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

TRAMPUS ConsultancyMotto „Remember, Caesar, thou art mortal”

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

TRAMPUS Consultancy Timeline of First Industrial Scale NPPs around the World

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

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

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

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

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

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)

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

TRAMPUS Consultancy Criticality Accidents with Death Los Alamos (USA), dead Los Alamos (USA), dead (20 Sv) Vinca (former Yugoslavia), dead Los Alamos (USA), dead (60 Sv) Idaho Falls (USA), dead Woods River Junction (USA), dead Constituyentes (Argentine), dead Chernobyl (former SU), /50 dead Tokai-mura (Japan), dead

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)

TRAMPUS Consultancy Accidents with Staff Exposure Chalk River (Canada), to 200 mSv Chinon A1 (France), mSv Chinon A2 (France), / 340 mSv

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

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

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

TRAMPUS Consultancy Radioactive Source Accidents False radiotherapy –Costa Rica, dead –Spain, dead –Morocco, dead –Mexico, dead Lost sources –Brazil, dead (children) –Further 89 dead in various countries

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

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)

TRAMPUS Consultancy Immediate Mortality Risk due to Severe Accidents

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