A new piece of kit, the sludge retrieval hood, will allow staff at the Sellafield nuclear site to begin full-scale decommissioning of the historic pile fuel storage pond and thus achieve an important UK legacy waste objective.
Built in 1948, the pile fuel storage pond was the first storage pond to be installed at the Sellafield nuclear site and was used to store both fuel and general waste. A far cry from modern facilities, the open-air pond has over time filled with corrosion products and airborne contaminants that have settled to form sludge on the pond floor and in the fuel skips.
The sludge has so far impeded efforts to decommission the pond. Together with a remotely operated vehicle, the hood will allow the sludge to be sucked off the pond floor and transferred to a corral – a structure adhering to contemporary waste containment standards. Two further pieces of equipment, a skip tipper and cleaner will similarly facilitate cleaning of the skips. Sludge collected will be processed at a local treatment facility.
Decontamination of the pond is scheduled to take about five years, and will involve the complicated rearrangement of skips within the pond. Skips empty of fuel and waste will be cleaned of sludge and removed from the pool immediately, while full skips will be moved to clean area of the pond to await disposal at a later date.
Head of program acceleration Steve Cottam said, "It is quite exciting to see the plant make the transition into full blown retrieval operations. Getting the plant to this stage has however been a series of challenges. Equipment was initially designed for the legacy pond based on existing drawings and plant records, but we quite often discovered that the conditions were not as expected, and sometimes had to make last minute modifications to equipment. Even now we still find unexpected things."
Researched and written
by World Nuclear News