Bending strength at the fuel claddings quenched during LOCA

Yamato, Masaaki; Nagase, Fumihisa 

The loss of coolant accident (LOCA) is included in the design standard phenomenon of the light water reactor. The safety criteria for LOCA are established for the purpose of core cooling at the time of an accident and after the accident. In JAEA, the four points bending tests has been developed to evaluate the embrittlement of cladding which is important to core cooling. In this study, it was measured the bending strength by the four points bending tests for the non-irradiation cladding experienced fuel behavior assumed LOCA. As a result, it was confirmed that oxidation temperature isn't influenced on bending strength and bending strength was reduced with increasing oxidation rate. In addition, it found that the bending strength of cladding oxidized to 15% ECR, which is the upper limit of oxidation rate in the safety criteria, was higher than the bending load at design basic earthquake ground motion S .