Irradiation behavior analyses of metallic fuel pins for sodium-cooled fast reactors

Mizuno, Tomoyasu; Koyama, Shinichi  ; Kaito, Takeji ; Uwaba, Tomoyuki ; Tanaka, Kenya

In order to be an alternative concept to the conventional concept consisting of mixed oxide (MOX) fuel, Metallic fuel, U-Pu(TRU)-Zr metallic fuel slug and ODS cladding were considered for Sodium-cooled fast reactor (SFR) cycle system. The capability of the U-Pu(TRU)-Zr metallic fuel with ODS cladding under a high burnup condition was calculated and conducted by a simplified calculation grogram developed in JAEA. The fuel temperature profiles, gap width profiles, and radial temperature distribution at EOL were evaluated. Those results show that the fuel pin had enough safety margin to fuel melting under the irradiation. Evaluation of the profiles of plenum gas pressure and the cladding deformation after irradiation shows that the fuel pin had enough plenum volume not to cause considerable cladding deformations by plenum gas pressure. In case of 0.4% Am bearing fuel, calculation result shows that fuel centerline temperature becomes high, but increase from U-Pu-Zr fuel is insignificant.