[2O01-06] Accident Behavior, Emergency Exercise

[2O01] Experiments to evaluate the accumulation behavior of fuel fragments on the grid under FFRD condition

*Yuki Shimizu¹, Koichi Ogata¹, Yasunari Shinohara¹, Masaaki Yamato² (1. MHI Nuclear Development Corporation, 2. Mitsubishi Heavy Industries, Ltd.)

Keywords:FFRD, Fuel fragmentation, fuel dispersal, fragments accumulation, core coolability, high burnup fuel, LOCA

The whole phenomena of FFRD (Fuel Fragmentation, Relocation and Dispersal) are still unclear, and knowledge and experimental data concerning the effect of expelled fuel fragments on core coolability are insufficient.
In this study, we developed test equipment that enables us to obtain data concerning the dispersal and the accumulation of fuel fragments on the grid under FFRD condition by means of the unirradiated 17×17 PWR full-sized bundle system. In addition, it was confirmed that parameters related to the dispersal and accumulation behavior of fuel fragments affected the deposition state of fuel fragments using the equipment.