During a routine inspection at the Sellafield Nuclear processing plant in Cumbria, UK, it was found that a category of the processing chemicals had changed state. Soon, bomb disposal experts were brought at the Magnox site at Sellafield. The chemical was organic peroxide, which was found to have changed its state and steps were followed as per the regulations of the Explosive Ordnance Disposal. The EOD requires the said chemical to be incinerated at a designated pit under the specific specialist disposal rules. The nuclear processing site has been evacuated. The storage facility has been segregated from the parts of the plants handling nuclear operations. The risk posed by the changed chemical state of the organic peroxide has been identified as a conventional safety risk, not a nuclear safety risk.

The Sellafield is a large scale multi-functional nuclear site near the Cumbria Coast in north west of England. The only operations being carried out at the site are nuclear decommissioning and nuclear waste storage as of 2020. The site has the first generation of UK’s nuclear reactors. It is the site with the world’s first full scale nuclear reactor power station to generate electricity on an industrial scale.  This site has the Magnox design of nuclear reactor which incorporates natural uranium as fuel, graphite as moderator and carbon dioxide as coolant in a heat exchange format. It is a type of gas cooled nuclear reactor site. In UK, it had dual purpose of generating electricity and producing Plutonium 239 for nuclear weapons. Magnox plant at Sellafield was non-operational at the time of the detection and would remain in the same state till the time the chemical is safely disposed away.