Evaluation and adaptation of the RIA code SCANAIR for modelling BWR fuel and conditions

The SCANAIR code, developed by the Institut de Radioprotection et de Sûreté Nucléaire (IRSN), is designed for modelling the behaviour of a single fuel rod in fast transient and accident conditions during a reactivity initiated accident (RIA) in pressurized water reactor (PWR). In SCANAIR, the available fuel material properties and the thermal-hydraulics (TH) model are for PWR fuel and coolant conditions, respectively, but the code does not have similar models for boiling water reactor (BWR) to be applied in BWR RIA, the rod drop accident (RDA). Thus, the code lacks material properties of Zircaloy 2 (Zry-2) which is the cladding material in BWR fuel rod. Up until now, the only Zry-2 models implemented into the code are the laws for yield stress (YS) and ultimate tensile stress (UTS) of irradiated cladding from a bibliographic study, and the laws have not been validated with SCANAIR. New YS and UTS laws are now fitted based on PROMETRA mechanical tests and implemented into SCANAI