• Search

A revised approach

4 December 2025
Photograph of a pebble beach at dusk

Sizewell nuclear power station in Suffolk, UK (Credit: Zorba the Geek / Sizewell A and Sizewell B beyond/ CC-BY-SA-2.0 / via Wikimedia Commons)

Dear Editors,

Jonathan Turner’s article on nuclear waste disposal (Geoscientist 35 (3), 18-19) raises interesting questions. I have no doubt that we need nuclear power for the future, since it is reliable in a way that wind is not, and we need to deal with the waste that will arise, and with legacy waste too. The UK is making remarkably slow ‘progress’. When I was working on the Nirex project (a body set up by the UK nuclear industry to examine geological disposal of radioactive waste) in the 1990s, the target operation date was 2015 – the year I would retire. I’ve now been retired 10 years, and we are less far forward.

I agree with Dr Turner that the Borrowdale Volcanics near Sellafield are not very promising as a repository host, but the site investigated had the advantage that it is close to Sellafield, where most of the waste for disposal is currently stored. Many criteria must be considered: suitable geology is clearly essential, but transport and other logistics cannot be ignored, and cooperation from the host community is also necessary. The Eocene clays beneath north London might be a possible repository host formation, but I can’t imagine this proving acceptable for many reasons.

the real need is for extremely low rates of groundwater flow

The search for a location could be made easier by taking a different approach to what is a suitable geological environment. The emphasis so far has been on low-permeability formations: evaporites, clays and igneous/metamorphic rocks. But the real need is for extremely low rates of groundwater flow, both to protect the containment materials and to minimise the flux of waste radionuclides into the accessible environment, and confidence that this will continue for the long term.

Long-term persistence of saline water with no support from evaporites is a good indicator of very low groundwater flow, whatever the permeability of the rock. I’m aware of such in the St Bees Sandstone beneath Sellafield (Bath et al., 1996), and at depth in the Chalk of East Anglia, proven at Trunch in Norfolk but probably present under Sizewell in Suffolk (Heathcote, 2024). My own preferred location, on geological grounds, would be near Sizewell in the lower part of the Chalk, which is characterised by very old saline groundwater, an area of likely glacial deposition rather than erosion, and long-term tectonic subsidence. Excavating tunnels in the Chalk beneath the water table is very well understood (e.g. the Channel Tunnel) and it’s not necessary to go very deep.

Local acceptance (not the same as volunteering) remains important, though. I appreciate the concept of ‘acceptance’, since where I live now in Scotland, a great deal of renewables electricity infrastructure is being foisted on us to meet needs in England, and it is meeting much opposition from host communities.

Dr John Heathcote MA PhD CGeol FGS

Director at John Heathcote Consulting Ltd.

Further reading

Related articles