2017 | AFC ACCOMPLISHMENTS 156 Metallic Fuel Modeling and Simulation Using BISON is pusued with the following objectives a. Predict cladding failure b. Justify and extend peak fuel burnup c. Justify and extend peak fuel temperature d. Simulate LOCA and RIA e. Investigate impact of engineer- ing changes on fuel performance, especially during transients f. Coatings, liners, annular fuel g. Justify fast reactor fuel testing in a thermal spectrum with Cd shrouds h. Design better irradiation experiments Metallic Fuel Modeling and Simulation Using BISON Principal Investigator: Pavel Medvedev Collaborators: Al Casagranda Project Description: BISON is a finite element-based nuclear fuel performance code applicable to a variety of fuel forms. It solves the fully-coupled equations of thermomechanics and species diffusion, for either 1D spherical, 2D axisymmetric or 3D geometries. Fuel models are included to describe temperature and burnup dependent thermal properties, fission product swelling, densification, thermal and irradiation creep, fracture, and fission gas production and release. Plasticity, irradiation growth, and thermal and irradiation creep models are implemented for clad materials. Models are also available to simulate gap heat transfer, mechanical contact, and the evolution of the gap/plenum pressure with plenum volume, gas temperature, and fission gas addition. BISON has been coupled to the mesoscale fuel performance code MARMOT, demonstrating fully- coupled multiscale fuel performance capability. BISON is based on the MOOSE framework and can therefore efficiently solve problems using standard workstations or very large high-performance computers. This project is important because it transforms AFC into a goal-oriented science based program.