US to trial pioneering deep-hole nuclear waste disposal technique

The technique, developed in the UK by researchers at the University of Sheffield, involves drilling a borehole around 0.6 metres wide and five kilometres deep, and lowering the waste into it.

Known as deep borehole disposal (DBD), the technique is much cheaper than the mined repository proposed by the UK government for burying the country’s nuclear waste, according to its pioneer Fergus Gibb, emeritus professor of petrology and geochemistry at the University of Sheffield.

Each borehole would cost a few tens of millions of dollars to drill, compared to hundreds of millions to tens of billions for a mined repository. Around six boreholes would be enough to store all of the UK’s existing high level waste, said Gibb, with each taking less than five years to drill, fill and seal.

Deep borehole disposal should also be safer than a mined repository, which at 500 metres deep would still be within the zone of circulating ground water, meaning any leakage caused by an earthquake, for example, could potentially return to the surface, he said.