A consideration of the single release location for the multi-unit accidents

Abstract

The objective of this study is to find a single release location that can represent multi units for the level 3 multi-unit PSA, based on the current limitations of computational codes. For this purpose, the method of using the weighted average of units’ locations was proposed. Thus, the elements that can be considered as the weighting factors were classified, selected, applied to the reference plants. Also, MSPAR-SITE, the program to create site information by using this method and to visualize the results, were developed. Then, the concentration of the radionuclide and the early health effect were evaluated based on the derived locations. Through the results, it was confirmed that there was no significant difference in the all of the considered weighted single locations. In the area close to the site, the results of the single locations were not consistent with those of the multiple locations well. It may cause the under- or overestimation of the early fatality risk. However, in the case that the distance between the units is relatively very close, it is expected that the use of the single location will not substantially impact.