Status on the development of the fabrication and analysis equipment of the pseudo fuel debris

Kobayashi, Fuyumi; Fukaya, Hiroyuki; Izawa, Kazuhiko; Kida, Takashi; Sono, Hiroki; Suyama, Kenya

Proceedings of 12th International Conference on Nuclear Criticality Safety (ICNC2023) (Internet), 7 Pages, 2023/10

In the criticality experiment in the new STACY, pseudo fuel debris samples are used to acquire data for validation of the system used for 1F debris criticality safety assessment. The pseudo fuel debris is a pellet with a diameter of 8 mm and a height of 10 mm containing uranium oxide and structural materials (iron, silicon, zirconium, etc.). The pellets are made by mixing, pressing and sintering uranium dioxide powder and structural materials powder. The UO powder uses the same composition of uranium as the STACY driver fuel rods, in order to reduce the errors in fuel composition. The pseudo fuel debris fabrication devices and analysis equipment are installed at the BECKY in order to evaluate the critical properties of fuel debris with high accuracy in dimension and analysis. This equipment is located in the same laboratory and can quickly respond to experimental needs such as preparation of the pseudo fuel debris and analysis before and after irradiation.