A RIA failure criterion based on cladding strain

This note intends to contribute to the interpretation of the RIA tests that have been performed during the last decade on high burn-up PWR and BWR rods and that have been reported in the open literature. A failure threshold based on cladding deformation is proposed. This criterion predicts well all CABRI data with the exception of one. NSRR fuel failures are also reasonably well predicted by the proposed criterion. Further MOX tests are needed in order to clarify differences between MOX and UO2. For what concerns mechanisms, fuel swelling is important and FGR less important for the failure mechanism at high burnup (∼60 MWd/kg). (author)