CUPID 코드를 활용한 ROCOM 붕소 혼합 문제 해석

Abstract

The concentration of boron in the coolant of reactor cooling system in nuclear power plants(NPPs) plays an important role in controlling the reactivity according to fuel burn-up. Thus, an accurate prediction of the boron concentration after an unexpected de-borated water injection is required for the safety of NPPs. Korea Atomic Energy Research Institute(KAERI) participates in the ROCOM boron dilution benchmark in a framework of IAEA coordinated research projects. Through the benchmark, the capability of the CUPID code to predict the boron mixing behavior was validated. Two-equations RANS turbulence models were tested such as the standard k-ε model, RNG k-ε model, and SST k-ω model. The calculation results showed that the standard k-ε model reasonably predicted the boron mixing behavior when appropriate y+ values were verified even though the k-ε model required less number of cells comparing to the SST k-ω model because of larger y+ values.