Study on Calculation Difference of the SCWR Core Steady State Analysis Code

The three-dimensional code system supercritical water-cooled reactor (SCWR) coupled neutronics/thermal-hydraulics analysis (SNTA) code is developed for SCWR core steady-state analysis by coupling neutronics/thermal-hydraulics (N/T). This paper studies the calculation difference between the SNTA code and the standard reactor analysis code (SRAC). By using the impacts exclusive method, it is confirmed that the calculation difference between these two codes is caused by different feedback of the cross section. The cross section data and the energy group structure of the SRAC code differ from the SNTA code, and the density coefficient of reactivity calculated by the SRAC code is higher, which means the feedback of the density and power distribution is bigger and the axial power distribution varies rapidly. The SNTA code with finer energy group structure is suitable for the performance analysis of SCWR core which has strong N/T coupling characteristics.