Implications of the Fukushima Accident on Research Reactor Safety

Preliminary findings of Fukushima accident show that there is no evidence of major human errors as in previous accidents in the nuclear power industry, namely, Three Mile Island (USA) and Chernobyl (Soviet Union), and that the initiating event, a natural catastrophe of extraordinary magnitude, caused a long term loss of the normal power supply producing the failure of each defence-in depth barriers with the final release of radioactive material to the atmosphere. It is worth noticing that the direct damage caused in Japan by the earthquake and tsunami far exceeded any damage caused by the accident at the nuclear plant. In the light of this event the question whether safety systems of research reactors will cope with this type of scenarios arises. The objective of this works is to present an overview of the current practice commonly used in the safety analysis in research reactors and to assess the capability to mitigate conditions from a beyond-design-basis event like the one occurred at Fukushima power plant. (author)