‘Hazardous’ facility at UK nuclear site dates back to 1950s
Work has started to remove historic waste from the pile fuel cladding silo – one of the oldest and most hazardous storage facilities at the Sellafield nuclear site in Cumbria, northwest England.
The start of waste removal, which could take 20 years, follows approval by the Office for Nuclear Regulation (ONR). The silo was originally commissioned in the early 1950s.
The ONR said it is priority to ensure the waste stored in the ageing silo is removed and placed into storage facilities that meet modern safety standards.
Built in the 1950s to store cladding from used nuclear fuel from the Windscale Piles – the first nuclear reactors to be built at Sellafield – the vast concrete silo was designed as a “locked vault” with no plan for how to retrieve its contents or decommission the building.
Sellafield Ltd, the government body overseeing the Sellafield site, said the silo was cut open for the first time in 2017, making the first of six holes that will allow radioactive waste to be removed.
The silo contains around 3,200 cubic metres of intermediate level waste, which was routinely tipped into the silo until 1964, with further occasional tipping work continuing until 1972.
Since then, the silo has been in a state of care and maintenance with the waste inventory remaining largely untouched. The building underwent several upgrades to ensure it could continue to store its contents safely while a plan for retrievals was developed.
Work Could Take 20 Years
The silo is internally divided into six compartments. Waste contained in the silo consists largely of fuel cladding and experimental residues that were tipped into the compartments through access points in a roof tunnel.
Cladding is the term used for the metal casing that surrounded the uranium fuel rods that were loaded into nuclear reactors. After the rods had been used in the reactors the cladding was peeled away so the fuel inside could be reprocessed.
Once waste is removed it will be transferred and stored in modern facilities on site, pending long-term disposal in a deep geological disposal facility, a site for which has not yet been chosen.
The Sellafield site is one of the largest and most hazardous nuclear facilities in Europe.
It comprises of a range of nuclear facilities, including redundant facilities associated with early defence work, as well as operating facilities associated with the Magnox reprocessing programme, a mixed oxide fuel plant and a range of waste treatment plants.
It began life in the early 1950s making plutonium for nuclear weapons, and later that decade became the location of Calder Hall, the world’s first commercial nuclear power station.
The pile fuel cladding silo under construction at Sellafied in 1951. Courtesy Sellafield Ltd.
