Numerical thermal-hydraulic simulation of LBE target mock-up loop "IMMORTAL" by using RELAP5-3D

Watanabe, Nao  ; Obayashi, Hironari  ; Nishihara, Kenji  

JAEA investigates lead-bismuth eutectic alloy (LBE) as a candidate of coolant and spallation target of Accelerator Driven System (ADS). Construction of an experimental facility for LBE spallation target is planned within the J-PARC project for feasibility study of ADS's beam window, which is exposed to high temperature LBE flow and strong proton and neutron irradiation environment. As a demonstration, an LBE target mock-up loop "IMMORTAL" was constructed to confirm the operation of a primary cooling system and to implement integration tests of developing components of LBE technologies. The thermal-hydraulic characteristic of LBE is very important, however, studies about it are still limited compared with that of light water. Therefore, in this research, a calculation model of IMMORTAL's primary loop was made and the thermal-hydraulic behavior was numerically simulated by using the RELAP5-3D code. Then, simulation results and experimental data are compared to validate heat transfer coefficient correlations and properties of LBE.