1. IAEA International Atomic Energy Agency Emergency Response Protective Actions Day 10 – Lecture 3

2. IAEA Introduction In order to respond correctly in an emergency situation, predefined criteria for action must be available This lecture covers the basic internationally accepted intervention criteria

3. IAEA Content Basic principles of intervention Optimization of intervention Projected and avertable dose Action level dose for organs and tissue Principles for intervention levels Urgent protective action levels Generic action levels for foodstuffs Emergency worker protection guidance Classes of emergency related work

4. IAEA Practices and Interventions Systems for Radiation Protection Each practice should be justified The doses adding up in a practice should be kept as low as reasonably achievable The sum of doses in a practice should be kept below specified dose limits Each protective action should be justified The level of protective actions resulting in dose subtraction should be optimized

5. IAEA Basic Principles of Intervention All possible efforts should be made to prevent serious deterministic health effects and to reduce the occurrence of stochastic effects Intervention should be justified, such that the introduction of protective action should achieve more good than harm Levels at which intervention is introduced and at which it is later withdrawn should be optimized, so that protective action will produce the maximum net benefit

6. IAEA Factors Entering Optimization Benefit Avertable individual risk Avertable collective risk Reassurance Harm Individual physical risk Collective physical risk Monetary costs Social disruption Individual disruption Countermeasure anxiety Worker risk

7. IAEA Projected Dose Time after start of the accident Dose rate Projected dose

8. IAEA Action Level of Dose for Acute Exposure to Organ or Tissue Organ or tissueAction level of dose: Projected absorbed dose to the organ or tissue in less than 2 days (Gy) Whole body1 Lung6 Skin3 Thyroid5 Lens of the eye2 Gonads3

9. IAEA Avertable Dose Time after the start of the accident Dose rate Avertable dose t1t1 t2t2

10. IAEA Principles for Intervention Levels Dose quantity to express the intervention level is the avertable dose Only pathways and doses that can be influenced by protective action should be taken into account Estimate of avertable doses should be as realistic as possible and for an average member of affected population

11. IAEA Application International guidance specifies: “Generic Intervention Levels” (GILs), at which urgent and long term protective actions should be taken “Generic Action Levels” (GALs), at which controls should be placed on contaminated food

12. IAEA GIL and GALs GIL and GALs set so that action would do more good than harm Taking action at a considerably lower level could increase overall harm to the public Not applicable if protective action is overly hazardous or disruptive (e,g. evacuation during a snow storm justified at a higher GIL)

13. IAEA GILs for Urgent Protective Actions Table AI-I Protective actionGIL (dose avertable) Sheltering10 mSv in 2 days Evacuation50 mSv in 1 week Iodine prophylaxis100 mGy

14. IAEA Generic Action Levels for Relocation And Resettlement Table A1-II Protective actionGIL (Dose avertable) Temporary relocation 30 mSv/month Terminating temporary relocation 10 mSv/month Permanent resettlement 1000 mSv/life time

15. IAEA Generic Action Levels for Foodstuffs Table A1-III Radio nuclides in foods destined for general consumption GAL kBq/kg Cs-134, Cs-137, I-131, Ru-103, Ru-106, Sr-89 1 Sr-900.1 Am-241, Pu-238, Pu-239, Pu-240 0.01

16. IAEA Protection of Workers Undertaking an Intervention (GS-R-2) No worker undertaking an intervention shall be exposed in excess of the maximum single year dose limit for occupational exposure except: For the purpose of saving life or preventing serious injury If undertaking actions intended to avert a large collective dose If undertaking actions to prevent the development of catastrophic conditions

17. IAEA IAEA Guidance for an Emergency Worker Appendix 3 TaskTotal effective dose guidance (mSv) Life saving actions>500 Prevent the development of catastrophic conditions >100 Emergency phase intervention>50 Longer term recovery operations and work not directly connected with an accident Occupational exposure guidance

18. IAEA Importance of Establishing Criteria (OILs) Major lessons: Establish in advance, operational criteria for the instruments used Act on instrument readings not GILs or GALs

19. IAEA GIL, GAL and Worker Guidance Not designed to be used during an emergency Must develop observable criteria to be used during an emergency Operational intervention levels (OILs) Worker turn back guidance Measurable during an emergency with available instruments (e.g. expressed as dose rate)

20. IAEA Example OILs - Dose Rates at 1 m Above Ground Reactor release (TECDOC-955) Evacuate 1 mSv/h Restrict Food 1  Sv/h Radiological emergency (TECDOC-1162) Cordon 100  Sv/h

21. IAEA Expanded Guidance Current international guidance was found to be incomplete during past emergencies TECDOC - 1432 – proposes an extended framework of generic criteria that is intended to address the lessons from past emergencies

22. IAEA Summary EP guidance is based partly on international intervention guidance Action levels GILs GALs International guidance Not useable during an emergency - need OILs May not address all conditions Taking action at lower levels could do more harm than good

23. IAEA Where to Get More Information IAEA, Method for developing arrangements for response to a nuclear or radiological emergency, EPR-METHOD, IAEA, Vienna (2003) IAEA, Development of extended framework for emergency response criteria, Interim report for comments, TECDOC-1432, IAEA, Vienna (2005)