[1J05-08] Development of Methodology 2

[1J07] Impact of Diffusion Coefficient and Correction Term on Convergence Performance of CMFD Acceleration

*Yoshiki Oshima¹, Tomohiro Endo¹, Akio Yamamoto¹ (1. Nagoya Univ.)

Keywords: CMFD acceleration , diffusion coefficient, correction term, convergence, MOC

Since the net neutron current obtained by a coarse mesh finite difference diffusion calculation is not consistent to that of a fine mesh transport calculation, the correction term is used in the CMFD acceleration to reproduce transport net current. However, the acceleration calculation tends to diverge for an optically large mesh. Various studies have been conducted to improve the stability of CMFD by correcting the diffusion coefficient. However, the relation between the diffusion coefficient and magnitude of the correction term has not been investigated. In this study, the magnitudes of the correction term using various diffusion coefficients are evaluated and the relation between the correction term and convergence performance is studied.