001 <0.0010.005 0.005 0.001 <0.001
<0.001 <0.001 <0.001 <0.001
0.28 0.31 0.09 0.14
Beef offal
Adult Child Infant Foetus
0.002 0.001 0.001 0.0030.03 0.02 0.01 0.040.004 0.007 0.005 0.0020.08 0.10 0.05 0.12
<0.001 <0.001 <0.001 <0.001<0.001 <0.001 <0.001 <0.0010.004 0.004 0.004 0.0020.02 0.02 0.007 0.007
- - - -- - - -
0.04 0.02 0.007 0.020.002 0.001 <0.001 <0.0010.003 0.001 <0.001 <0.0010.001 <0.001 <0.001 <0.001
0.19 0.18 0.09 0.20
Radionuclide
Total tritiumCarbon-14b
Cobalt-60Strontium-90Technetium-99Ruthenium-106c
Antimony-125Iodine-129Iodine-131Caesium-134Caesium-137Plutonium alphaPlutonium-241Americium-241
Total
Mutton
Adult Child Infant Foetus
0.002 0.001 <0.001 0.003- - - -
0.004 0.007 0.003 0.0020.007 0.008 0.002 0.01
<0.001 <0.001 <0.001 <0.001<0.001 <0.001 <0.001 <0.0010.004 0.003 0.002 0.0020.03 0.02 0.005 0.01
- - - -- - - -
0.11 0.04 0.01 0.050.001 <0.001 <0.001 <0.0010.003 0.002 <0.001 <0.001
<0.001 <0.001 <0.001 <0.001
0.16 0.09 0.03 0.08
Poultry
Adult Child Infant Foetus
0.003 0.002 0.002 0.0040.15 0.11 0.08 0.200.003 0.006 0.005 0.0020.009 0.01 0.006 0.01
- - - -<0.001 <0.001 <0.001 <0.0010.004 0.005 0.005 0.0020.03 0.03 0.01 0.01
- - - -- - - -
0.04 0.02 0.007 0.02<0.001 <0.001 <0.001 <0.001
- - - -<0.001 <0.001 <0.001 <0.001
0.24 0.19 0.12 0.25
Eggs
Adult Child Infant Foetus
0.001 0.001 0.002 0.002- - - -
0.003 0.007 0.010 0.0020.01 0.02 0.02 0.02
- - - -<0.001 <0.001 <0.001 <0.0010.004 0.005 0.01 0.0020.03 0.04 0.03 0.01
- - - -- - - -
0.01 0.006 0.005 0.004<0.001 <0.001 <0.001 <0.0010.002 0.002 0.001 <0.001
<0.001 <0.001 <0.001 <0.001
0.06 0.08 0.08 0.04
a. Values in grey have been calculated using FSA monitoring data b. Calculated using background corrected activity concentrations (see paragraph 47).c. Derived from standard modelling techniques.
Table 26. Summary of doses to the terrestrial critical group from terrestrial foodstuffs and inhalation in 2009 (µSv)a
Radionuclide
Total tritiumCarbon-14b
Cobalt-60Strontium-90Technetium-99Ruthenium-106c
Antimony-125Iodine-129Iodine-131Caesium-134Caesium-137Plutonium alphaPlutonium-241Americium-241
Total
Game
Adult Child Infant Foetus
0.004 0.004 0.002 0.0070.004 0.004 0.001 0.0050.004 0.009 0.005 0.0020.01 0.02 0.004 0.02
<0.001 <0.001 <0.001 <0.001<0.001 <0.001 <0.001 <0.0010.003 0.003 0.002 0.0010.02 0.02 0.004 0.006
- - - -- - - -
0.53 0.27 0.07 0.230.003 0.002 <0.001 <0.0010.004 0.003 <0.001 <0.001
<0.001 <0.001 <0.001 <0.001
0.59 0.34 0.09 0.28
Honey
Adult Child Infant Foetus
<0.001 <0.001 0.002 0.001- - - -
0.002 0.004 0.01 <0.0010.003 0.005 0.007 0.005
- - - -<0.001 <0.001 <0.001 <0.0010.002 0.003 0.009 <0.0010.006 0.008 0.009 0.002
- - - -- - - -
0.12 0.07 0.09 0.05<0.001 <0.001 <0.001 <0.0010.002 0.002 0.002 <0.001
<0.001 <0.001 <0.001 <0.001
0.14 0.10 0.13 0.06
Potatoes
Adult Child Infant Foetus
0.01 0.02 0.008 0.020.01 0.02 0.008 0.020.05 0.15 0.08 0.030.05 0.09 0.03 0.07
- - - -<0.001 <0.001 <0.001 <0.001
0.02 0.04 0.03 0.010.06 0.09 0.02 0.02
- - - -- - - -
0.05 0.03 0.009 0.02- - - -- - - -- - - -
0.25 0.44 0.19 0.19
40
Table 26. continued
Radionuclide
Total tritiumCarbon-14b
Cobalt-60Strontium-90Technetium-99Ruthenium-106c
Antimony-125Iodine-129Iodine-131Caesium-134Caesium-137Plutonium alphaPlutonium-241Americium-241
Total
Root Vegetables
Adult Child Infant Foetus
0.002 0.001 0.003 0.0030.002 0.002 0.003 0.0030.005 0.009 0.02 0.0030.04 0.06 0.07 0.06
- - - -<0.001 <0.001 <0.001 <0.0010.004 0.005 0.01 0.0020.03 0.03 0.03 0.01
- - - -- - - -
0.01 0.005 0.005 0.004- - - -- - - -- - - -
0.09 0.11 0.14 0.09
Green Vegetables
Adult Child Infant Foetus
0.003 0.001 0.002 0.004- - - -
0.005 0.007 0.009 0.0030.05 0.04 0.03 0.07
- - - -<0.001 <0.001 <0.001 <0.0010.006 0.004 0.007 0.0020.03 0.02 0.02 0.01
- - - -- - - -
0.01 0.004 0.003 0.0060.001 <0.001 <0.001 <0.0010.005 0.002 0.001 <0.001
<0.001 <0.001 <0.001 <0.001
0.11 0.08 0.08 0.10
Legumes
Adult Child Infant Foetus
0.004 0.002 0.002 0.006- - - -
0.01 0.02 0.02 0.0080.08 0.07 0.04 0.12
- - - -<0.001 <0.001 <0.001 <0.0010.008 0.006 0.006 0.0030.07 0.05 0.02 0.03
- - - -- - - -
0.03 0.009 0.004 0.010.006 0.003 0.002 <0.0010.005 0.002 <0.001 <0.0010.008 0.004 0.002 <0.001
0.22 0.17 0.10 0.18
Radionuclide
Total tritiumCarbon-14b
Cobalt-60Strontium-90Technetium-99Ruthenium-106Antimony-125Iodine-129Iodine-131Caesium-134Caesium-137Plutonium alphaPlutonium-241Americium-241
Total
Drinking water
Adult Child Infant Foetus
0.09 0.07 0.12 0.14- - - -- - - -
0.06 0.08 0.08 0.10- - - -- - - -- - - -- - - -- - - -- - - -
0.04 0.02 0.02 0.020.18 0.11 0.13 0.007
- - - -0.17 0.11 0.14 0.002
0.54 0.39 0.49 0.27
Inhalation
Adult Child Infant Foetus
- - - -- - - -- - - -
0.002 0.001 0.001 <0.001- - - -
0.01 0.01 0.009 <0.001<0.001 <0.001 <0.001 <0.001
- - - -- - - -
<0.001 <0.001 <0.001 <0.0010.002 <0.001 <0.001 <0.0010.26 0.14 0.08 0.010.18 0.09 0.04 0.0020.25 0.13 0.08 0.002
0.71 0.37 0.21 0.01
Radionuclide
Total tritiumCarbon-14b
Cobalt-60Strontium-90Technetium-99Ruthenium-106c
Antimony-125Iodine-129Iodine-131Caesium-134Caesium-137Plutonium alphaPlutonium-241Americium-241
Total
Mushrooms
Adult Child Infant Foetus
<0.001 <0.001 <0.001 0.0010.009 0.006 0.005 0.010.002 0.003 0.003 0.0010.06 0.06 0.03 0.08
- - - -<0.001 <0.001 <0.001 <0.0010.001 0.001 0.001 <0.0010.01 0.01 0.005 0.005
- - - -- - - -
0.01 0.004 0.002 0.0040.009 0.005 0.003 <0.0010.001 <0.001 <0.001 <0.0010.01 0.007 0.004 <0.001
0.11 0.10 0.06 0.11
Domestic Fruit
Adult Child Infant Foetus
0.02 0.02 0.03 0.030.20 0.19 0.26 0.280.06 0.12 0.20 0.030.20 0.29 0.28 0.30
<0.001 <0.001 0.001 <0.001<0.001 <0.001 <0.001 <0.001
0.03 0.04 0.07 0.010.30 0.35 0.28 0.12
- - - -- - - -
0.08 0.04 0.04 0.040.009 0.007 0.007 <0.0010.02 0.01 0.01 <0.0010.02 0.01 0.02 <0.001
0.94 1.1 1.2 0.82
Wild Fruit
Adult Child Infant Foetus
0.002 0.001 <0.001 0.0040.03 0.02 0.01 0.040.005 0.007 0.005 0.0030.17 0.15 0.07 0.25
- - - -<0.001 <0.001 <0.001 <0.0010.004 0.003 0.003 0.0020.03 0.02 0.008 0.01
- - - -- - - -
0.03 0.01 0.004 0.010.005 0.002 0.001 <0.0010.002 <0.001 <0.001 <0.0010.007 0.003 0.002 <0.001
0.29 0.22 0.11 0.32
a. Values in grey have been calculated using FSA monitoring data.b. Calculated using background corrected activity concentrations.c. Derived from standard modelling techniques.
41
TritiumCarbon-14a
Cobalt-60Strontium-90Technecium-99Ruthenium-106Antimony-125Iodine-129Iodine-131Caesium-134Caesium-137Plutonium alphaPlutonium-241Americium-241
Total overall dose
Inhalation
All foodstuffs
Milk
Foodstuffs other than milk
Radionuclide
Carbon-14a
Cobalt-60Technetium-99Ruthenium-106Caesium-137Plutonium alphaAmericium-241
Total
0.540.0010.010.031.20.100.11
2.0
0.140.0010.0050.010.180.020.02
0.39
0.070.0010.0050.0090.060.0080.009
0.16
0.740.0010.0080.0020.530.0040.002
1.3
Dose in 2009 (µSv)
Adult Child Infant Foetus
Table 28. Summary of doses to the terrestrial critical group from seafood consumption in 2009
RadionuclideAdult Child Infant Foetus
0.19 0.18 0.31 0.290.72 0.75 1.4 0.980.16 0.38 0.38 0.092.0 3.5 5.5 3.0
0.005 0.005 0.005 0.0050.03 0.03 0.02 0.020.12 0.18 0.34 0.051.0 1.3 1.2 0.39
0.008 0.02 0.08 0.0080.001 0.001 0.001 0.0012.0 1.3 1.2 0.900.48 0.28 0.23 0.020.23 0.12 0.06 0.010.47 0.27 0.26 0.02
7.5 8.3 11 5.8
0.71 0.37 0.21 0.01
6.8 7.9 11 5.8
2.6 4.0 7.8 2.7
4.2 3.9 3.0 3.1
Table 27. Summary of doses by radionuclide to the critical group from terrestrial foodstuffs and from inhalation in 2009
Total dose per radionuclide (µSv)
a. Calculated using background corrected activity concentrations.
a. Calculated using background corrected activity concentrations.
