The Legacy Ponds and Silos (LP&S) at Sellafield represent some of the most complex and difficult decommissioning challenges in the world, and they remain the highest risk in the NDA estate. They date back to the very start of the nuclear industry and were constructed at a time when priorities were very different to those of today. As a result, decommissioning the LP&S at Sellafield is a complex task which remains a top priority for the NDA.
In our previous Strategy (ref 3) we said that the retrieval of high hazard materials from the Sellafield LP&S was an area of specific focus, with the objective of urgently reducing the intolerable risk that they pose.
Since then, significant progress has been made in retrieving waste from the LP&S, with some major milestones being achieved. In 2018, we started the removal of empty nuclear fuel skips from the First Generation Magnox Storage Pond (FGMSP). Sellafield Limited worked with the supply chain to manufacture suitable storage containers, which was an essential enabler to starting this work, and also drew on lessons from skip operations elsewhere in the NDA group.
More than 50 skips have now been cleaned and removed, which has created enough space to enable the removal of sludge, fuel and debris from the pond floor. Sludge retrievals have also started in the highest priority area in the facility, which contains the most significant inventory. Across the Ponds and Silos projects we have now:
- removed significant quantities of bulk fuel and over 300 tonnes of solid Intermediate Level Waste (ILW) from the Pile Fuel Storage Pond (PFSP) (SO2&7). One of the pond operating bays has now been fully cleared of sludge, equipment and operational waste (SO31). This bay is now being prepared to be isolated from the rest of the pond so that it can be drained of water. This will provide essential learning for the development of the strategy for the removal of water from the entire pond
- removed more than 100 cubic metres of sludge from the FGMSP (SO31), to the extent that areas of the pond floor are now visible for the first time in over 50 years. Over 100 tonnes of fuel has also been removed from the pond (SO7)
- the first of the 400 tonne silo emptying plants has now been installed in the Magnox Swarf Storage Silo (MSSS). It is now in the final phases of commissioning before retrieval operations begin, which represents a momentous step forward in the delivery of the NDA's mission (SO31)
- new access has been created for the retrieval of waste from the Pile Fuel Cladding Silo (PFCS) and the equipment has been installed, ready for retrieval (SO31) to begin shortly.
