iaea international atomic energy agency exemption, clearance, discharges luc baekelandt...
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IAEAInternational Atomic Energy Agency
Exemption, Clearance, Discharges
Luc Baekelandt ([email protected])Safety of radioactive waste management facilities
Amman (Jordan), 14-18 December 2014
IAEA
Concepts of exclusion, exemption, clearance
Exemption: criteria, derivation of levels
Clearance: criteria, derivation of levels
Discharges
Control of discharges
Summary
Contents
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Exclusion
Exemption
Clearance
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Relevant Safety Requirements
The concepts of exemption and clearance only apply to planned exposure situations.
Exemption shall not be granted to practices deemed not to be justified.
Exposure due to natural sources is generally considered as an existing exposure situation.
Schedule I deals with exemption and clearance specifically.
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Concepts of exclusion, exemption and clearance (1)
ExclusionAuthorizeddischarge
Radiationsources
Regulatorycontrol
Authorized
disposal
Exemption Clearance
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Concepts of exclusion, exemption and clearance (2)
EXCLUSION
(de minimis non curat lex)
EXEMPTION
(de minimis non curat praetor)
CLEARANCE
exposure is essentiallyunamenable to control
exposure and riskare trivial
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• Radiation risks arising from the practice or from a source within a practice are sufficiently low as not to warrant regulatory control, with no appreciable likelihood of situations arising that could lead to a failure to meet this criterion.
• Regulatory control of the practice or the source would yield no net benefit, in that no reasonable measures for regulatory control would achieve a worthwhile return in terms of reduction of individual doses or of health risks.
Exemption – general criteria
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Effective dose to be incurred by any individual owing to the exempt practice or the exempt source within the practice:
• of the order of 10 µSv or less in a year
• 1 mSv in a year for low probability scenarios
Exemption – radiological criteria
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Derivation of Exemption Levels (1)
For moderate amounts (of the order of a tonne)
in terms of activity (Bq) and activity concentration (Bq/g)
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Derivation of Exemption Levels (2)F
or m
oder
ate
amou
nts
Radionuclide
H-3C-14P-32S-35Co-60Kr-85Sr-90 +Tc-99mI-125I-131Cs-137 +Ir-192Ra-226U-235U-238Pu-239Am-241
Activty Concentration (Bq/g)
1 000 00010 0001 000
100 00010
100 000100100
1 0001001010101111
Total activity (Bq)
1 000 000 00010 000 000
100 000100 000 000
100 00010 00010 000
10 000 0001 000 0001 000 000
10 00010 00010 00010 00010 00010 00010 000
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Derivation of Exemption Levels (3)
For bulk amounts, solid material, artificial nuclides
in terms of activity concentration (Bq/g)
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Derivation of Exemption Levels (4)F
or b
ulk
amou
nts
Sol
id m
ater
ial
Art
ifici
al n
uclid
esRadionuclide
H-3C-14P-32S-35Co-60Kr-85Sr-90 +Tc-99mI-125I-131Cs-137 +Ir-192Ra-226U-235U-238Pu-239Am-241
Activity Concentration (Bq/g)
1001
1 0001000.1-1
100100100.11---
0.10.1
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Derivation of Exemption Levels (5)
For bulk amounts of material with natural nuclides: - case by case- dose criterion of the order of 1 mSv in a year ( commensurate with typical doses due to
natural background levels of radiation)
Note:Material containing radionuclides of natural origin at an activity concentration of less than 1 Bq/g for any radionuclide in the uranium decay chain or the thorium decay chain and of less than 10 Bq/g for K-40 is not subject to the requirements for planned exposure situations. The concept of exemption does not apply for such material.
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Practical Application of Exemption
• smoke detectors (Am-241)
• use of Th and Kr-85 in high intensity gas discharge lamps
• exhibition rooms (cloud chamber)
• small scale laboratories
• use of Th in soldering bolts
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• Radiation risks arising from the cleared material are sufficiently low as not to warrant regulatory control, and there is no appreciable likelihood of occurrence for scenarios that could lead to a failure to meet this criterion.
• Continued regulatory control of the material would yield no net benefit, in that no reasonable measures would achieve a worthwhile return in terms of reduction of individual doses or of health risks.