Pathway
Food consumption:terrestrial foods 6.8 7.9 11 5.8marine foods 2.0 0.39 0.16 1.3
Inhalation 0.71 0.37 0.21 0.01
Immersion:krypton-85 0.64 0.45 0.45 0.64
Externala 1.1 0.57 0.03 1.1
Total 11 9.7 12 8.9
Dose in 2009 (µSv)
Adult Child Infant Foetus
Table 29. Summary of doses to the terrestrial critical group in 2009
a. Taken from RIFE-14, Data from 2009 Total Dose assessment. Infant taken from Doses - gaseous. Adult and Child calculated from Child ratios. Foetus set equal to adult.
42
the reason that these doses are higher than thosereported before 2006. These doses are howeverconsiderably lower than in earlier years when theCalder Hall reactors were operational. Conservatively,it is assumed that members of this critical group arealso exposed to direct radiation (see next paragraphand table 1).
Direct radiation
70 Due to the closure of Calder Hall in March 2003,direct radiation doses to local residents have reducedsignificantly. Based on recent surveying workconducted in 2008 the upper bound of the doserange to residents living closest to the site is about 1.4 µSv.
Collective doses
71 Collective doses resulting from the effects ofdischarges from Sellafield in 2009, summed over 500 years, have been calculated in accordance withparagraphs 26-29 and 36 of the Introduction(amplified in the Appendix). The results (table 30) givecollective dose commitments (combined aerial and
marine) of about 3.0 man Sv to the UK population, 12 man Sv to the European population (including theUK) and 120 man Sv to the world population. Theseare slightly higher than the values reported in 2008due to an increase in carbon-14 and krypton-85discharges reflecting increased reprocessingthroughputs (paragraphs 11 and 12).
72 Most of the collective dose commitment fromSellafield discharges results from carbon-14 becauseof its long radioactive half-life (5730 years) and itsincorporation into the global carbon cycle. However,concentrations of carbon-14 in the atmosphere whichare attributable to Sellafield are indistinguishable fromnaturally occurring background concentrations atdistances exceeding 100 km. The natural backgroundresults in collective doses that are many orders ofmagnitude higher than the doses resulting fromSellafield’s discharges of carbon-14. This reflects thefact that natural sources of radiation constitute thelargest source of public radiation exposure on anational or global scale15.
Table 30. Collective doses from Sellafield’s discharges in 2009
Collective dose (man Sv) from discharges in 2009
Radionuclide Aerial discharges Marine discharges
UK Europe World UK Europe World
TritiumCarbon-14Krypton-85Technetium-99Iodine-129Caesium-137Plutonium AlphaAmericium-241Other nuclides
Total
0.130.080.21
-0.34
0.00050.0040.0020.008
0.77
0.300.761.1-
1.60.0010.0070.0040.01
3.8
0.366.811-
2.30.0010.0070.0040.01
20
0.00082.0-
0.0060.0060.060.010.0010.09
2.2
0.0037.3-
0.020.020.160.020.0010.19
7.7
0.0798-
0.020.070.180.020.0010.20
99
43
Non-radioactive discharges and disposals
73 Non-radioactive discharges and disposals from theSellafield site are made in accordance with therequirements of appropriate permits, consents andlicences. Liquid effluent discharges are summarised intable 31 and include all discharges for which annualmass limits are specified. Aerial discharges aresummarised in table 32.
Disposals made under the terms of Waste
Disposal or Waste Management Licences
74 There are five licensed landfill sites at Sellafieldalthough three are effectively closed. The SouthLandfill Site and the Calder Floodplain LandfillExtension are operational and are permitted to take arange of inert, non-radioactive wastes and are alsoauthorised to take radioactive soil (see paragraph 29).In recent years, these two sites have been reservedalmost exclusively for radioactive soil, as the onlyalternative site is the LLWR. Non-radioactive soil andother non-radioactive wastes are usually sent for off-site disposal.
Ozone depleting substances and fluorinated
greenhouse gases
75 The Company is committed to minimising the use ofozone depleting substances and replacing equipmentcontaining ozone depleting substances and fluorinatedgreenhouse gases. Routine releases are estimatedfrom the amounts of refrigerants used to top upsystems on site. Site releases of ozone depletingsubstances are summarised in table 33.
Carbon dioxide and other greenhouse gases
76 Sellafield’s discharges of carbon dioxide and methaneare mainly from Fellside combined heat and powerplant (CHP), which is managed and operated bySellafield Ltd, and its emissions controlled by theSellafield Environmental Permit and an EmissionsTrading Permit. Carbon dioxide may also be emittedfrom standby generators on Sellafield site which alsohave an Emissions Trading Permit. In addition, smallamounts of carbon dioxide are released from theprocess plants (table 32). Discharges of carbondioxide and methane in 2009 were similar to those in2008.
Table 31. Non-radioactive liquid effluent discharges in 2009a
Substance Release points
Mercury SETP, SIXEP, EARP, Laundry, Inactive Tank Farm Neutralising Pit,Thorp-C14 removal plant, Water Treatment Plant
Chromium SETP, SIXEP, EARP
N as NO2 and NO3 SETP, EARP
N as NO2 and NO3 Thorp-C14 removal plant
Glycol SETP, SIXEP, EARP
a. Annual mass limits reported under the Environmental Permit.
Discharge (te)
0.002
0.04
1,300
2.4
1.0
Annual Limit (te)
0.01
1.2
4,100
27
12
a. Annual mass limits reported under the Environmental Permit.
Table 32. Non-radioactive aerial effluent discharges in 2009
Substance Release pointDischarge Annual Limit
(te) (te)a
Oxides of nitrogen (as NO2) Vitrification Test Rig Secondary Off-gas Systems 0.02 1.00
Oxides of nitrogen (as NO2) BTC Fume Cupboard Extract Stack 0.02 0.50
Particulate matter CHP (as PM10) 0.4 -
Volatile organic compounds B204 stack, B6 cell vent stack, STP stack,(VOCs) flask maintenance paint spray booth, 48 -
Thorp main stack and CHP
Carbon dioxide CHP, B204 stack, B6 cell vent stack, SIXEP stack 460,000 -
Carbon monoxide CHP, B230 stack 25 -
Methane CHP, STP stack 9.5 -
Sulphur hexafluoride Ventilation system commissioning and testing 0.00002 -
77 Sulphur hexafluoride is used periodically in smallquantities for testing the effectiveness of stack andduct sampling systems (table 32). Discharges wereabout 20 g in 2009 compared to about 5 g in 2008.
Off-site disposals of solid waste
78 Non-radioactive controlled wastes consisting of office,canteen, workshop or general waste (mainly solid butincluding some sludges and liquids) are disposed ofoff-site via a specialist waste disposal contractor.Wherever possible, waste is recycled but if this is notpracticable, it is disposed of to a licensed landfill.Waste that is particularly hazardous may have to beconsidered as special waste and disposed of tospecially licensed disposal facilities after pre-notifyingthe Environment Agency. In order to reduce theamount of low-level radioactive waste sent fordisposal at the LLWR, which is a national resourcewith limited capacity, some wastes arising in processareas of the site are carefully monitored to confirm thatthey are not radioactive before they too are sent fordisposal off-site with other controlled wastes. It shouldbe noted that radioactive special waste is alsoincluded in the LLWR disposal figures.
Non-radiological monitoring of the environment
79 The Environmental Permitting Regulations (2007)permit includes a monitoring programme (see figure 5). Compared to the radiological environmentalmonitoring programme, its scope is limited andcomprises local air sampling on the Sellafield site,water sampling from the Rivers Calder and Ehen, andseawater sampling from local beaches. A morecomprehensive summary of non-radioactive releasesto air, controlled waters, land and off-site transfers ofwaste is given in the Pollution Inventory supplied tothe Environment Agency each year and available fromtheir website.
Air sampling
80 Measurements of nitrogen dioxide concentrations inair are made at five locations on the Sellafield site:West Ring Road, Meteorological Station, North Grouproundabout, Calder Gate and South Side. A shortcampaign of off-site gas monitoring was also carriedout at Calder Farm in 2009 to monitor the effect ofreduced stack heights on the Fellside Combined Heatand Power plant and these will strongly influenceairborne concentrations measured in the environmentin the vicinity of Sellafield). Measurements are madeusing passive diffusion tubes which are exposed forone month before being analysed. Air sampling resultsare summarised in table 34.
44
a. HCFCs are ozone depleting substances and HFCs are fluorinatedgreenhouse gases. Note: The range of substances discharged varieseach year depending on which equipment is topped up withrefrigerants.
Substancea Discharge (te)
22 HCFC 0.10R407c HFC 0.13R134A HFC 0.07R422d HFC 0.007
Table 33. Discharges of ozone depleting substances and
fluorinated greenhouse gases in 2009
a. National Air Quality Standard (annual mean)16
a. National Environmental Quality Standard.
