How is radioactive waste managed now?
Old nuclear fuel storage pond
How radioactive waste is dealt with depends to a large extent on how radioactive it is. Thus:
- Most Low Level Waste (LLW) is sent to the national LLW Repository near Drigg in Cumbria (the LLWR) or in certain cases to specific landfill sites soon after it is produced;
- Intermediate Level Waste (ILW) is stored in tanks, vaults and drums, with most waste requiring concrete to shield operators from the radiation. Some ILW is being cemented as it arises;
- High Level Waste (HLW) is stored as liquid in water-cooled, stainless steel tanks or as glass blocks, and needs thick concrete walls to shield operators from the high radiation.
Many radioactive wastes are treated in some way soon after they arise to reduce their volume and so minimise the requirements for storage. Techniques include compaction and incineration (for solid wastes) and evaporation and filtration (for liquid wastes). Other radioactive wastes are stored untreated.
LLW Repository near Drigg
A particular concern and priority is untreated historic wastes, largely created in the 1940s, 50s and 60s, held in old facilities. Records may be incomplete, meaning that the exact contents of these facilities are uncertain. Some wastes are corroding, and so are potentially mobile. Plans are being made to reduce the hazard posed by these wastes by retrieving, treating and packaging them, although this will take many years.
In time, most radioactive wastes will be packaged. This immobilises the radioactivity, and so reduces the hazard the waste presents compared to its untreated or partly treated form. The process of packaging converts the waste into a solid, stable passively safe form, within high integrity stainless steel or concrete containers.
