Methods of implementation and sequestration of iodine in UO2 nuclear fuels

Corrosive iodine is formed during fission of uranium in UO2 nuclear fuels. This iodine oxidises zirconium claddings used as sheaths for fuel. In addition to extreme mechanical interaction between the fuel pellets and cladding, this can lead to stress corrosion cracking (SCC) of the cladding and fuel failure. Nowadays, reactors are limited in their ramping capacity to mitigate this interaction, however, with the introduction of small modular reactors and their potential to be used in a load-following scenario (requiring more strenuous ramping on nuclear fuels), SCC becomes a primary concern for fuel lifetimes. This project aims to utilise facilities at ANSTO and Royal Institute of Technology (KTH) in Sweden to fabricate UO2 fuel with additives that can delay the release of or sequester iodine, thereby delaying SCC and potentially increasing fuel lifetimes.