Mean concentration in air (µg m-3)
NOx
North Gate 12 Meteorological Station 11 Calder Gate 10 West Ring Road 13 South Side 11 Calder Farm 11
NAQS objectivea 40
Table 34. Non-radioactive monitoring of air in 2009
Table 35a. Non-radioactive monitoring of river waters in 2009
Location
River Calder - downstream of siteRiver Calder - upstream of siteRiver Ehen - downstream of pipebridgeRiver Ehen - upstream of Factory Sewer outfall
EQSa
pH
7.97.48.17.9
6.0 - 9.0
mg per litre
NO -3
1.20.571.11.1
N/A
Table 35b. Non-radioactive monitoring of coastal waters
in 2009
Location
DriggSeascaleSellafieldSt. Bees
Boron
4.23.83.74.2
N as NO-2
<0.04<0.04<0.04 <0.04
NO-3
<0.080.310.140.18
milligrammes per litre
45
Gas spike probe monitoring CH4 (ppm) CO2 (%) O2 (%)
North Landfill Site Extension 0 2.4 18North Landfill Site 0 3.9 16Calder Floodplain Landfill 0.53 1.5 17Calder Floodplain Landfill Extension 0 1.2 19South Landfill Site 0 1.5 18
Table 36b. Non-radioactive monitoring of gases on Sellafield's landfill sites
Surface water analysis pHTemperature Conductivity Dissolved O2 NH3N CI- COD Total
(°C) (mS cm-1) (ppm) (4g l-1) (ppm) (mg l-1) suspendedsolids (mg l-1)
North Landfill Site ExtensionStream to north River Calder upstream River Calder downstream
North Landfill SiteRiver Calder upstream River Calder downstream
Calder Floodplain LandfillRiver Calder downstream
Calder Floodplain Landfill ExtensionNew Mill Beck upstream River Calder downstream
South Landfill SiteRiver Calder upstreamRiver Calder downstream
7.47.47.4
--
7.7
7.77.8
--
0.290.100.08
--
0.22
0.340.26
--
8.81010
--
10
9.79.8
--
0.040.0080.004
--
0.14
0.200.16
--
351111
--
26
5233
--
245.26.9
--
31
3130
--
353.32.2
--
8.5
147.8
--
Table 36a. Non-radioactive monitoring of surface water and gases on Sellafield's landfill sites in 2009
9.38.58.5
--
6.5
7.98.6
--
Water sampling
81 Water samples are obtained from the Rivers Calderand Ehen at locations both upstream and downstreamof the site (table 35a). The downstream samples aretaken above the confluence of the two rivers, and attimes which minimise contamination with seawater. As a result of the review of the Monitoring Programme(paragraph 14), seawater samples are now obtainedfrom the shoreline areas given in table 35b rather thanfrom offshore sites as performed up to 2006.
Monitoring of Sellafield’s landfill sites
82 The Waste Management Licences for the North LandfillSite and Calder Floodplain Landfill Extensions requirethat environmental monitoring be carried out in thevicinity of the two sites. Although not a requirement ofits Waste Management Licence, environmentalmonitoring is also carried out in the vicinity of the SouthLandfill Site. The monitoring comprises water samplingfrom the River Calder and New Mill Beck upstreamand downstream of the tips and gas monitoring overtheir surfaces. The river water was sampled monthlyand gas monitoring carried out quarterly. The resultsare summarised in tables 36a and b.
Environmental impact of non-radioactive
discharges
83 In this report, the impact of aerial discharges has beenaddressed (table 34) by comparing the measuredenvironmental concentrations with the most stringent(annual mean) national air quality objectives16 fornitrogen dioxide. The interpretation of these results isnot straightforward since discharges are made not onlyfrom Sellafield but also from other industrial sites inWest Cumbria and from natural sources. The data intable 34 show that the measured concentrations in airon the Sellafield site were all below the guideline value.
84 The results in table 35a and 35b confirm that theliquid discharges from Sellafield are not causing theEnvironmental Quality Standards (EQS) andEnvironmental Assessment Levels (EAL)16 to beexceeded. Continuous concentrations at the EQS orEAL should not produce any significant detriment.
85 Environmental monitoring results (table 36a and b)confirm that the impact of Sellafield's landfill sitesremains negligible. No significant concentrations ofcarbon dioxide or methane have been measured atthese sites.
References
1. Environment Agency, Environment and HeritageService, Food Standards Agency and ScottishEnvironment Protection Agency (2009).Radioactivity in food and the environment,
2008. RIFE-14.
2. Peirson DH (1988). Artificial radioactivity in
Cumbria: A summary of an assessment by
measurement and modelling. J. Env.Radioactivity 6: 61-75.
3. Howarth JM and Eggleton A E J (1988). Studies
of environmental radioactivity in Cumbria.
Part 12: Modelling of sea-to-land transfer of
radionuclides and an assessment of the
radiological consequences. AERE-R11733,HMSO, London.
4. Howard BJ (1987). Cs137 uptake by sheep
grazing tidally inundated and inland pastures
near the Sellafield reprocessing plant. In:Coughtrey P J et al (Eds) Pollutant Transport andFate in Ecosystems, pp 371-383. BlackwellScientific Publications, Oxford.
5. Cook GT and McKenzie AB (1996). Marine
background of carbon-14. ProjectRP/GNSR/5003, Scottish Universities Researchand Reactor Centre, East Kilbride.
6. Food Standards Agency (2010). Radiological
Habits Survey: Sellafield Review 2009.
Environment Report RL 07/10 (Draft 2).
7. Allott R (2005) Principles for the assessment of
total retrospective public doses,
NDAWG/2/2005. Environment Agency, FoodStandards Agency, NRPB, NII, Chilton.
8. NDAWG Paper 11-03 (2007) Use of
measurements in determining retrospective
dose assessments in RIFE.
9. Food Standards Agency (2009). Radiological
Habits Survey, 2008. Environment ReportL02/09.
10. Byrom J, Robinson CA, Simmonds JR, Walters Band Taylor RR (1995). Food consumption rates
for use in generalised radiological dose
assessments. J. Radiol. Prot. 15(4): 335-342.
11. Cabianca T, Fayers CA, Mayall A, Robinson CAand Simmonds JR (1995). Peer review of BNFL
radiological assessment methodologies.
NRPB Report M815.
12. Smith KR and Jones AL (2004). Generalised
habit data for radiological assessments.
NRPB Report W41.
13. Simmonds JR et al. (1995). Methodology for
assessing the consequences of routine
releases to the environment. EUR 15760. Officefor the Publication of the European Communities.
14. International Commission on EnvironmentalProtection (1996). Age-dependent doses to
members of the public from intakes of
radionuclides: Part 5. Compilation of ingestion
and inhalation dose coefficients. ICRPPublication 72. Ann. ICRP 26 (1).
15. Watson SJ, Jones AL, Oatway WB and HughesJS (2005). Ionising radiation exposure of the
UK population: 2005 Review. Health ProtectionAgency Report HPA-RPD-001, HMSO, London.
16. Environment Agency (2010). Horizontal
Guidance Note H1- Environmental risk
assessment. Environment Agency, Bristol.
17. Health Protection Agency (2007). Centre for
Radiation, Chemical and Environmental
Hazards. Letter to Mr A Mayall, Environment
Agency from Dr John Cooper, Deputy
Director, Health Protection Agency. HealthProtection Agency, Oxfordshire.
46
47
CapenhurstDischarges and Monitoring in the United Kingdom
Annual Report 2009
Summary
1 At no time during 2009 havedischarges and disposals ofradioactive or non radioactivewaste through authorised andscheduled outlets at Capenhurstexceeded numerical limits in anyof the authorisations. The annualradiation doses to the criticalgroups from liquid and aerialdischarges are shown in Table 1.The value continued to be less than 1 µSv and wastherefore radiologically insignificant.
Operations at Capenhurst
2 The Capenhurst Works, situated near Ellesmere Portis operated by two separate companies each holdinga Nuclear Site Licence. These are Sellafield Ltd andUrenco UK Ltd. Sellafield Ltd undertakesdecommissioning operations related to the redundantgaseous diffusion plant and storage of uranic material(as either oxide powders or fluoride compounds).Urenco UK Ltd own and operate principallyenrichment plants. For future reference throughoutthis chapter, Capenhurst relates to the site run bySellafield Ltd. Urenco UK Ltd will be referred to asappropriate. The main activities undertaken during2008 at Capenhurst were the continueddecommissioning of the gaseous diffusion plant andassociated facilities. Capenhurst continued to providea uranic storage service to the nuclear industry.
3 Urenco UK Ltd has applied for a transfer ofauthorisation limits to Urenco ChemPLants Ltd;Urenco ChemPlants will thus have its ownEnvironmental Permit1 under the EnvironmentalPermitting Regulations 2010, which allows transfer ofliquid wastes to Sellafield Ltd. Summaries ofcontinuing transfers of liquid and solid waste toCapenhurst for onward disposal are given in theHealth, Safety and Environmental Report 2009published by Urenco UK Ltd. This is available fromthe latter's Health, Physics and Safety Records Office,Capenhurst, Chester CH1 6ER.
Radioactive discharges and disposals
4 Issued in 2007, Capenhurst holds a single multi-mediaauthorisation (MMA) covering discharges anddisposals of radioactive wastes to the Rivacre Brook,to atmosphere and by burial in the ground at theClifton Marsh landfill site and the Low Level WasteRepository.
Liquid discharges into the Rivacre Brook
5 Liquid wastes principally arise from decommissioningoperations. These wastes, together with those fromUrenco UK Ltd, are all discharged into the RivacreBrook by means of a partly culverted ditch.
6 Collectively, the Permit includes quarterly limits for anumber of individual radionuclides. Discharges of'total alpha' activity are subject to daily (24 hour) limits.In order to demonstrate compliance with the terms ofthe authorisation, samples from each waste streamare analysed daily or prior to discharge (e.g.decommissioning effluent delay tanks) along with dailysampling and analysis of the site outlet.
7 Table 2 presents data on discharges for the past fiveyears and provides a basis for comparison with theauthorised limits. Variations in these small dischargelevels reflect the various phasing of decommissioningoperations.
Aerial discharges
8 Radioactive effluents are discharged to atmospherevia stacks on the Capenhurst site. These dischargesconsist principally of incinerator gases and ventilationair from decommissioning operations in the legacydiffusion plant and the hexafluoride bottle washingfacility. Note: The incinerator is not currentlyoperational and is a state of care and maintenance;therefore no emissions are generated.
9 The radioactive content of discharges from releasepoints on site consist predominantly of uraniumaccompanied by an approximately equal beta activityfrom uranium daughters and lesser activities ofTechnetium-99. The Permit includes the quantitativelimits on airborne radioactive discharges.
10 Discharges of uranium over the past five years areshown in Table 3. Variations in these small dischargelevels reflect various phasing of decommissioningoperations.
