Borehole system could seal radioactive waste deep underground

A new ‘cutting edge’ system designed to seal deep boreholes with a low-permeability material is being tested, ahead of plans for an underground disposal facility for UK radioactive waste.

Engineers, scientists and geologists from Radioactive Waste Management (RWM) have worked with Jacobs on a £5m research project to develop the new system. Known as the Downhole Placement System, it will be lowered from a 25m rig to seal boreholes at depth.

A full-scale demonstration is first taking place at a Nuclear Decommissioning Authority site in Harwell, Oxfordshire, where there are existing boreholes up to 400m deep, originally drilled in the 1980s. After that test, the DPS will demonstrate its capabilities in higher-strength rock in Cornwall.

The system will seal the boreholes with bentonite, which has very low permeability. Waste could be stored up to 1km below the surface, to keep it safe for hundreds of thousands of years.

RWM is responsible for identifying a suitable site for a geological disposal facility in England or Wales. A site has not yet been selected, and the process depends on seeking consent from the local community.

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