Modeling TBM Components by Using RELAP5 Code

RELAP5 is a best estimate system code suitable for the analysis of all transients and postulated accidents in Light Water Reactor systems. It was usually used to solve plant thermal-hydraulic problems on system scale. RELAP5 was used to study thermal-hydraulic behavior on component level in this paper. The Test Blanket Module (TBM) was a key component in Chinese Helium-Cooled Solid Breeder (CN HCSB) system. One sub-module of TBM was simulated by RELAP5/MOD3.4. The flow paths, Be pebbles neutron multiplier as well as Li₄SiO₄ pebbles tritium breeder of TBM were modeled by using hydrodynamic components models as well as heat structure models provided by RELAP5. Steady-state condition was studied and the results were compared with CFD results provided by Fluent code. The steady-state results were in consistent with CFD results when the sub-module was well modeled by RELAP5. The results showed that RELAP5 could be used to solve thermal-hydraulic problems on component scale when the component was well modeled. With a detail-modeled TBM, the transient conditions of CN HCSB system could be simulated more precisely by RELAP5.