1. TRAMPUS Consultancy Reactor Accidents – An Overview P. Trampus trampusp@trampus.axelero.net 1st Hungarian-Ukrainian Joint Conference on Safety-Reliability and Risk of Engineering Plants and Components Miskolctapolca, Hungary, 11 – 12 April 2006

2. TRAMPUS ConsultancyMotto „Remember, Caesar, thou art mortal”

3. TRAMPUS ConsultancyContent Reactor figures Terminology The INES Major reactor accidents Accident risks

4. TRAMPUS Consultancy Timeline of First Industrial Scale NPPs around the World

5. TRAMPUS Consultancy Power Reactor Figures (December 2004) Reactors in operation: 440 Reactors under construction: 26 Reactors shut down:107 Operational experience: 11695years License renewal issued:> 40 License renewal in progress: 10 Letter of intent: 27

6. TRAMPUS Consultancy Research Reactor Figures (June 2004) Reactors in operation: 274 Reactors shut down:214 Total number of reactors:674

7. TRAMPUS ConsultancyTerminology Events: Accidents –Mortality –Radiation release –Financial consequences (core melt) – Serious / Severe accidents Incidents Anomaly Deviations

8. TRAMPUS Consultancy Concept of the International Nuclear Event Scale (INES)

9. TRAMPUS Consultancy The INES Jointly developed by experts of the IAEA and OECD/NEA, in 1989

10. TRAMPUS Consultancy Nature of Reactor Accidents Statistics cover –Nuclear power plants civil military –Experimental reactors –Research reactors –Reprocessing plants –Fuel manufacturing facilities –Food sterilization plants –Radioactive source accidents –… Accidents types –Criticality accidents –Non-nuclear accidents (e.g. turbine fire)

11. TRAMPUS Consultancy Possible Classification of Reactor Accidents Accidents led to death by exposure to ionizing radiation Accidents with consequences on the environment and the public Accidents led to staff exposure above permissible level Accidents with consequences on plant availability

12. TRAMPUS Consultancy Criticality Accidents with Death Los Alamos (USA), 19451 dead Los Alamos (USA), 19461 dead (20 Sv) Vinca (former Yugoslavia), 19581 dead Los Alamos (USA), 19581 dead (60 Sv) Idaho Falls (USA), 19613 dead Woods River Junction (USA), 19641 dead Constituyentes (Argentine), 19831 dead Chernobyl (former SU), 1986 31/50 dead Tokai-mura (Japan), 19992 dead

13. TRAMPUS Consultancy Accidents with Consequences on the Environment and the Public Windscale (GB), 1957 –mainly 740 TBq I-131, and others (~1/1000 of Chernobyl) –126 persons contaminated (max. individual dose 0,16 Sv) –98 plant workers (max. 0,1 Sv) –external exposure (max. 47 mSv)

14. TRAMPUS Consultancy Accidents with Staff Exposure Chalk River (Canada), 1958 10 to 200 mSv Chinon A1 (France), 1965 500 mSv Chinon A2 (France), 1979 110 / 340 mSv

15. TRAMPUS Consultancy Accidents with Plant Unavailability (1) Heavy Water Reactors –NRX (Canada), 1952 repaired –Lucens (Switzerland), 1969 closed –EL4 (France), 1968 SG replaced Gas-Cooled Reactors –Chapel Cross (GB), 1967 repaired –Saint-Laurent A1 (France), 1969 repaired –Saint-Laurent A2 (France), 1980 repaired

16. TRAMPUS Consultancy Accidents with Plant Unavailability (2) Pressurized Water Reactors –Reactor internals damage (some 20 plants in USA, France, Italy, SU, Germany, China) –SG tube rupture (many plants) –Other incidents – Three Mile Island (partial core melt, extensive inside contamination) - closed Boiling Water Reactors –Browns Ferry (USA), 1975 – fire –Vandellos 1 (Spain), 1989 – fireclosed –Other plants

17. TRAMPUS Consultancy Accidents with Plant Unavailability (3) Fast Breeder Reactors –EBR 1 (USA), 1955 –Fermi 1 (USA), 1966 –KNK (Germany), 1971 –BN 350 (former SU), 1973 –Phoenix (France), 1976 –Rapsodie (France), 1982 –Phoenix (France), 1982 each reactor was repaired

18. TRAMPUS Consultancy Radioactive Source Accidents False radiotherapy –Costa Rica, 1966 40 dead –Spain, 199011 dead –Morocco, 1984 8 dead –Mexico, 1962 4 dead Lost sources –Brazil, 1987 4 dead (children) –Further 89 dead in various countries

19. TRAMPUS Consultancy Chernobyl Windscale, Three Mile Island Saint-Laurent A2, Constituyentes Vandellos Accidents in the INES

20. TRAMPUS Consultancy Historical Review of Accident Forecast The Brookhaven Report: Theoretical Possibilities and Consequences of Major Accidents in Large Nuclear Power Plants (WASH-740), U.S.AEC, 1957 Qualitative risk assessment The Rasmussen Report: Reactor Safety Study, an Assessment of Accident Risks in U.S. Commercial Nuclear Power Plants (WASH-1400), U.S.NRC, 1975 Quantitative risk assessment (first in its kind)

21. TRAMPUS Consultancy Immediate Mortality Risk due to Severe Accidents

22. TRAMPUS Consultancy A Scientist’s View „The chance of such an event (i.e. kamikaze-style terrorists aim NPPs) cannot be assessed even by the most astute technicians or engineers: it is a matter of political or sociological judgement. But one would surely have to be a naive optimist to rate it as less than one in a hundred per year.” Martin Rees: Our Final Century, 2003