Study on Selecting Conservative Axial Power Shape for DNBR Design Limit

摘要

In OPR1000 and APR 1400 type nuclear power plants, DNBR SAFDL is calculated by statistically combining uncertainties of system parameters. When combining uncertainties, the conservative axial power shape is selected and fixed because the axial power shape is one of state parameters. The purpose of this study is to find the conservative axial power shape as a state parameter and it's concluded that uncertainties of DNBR distribution is larger with higher limiting heat flux at the target DNBR. Hence, the axial power shape at the maximum limiting heat flux is a good candidate for the DNBR SAFDL calculation.