Benchmark Analysis of EBR-Ⅱ Shutdown Heat Removal Test-17 using of Plant Dynamics Analysis Code and Subchannel Analysis Code

摘要

IAEA's Coordinated Research Project (CRP) on Benchmark Analyses of Shutdown Heat Removal Test (SHRT) performed at the Experimental Breeder Reactor Ⅱ (EBR-Ⅱ) has been carried out since 2012. JAEA participated in this CRP and applied two analysis codes developed by JAEA to the SHRT-17, which was provided by ANL as a benchmark analysis problem simulating a protected loss of flow accident (PLOF). In this study, the system code Super-COPD was used to simulate thermal-hydraulics in core, upper and lower plenums, cold pool, two primary loops with pumps, and an IHX. As for the core, flow re-distribution and inter-subassembly heat transfer were considered by modeling all subassemblies as independent channels and inter-subassembly gap in the core barrel. The temperature distributions in instrumented subassembly XX09 and XX10 were simulated by using the subchannel analysis code ASFRE through setting its boundary conditions of the core inlet temperature, the flow rate of the subassembly and the heat flux across the wrapper tube at the quantities obtained by the system analysis. These results indicate that the two analysis codes reasonably predict the temperatures in the core and the flow rates of the primary loops and the subassemblies during PLOF.