Corrosion of Cladding

The closure of the Thermal Oxide Reprocessing Plant (ThORP) at Sellafield will result in spent nuclear fuel being retained in storage facilities for an extended period of time, before a viable permanent disposal route can be introduced. While the structural integrity of the fuel cladding materials is understood for the short periods within the storage facilities, it is not fully known what will happen over longer times.

The PhD will investigate the corrosion of spent fuel cladding during pond storage; specifically examining how the long-term corrosion products that form as a result of the conditions in wet storage will affect the corrosion behaviour. This will be done by using the knowledge obtained via historic post-irradiation examination of fuel cladding for both AGR and LWRs. Coatings, that mimic the corrosion products found on irradiated cladding, will then be applied to fresh, non-irradiated material for accelerated corrosion testing. These tests will look into the effects that defects, cracks and stress have on the corrosion mechanisms taking place. It is hoped that the research will lead on to coatings that could be used to increase accident tolerance within LWR cladding, while simultaneously enhancing the corrosion resistance.