The Nuclear Decommissioning Authority

 

The amount of Fuel Element Debris (FED) requiring interim storage and final disposal is being drastically reduced, due to the success of an innovative technique spearheaded by the Magnox sites.

Dungeness A in Kent was the first site to introduce dissolution more than 10 years ago. FED, made up of metal components removed from the casing of fuel elements after use, is the largest radioactive waste-stream in terms of volume after the fuel itself.

The waste is dissolved in an acid solvent and then treated to capture the majority of radioactivity. The effluent is then discharged within the site's authorised discharge limits. Assessments by the Nuclear Installations Inspectorate and Environment Agency have demonstrated the process has negligible environmental impact.

Following the success of the Dungeness programme – which has so far dissolved more than 80 tonnes of waste and is predicted to save the taxpayer more than £35 million during its life - other sites are beginning to adopt this approach. Bradwell has led the development of an updated dissolution programme, taking account of the latest technology and the learning from Dungeness, which has resulted in dissolution replacing encapsulation of FED in the site's Lifetime Plan.

Programme director Steve Walters said:

"A thorough review has demonstrated that dissolution is the best practicable environmental option for Bradwell. Not only does it save money, but Bradwell alone can save 269m³ of packaged container space within the national Geological Disposal Facility (GDF) using this approach."

Lessons learned from the Bradwell development are now helping Sizewell A, Hinkley Point A and Oldbury undertake similar changes to their plans. Steve added: "The four sites combined have more than 2,000m³ of raw FED on site that needs to be managed – meaning there is plenty to gain from the safe and efficient use of dissolution to reduce waste volumes by 97%."

A contract will be awarded later this year to build a dissolution facility at Bradwell, with the three remaining sites expected to update their plans over the coming months.

• More information on dissolving waste