Development and verification of the coupling code of discrete ordinates and Monte Carlo methods

This paper studies the discrete ordinates (SN) and Monte Carlo (MC) coupling method, which aims to combine the advantages of the high computational efficiency of SN method and the good geometric modeling ability of MC method. Base on the SN code NECP-Hydra and the MC code NECP-MCX, this paper develops a coupling code NECP-Alter, which converts the angular flux file generated by the SN code into the surface source file for the MC code. Thus, for a shielding problem, the SN calculation is first carried out and the angular flux file of the coupling interfaces is generated. Second, NECP-Alter is adopted to convert the angular flux file to surface source file which can be read by the MC code. Last, the MC calculation is carried out. The numerical results show that the SN-MC coupling method can improve the comprehensive performance of computational accuracy and efficiency in the large-scale PWR shielding problem.