state nuclear regulatory committee of ukraine 56th regular session of the general conference senior...

State Nuclear Regulatory Committee of UkraineState Nuclear Regulatory Committee of Ukraine

56th Regular Session of the General Conference Senior Regulators’ Meeting 20 September, 2012 Austria, Vienna

State Nuclear Regulatory Inspectorate of UkraineState Nuclear Regulatory Inspectorate of Ukraine

Olena Mykolaichuk Olena Mykolaichuk State Nuclear Regulatory Inspectorate of Ukraine, ChairpersonState Nuclear Regulatory Inspectorate of Ukraine, Chairperson

Valeriy Kashparov Valeriy Kashparov Ukrainian Scientific Institute of Agriculture RadiologyUkrainian Scientific Institute of Agriculture Radiology

APPLICATION OF THEAPPLICATION OF THEOPTIMIZATION PRINCIPLE OPTIMIZATION PRINCIPLE

IN POST-ACCIDENT COUNTER-MEASURES IN POST-ACCIDENT COUNTER-MEASURES IMPLEMENTATION IMPLEMENTATION

(POST-CHERNOBYL (EXPERIENCE) (POST-CHERNOBYL (EXPERIENCE)



Post-Chernobyl counter-measuresPost-Chernobyl counter-measures

• After Chernobyl accident a wide range of urgent immediate and long-term protective measures (counter-measures) was applied

• The world community recognized that the application of counter-measures/remediation after the Chernobyl accident had made possible to reduce the public exposure doses more than twice

• The Chernobyl experience became the basis for the national standards and Chernobyl Forum recommended to apply it



• While planning and application of immediate and long-term counter-measures/remediation the three main radiological protection principles shall be considered : – Justification– Not exceeding– Optimization

• Optimization is especially important for the main immediate counter-measures that despite high avert dose are expensive, need a lot of organizational resources and course big discomfort, losses and inconvenience for public

• Basis for immediate counter measures optimization should be prepared in advance to provide quick decisions

National standardsNational standardsand post-Chernobyl experienceand post-Chernobyl experience



• Justification of counter-measure shall be made on the basis of the assessment and comparison of social and economical losses, damages and inconvenience, coursed by counter measure and the level of avert dose due to counter measure application

• Appling “not exceeding” principle counter-measure could be: - unconditionally justified - justified - not justified • Radiological criteria for justification are fixed in national

radiation safety standard (NRBU-97)

National standardsNational standards



• Between the lower justification limit and unconditionally justified levels the decision of undertaking of counter-measure requires the procedure of optimisation.

• Though all these countermeasures located within specified area are justified, optimization procedure prior their undertaking (or not undertaking) is important and absolutely necessary step that takes into account of all the damage kinds due to countermeasure undertaking.

National standardsNational standardsApplication of OptimizationApplication of Optimization



ExampleExample

JUSTIFICATION FOR IMMEDIATEJUSTIFICATION FOR IMMEDIATE COUNTER-MEASURESCOUNTER-MEASURES (NRBU-97)(NRBU-97)

Counter-measure Avert dose during the first 2 post-accident weeks

Lower justification limits Unconditionally justified levels

mSv mGy mSv mGy For whole

bodyFor thyroid gland For skin For whole

bodyFor thyroid

glandFor skin

Sheltering 5 50 100 50 300 500

Evacuation 50 300 500 500 1000 3000

Iodine prophylactics

Children

- 501 - - 2001 -

Adults - 2001 - - 5001 -

Restriction of staying at open air

Children 1 20 50 10 100 300

Adults 2 100 200 20 300 1000

1 – Dose expected under internal exposure by iodine radioisotopes that enter organism during the 1st two weeks since the accident beginning



When counter- measures application is justified the optimization is performed to ensure maximum level of their effectiveness with account to:

• Radiological aspects (the avert dose, reduction of contamination level of territories, environment, foodstuff etc.)

• Economical aspects (scopes of funding, equipment and technologies availability, etc.)

• Socio-psychological aspects (acceptability of counter-measures, impact on public opinion, cultural aspects etc.)

• Political aspects (political decisions, international situation, ets.)

