A new pin-resolved ultra-fine-group method based on global–local resonance treatment framework

Abstract

In order to accurately consider intra-pin effects such as the spatial self-shielding effect and non-uniform temperature effect, several pin-resolved resonance self-shielding methods have been developed recently. The basic strategy of these pin-resolved resonance self-shielding methods is to divide resonance calculation into the whole domain calculation (global) and the 1-D fuel pin calculation (local), which we call the global–local resonance treatment framework. The spatial self-shielding effect, non-uniform temperature effect and resonance interference can be considered accurately by the 1-D fuel pin calculation with the ultra-fine-group method. Due to the simplified geometry, the computation time is short. In addition, the 1-D fuel pin calculation can be performed in parallel. This paper reviews pin-resolved resonance self-shielding methods that have been proposed and proposes a new pin-resolved ultra-fine-group method. These methods are implemented in the numerical nuclear reactor neutronics code SHARK developed by Nuclear Power Institute of China. Numerical results show good accuracy in the pressurized water reactor analysis.