The modelling of nuclear fuel performance is critical to the safe and economic operation of nuclear power plants. It is necessary to be able to properly understand and predict the behaviour of fuel in both normal and transient conditions. As fuel is taken to higher burnups, it is important to ensure that the tools used to model the behaviour remain appropriate as fuel designs and materials change. This publication presents the results of a code comparison exercise against a wide range of experimental and idealized data designed to test the limits of code capabilities and to allow data for verification and validation at high burnup. It provides an overview of the codes, their limitations and the main challenges in understanding the behaviour of high burnup fuel and how these are met.
