Determination of Large Early Release Frequency Used in PSA

Abstract

The correlations between Large Early Release Frequency (LERF) and Early Fatality need to be investigated for risk-informed application and regulation. In RG-1.174, there are decision-making criteria using the measures of CDF and LERF, while there are no specific criteria on LERF. Since there are both huge uncertainty and large cost need in off-site consequence calculation, a LERF assessment methodology need to be developed and its correlation factor needs to be identified for risk-informed decision-making. This regards, the robust method for estimating off-site consequence has been performed for assessing health effects caused by radioisotopes released from severe accidents of nuclear power plants. And also, MACCS2 code are used for validating source term quantitatively regarding health effects depending on release characteristics of radioisotopes during severe accidents has been performed. This study developed a method for identifying correlations between LERF and Early Fatality and validates the results of the model using MACCS2 code. The results of this study may contribute to defining LERF and finding a measure for risk-informed regulations and risk-informed decision-making.