The behavior of advanced gas reactor simulated spent nuclear fuels in wet interim storage conditions

The safe interim storage of spent nuclear fuel is important to prevent the degradation of the containers and fuel rods – both fuel pellets and cladding – thus avoiding the release of radiation and allowing the fuel to be safely handled on transfer to a long term disposal facility. The corrosion of pure UO2 and UK Advanced Gas-cooled Reactor (AGR) simulated spent nuclear fuels (SIMFUELs) was studied under conditions typical of those found in interim spent fuel storage pond waters. With respect to the dissolution of spent fuel, it appears to be advantageous to dose the ponds to pH≈11.4. The alkaline conditions in the pond water suppress the dissolution as UO2 which may otherwise occur at neutrality and lower pHs.