By: Vick Nazareth and Bill Lyon
The Pegasus code is a culmination of nuclear fuel behavior knowledge and experience that spans a period of over five decades. It is a total fuel-cycle simulation of fuel response from initial insertion in reactor to deposition in permanent storage. The goal of Pegasus is to treat, with equal fidelity, the modeling of fuel behavior during the active fuel cycle and the back-end cycle of spent-fuel storage and transportation in a single, self-consistent, and highly cost-effective analysis approach. In the active part of the fuel cycle, Pegasus’s superior three-dimensional thermo-mechanics, coupled with validated nuclear and material behavior models, and robust fuel-cladding interface treatment make it a high-fidelity predictor of fuel-rod response during flexible power operations and operational transients.