Construction and Verification of Variance Reduction Technique System Based on Automatic Importance Sampling
According to different objectives,shielding calculation problems can be divided into regional problem,source-detector problem,and global problem.To solve the deep penetration problem of the three kinds of problems,the MCShield research team systematically proposed a series of variance reduction methods.According to these works,this article constructed a variance reduction technique system based on the automatic importance sampling(AIS)method,and conducted some verification work.For the source-detector problem,the NUREG/CR-6115 PWR pressure vessel calcula-tion benchmark was used to verify the small detector automatic importance sampling(SDAIS)method.The result shows that the SDAIS method is more efficient than the AIS method for the source-detector problem.In addition,an AIS-based Monte Carlo coupled variance reduction(AIS-CADIS)method was also proposed which introduces the AIS method into Monte Carlo adjoint calculations and was verified against bench-mark problems.For global problems,the grid-based AIS method was proposed and verified using a simplified reactor shielding calculation problem.The results show that compared with the AIS method and analog Monte Carlo methods,the grid-based AIS method can improve calculation efficiency.
Monte Carloautomatic importance sampling methodvariance reduction techniqueMCShield program
国家科技期刊平台
NSTL
万方数据
