Impact of inflow transport approximation on reactor analysis

Abstract

The methodologies for transport approximations are investigated. The methods include the consistent PN approximation, the outflow transport approximation and the inflow transport approximation. The detailed derivation for the approximation is described. The three transport approximations are implemented in the lattice physics code STREAM and tested for several verification problems in order to investigate the effect and accuracy of each transport approximation. From the verification, the consistent PN approximation and the outflow transport approximations cause the significant error in the eigenvalue and the power distribution for the high leakage problems. The inflow transport approximations show the most accurate and consistent results for the verification problems.