17 Validating loss-of-coolant simulations INL used the BISON fuel performance code to simulate a real Loss-of-Coolant- Accident experiment performed on a pressurized water reactor fuel rod. BISON results were compared with experimental data for a number of material properties including rod pressure, ballooning, time to rupture and end-of-life cladding surface roughness. Researchers also compared BISON’s results with those from other advanced fuel performance codes from nations participating in the International Atomic Energy Agency’s ongoing Fuel Modeling Under Accident Conditions exercise. By comparing BISON predictions with results from actual experiments and the best codes from other nations, INL can improve its fuel performance modeling. The BISON team (left) continues to advance the fuel performance modeling code (above left).