3 Computational thermochemistry of nuclear fuel

Thermochemical behaviors of nuclear fuel have implications at all stages of the nuclear fuel cycle, which are discussed throughout this book. Having the ability to predict the chemical behavior of the fuel provides a mechanism to inform decision-making processes at the engineering design stage, operations, and also safety analyses. Thermochemical predictions can potentially be used to explore chemical extraction processes involving various minerals at the mining and milling stage, fluorination processes during conversion, controlling oxidizing/reducing environments during fuel fabrication, understanding the evolution of fuel chemistry with respect to irradiation in-reactor, uranium and plutonium extraction processes during reprocessing, and finally the behavior of spent nuclear fuel in a repository, which may include possible groundwater contamination. Furthermore, predicting the behavior of irradiated nuclear fuel in the event of a severe accident provides an important capability in prevention, informing decision-makers in response initiatives, and decommissioning.