Operations have started to remove nuclear fuel from the Pile Fuel Storage Pond (PFSP) at the Sellafield site in the UK. The move marks the first time that fuel has been retrieved from the pond since the 1960s.
The pond - built and commissioned between 1948 and 1952 - and the adjoining decanning building provided the storage and cooling facility for irradiated fuel and isotopes from the two Windscale pile reactors. The PFSP processed 2100 tonnes of pile fuel and 300 tonnes of Magnox fuel. All operations in the pond - the first nuclear fuel storage pond to be constructed at Sellafield - ceased in the 1970s. Extensive refurbishment and re-equipping took place in the 1980s and decommissioning started in the 1990s.
The sub-divided outdoor storage pond is some 100 metres long, 25 metres wide, 7 metres deep and contains over 15 million litres of water. It is the world's largest open-air nuclear storage pond. The PFSP contains skips of irradiated fuel and waste, each skip containing up to 6 to 12 cubic metres of material. So far, 26 redundant skips have already been removed from the pond and disposed of. Almost 50 skips remain within the PFSP.
Before fuel could be removed from the pond, sludge that had accumulated in it needed to be removed. Operations to retrieve this sludge - consisting of algae, corrosion products and wind-blown material - began in 2008.
On 20 September, the UK nuclear regulator gave approval for the removal of fuel from the PFSP. The first of the fuel - some 0.5 tonnes - was moved from the pond to a transport flask on 24 September. It was then exported to the modern fuel storage pond on 26 September, where it will be held pending final disposal..
Jim French, executive decommissioning director at Nuclear Management Partners, said: "Our original timescale was to start retrieving this fuel in 2016, however we've been able to bring this forward by concentrating significant resources and technical expertise on this priority project. This achievement underpins our commitment to accelerating the decommissioning of our high hazard projects at Sellafield." The PFSP is one of four old facilities at Sellafield identified by the Nuclear Decommissioning Authority as the top priority for risk and hazard reduction.
French added, "The plan is that all the fuel will now be retrieved by July 2015, however opportunities are being sought to bring this date even further forward."