State Nuclear Regulatory Inspectorate of Ukraine

1. State Nuclear Regulatory Inspectorate of Ukraine APPLICATION OF THEOPTIMIZATION PRINCIPLE IN POST-ACCIDENT COUNTER-MEASURES IMPLEMENTATION (POST-CHERNOBYL (EXPERIENCE) Olena Mykolaichuk State Nuclear Regulatory Inspectorate of Ukraine, Chairperson Valeriy Kashparov Ukrainian Scientific Institute of Agriculture Radiology

2. 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 Post-Chernobyl counter-measures

3. National standardsand post-Chernobyl experience • 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

4. National standards • 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)

5. National standardsApplication of Optimization • Between the lower justificationlimit 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.

6. ExampleJUSTIFICATION FOR IMMEDIATECOUNTER-MEASURES(NRBU-97) 1 – Dose expected under internal exposure by iodine radioisotopes that enter organism during the 1st two weeks since the accident beginning

7. Application of Optimization 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.)

8. Optimization 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

9. Optimization by socio-psychological factors • 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.

10. Inadequate 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).

11. Example. Optimization in Restrictions of Foodstuff Consumption • 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

12. Example. Optimization in Restrictionsof 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

13. Example. Optimization for Urban Decontamination • 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

14. Example. Optimization for Meat, Soil and Forests” • 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

15. Example. Optimization “for Water Protection” 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 Optimized In 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.

16. 1986 90Sr 1993 1999

17. Remediation Optimization Prerequisites and 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

18. Immediate and Long-term Countermeasures Optimization 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

19. 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 theterritories 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)

20. ReSCA • 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€.

21. after the application of countermeasures in 2011 ReSCA calculations results. Reduction of settlements where dose > 1 mSv/year

22. ReSCA 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.

23. Reduction factors in ReSCA • 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

24. Optimization 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

25. Conclusions • 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 reasonableto continue gathering and analyzing remediation optimization experience.

26. References More detailed information about post-Chernobyl optimization experience and ReSCA use can be provided by: • Valeriy Kashparov - Ukrainian Scientific Institute of Agriculture Radiology (vak@uiar.org.ua) • Volodymyr Berkovskyy – IAEA (V.Berkovskyy@iaea.org) More detailed information for remediation of aquatic systems and lands can be provided by: - Oleg Voitsekhovych - Ukrainian Hydrometeorological Institute (o.voitsekhovych@gmail.com)