Applying the waste hierarchy

Reducing the amount of waste produced and managing raw materials carefully can help reduce costs and safeguard our workforce.

The nuclear sector is working to:

• Prevent waste from arising in the first place;
• Minimise the quantity of radioactive waste produced;
• Accurately classify radioactive wastes; and
• Minimise the volume of waste sent for disposal.

These activities help waste producers to manage their materials more effectively, reduce costs and save valuable space at disposal facilities. Examples include:

• Planning decommissioning operations to control and minimise resource use;
• Minimising exposure of equipment and packaging to radiation to reduce the amount of radioactive waste produced;
• Sorting wastes on site to identify items or parts of items contaminated by higher levels of radioactivity. These ‘hotspots’ can then be separated out and sent for disposal, whilst the remaining material may be suitable for reuse or recycling; and
• Reducing the volume of the waste to ensure best use of the limited space in our disposal facilities. Techniques include compaction and incineration (for solid wastes) and evaporation and filtration (for liquid wastes).

Waste producers look for opportunities to reuse equipment and materials to minimise waste.

Equipment and materials can be reused, either directly or after refurbishment. This helps to ensure that we make best use of our resources. We can avoid sending items for disposal that could be useful elsewhere.

An example of reuse in the nuclear sector is the use of ‘mules’. Mules are containers for temporarily storing waste materials until a permanent disposal package is available. After each use, the site will clean, check and prepare the mules for reuse.

The nuclear sector also reuses lead shielding bricks from buildings. Lead is an excellent barrier against radiation.

Waste producers look for opportunities to recycle waste where possible. There have been significant achievements in recycling metals with low levels of radioactivity.

One major success was the recycling of 15 large steel boilers from the Berkeley site in Gloucestershire. Each boiler was 21m long and weighed some 300 tonnes. A special facility smelted the metal, skimmed off the contaminated material for disposal and separated the clean metal for recycling. This process saved over two years’ disposal capacity at the Low Level Waste Repository in Cumbria (LLWR). It also released more than 4,000 tonnes of metal for recycling.

On a smaller scale, lightly contaminated metals are also routinely sent for treatment and recycling. Shot blasting removes the contaminated surface of the metal. After rigorous testing, the clean, uncontaminated metal can be recycled.

If radioactive waste cannot be safely and cost-effectively reused or recycled, it will be disposed of. Disposal means placing the waste into specially engineered facilities where it will remain permanently.

Higher Activity Waste – In the UK, these wastes are being kept in temporary storage facilities until a long-term disposal route is developed.

Low Level Waste – The national Low Level Waste Repository (LLWR) is located south of Sellafield, in Cumbria. This is a specially engineered facility with concrete-lined ‘vaults’ for the disposal of Low Level Waste (LLW). Metal containers containing the LLW are stacked until the repository can be covered with an engineered cap and closed. In the north of Scotland, the Dounreay site has a LLW repository for waste from the site and the nearby Ministry of Defence’s Vulcan Naval Reactor Test Establishment. A few landfill sites can accept some Very Low Level Waste (VLLW) for disposal alongside municipal, commercial and industrial wastes.