Research on Multi-Group Monte Carlo Calculations Based on Group Constants Generated by RMC

Abstract Nowadays, deterministic two-step or Monte Carlo methods are commonly used in core physics calculations. However, with the development of reactor core design, traditional deterministic two-step methods are becoming increasingly difficult to adapt to complex core and fuel geometry designs. However, Monte Carlo methods require high computational resources to obtain accurate full reactor simulation results. Therefore, using the Monte Carlo two-step method has become a good choice. The Monte Carlo two-step method involves obtaining group constants using the Monte Carlo method at a smaller geometric scale and conducting multi group Monte Carlo transport based on this result. This article uses the Monte Carlo software RMC to perform critical and burnup calculations on a custom core model using different group constant generation methods using the Monte Carlo two-step method. The results show that compared to continuous energy accurate simulation, the Monte Carlo two-step method requires extremely low computational resources and high computational efficiency. Therefore, the Monte Carlo two-step method can provide reference and assistance for subsequent core calculations.