Development and Validation of a Cross-section Interface for Coupled NK/TH Calculations

The need of a more accurate method for modeling cross-section during off-nominal core conditions is becoming an important issue with the increased use of coupled 3D neutronics/T-H transient simulations. In the current two-step PWR core analysis method, fuel assembly homogenized parameters should be pre-generated before reactor core physics calculation at certain reference conditions. And then retrieved in the later core analysis procedure. So, how to retrieved the cross-section with the independent parameters accurately is important. In this paper, a method is developed as a cross-section interface for NGFM and sub-channel TH code based on tabulation is developed. Its accuracy is testified by several test cases. It has been concluded that the cross-section calculated by this method agrees well with the requirement of accurately determine values