48
Table 1. Critical dose
Pathway Liquid Aerialdischarges discharges
2008 2009* 2008 2009
Rivacre Brook: child playing 0.017 0.015 - -
Milk consumption: infant - - N/A** N/A**
* 2009 Figure taken from RIFE-14 ** Off site sampling ceased September 2007
49
Annual discharge
Radionuclide Authorised MMALimit (GBq) 2005 2006 2007 Limit 2008 2009
Uranium N/A 0.001 <0.001 <0.001 0.0025 <0.001 <0.001
Table 3. Airborne radioactive waste discharges
Annual discharge
Radionuclide Authorised MMALimit (pre 2005 2006 2007 Limit 2008 2009
MMA GBq) (GBq)
Bulk weight (tonnes) N/A 1100 1100 480 NA 61 200
Uranium alpha content (GBq) N/A 98 61 14 36 32 36
Technetium-99 (GBq) N/A 9.5 7.9 2.9 68 66 14
Table 4. Disposals of solid waste to Clifton Marsh from Capenhurst
Mean radionuclide concentration
Radionuclide Authorised MMALimita 2005 2006 2007 Limit 2008 2009
Total alpha (Bq l-1) 100 <5 <5 <5 N/A <5 <5
Tritium (Bq ml-1) 111 0.05 0.05 0.05 N/A N/A N/A
Annual discharge (GBq)
Total uranium alpha activity 20 0.19 0.10 0.09 0.75 0.14 0.08
Uranium daughters 20 0.39 0.18 0.07 1.4 0.01 0.01
Non-uranic alpha emitters(mostly neptunium-237) 3 0.009 0.02 0.03 0.22 0.02 0.02
Technetium-99 100 0.17 0.08 0.04 1.00 0.02 0.01
Table 2. Radioactive discharges to the Rivacre Brook (includes UUK transfers)
a Where authorised limits are specified for periods of three consecutive calendar months, annual equivalents have been derived by multiplyingthese limits by four.N/A Not applicable.
Annual discharge
Radionuclide Authorised MMALimit (GBq) 2005 2006 2007 Limit 2008 2009
Volume (m3) 6000 1900 98 0 6000 210 440
Uranium (GBq) 250 18 18 0 250 3.3 21
Other alpha emitters (GBq) 15 5.3 0.11 0 50 0.50 0.93
Others (GBq) 3000 770 62 0 4000 56 220
Table 5. Disposals of solid radioactive waste to LLWR from Capenhurst
Solid wastes
11 Solid waste disposals at Clifton Marsh are shown inTable 4. The waste consists of ash, scrap metal andother non-combustible materials, such as glasswareand building rubble. It can also include incinerator ashgenerated from waste transferred from Urenco UK Ltdunder the terms of the inter-site transfer Permit. Thealpha radioactivity in the solid waste, due almostentirely to uranium is accompanied by anapproximately equal amount of beta activity fromuranium daughters. Annual activity limits are part ofthe Permit.
12 Solid waste which does not conform to therequirements of the Clifton Marsh Condition ofAcceptance is disposed of at the LLWR. Solid wastedisposals at LLWR are shown in Table 5. Generally theCapenhurst waste is consigned to Clifton Marsh inpreference to the LLWR.
Monitoring of the environment for radioactivity
13 During the many years of site operations the principalexposure pathways for radioactivity discharged fromthe Capenhurst site, as identified by environmentalmonitoring and habits surveys, have been theingestion of milk produced at local farms and theexternal radiation to, and potential inadvertentingestion of, water and silt by children playing in theRivacre Brook. These pathways are covered by thesite's Statutory Environmental and MonitoringProgramme (illustrated in figure 1- which now onlyincludes the sampling of water weed and grass) andFood Standards Agency's monitoring programme2.The monitoring of milk and bovine faeces ceased aspart of the Statutory Programme in 2007. The lowdirect radiation dose rates from the site are alsoroutinely monitored.
Aquatic pathways
14 There is a requirement under the StatutoryEnvironmental Monitoring Programme to analysesamples from the Rivacre Brook of water, silt and thewater weed Cladophora (Table 6). The levels ofradioactivity are similar to those in the previous year asthey arise from ongoing decommissioning activities onthe site. Levels of activity at the plant outlet (Point A),which is within the boundary of the licensed site, aresignificantly higher than downstream (Point B) due toaccumulation of radioactivity in silt. The silt isperiodically removed from the outlet and disposed of toa local landfill site or to the LLWR, depending on theradioactive content. Measurements have also beencarried out by the regulatory bodies for many years.
Airborne and terrestrial pathways
15 The discharges to atmosphere are radiologicallyinsignificant. However, Sellafield Ltd collects samplesof grass from two on-site locations and analyse themfor technetium-99 and uranium on a fresh mass basis.The results for grass were all below the limit ofdetection.
16 The Food Standards Agency undertakes a monitoringprogramme for uranium in samples of milk. Recentresults show that mean uranium concentrations in milksamples collected from a local farm were below thelimits of detection (0.0032 Bq l-1). Milk samples are nottaken by Sellafield Ltd.
Direct radiation
17 The monitoring programme includes measurements toaccount for line of sight and shine effects. The site hasrecently been asked by the regulatory bodies toinvestigate and understand an apparent increase inneutron does around site. Currently the site isinvestigating if this effect is due to natural variations inbackground that affect the method of calculation or ifatmosphere effects are influencing the results. Nodirect link has been established with site operators.
50
Mean radionuclide concentration (Bq kg-1 wet weight for Cladophora, Bq kg-1 dry weight for silt)
Location/sample Number of
Uranium Technetium-99 Neptunium-237samples
Point A - Water 4 0.21 0.2 0.02
Algae Nil** Nil Nil Nil
Silt 4 950 1300 10
Point B - Water 4 0.1 0.20 0.02
Algae 1 66 37 0*
Silt 4 61 120 5.0
Table 6. Environmental Sampling
* Insufficient sample to analyse for Neptunium-237** No algae present to take sample
51
River Mersey
Manchester Ship Canal
OverpoolRivacre Brook
Hooton
M53
M53
Whitby
Plant outlet(Point A)
Capenhurst Works
0 1
Kilometres
1.5 kmDownstream(Point B)
N
Willaston
Great Sutton
Capenhust
Shotwick
BackfordA5117
A41
M56Key:
Rivacre Brook
Herbage
●
■
Figure 1. Environmental monitoring around Capenhurst
Radiological impact of operations at Capenhurst
Critical group doses
Aquatic pathways
18 The critical group pathway3 for liquid discharges isconsidered to be children playing on or near RivacreBrook. The estimated dose from inadvertent ingestionof water and silt is less than 1 µSv per year from allsite discharges (Table 1). Potential doses (3 µSv) fromexternal radiation over the banks of the brook couldbe attributable to variations in natural backgrounddose rates. The number of hours children play on ornear the Rivacre Brook and any potential water andsilt ingestion rates are those recommended by theHealth Protection Agency4 for generic use where nohabit survey has been carried out3, and previouslyused by the Environment Agency. This data is morerealistic for the critical group pathway applicable toCapenhurst, than the pessimistic assumptions usedby the Food Standards Agency and the EnvironmentAgency.
Airborne and terrestrial pathways
19 The radiotoxicity of uranium is low compared with itschemical toxicity. Based upon the previous samplingregime that included bovine faeces, the uraniumconcentrations in that material have been historicallyequivalent to about 0.1% of the concentrationestimated to begin to affect the health of cattle andare within the range of concentrations observednaturally. Hence, there are no radiological ortoxicological implications for food safety.
20 Sampling of milk consumption for the most exposedmember of the public i.e. a one year old infant,ceased in 2007 as values were less than 1 µSv (Table 1).
Direct radiation
21 Dose rates at the site perimeter and other locationsare measured annually5. Any increase above thebackground level of about 0.1 µGy h-1 is attributable todirect radiation from the plant rather than wastedischarges. The dose rate was approximately 0.19 mSv slightly higher than 2008 figures (abovebackground) compared to the site limit of 1 mSv.
22 Members of the public spend very little time in theimmediate vicinity of the perimeter of the combinedsites and so radiation levels are of very littlesignificance in terms of public radiation exposure.Detailed HPA studies into the direct radiation exposureto the general public in the vicinity of the site havebeen carried out on an annual basis3. A combinationof dose rate measurements and theoretical
extrapolation to locations occupied by the public has given a maximum potential dose range of 15 - 160 µSv (based on pessimistic assumptions) forlocal residences and up to 470 µSv for adjacentindustrial premises. An estimated dose of 1mSv hasbeen calculated for locations immediately adjacent tothe site perimeter and based upon 100% occupancyover the year. Based upon more realistic assumptionsof occupancy actual doses are likely to be muchlower.
Collective doses
23 Collective doses from discharges from Capenhurstwere calculated and are presented in Table 7. Until 2000, over 99% of the collective dose arosepredominantly from aerial discharges of tritium.
Non-radioactive discharges and disposals
24 Discharges to the Rivacre Brook are made inaccordance with the Water Resources Act consent(also now issued under Environmental PermittingRegulations 2010). There were no non-complianceswith discharge limits and conditions. Off-sitedisposals of solid waste were made in accordancewith Duty of Care requirements and the HazardousWaste Regulations.
Discharges made under the terms of Prescribed
Process authorisations
25 The incinerator was not operational during 2009 andhence there were no discharges made during the year.However, when operational, an EA PollutionPrevention Control (PPC) authorisation regulates thedischarge of gaseous effluents from the incineratorstack. Concentration limits are specified for certainoff-gases generated as a result of the hightemperature combustion process. When necessary,compliance checking is completed by passing the fluegases through bubbler trains, filters and by directspectrometry. The resultant solutions and used filtersare sampled and analysed by UKAS accreditedmethods. Radioactive combustible waste which isnecessarily generated is currently transferred to Clifton Marsh for disposal.
52
Collective dose (man Sv)Discharge route
UK Europe World
Aerial 1.2 x 10-4 1.4 x 10-4 1.4 x 10-4
Liquid 7.2 x 10-7 1.8 x 10-6 1.9 x 10-6
Table 7. Collective dose from Capenhurst's discharges
in 2009
Discharges made under terms of consents
26 Non-radioactive liquid wastes arise principally fromdecommissioning operations on the Capenhurst site.These wastes, together with those transferred toCapenhurst from the Urenco UK Ltd site, those fromneighbouring companies (e.g. Capenhurst TechnologyCentre, EA Technology, Sutton Nurseries) and certainlocal domestic properties, are all discharged into theRivacre Brook by means of the partly culverted culvertused for radioactive effluents.
27 The discharges from Capenhurst are made under theterms of a consent relating to treated sewage effluentand a delay tank. From 2002, compliance with theconsent has been checked by regular and periodicsampling at the authorised point of discharge from theon-site Rivacre Brook culvert. Non-radioactive wastes,together with those from neighbouring companies,pass through a sewage plant. Consequently, sitedischarges are assumed to originate predominantlyfrom the sewage farm and Urenco UK Ltd rather thanat the site outlet where non-radioactive results can beaffected by events unrelated to Capenhurst or Urenco UK Ltd operations.
Ozone depleting substances
28 Use of ozone depleting substances is limited to thosewhich are necessarily contained within domesticrefrigeration units. Wherever practicable, the use ofthese substances will be phased out as equipment isreplaced due to age and through to implementation ofenvironmentally sound substitutes.
