[3J14-16] Behavior of FPs 2

[3J14] Axial migration and accumulation behavior of cesium in fast reactor fuel pins

(1)Axial migration and accumulation behavior of cesium observed in irradiation test of Joyo and foreign reactors

*Hiroshi Oka¹, Takashi Tanno¹, Yoshihisa Ikusawa¹, Tomoyuki Uwaba¹, Takeji Kaito¹ (1. JAEA)

Keywords:Fast reactor, Cesium, High burnup, FCMI, MOX, Post irradiation experiment

Through the irradiation test of Joyo and foreign reactors, the behavior of cesium migration and accumulation in axial heterogeneous fuel pins was investigated. The local increase of cladding tube diameter at MOX/UO₂ boundary was observed at a burnup of 115 GWd/t, which seems to be caused by the accumulation of cesium.