Multi-Dimensional Creep Analysis Using the Novel Offbeat Fuel Performance Code

The EPFL and the PSI are currently working to enhance the knowledge of complex phenomena relevant for reactor safety, by developing advanced methodologies based on physics-based and high- simulations In this framework, a new multi-dimensional fuel behaviour solver is under collaborative development at the two institutes The new tool, OFFBEAT, which has been developed based on the C++ library OpenFOAM, is envisioned as a complement to traditional fuel performance codes for the investigation of complex phenomena affecting fuel integrity, such as a PCMI with a missing pellet surface defect or an asymmetric heat exchange In this regard, efforts are underway to devise an optimal coupling strategy with the TRANSURANUS code Additionally, OFFBEAT can be used to perform more traditional axisymmetric analyses of the nuclear fuel rod, using semi-empirical correlations for swelling, densification and relocation strains, and for the temperature and burnup dependence of the material properties Recently, models that capture the non-elastic behaviour of the zircaloy cladding, both in terms of instantaneous plasticity and thermal and irradiation creep, have been introduced This paper focuses on the methodological development associated with creep modelling in OFFBEAT and presents a preliminary multi-dimensional creep analysis for a test-case rodlet (author)

Technical Meeting on Progress on Pellet Cladding Interaction and Stress Corrosion Cracking: Experimentation, Modelling and Methodologies Applied to Support the Flexible Operation of Nuclear Power Plants

Multi-Dimensional Creep Analysis Using the Novel Offbeat Fuel Performance Code Conference Paper