Off-site disposals of solid waste
29 If they cannot be directly recycled, controlled wastesfrom offices, workshops and other sources aredisposed of via specialist waste contractor where 99%of the waste is recycled or reused. The waste disposalcontractor operates a rigorous process of segregationof wastes once collected to increase the proportion ofmaterial recycled. Furthermore, they utilise a secondstage of recycle and reuse that aims to retrieve furtherrecyclable material that has been cross-contaminatedwith food waste and is this not suitable for the initialsort process. Non-recyclable material from thatprocess is subsequently converted into replacementfuels to maximise the reuse of the material.
30 Hazardous wastes are sent for recycling or to licenseddisposal facilities. Hazardous wastes, which are alsoradioactive, are included in the LLWR disposal figures. The total amounts of non-radioactive wastes disposedof or recycled in 2009 are categorised andsummarised in Table 8.
31 The site's accelerated decommissioning programmehas involved the dismantling of a number of redundantbuildings, resulting in increased quantities of buildingrubble and other associated waste streams. Therubble is ordinarily disposed of to landfill and wherepossible steelwork has been sent for recycle. Much ofthe demolition material has been processed andreused on site to minimise the overall disposalquantities.
References
1 Application Reference EA/EPR/ZP3835TC/A001URENCO ChemPlants Ltd.
2 Environment Agency, Environment and HeritageService, Food Standards Agency and ScottishEnvironment Protection Agency (2009). Radioactivity
in food and the environment, 2008. RIFE-14.Environment Agency, EHS, Food Standards Agencyand SEPA; Bristol, Belfast, London and Stirling.
3 Environment Agency (2002); Radioactivity in theEnvironment. A summary and radiological
assessment of the Environment Agency's
monitoring programmes. Report for 2001.
4 National Radiological Protection Board (2003);Generalised habit data for radiological
assessments. NRPB-W-41.
5 Health Protection Agency, Radiation Protection
Adviser Visit Report; October 2009.
53
Waste type Quantity (te)
Inert 0
Non-hazardous 499
Hazardous 20.57
Table 8. Disposal of Controlled Wastes (non-radioactive)
54
AppendixDischarges and Monitoring in the United Kingdom
Annual Report 2009
Values for individual dose per unit intake andcollective dose per unit discharge
Individual doses
1 Radionuclides taken into the body, either by ingestionor by inhalation, cause exposure both to the localtissue and to the whole body. For the purposes ofdosimetry, monitoring and control, it is the whole-bodyexposure which is often of prime concern. The actualexposure will depend on many factors, such as thesolubility of the radionuclide and its characteristicretention time in the body.
2 The dose coefficients in Tables 1 and 2 reflect themost recent advice of the International Commission onRadiological Protection (ICRP)1. They represent thecommitted effective dose (CED) that would beincurred by an individual up to the age of 70 yearsfollowing the uptake of a unit amount of aradionuclide. Since biokinetic behaviour (and hencedose incurred) may change with age, differing valuesare presented depending on the age of the individualat the time of intake. The methods and parametervalues used for the radiological assessments generallyfollow the values and relationships given in Annexes IIand III to the Council Directive 96/29/Euratom of 13 May 1996.
3 In determining the dose arising from ingestion ofmaterial containing radioactivity, it is necessary toconsider the fraction of the radioactivity which is likelyto be absorbed across the wall of the gastro-intestinaltract. Such absorption is referred to as the gut uptakefactor (f1) and varies with the physical and chemicalform of the radionuclide and with the metabolism andphysiology of the individual. In general, young infantsabsorb some molecular species more readily thanolder children or adults and f1 values tend to becorrespondingly larger for infants in a number ofcases. In general, more soluble elements, such ascaesium or tritium, tend to be absorbed more readilythan less soluble elements, such as plutonium, acrossall age ranges.
4 With respect to intakes of radionuclides by ingestion,a number of studies2,3,4 have established moreappropriate gut uptake values for the actinides presentin winkles and other molluscs in the Sellafield area, foruse in critical group studies. For winkles, these valueshave been endorsed by the Health Protection Agency5
and supported by other studies6. These values arepresented here and are used in this report to estimatedoses arising from consuming winkles from the WestCumbrian coast. For seafoods other than winklesclose to Sellafield, the Health Protection Agencyconsiders that using a gut transfer factor of 0.0005 forboth plutonium and americium will not lead to
underestimates of critical group doses4,7. Theseapproaches are consistent with the dose assessmentsperformed within RIFE-148.
5 Dose per unit intake values for the inhalation ofradionuclides are derived from the most recentrecommendations of ICRP 1,9. The dose followingintake of radionuclides by inhalation depends upon anumber of factors in addition to the radioactiveproperties of the nuclide(s) involved - in particular, onthe particle size of the inhaled material (whichinfluences the extent and distribution of depositionwithin the respiratory tract) and the rate at whichdeposited material can be absorbed into body fluidswithin the respiratory tract, and subsequently entergeneral systemic circulation. A significant proportion ofparticulate material deposited in the respiratory tract iscleared directly via the gastro-intestinal tract inswallowed mucus, so the proportion of this swallowedmaterial which is absorbed across the gut wall alsoinfluences the dose. Regarding particle size, ICRPrecommends the calculation of doses to members ofthe public assuming an activity median aerodynamicdiameter of 1 micron (10-6 m) for the inhaled material9.For most nuclides, this maximises the resulting doseby maximising deposition in the alveolar region of therespiratory tract.
6 ICRP has derived a standard classification for inhaledmaterial (the 'lung absorption type') based on the rateof absorption of different chemical forms ofradionuclides into body fluids. These absorption typesare denoted as V, F, M and S with type V being themost rapidly absorbed and type S the slowest. Foreach absorption type ICRP recommends anappropriate factor (the 'f1 value') for the fraction ofswallowed material which is absorbed through the gut wall.
7 ICRP has provided calculated values for thecommitted effective dose to members of the public ofdifferent ages, for inhalation of airborne particles witha median diameter of 1 micron, for all theradionuclides of relevance to this report9. Severalvalues are generally cited for each radionuclide,reflecting the range of absorption types which may beencountered. However, for most radionuclides, ICRPrecommends a default absorption type which may beassumed in the absence of specific information aboutabsorption behaviour; in most cases the dose per unitintake values corresponding to those defaultabsorption types are used in the dose assessments inthis report. For some radionuclides, ICRP does notspecify a default absorption type and in theseinstances the absorption type producing the highestvalue of dose per unit intake is assumed for doseassessments. Finally, for some discharges of uranium
55
Continued page 58
56
Table 1. Committed effective doses per unit intake for ingestion
Radionuclide f1a
Dose per unit intake (Sv Bq-1)
Foetus 1y 10y Adult
H-3 oxide 1E+00 3.1E-11 4.8E-11 2.3E-11 1.8E-11
H-3 organic 1E+00 6.3E-11 1.2E-10 5.7E-11 4.2E-11
C-14 1E+00 8.0E-10 1.6E-09 8.0E-10 5.8E-10
S-35 organic 1E+00 1.6E-09 5.4E-09 1.6E-09 7.7E-10
Mn-54 1E-01 7.1E-10 3.1E-09 1.3E-09 7.1E-10
Fe-55 1E-01 8.1E-11 2.4E-09 1.1E-09 3.3E-10
Co-60 1E-01 1.9E-09 2.7E-08 1.1E-08 3.4E-09
Zn-65 5E-01 4.1E-09 1.6E-08 6.4E-09 3.9E-09
Sr-90 3E-01 4.6E-08 9.3E-08 6.6E-08 3.1E-08
Zr-95 1E-02 7.6E-10 8.8E-09 3.0E-09 1.5E-09
Nb-95 1E-02 3.7E-10 3.2E-09 1.1E-09 5.8E-10
Tc-99 5E-01 4.6E-10 4.8E-09 1.3E-09 6.4E-10
Ru-103 5E-02 2.7E-10 4.6E-09 1.5E-09 7.3E-10
Ru-106 5E-02 3.8E-10 4.9E-08 1.5E-08 7.0E-09
Ag-110m 5E-02 2.1E-09 1.4E-08 5.2E-09 2.8E-09
Sb-125 1E-01 4.7E-10 6.1E-09 2.1E-09 1.1E-09
I-129 1E+00 4.4E-08 2.2E-07 1.9E-07 1.1E-07
I-131 1E+00 2.3E-08 1.8E-07 5.2E-08 2.2E-08
Cs-134 1E+00 8.7E-09 1.6E-08 1.4E-08 1.9E-08
Cs-137 1E+00 5.7E-09 1.2E-08 1.0E-08 1.3E-08
Ce-144 5E-04 3.1E-11 3.9E-08 1.1E-08 5.2E-09
Pm-147 5E-04 2.6E-10 1.9E-09 5.7E-10 2.6E-10
Eu-154 5E-04 2.0E-09 1.2E-08 4.1E-09 2.0E-09
Eu-155 5E-04 3.2E-10 2.2E-09 6.8E-10 3.2E-10
Ra-226 2E-01 3.2E-07 9.6E-07 8.0E-07 2.8E-07
Th-228 5E-04 2.4E-07 1.1E-06 4.3E-07 1.4E-07
Th-230 5E-04 8.6E-09 4.1E-07 2.4E-07 2.1E-07
Th-232 5E-04 9.4E-09 4.5E-07 2.9E-07 2.3E-07
Th-234 5E-04 1.5E-11 2.5E-08 7.4E-09 3.4E-09
U-234 2E-02 1.5E-08 1.3E-07 7.4E-08 4.9E-08
U-235 2E-02 1.4E-08 1.3E-07 7.1E-08 4.7E-08
U-238 2E-02 1.3E-08 1.5E-07 7.5E-08 4.8E-08
Np-237 5E-04 3.6E-09 2.1E-07 1.1E-07 1.1E-07
Pu-238 5E-04 9.0E-09 4.0E-07 2.4E-07 2.3E-07
Pu-239 5E-04 9.5E-09 4.2E-07 2.7E-07 2.5E-07
Pu-240 5E-04 9.5E-09 4.2E-07 2.7E-07 2.5E-07
Pu-241 5E-04 1.1E-10 5.7E-09 5.1E-09 4.8E-09
Am-241 5E-04 2.7E-09 3.7E-07 2.2E-07 2.0E-07
Cm-242 5E-04 4.7E-10 7.6E-08 2.4E-08 1.2E-08
Cm-243 5E-04 1.5E-07 3.3E-07 1.6E-07 1.5E-07
Cm-244 5E-04 2.2E-09 2.9E-07 1.4E-07 1.2E-07
Plutonium and americium values for application to the consumption of Cumbrian winkles
Pu-238 2E-04 3.6E-09 1.6E-07 9.6E-08 9.2E-08
Pu-239 2E-04 3.8E-09 1.7E-07 1.1E-07 1.0E-07
Pu-240 2E-04 3.8E-09 1.7E-07 1.1E-07 1.0E-07
Pu-241 2E-04 4.4E-11 2.3E-09 2.0E-09 1.9E-09
Am-241 2E-04 1.1E-09 1.5E-07 8.8E-08 8.0E-08
a. The gastro-intestinal absorption fraction does not apply to neonates or infants aged below about one year.