Clearance – general criteria
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Effective dose to be incurred by any individual owing to the cleared material:
• of the order of 10 µSv or less in a year
• 1mSv in a year for low probability scenarios
Clearance – radiological criteria
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Derivation of Clearance Levels (1)
For solid material
in terms of activity concentration (Bq/g)
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Derivation of Clearance Levels (2)S
olid
mat
eria
l A
rtifi
cial
nuc
lides
Radionuclide
H-3C-14P-32S-35Co-60Kr-85Sr-90 +Tc-99mI-125I-131Cs-137 +Ir-192Ra-226U-235U-238Pu-239Am-241
Activity Concentration (Bq/g)
1001
1 0001000.1-1
100100100.11---
0.10.1
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Derivation of Clearance Levels (3)
For radionuclides of natural origin:
- 10 Bq/g for K-40
- 1 Bq/g for each radionuclide in the uranium decay chain or the thorium decay chain
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Derivation of Clearance Levels (4)
For radionuclides of natural origin in residues that might be recycled into construction materials, or the disposal of which is liable to cause contamination of drinking water supplies:
on the basis of a dose criterion of the order of 1 mSv in a year ( commensurate with typical doses due to natural background levels of radiation)
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Practical Application of Clearance
• storage of radioactive waste for decay
• reduction of waste to be managed as radioactive waste (cost reduction)
• guidance for decommissioning of nuclear installations
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Specific Clearance Levels
• in case the destination of the cleared material is known, for instance recycling and re-use of material for road construction works
• dose criteria are the same as those for the derivation of generic clearance levels
• IAEA guidance available:Application of Exemption Principles to the Recycleand Reuse of Materials from Nuclear Facilities(1992)
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Verification of Clearance Levels (1)
• knowledge of the history of the material is very important
• procedures to be integrated in the management system
• monitoring
• record keeping and reporting to the regulatory body
Deliberate dilution in order to meet the values is should not be permitted.
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Verification of Clearance Levels (2)
published in 2012
Relevant IAEA publication
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Discharges
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Discharges
= planned and controlled releases of (usually gaseous and liquid ) radioactive material to the environment
(IAEA Safety Glossary)
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Relevant Safety Requirements
R 31 – The relevant parties shall ensure that radioactive waste and discharges of radioactive material to the environment are managed in accordance with the authorization.
R 32 – The regulatory body and relevant parties shall ensure that programmes for source monitoring are in place and that the results from the monitoring are recorded and made available.
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Relevant Safety Guides
Published in 2000 Published in 2005
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Supporting Safety Reports
Published in 2001 Published in 2010
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GSR Part 3, requirement 31 (1)
The application for an authorization for discharges shall comprise information on:
• the characteristics and activity of the material to be discharged, and the potential points and methods of discharge
• the significant exposure pathways by which discharged radio-nuclides can deliver public exposure
• the doses to the representative person due to the planned discharges
• the environmental impact
(input to the establishment by the regulatory body of authorized limits on discharge and conditions for their implementation)
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GSR Part 3, requirement 31 (2)
Discharge Limits
• established by the regulatory body (licence condition)
• basis:
• licence application (see previous slide)
• dose constraint, which is a fraction of the dose limit for members of the public (takes account of other radiation sources, now and in the future)
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GSR Part 3, requirement 31 (3)
Registrants and licensees shall, as appropriate and in agreement with the regulatory body, review and adjust their discharge control measures, taking into account:
• operating experience,
• any changes in exposure pathways and the characteristics of the representative person that could affect the assessment of doses due to the discharges.
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GSR Part 3, requirement 32 (1)
Responsibilities of the Regulatory Body
• Review and approval of monitoring programmes
• Review of periodic reports on public exposure
• Making provision for an independent monitoring programme
• Assessment of the total exposure of the public from authorized sources and practices
• Making provision for maintaining records (discharges, results of monitoring programmes, results of assessment of public exposure)
• Verification of compliance with regulatory requirements
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GSR Part 3, requirement 32 (2)
Responsibilities of the Operator
• Establishment and implementation of a monitoring programme
• Record keeping of results and estimated exposure
• Reporting of results to the regulatory body
• Reporting of discharges that exceed the limits
• Reporting of external exposure levels that exceed the authorized limits
• Reporting increase of dose rate or content of radionuclides in the environment
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GSR Part 3, requirement 32 (3)
Responsibilities of the Operator (cont’d)
• Establishment and maintenance of capability to carry out emergency monitoring
• Verification of the adequacy of the assumptions made for the assessment of public exposure and environmental impact
• Publication of results of environmental monitoring programmes and assessments of public exposure
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Safety Guide WS-G-2.3
Published in 2000
Provides guidance to the regulatory body on a structured approach to the limitation of risk to members of the public and optimization of protection.
Provides guidance to the responsibilities of operators in conducting discharge operations
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Safety Guide RS-G-1.8
Published in 2005
Provides guidance on the strategy of monitoring in relation to the control of discharges and situations requiring intervention.
Three categories of monitoring are discussed:- monitoring at the source (called
“source monitoring”)
- monitoring in the environment (called “environmental monitoring”)
- monitoring of individual exposure (called “individual monitoring”)
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Summary
Exclusion refers to scope of regulatory control
Exemption refers to practices and sources that give rise to trivial doses exempted from the regulatory control system
Clearance refers to material that gives rise to trivial doses and me removed from the regulatory control system
Discharges are authorized b y the regulatory body
Discharges are controlled (monitoring)
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