Application of OptimizationApplication of Optimization



Optimization by radiological factorOptimization by radiological factor

• Currently in new BSS for existing exposure, each Member State could set its own acceptable reference level of exposure of representative individual in the frame of 1 to 20 mSv/year above which the long-term counter-measures application should be optimized

• In Ukraine this level is considered as 1 mSv/year



• Social, psychological and political factors could overweight the economical and radiological ones

• Optimization by socio-psychological factors can be done by means of public involvement into decision making, especially in long-term remediation counter-measures application

Examples• After Chernobyl accident the compensatory payment was

established in contaminated regions. Due to socio-political reasons the compensatory payment can’t be cancelled although the radiological situation have changed

• One year after Fukusima accident Japan established the most severe in the world permissible levels for foodstuff radionuclide concentration due to socio-psychological factor.

Optimization by socio-psychological factorsOptimization by socio-psychological factors



Inadequate risk perceptionInadequate risk perception

• Lack of information in the initial post-accident period about impact of water pathway into overall dose

• Inadequate “water” risk perception by Public and Decision makers and overestimation of risk

• Not optimized decision for large number of inadequate water protection measures carried out during initial post-accidental period (river canal and run-off regulation by dams on the contaminated catchments).



• Restrictions of foodstuff consumption shall be the subject for optimization by three main factors:– Averted Internal dose– Necessity to support profitable agricultural

production– Negative health effects as result of restriction

in some food products consumption

Example. Example. Optimization in Optimization in RestrictionsRestrictions of Foodstuff Consumption of Foodstuff Consumption



• As a result of optimization permissible levels for foodstuff went down as time passed after the accident

• In Ukraine permissible levels for foodstuff were revised twice in 1986 and than in 1987, 1988 and 1991

• Actual levels are lower than EC import levels and reference levels in Codex Alimentaris

Example. Optimization inExample. Optimization in

RestrictionsRestrictions of Foodstuff Consumptionof Foodstuff Consumption



• Optimization factors: type of fall out, averted dose and cost• Optimization conclusions were done for urban surfaces

decontamination in the case of the dry fallout: – Streets cleaning, trees and bushes removal, green

places ploughing-up – optimized– Roofs cleaning – not optimized by cost though high

averted doses– Walls cleaning - not optimized because of low averted

doses• 25% - maximum reduction of dose due to urban

decontamination. Not overall decontamination reduced effectiveness

Example. Example.

Optimization for Urban DecontaminationOptimization for Urban Decontamination



• Meat– Butchering with following meat storage and disposal was done

without optimization that lead to significant exceeding of damage over benefit

• Moving of the upper layer of the soil proved to be not optimized counter measure due to:– high cost of work– radioactive waste disposal costs

• As a result of optimization process “ for forests” following countermeasures proved to be effective for forests:– Restrictions of: access, forest products gathering, use of firewood

and ashes– Forest fire prevention

Example. Example.

Optimization for Meat, Soil and Forests”Optimization for Meat, Soil and Forests”



Not optimized Initial post-accident measures to protect water systems

from radionuclide transfer from contaminated soil can not be optimized due to high costs and workers high doses

OptimizedIn the later phase of the remediation:• wide scale multi-disciplinary studies• model simulation created a basis for optimization water remedial actions and

identified the only limited set of effective actions, which sufficiently reduced secondary long-term significant contamination of the aquatic system: dyke the most heavy contaminated radioactive hot spot in vicinity of ChNPP site.

Example. Example. Optimization “for Water Protection”Optimization “for Water Protection”



19861986

19931993

19991999

9090SrSr



Remediation Optimization Prerequisites Remediation Optimization Prerequisites and Factorsand Factors

• Prerequisites– Regulatory framework with established radiological criteria– Emergency preparedness infrastructure than includes:

• Expert groups (national and international)• Tools: handbooks of parameters’ values, codes, guides, monitoring

system• Knowledgeable decision makers• Communication with public

• Factors: Source term; Fallout details; Environmental conditions (landscape, soil types, vegetation, land use, hydrology etc); Social conditions



Immediate and Long-term Countermeasures Immediate and Long-term Countermeasures Optimization PreparednessOptimization Preparedness