57
Table 2. Committed effective doses per unit intake by inhalation
Radionuclide Lung f1a
Dose per unit intake, Sv Bq-1
Basis for choice of lungabsorption type Foetus 1y 10y Adult absorption type
H-3 oxide V 1E+00 2.6E-12 2.7E-10 8.2E-11 4.5E-11 Water vapour
H-3 organic V 1E+00 6.3E-11 1.1E-10 5.5E-11 4.1E-11 Organically bound tritium
C-14 M 1E-01 6.6E-11 6.6E-09 2.8E-09 2.0E-09 ICRP recommended default
S-35 M 1E-01 1.5E-11 4.5E-09 2.0E-09 1.4E-09 ICRP recommended default
Mn-54 M 1E-01 1.5E-09 6.2E-09 2.4E-09 1.5E-09 ICRP recommended default
Co-60 M 1E-01 1.2E-09 3.4E-08 1.5E-08 1.0E-08 ICRP recommended default
Zn-65 M 1E-01 7.4E-10 6.5E-09 2.4E-09 1.6E-09 ICRP recommended default
Sr-90 M 1E-01 1.0E-08 1.2E-07 5.4E-08 3.8E-08 ICRP recommended default
Zr-95 M 2E-03 4.6E-10 2.1E-08 9.0E-09 6.3E-09 ICRP recommended default
Nb-95 M 1E-02 1.6E-10 5.2E-09 2.2E-09 1.5E-09 ICRP recommended default
Tc-99 M 1E-01 8.3E-11 1.3E-08 5.7E-09 4.0E-09 ICRP recommended default
Ru-103 M 5E-02 1.1E-10 8.4E-09 3.5E-09 2.4E-09 ICRP recommended default
Ru-106 M 5E-02 4.1E-10 1.1E-07 4.1E-08 2.8E-08 ICRP recommended default
Ag-110m M 5E-02 1.5E-09 2.8E-08 1.2E-08 7.6E-09 ICRP recommended default
Sb-125 M 1E-02 2.6E-10 1.6E-08 6.8E-08 4.8E-08 ICRP recommended default
I-129 F 1E+00 1.5E-08 8.6E-08 6.7E-08 3.6E-08 ICRP recommended default
I-131 F 1E+00 8.1E-09 7.2E-08 1.9E-08 7.4E-09 ICRP recommended default
Cs-134 F 1E+00 3.0E-09 7.3E-09 5.3E-09 6.6E-09 ICRP recommended default
Cs-137 F 1E+00 2.0E-09 5.4E-09 3.7E-09 4.6E-09 ICRP recommended default
Ce-144 M 5E-04 4.2E-10 1.6E-07 5.5E-08 3.6E-08 ICRP recommended default
Pm-147 M 5E-04 5.0E-09 1.8E-08 7.0E-09 5.0E-09 Most restrictiveb
Eu-154 M 5E-04 5.3E-08 1.5E-07 6.5E-08 5.3E-08 Most restrictiveb
Eu-155 M 5E-04 6.9E-09 2.3E-08 9.2E-09 6.9E-09 Most restrictiveb
Ra-226 M 1E-01 9.9E-08 1.1E-05 4.9E-06 3.5E-06 ICRP recommended default
Th-228 S 5E-04 2.5E-07 1.4E-04 5.9E-05 4.3E-05 ICRP recommended default
Th-230 S 5E-04 2.6E-08 3.5E-05 1.6E-05 1.4E-05 ICRP recommended default
Th-232 S 5E-04 2.8E-08 5.0E-05 2.6E-05 2.5E-05 ICRP recommended default
U-234 M 2E-02 4.9E-08 1.1E-05 4.8E-06 3.5E-06 ICRP recommended default
U-235 M 2E-02 4.5E-08 1.0E-05 4.3E-06 3.1E-06 ICRP recommended default
U-238 M 2E-02 4.4E-08 9.4E-06 4.0E-06 2.9E-06 ICRP recommended default
Np-237 M 5E-04 4.3E-07 4.0E-05 2.2E-05 2.3E-05 ICRP recommended default
Pu-238 M 5E-04 1.1E-06 7.4E-05 4.4E-05 4.6E-05 ICRP recommended default
Pu-239 M 5E-04 1.2E-06 7.7E-05 4.8E-05 5.0E-05 ICRP recommended default
Pu-240 M 5E-04 1.2E-06 7.7E-05 4.8E-05 5.0E-05 ICRP recommended default
Pu-241 M 5E-04 1.4E-08 9.7E-07 8.3E-07 9.0E-07 ICRP recommended default
Am-241 M 5E-04 3.2E-07 6.9E-05 4.0E-05 4.2E-05 ICRP recommended default
Cm-242 M 5E-04 5.1E-08 1.8E-05 7.3E-06 5.2E-06 ICRP recommended default
Cm-243 M 5E-04 3.1E-05 6.1E-05 3.1E-05 3.1E-05 ICRP recommended default
Cm-244 M 5E-04 2.6E-07 5.7E-05 2.7E-05 2.7E-05 ICRP recommended default
a. The gastro-intestinal absorption fraction does not apply to neonates or infants aged below about one year.b. No default inhalation class recommended - most restrictive value cited by ICRP used.
to atmosphere from Capenhurst, specific informationon chemical composition and lung absorption type isavailable. In these instances, the dose per unit intakecorresponding to the actual lung absorption type isused for dose assessment.
8 Sellafield Ltd have considered the information in ICRPPublication 8810, which provides dose coefficients forthe embryo and foetus after intakes of radionuclidesby the mother, but does not advise on dose limitationor dose constraints for the embryo11. A reportproduced by the Health Protection Agency12 providesguidance on the use of the ICRP dose coefficientsand advice regarding the situations for which theassessment of foetal dose is required. In consultingthis document, the foetal dose has been calculated bymultiplying the adult dose by the ratio of the foetus toadult dose conversion factors12.
9 Only radionuclides which are known to be present inSellafield Ltd discharges from Sellafield andCapenhurst and are listed in the dischargeauthorisations, are included here. In the case ofkrypton-85, which is present in aerial discharges, nodose per unit intake value is presented since exposurefor this nuclide is determined by external rather thaninternal dosimetry.
Collective doses
10 The collective committed effective dose estimatesresulting from discharges from Sellafield have beencalculated using the 1998 upgrade of the HealthProtection Agency model PC CREAM13, which isbased on a methodology for assessing the radiologicalconsequences of routine releases to the environmentpublished by the European Commission14. The HealthProtection Agency recommends15 that the calculationof marine collective dose coefficients using PCCREAM should take account of the contributions ofdaughter radionuclides, and this recommendation hasbeen followed in this report. The collective dosecoefficients have been recalculated for all relevantradionuclides in the liquid discharges. The effects ofthese recalculations on collective doses are nearly allnegligible. The only significant increase in collectivedose that occurs is a small increase (< 10%) in thecollective dose from Sellafield arising from the Te-125m daughter of Sb-125.
58
Radionuclide Sellafield Capenhurstb
UK EUa World UK EUa World
H-3 6.9E-16 1.6E-15 1.9E-15 2.40E-15 3.70E-15 4.00E-15C-14 2.2E-13 2E-12 1.8E-11S-35 2.8E-13 8.4E-13 8.4E-13Ar-41 7.7E-17 7.7E-17 7.7E-17Co-60 4.8E-12 7.1E-12 7.1E-12Kr-85 5E-18 2.7E-17 2.6E-16Sr-90 2.1E-12 1E-11 1E-11Zr-95 1.7E-13 2.4E-13 2.4E-13Nb-95 4.8E-14 6.9E-14 6.9E-14Ru-106 2.8E-13 4.2E-13 4.2E-13Sb-125 5.6E-13 7.9E-13 7.9E-13I-129 4.4E-11 2.1E-10 3E-10I-131 8.7E-13 8.7E-13 8.7E-13Cs-134 3E-12 8.8E-12 8.8E-12Cs-137 4.1E-12 9.7E-12 9.7E-12Ce-144 1.3E-13 2.2E-13 2.2E-13U-234 1.5E-10 2.4E-10 2.4E-10 1.30E-10 1.50E-10 1.50E-10U-235 1.20E-10 1.40E-10 1.40E-10U-238 2.6E-12 4.3E-12 4.3E-12 1.10E-10 1.30E-10 1.30E-10Pu-239 1.5E-10 2.4E-10 2.4E-10Pu-240Pu-241 2.6E-12 4.3E-12 4.3E-12Am-241 1.2E-10 2E-10 2E-10
Table 3. Collective dose commitment from Sellafield Ltd sites (man Sv per Bq discharged,
integrated to 500 years): atmospheric discharges
a. EU is defined as the population of the member states of the European Union, including the UK.b. Data reflect actual chemical compounds discharged by Capenhurst.
59
Radionuclide Sellafield Capenhurst
UK EUb World UK EUb World
H-3 5E-19 2.2E-18 4.4E-17 5.20E-19 2.20E-18 4.40E-17C-14 2.4E-13 8.9E-13 1.2E-11S-35 3.8E-18 7.4E-18 7.5E-18Mn-54 1.3E-15 1.3E-15 1.3E-15Fe-55 2.1E-15 3.6E-15 3.6E-15Co-60 1.5E-14 1.6E-14 1.6E-14Ni-63 9.9E-17 1.9E-16 2E-16Zn-65 1.1E-13 1.7E-13 1.7E-13Sr-89 6.7E-18 1.3E-17 1.3E-17Sr-90 7.7E-16 2E-15 2.2E-15Zr-95 5.3E-16 5.4E-16 5.4E-16Nb-95 1.4E-16 1.4E-16 1.4E-16Tc-99 1.9E-15 5E-15 5.3E-15 2.50E-15 6.10E-15 6.50E-15Ru-103 3.8E-16 5.7E-16 5.7E-16Ru-106 1E-14 2E-14 2E-14Ag-110m 3.4E-14 6.2E-14 6.3E-14Sb-125 1E-14 2.5E-14 2.7E-14I-129 2.2E-14 7E-14 2.9E-13Cs-134 1.3E-14 3E-14 3.2E-14Cs-137 1.5E-14 3.7E-14 4.2E-14Ce-144 2.1E-16 2.4E-16 2.4E-16Pm-147 8.2E-18 1E-17 1E-17Eu-152 9.6E-15 9.7E-15 9.7E-15Eu-154 8.9E-15 9E-15 9E-15Eu-155 3.7E-16 3.8E-16 3.8E-16Th-228 5.5E-15 5.9E-15 5.9E-15Th-230 5.3E-15 9.6E-15 1.1E-14 6.60E-15 1.50E-14 1.60E-14Th-232 3.4E-13 8.1E-13 8.8E-13Th-234 2.9E-16 3E-16 3E-16 1.60E-16 1.90E-16 1.90E-16U-234 2.8E-15 7.9E-15 8.9E-15 3.50E-15 9.20E-15 1.00E-14U-235 2.9E-15 7.7E-15 8.6E-15 3.60E-15 9.00E-15 9.90E-15U-238 2.6E-15 7.1E-15 7.8E-15 3.20E-15 8.30E-15 8.90E-15Np-237 5.6E-14 1.5E-13 1.6E-13 6.50E-14 1.60E-13 1.70E-13Pu-238 7.6E-14 1.2E-13 1.2E-13Pu-239 8.6E-14 1.4E-13 1.5E-13Pu-240 Pu-241 1.6E-15 2.6E-15 2.6E-15Am-241 2.1E-14 2.6E-14 2.6E-14Cm-242 1.6E-15 1.9E-15 1.9E-15Cm-243 Cm-244 2.3E-14 2.8E-14 2.8E-14
a. The collective dose factors include the contribution from the first decay product where appropriate.b. EU is defined as the population of the member states of the European Union, including the UK.
