[3D09-13] Methodology Development

[3D13] Development of core deformation reactivity evaluation method

(1) Application to the EBR-II SHRT-45R test

*Norihiro Doda¹, Shinya Kato¹, Kazuo Yoshimura¹, Tomoyuki Uwaba¹, Kenji Yokoyama¹, Masaaki Tanaka¹ (1. JAEA)

Keywords:reactivity feedback, core deformation reactivity, coupled analysis, EBR-II, sodium-cooled fast reactor

An evaluation method for reactivity feedback due to core deformation during reactor power variation in sodium-cooled fast reactors has been developed by JAEA for core design optimization. This core deformation reactivity is a complex phenomenon caused by the interaction between reactor physics, thermal-hydraulics, and structural mechanics. To capture the phenomenon, the evaluation method couples the MARBLE code for reactor physics, the Super-COPD code for system-scale thermal-hydraulics, the ASFRE code for fuel-assembly-scale thermal-hydraulics, and the FINAS code for core structural deformation. This reports the analysis results of the EBR-II shutdown heat removal test (SHRT)-45R using this evaluation method to understand the physical behaviors related to the core deformation reactivity, and future development issues.