To improve the current deterministic regulation of nuclear power plant risk, the numerical guide lines for the probabilistic regulation are proposed by using the limit line approach which includes risk aversion concept. Approaches to the regulation of risk from nuclear power plants in which potential accidents may result in a broad range of adverse consequences must take into account several different aspects of risk. These include overall or average risk, risk aversion, and the impact of low consequence-high frequency accidents. The purpose of this study is to set limit lines for the nuclear power plant risks which meet all the requirements for the regulatory tool and to give the acceptable risk level for the individual and public radiation risk and utility financial risk. This study is composed of proposals for individual fatality, public fatality, I-131 \& Xe-133 release, and the financial risk limit lines, as form of Complementary Cummulative Distribution Function. Another important result of this study is the proposal for cost-effectiveness criterion including risk aversion concept to improve the weak point of current cost-benefit guide line. Numerical examples are shown in the figure or tables to illustrate the way in which an assessment to acceptable limit line could be possible.