Development of pre-cracking method for evaluating the RIA failure behavior of high burn-up fuels

Fukuda, Takuji; Sugiyama, Tomoyuki ; Mihara, Takeshi  ; Nagase, Fumihisa 

The hydride Precipitation occurs due to absorption of hydrogen and its oxidation in the high burn-up fuel cladding. The hydride precipitated densely near the outer surface of the cladding could be considered the origin of the crack growth its own brittle property. RAG (Roll After Grooving) has been developed to simulate the outer surface of hydride precipitation on the origin of the crack. The fracture behavior was evaluated to define the effect of origin of the crack compared with milled cladding by EDC (Expansion Due to Compression) test. The crack extension occurred in smaller circumferential strain on RAG cladding than milled cladding. It was shown that RAG can simulate the crack growth of outer surface hydride cracking.