稠密燃料集合体における燃料棒曲がりの限界出力への影響評価

Numerical estimation of rod bowing effect in tight lattice fuel assembly based on X-ray CT data

三澤 丈治; 大貫 晃; 勝山 幸三 ; 中村 保雄; 秋本 肇

Misawa, Takeharu; Onuki, Akira; Katsuyama, Kozo; Nakamura, Yasuo; Akimoto, Hajime

In the JAEA, in order to investigate influence of the fuel rod bowing upon the critical power of the fuel assembly in the Innovative Water Reactor for Flexible Fuel Cycle (FLWR), the large scale thermal hydraulic experiment which simulates the fuel rod bowing was performed, and the fuel rod position in the test section was measured using the X-ray CT equipment. In this study, in order to investigate influence of the displacement of the fuel rod from the design-based rod position upon the critical power of the test section, the experimental analysis using the subchannel analysis code NASCA was performed based on the fuel rod position measured by the X-ray CT.