Decision Making Methodology of Cost-benefit Analysis Based on Probabilistic Safety Assessment for Accident Mitigation Alternatives

Abstract

Various types of safety enhancements for operating nuclear power plants have progressed since the Fukushima accident. There have been various justification principles of risk criteria for decision-making based on societal risk acceptance, cost-benefit analyses, or operating experience. The decision making from the cost benefit analysis compares the investment required for addition or replacement with the benefit of a risk reduction for the core damage and large release accidents. The proposed decision making methodology estimates the investment costs and the benefits gained by calculating the risk reduction from a designated change. The accident mitigation alternatives including additional electrical power generators and passive safety systems were estimated. Instead of the net-benefit method, ratio assessment method presents the ratio of the results of the PSA methodology to the relative investment cost. The ratio of usefulness to the relative investment cost presents the degree of cost-benefit.