Conceptual Design Enhancement for Prevention and Mitigation of Severe Accidents

The Fukushima accident suggests that serious consideration must be given to changing current safety goals to properly address the major impacts of nuclear accidents on society, including health effects, property damage, and environmental contamination. Based on lessons learned from the Fukushima accident, a conceptual design and a new approach for implementing prevention and mitigation measures for severe accidents are proposed. Instead of an optimistic view on the progression of a severe accident and available resources, a worst-case scenario is considered to prepare for an unexpected situation. With a safety goal of practically eliminating the significant release of radioactive material, an improved approach for a prevention and mitigation strategy is proposed. This approach consists of a new severe accident management strategy with dedicated mitigation measures and suitable essential instrumentation to take timely recovery actions. The approach is designed to be more robust and resilient than the conventional system.