• Basis for immediate counter measures optimization should be prepared in advance to provide quick expert decisions

• For long-term remediation measures should be supported by system for remediation strategy optimization



ReSCA ReSCA

• In the frame of IAEA regional projects RER/9/074, RER/3/004 and RER/9/123 the support system for making decisions on remediation of radioactive contaminated areas after Chernobyl accident - ReSCA has been established

• ReSCA considers the factors important for optimization of the appropriate counter-measures application at the territories affected by the Chernobyl accident aiming to:

- minimize the costs of avert dose of the public

- decrease the exposure dose of a representative individual below the accepted reference level (according to the latest BSS approach)



ReSCAReSCA

• Optimization of remediation strategy requires consideration of a wide range of factors

- technical (e.g. effectiveness, feasibility) - economical (cost, resources) - environmental (coefficients of improvement) - social (acceptability, opportunities for self help in rural

communities)

• In Ukraine, the implementation of the optimized remediation strategy will reduce the annual doses in the affected settlements below 1 mSv with overall costs less than 1 M€.



ReSCA calculations results. Reduction of ReSCA calculations results. Reduction of settlements where dose > 1 mSv/yearsettlements where dose > 1 mSv/year

after the application of countermeasures in 2011



ReSCA practical testReSCA practical test

• ReSCA calculations for 14 Ukrainian settlements• Calculations proved that most effective countermeasures

by all factors optimization (coefficient of improvement, public acceptability, stability, cost etc) will be ferrocyanide blue application for cattle feeding and radical improvement of meadows

• 3 test settlement with optimized counter-measures applied in practice

• Annual dose reduced from 1.6 to 0.6 mSv due to milk contamination reduction from 900 kBq/kg to 150 kBq/kg

• Cost was 5 kEuro per 1 manSv• Remediation measures for meat, potatoes, drinking water,

inhalation, external exposure proved to be not optimized.



Reduction factors in ReSCAReduction factors in ReSCA

Exposure pathway Remedial actions

RI SI FA FP MF IM RS

Internal exposure

Milk 4.00 1.50 3.00 - - - -

Beef 4.00 1.50 2.00 - - - -

Pork - - - 3.00 - - -

Potatoes - - - - 2.00 - -

Mushrooms

- - - - - 1.50 -

External exposure - - - - - - 1.50

Counter-measures:• RI - Radical Improvement• SI - Surface Improvement• FA - Ferrocyn Application

• FP - clean Feed for Pigs• MF - Mineral Fertilizers for potato• IM - Information on Mushrooms• RS - Removal of Soil in the settlement area



Optimization factors in ReSCAOptimization factors in ReSCA

Counter-measure:• RI - Radical Improvement• SI - Surface Improvement• FA - Ferrocyn Application

• FP - clean Feed for Pigs• MF - Mineral Fertilizers for potato• IM - Information on Mushrooms• RS - Removal of Soil in the settlement area

Characteristic RI SI FA FP MF IM RS

Stability (y) 4.00

4.00

1.00

1.00

1.00

2.00

27.0

Cost (euro) 350

300

30

6 1 3 325

Degree of acceptability

1.00

1.00

0.75

0.60

1.00

0.50

0.10



ConclusionsConclusions• Regulations should require that countermeasures and

remediation must be based on a cost-risk analyses that directly connects the main physical and chemical processes to environment (ecosystem) or human heath risks and costs

• National system for optimization preparedness as part of emergency preparedness should be created. This system as minimum should include regulations, experts, tools, knowledgeable decision makers and communication with public

• Systems to Support Remediation Strategies establishment is useful with customization to accident specific features

• As residual radioactive pollution still exists, and our knowledge yet are not exhaustive it is reasonable to continue gathering and analyzing remediation optimization experience.



ReferencesReferences

More detailed information about post-Chernobyl optimization experience and ReSCA use can be provided by:

- Valeriy Kashparov - Ukrainian Scientific Institute of Agriculture Radiology ([email protected])

- Volodymyr Berkovskyy – IAEA (V.Berkovsky[email protected]) More detailed information for remediation of aquatic

systems and lands can be provided by:

- Oleg Voitsekhovych - Ukrainian Hydrometeorological Institute ([email protected])