Tools and equipment that come into contact with plutonium during operations are classed as being ‘plutonium contaminated materials’. These are treated at Sellafield as a form of intermediate level waste and as such are grouted in cement which makes the material suitable for long term storage.
During spent fuel reprocessing, fuel fabrication, maintenance, decommissioning, refurbishment and other site operations, tools and equipment come into contact with plutonium and thus become contaminated.
These wastes are classified as ‘plutonium contaminated materials’. Due to the toxicity of plutonium, these plutonium contaminated materials are subject to a higher level of control than other radioactive wastes such as those disposed at the Low Level Waste Repository.
Plutonium contaminated material at Sellafield is classified into several generic groups, according to their type and how they are packaged for storage prior to treatment.
Mixed plutonium contaminated material predominantly consists of a combination of items such as PVC gloves, PVC protective suits, small items of plant, hand tools and laboratory equipment. These wastes are double-bagged in heat-sealed PVC linings within mild steel 200 litre drums.
Whole equipment and dismantled items consist of such things as contaminated gloveboxes and machinery. These items are packaged in crates.
Filters are used throughout Sellafield to remove particulate material, including plutonium containing dust, from air in building ventilation systems. Older filters are double-wrapped in heat-sealed PVC sheeting. The filters from newer Sellafield buildings are cylindrical and designed to fit directly into a 200 litre drum.
Plutonium contaminated material is treated at the waste treatment complex on the Sellafield site. The waste treatment complex provides for the supercompaction of mixed plutonium contaminated material in 200 litre drums. The resulting compacted pucks are stacked in larger 500 litre drums which are then backfilled with a cement grout.