Effects of Structural Materials on BP/CP Uncertainty Studies for RFSP-IST Modelling of Wolsong CANDU 6 Reactors

Abstract

A study has been carried out to gain a picture and some quantitative evaluations of the structural material mesh spacing layout effects of Wolsong CANDU 6 reactors by using the WIMS/DRAGON/RFSP-IST code system. The newly updated code system has been validated to some extents by comparing the Phase-B pre-simulation results of Wolsong Unit 1 against the previously acquired Phase-B commissioning test measurements of Wolsong Units 1,2,3,4. The code validation efforts resulted in the conclusions that the newly adopted code system could be used for the operational support of Wolsong CANDU 6 reactors. As an ongoing striving for the improvement of safe and economic operation of the reactors, a project on BP/CP uncertainty analysis with respect to the WIMS/DRAGON/RFSP-IST code system is planned. The results obtained in the present study strongly suggest that the effects of mesh spacing layouts of structural materials could be used as an important parameter to help grasp a more realistic glance on the overall off-line flux mapping errors that contribute to BP/CP uncertainties.