Optimization and verification of the coupled code TRACE/SubChanFlow using the VVER-1000 coolant mixing benchmark data

摘要

Recently, a coupling system of the best-estimate system code TRACE and the sub-channel code SubChanFlow (SCF) was implemented based on the Exterior Communication Interface (ECI) at the Karlsruhe Institute of Technology (KIT). The new capabilities were verified with two academic coolant mixing problems. This paper describes the optimization of two temporal coupling schemes for the steady-state and transient simulations to improve the calculation efficiency of the coupled system. The data provided by the VVER-1000 coolant mixing benchmark is used for the validation of the coupled codes. Based on the obtained results, it can be stated that TRACE/SCF predicts the hot leg coolant temperature closer to the measured data compared to the TRACE standalone simulation due to the better description of the mixing within the core along the core height. Furthermore, the computational efficiency of different coupling strategies was studied and the optimized coupling scheme was proved more efficient than the original coupling schemes.