Table 4. Collective dose commitment from Sellafield Ltd sites (man Sv per Bq discharged,
integrated to 500 years): liquid discharges a
11 Generally, the PC CREAM default dose per unit intakevalues have been applied. Where required, thepulmonary retention classes for nuclides have beenmodified on a site-specific basis. For example, site-specific ratios of the chemical forms of uranium inaerial discharges from the Capenhurst site have beenused to identify the most appropriate pulmonaryretention half times. The dose per unit dischargefactors have been derived accordingly.
12 The collective effective dose has units of man-sieverts(man Sv) and can be defined as the sum of all theexposures from a given source to a defined group ofpeople.
13 For this report, the collective committed dose followsthe current Health Protection Agency advice16,17 of a500 year integration period and the doses arecalculated to the populations of the UK, Europe andthe world. Europe is defined as the population of themember states of the European Union, including the UK.
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14 The values presented in tables 3 and 4 for Sellafield and Capenhurst are site specific and aregiven as man sieverts per becquerel discharged. Only radionuclides which are known to be present inSellafield Ltd discharges from Sellafield andCapenhurst and are listed in the dischargeauthorisations, are included here.
References
1 ICRP (1996). Age-dependent doses to
members of the public from intake of
radionuclides: Part 5. Compilation of ingestion
and inhalation dose coefficients. ICRPPublication 72. Ann. ICRP 26 (1).
2 Hunt G J, Leonard D R P and Lovett M B (1986).Transfer of environmental plutonium and
americium across the human gut. Sci. Tot.Environ. 53: 89-109.
3 Hunt G J, Leonard D R P and Lovett M B (1990).Transfer of environmental plutonium and
americium across the human gut: a second
study. Sci. Tot. Environ. 90: 273-282.
4 Hunt G J (1998). Transfer across the human
gut of environmental plutonium, americium,
cobalt, caesium and technetium: studies with
cockles (Cerastoderma edule L.) from the Irish
Sea. J. Radiol. Prot. 18: 101-110.
5 Harrison J D and Stather J W (1990). Gut
transfer factors - plutonium and americium in
shellfish and 'best estimates' for activities in
food. Documents of the NRPB 1(2): 17-26.
6 McKay W A and Halliwell C M (1994). The levels
of particulate associated nuclides in Irish Sea
shellfish and the implications for dose
assessment. J. Radiol. Prot. 14: 43-53.
7 Harrison J D (1998). Gut transfer and doses
from environmental plutonium and americium.
J. Radiol. Prot. 18: 73-76.
8 Environment Agency, Environment and HeritageService, Food Standards Agency and ScottishEnvironment Protection Agency (2009).Radioactivity in food and the environment,
2008. RIFE-14. Environment Agency, EHS,Food Standards Agency and SEPA; Bristol,Belfast, London and Stirling.
9 ICRP (1996). Age-dependent doses to
members of the public from intake of
radionuclides: Part 4. Inhalation dose
coefficients. ICRP Publication 71. Ann. ICRP25 (3-4).
10 ICRP (2001). Doses to the embryo and fetus
from intakes of radionuclides by the mother.
ICRP Publication 88. Ann. ICRP 31 (1-3).
11 Jones S R (2002). Foetal dosimetry - is the
ICRP dosimetric system for humans now
complete? J. Radiol. Prot. 22: 1-4.
12 Cooper J R, Bailey M R, Fry F A, Harrison J D,McDonnell C E, Meara J R, Phipps A W,Simmonds J R, Stather J W and Tattersall P J(2005). Guidance on the application of dose
coefficients for the embryo and fetus from
intakes of radionuclides by the mother.
Documents of the NRPB 16(2).
13 Mayall A, Cabianca T, Attwood C A, Fayers C A,Smith J G, Penfold J, Steadman D, Martin G,Morris T P and Simmonds J R (1997). PC CREAM 97. Chilton, NRPB-SR296/EUR-17791 (Code updated in 1998 – PC CREAM 98).
14 Simmonds J R, Lawson G and Mayall A (1995).Methodology for assessing the radiological
consequences of routine releases of
radionuclides to the environment.
Luxembourg, EC, EUR 15760.
15 Bexon A (2002). PC CREAM 98: Technical note'Separation of daughter radionuclides in
ASSESSOR - Marine and DORIS',http://www.hpa.org.uk/radiation/publications/software/sr296/technical_support.htm.
16 Mayall A, Cabianca T, Morris T P, Nightingale A,Simmonds J R and Cooper J R (1993).Collective doses from proposed Sellafield
discharges. NRPB note for COMARE. NRPB-M453.
17 Bexon A (2000). Radiological impact of routine
discharges from UK civil nuclear sites in the
mid-1990s. Chilton, NRPB-R312. R312.
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GlossaryDischarges and Monitoring in the United Kingdom
Annual Report 2009
Glossary of terms and abbreviations
Absorbed radiation dose Quantity of energy impartedby ionising radiation to unit mass of matter such as tissue.The unit is the Gray (Gy). 1 Gy = 1 joule per kilogram.
Activation products Radionuclides produced by theinteraction of neutrons with stable nuclides.
Activity See radioactivity.
Alpha activity Radionuclides that decay by emitting analpha particle. The latter consists of two protons and twoneutrons.
ALARA (As Low as Reasonably Achievable) Radiationdoses from a source of exposure are ALARA when theyare consistent with the relevant dose or target standardand have been reduced to a level that represents abalance between radiological and other factors, includingsocial and economic factors. The level of protection maythen be said to be optimised.
Authorisation Permission given by regulatory authorityunder the Radioactive Substances Act orEnvironmental Protection Act to dispose of respectivelyradioactive and non-radioactive waste, subject toconditions.
Basic Safety Standards Directive (BSS) EuropeanCommunity Directive 80/836/Euratom, Basic SafetyStandards for the Health Protection of the General publicand Workers against the Dangers of Ionising Radiation.These standards were adopted as European Law in 1980.A revised Directive 96/29/Euratom was adopted in May1996 for implementation in Member States by May 2000.The Radioactive Substances (Basic Safety Standards)Direction 2000 is the means by which the BSS Directivehas been implemented in England and Wales, and inScotland, with respect to the Radioactive Substances
Act 1993. Other provisions of the BSS Directive wereimplemented through the Ionising Radiation Regulations
1999.
Becquerel The SI unit of radioactivity equal to onetransformation per second.
BAT (Best Available Technique) “Best” – means themost effective techniques for achieving a high level ofprotection of the environment as a whole. “Available” –means techniques developed on a scale which allowsthem to be used in the relevant industrial sector, undereconomically and technically viable conditions, taking intoaccount of the costs and advantages. “Techniques” –includes both the technology and the way the installationis designed, built, maintained, operated anddecommissioned. Application of BAT is central to PPCcompliance and guidance on what constitutes BAT isprovided by the EA.
BATNEEC (Best Available Technique Not Entailing
Excessive Costs) The best available technique (BAT) isthe most effective process in preventing, minimising orrendering harmless polluting emissions taking into accountavailability and whether the costs are not out of proportionto the benefit. (See IPC.)
BPEO (Best Practicable Environmental Option)
A concept developed by the Royal commission onEnvironmental Pollution. It implies that decisions on wastemanagement have been based on an assessment ofalternative options evaluated on the basis of factors suchas the occupational and environmental impacts, the costsand social implications. ( See IPC.)
BPM (Best Practicable Means) Within a particularwaste management option, the BPM is that level ofmanagement and engineering control that minimises as faras practicable, the release of radioactivity to theenvironment whilst taking account of a wider range offactors including cost-effectiveness, technological status,operational safety, and social and environmental factors.
Beta activity Radionuclides that decay by emitting abeta particle (an electron with high energy).
CEFAS The Centre for Environment, Fisheries andAquaculture Science is a scientific research and advisorycentre for fisheries management and environmentalprotection. It is an Agency of the UK Government'sDepartment for Environment, Food and Rural Affairs
(defra). It was formed in 1997 from the FisheriesResearch Laboratory of MAFF and its Lowestoft laboratorycarries out habit surveys and monitoring of radioactivity inthe environment on behalf of the Food Standards
Agency.
Collective dose See dose.
Committed effective dose See dose.
Consent Discharges to controlled waters of sewage ortrade effluent, from processes not subject to EnvironmentalProtection Act authorisations, are regulated throughconsents under the Water Resources Act (1991) or theWater Industries Act 1991 (in England and Wales) andControl of Pollution Act 1974 or Sewerage Scotland Act1968 (in Scotland).
Critical group A group of members of the public whoseradiation exposure is reasonably homogeneous and istypical of the people receiving the highest dose from aradiation source. The critical group dose is calculated asthe mean effective dose to members of the group.
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defra (Department for Environment, Food and Rural
Affairs) Formed in 2001 from MAFF and theenvironmental section of the Department of Environment,Transport and the Regions (DETR). It is the sponsoringdepartment for the EA, and is responsible inter alia forenvironmental policy in England, including that for themanagement and disposal of radioactive wastes.
Direct radiation Term used to refer to radiation directfrom a nuclear site as distinct from the radiation emittedfrom discharged radioactive wastes.
Dose A measure of radiation received, which may bequantified in several different ways. The dose quantitiesmost commonly referred to are defined below. In thisdocument it is used primarily to mean the ‘effective dose’received by members of critical groups.
Absorbed dose The mean energy imparted byionising radiation to matter in a given volume dividedby the mass of the matter. Normally used in thecontext of the dose averaged over an organ or tissue.The unit is the Gray (Gy) (see inside front cover).
Equivalent dose The absorbed dose in a tissue ororgan weighted by the radiation weighting factor (e.g. alpha particles = 20, beta particles = 1, gamma rays = 1) which allows for the differenteffectiveness of various types of ionising radiations incausing harm to tissues. The unit is the Sievert (Sv)(see inside front cover).
Effective dose The sum of the equivalent doses inall tissues and organs of the body from internal andexternal radiation multiplied by the tissue weightingfactor (e.g. skin = 0.01, thyroid = 0.05, red bonemarrow = 0.12, gonads = 0.20). It allows the variousequivalent doses in the body to be represented by asingle number giving a broad indication of thedetriment to the health of an individual from exposureto ionising radiation, regardless of the energy and typeof radiation. For comparison with dose limits, theterm takes on a specific meaning (see below).
Committed effective dose The time integral of theeffective dose from ingested and inhaled radioactivitydelivered over 50 years (adults, who are cautiouslyassumed to be 20 years old at the time of intake) or toage 70 years (children). For a particular radionuclide itis a function of the distribution within, and clearancefrom, the body and also the radioactive half-life. For radionuclides which are cleared quickly from thebody (e.g. caesium-137) or which have a short half-life (e.g. sulphur-35), most of the committedeffective dose is delivered in the year in which theintake of activity took place. (e.g.caesium-137), mostof the committed effective dose is delivered in the yearin which the intake of activity took place. For others,
such as plutonium, the committed dose is deliveredover the remaining lifetime of the individual and so thedose in the year of intake is much lower than thecommitted dose.
Effective dose (definition used for calculation of
critical group doses and for comparison with dose
limits) The overall annual effective dose is the sum ofcommitted effective doses from intakes ofradionuclides in a given year and the effective dosefrom external irradiation in that year. It is this quantitythat should be compared with the annual limit oneffective dose (dose limit).
Collective dose The summation of individualeffective doses received by the population of a definedgeographical area over a defined period of time. A 500 year integration period is used in this report(see paragraph 29 of the Introduction). The unit is theman sievert (man Sv).
Dose constraint A restriction on annual dose to anindividual from a single source, applied at the design andplanning stage of any activity in order to ensure that whenaggregated with doses from all sources, excluding naturalbackground and medical procedures, the dose limit is notexceeded.
Dose limit For the purpose of discharge authorisations,the UK has (since 1986) applied a dose limit of 1 mSv(1000 µSv) per annum to members of the public from allman-made sources of radiation (other than medicalexposure). This limit is now incorporated into UK law (see Basic Safety Standards Directive).
EA (Environment Agency) The leading public body forprotecting and improving the environment in England andWales. (See defra).
Effective dose See dose.
Environment Act 1995 The legislation giving the EA itspowers, aims and objectives.
Environmental Protection Act 1990 See IPC.
Equivalent dose See dose.
Fission products Nuclear fission is the splitting of aheavy atomic nucleus such as uranium into (usually) twonuclei, either spontaneously or under the impact ofanother particle, with resulting increase of energy. The twonuclei are called fission products.
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Fluorinated Greenhouse Gases Fluorinated greenhousegases are powerful greenhouse gases that trap heat in theatmosphere and contribute to global warming. The mostcommonly used fluorinated greenhouse gases belong to aclass of chemicals known as hydrofluorocarbons (HFCs)and are being used to replace ozone depletingsubstances, in, for example, refrigeration and airconditioning equipment.
Food Standards Agency Formed in April 2000 fromparts of MAFF and the Department of Health. It isresponsible for food safety issues in the UK. Although it isa Government agency it does not report to a specificminister and is free to publish any advice it issues. It isaccountable to Parliament through Health Ministers, and tothe devolved administrations in Scotland, Wales andNorthern Ireland for its activities within their areas
Gray The SI unit of absorbed dose.
Half-life (radioactive) The time taken for the radioactivityof a radionuclide to decrease to one half of its initial valueby radioactive decay. Half-lives range from fractions of asecond to millions of years.
Half-life (biological) The effective half-life in the humanbody of a quantity of ingested radioactivity is a function ofthe radioactive half-life and biokinetic behaviour.
High Level Waste (HLW) Waste that is sufficientlyradioactive that the generation of heat needs to be takeninto account in the design of disposal or storage facilities.
HPA (Health Protection Agency) A non-departmentalpublic body established in 2003 to provide an integratedapproach to protecting UK public health through theprovision of support and advice to the NHS, localauthorities, emergency services, the Department of Healthand the devolved administrations in Scotland, Wales andNorthern Ireland. Merged with the NRPB on 1 April 2005to form the HPA Radiation Protection Division.
Intermediate Level Waste (ILW) Waste with radioactivitylevels exceeding the upper boundaries for low level wastebut which does not require heat generation by the wasteto be accounted for in the design of disposal or storagefacilities.
ICRP International Commission on radiologicalProtection. An independent group of experts founded in1928 which provides guidance on principles and criteria inthe field of radiological protection. The recommendationsare not legally binding but are accepted as the basis fornational legislation in most countries including the UK.
IPC (Integrated Pollution Control) A statutory means ofcontrolling industrial pollution set up under the EPA 1990.Thus, discharges from ‘Prescribed Processes’ arecontrolled by IPC authorisations (issued by the EA and
SEPA) or by air pollution control authorisations issued bylocal authorities. These ensure compliance with qualityobjectives and standards by specifying discharge limits(i.e. to air and water) and other conditions. There is also a‘residual duty’ in these authorisations that BATNEEC isused to prevent or minimise releases of the most pollutingsubstances and render them harmless. Where releases ofa substance may affect more than one environmentalmedium, the authorisation must have regard to the BPEO.See IPPC.
IPPC (Integrated Pollution Prevention and Control)
In October 2007 Prescribed Process (IPC) authorisationswere replaced by permits issued under the PollutionPrevention and Control Regulations 2000 (PPC). Theseregulations implement the requirements of the EC Directiveon IPPC.
Ionising Radiation Regulations 1999 (IRRs 1999)
These regulations under the Health and safety at Work Act1974 in part implement the European Basic Safety
Standards Directive of 1996.
ISTA Informal abbreviation for ‘inter-site transferauthorisation’ (Radioactive Substances Act).
Low Level Waste (LLW) Waste containing levels ofradioactivity greater than those acceptable for dustbindisposal but not exceeding 4 GBq per tonne of alpha-emitting radionuclides or 12 GBq per tonne of beta-emitting radionuclides.
LLWR Low Level Waste Repository.
MAFF (Ministry of Agriculture, Fisheries and Food)
Superseded by defra. MAFF’s statutory responsibilities forfood safety issues in the UK have been passed to theFood Standards Agency.
Magnox A magnesium/aluminium alloy that is used inthe manufacture of the canister for uranium fuel metal(‘Magnox fuel’) used in a type of nuclear reactor (‘Magnoxreactor’).
Multi-media Authorisation (MMA) Authorisation issuedby the Environment Agency under the RadioactiveSubstances Act 1993 of a ‘multi-media’ or integrated typecovering radioactive waste disposals to land, sea and air.
NDA (Nuclear Decommissioning Authority) The publicbody set up in 2005, tasked by Her Majesty's Governmentwith taking strategic responsibility for the decommissioningof civil public sector nuclear sites in the UK. The NDAowns the 20 nuclear legacy sites in the UK including theoperating and decommissioning plants at Sellafield in WestCumbria. The NDA does not carry out the operations orclean-up work itself but places contracts with Site
Licensee Companies, who are responsible for operationson site.
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NII (Nuclear Installations Inspectorate) Part of theHealth and Safety Executive. It is responsible for enforcinglegislation relating to nuclear safety under the Nuclearinstallations Act 1965.
NRPB (National Radiological Protection Board)
Merged with the Health Protection Agency on 1 April 2005 forming its new Radiation Protection Division.An independent statutory body set up by the RadiologicalProtection Act 1970 to advance the acquisition ofknowledge about the protection of mankind from radiationhazards and to provide information and advice on mattersrelating to radiological protection and radiation hazardsincluding the interpretation of ICRP recommendations.
Notice of Variation The means by which the conditionsor limitations of an Authorisation are changed.
OSPAR Convention The Oslo Paris Convention, wherecontracting parties (including the UK) agreed to take allpossible steps to prevent and eliminate pollution, and totake all necessary measures to protect the maritime areaagainst the adverse effects of human activities, so as tosafeguard human health and to conserve marineecosystems and, where practicable, restore marine areaswhich have been adversely affected. See Sintra
Agreement.
Ozone Depleting Substances (ODS) Substances that, ifallowed to escape, damage the ozone layer in the upperatmosphere. Ozone depleting substances includechlorofluorocarbons (CFCs) and hydrochlorofluorocarbons(HCFCs). Many ODS are banned or being phased out byfluorinated greenhouse gases.
PPC Pollution Prevention and Control Regulations 2000(see also IPPC)
Quarterly Notification Level (QNL) Quarterly dischargeor disposal levels that the EA may specify in RSA
authorisations They enable the application of BPM to bemonitored by the EA. Exceeding a QNL requires theoperator to submit a written justification of the BPM usedto limit discharges.
Radioactive Substances Act (RSA) 1960, 1993
Statutory legislation to control the keeping and use ofradioactive substances and the accumulation discharge ordisposal of radioactive waste.
Radioactive waste Material that contains radioactivityabove the appropriate levels specified in the Radioactive
Substances Act 1993 and which meets the definition ofwaste given in the Act.
Radioactivity The spontaneous disintegration of atomicnuclei. Radioactive substances or the radiation they emit(e.g. alpha particles, beta particles, gamma rays); the rateof radioactive decay. Measured in the standardinternational (SI) unit, Becquerels (Bq) or their multiples orsub-multiples (see inside front cover).
Radionuclide A radioactive isotope of an element.
SEPA Scottish Environment Protection Agency.
Sievert The SI unit of equivalent dose and effective
dose.
Sintra Agreement An agreement made at a ministerialmeeting of the Ospar Commission in Sintra, Portugal, 22-23 July 1998. The ultimate aim is to achieveconcentrations of radioactivity in the environment that arenear background levels for naturally occurring radioactivesubstances and close to zero for artificial radioactivesubstances.
Site Licence Company An organisation that holds thenuclear licence for a particular site and is responsible forthe maintenance and operation of the site.
Thorp (Thermal Oxide Reprocessing Plant) A plant atSellafield where oxide fuels from Advanced Gas CooledReactors and Light Water Reactors have beenreprocessed since 1995.
UKAEA United Kingdom Atomic Energy Authority.
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Sellafield Site
Sellafield, SeascaleCumbria CA20 1PG
www.sellafieldsites.com