Events / Features

Siting a geological disposal facility for our radioactive waste

At our February 2019 Public Lecture, Jonathan Turner from Radioactive Waste Management, introduced us to one of the UK’s largest planned environmental projects: a Geological Disposal Facility (GDF) for our radioactive waste.

The UK has been generating radioactive waste since the birth of the nuclear power industry in the 1950s. As it stands, we have generated around 750,000 m3, which is stored at or near the surface between 35 sites across the UK (see map below).

UK Radwaste Sites Map

Image: Map of UK nuclear sites and their uses. RWM, 2018.

Less than ten percent of this waste is highly radioactive, typically produced by the processing of nuclear fuel, and must be managed to minimise the risk of exposure or external interference at the surface.

Following an independent review of the management options available by the Committee on Radioactive Waste Management in 2003, geological disposal was deemed the safest management option for this waste, and the planning for a UK facility commenced. A GDF offers an isolated, contained, and passive disposal environment, maintaining safe separation between the waste and the surface environment.

A GDF will dispose of radioactive waste 200 – 1000m underground. Waste will be packaged into secure, highly-engineered containers and emplaced underground to allow the waste to decay naturally over time. The facility will have a surface footprint of about 1 – 2 km2 and a subsurface footprint of 20 km3 (see example image below).

GDF schematic

Image: A schematic representative of what a geological disposal facility might look like above, and below ground, annotated to scale. RWM, 2018.

Take a trip underground to see what a GDF might look like here.

Radioactive Waste Management are currently searching for a willing community to host a GDF in the UK. They have conducted a National Geological Screening (NGS) in tandem with the British Geological Survey to determine nationwide geological suitability for such a project. The geological screening categorises the subsurface by the following five categories:

  1. Rock type (strength, permeability, presence and frequency of fractures)
  2. Structure (complexity of overall structure)
  3. Natural processes (likelihood of impacts from glaciation, climate change, seismicity, etc.)
  4. Groundwater (presence, speed of movement, vertical segregation of systems)
  5. Past use (e.g. mining, drilling, oil and gas exploration, etc.)

These categories can provide an indication of an area’s suitability towards hosting a site and will be integral to the initial stages of siting a GDF. The results of the NGS have been summarised in regional documents and can be viewed online here.

Once a suitable site has been chosen, RWM will develop detailed site-specific models of the geological, hydrogeological, geochemical, mechanical, and thermal properties, creating the most detailed sub-surface description of anywhere in the UK.

It is a priority to ensure the safety of a GDF – as Jonathan emphasised in his lecture “if it is not safe, it will not be built”. RWM have researched many examples from other countries where sub-surface geological disposal is taking place effectively, such as in France, Sweden and in the USA, as well as natural examples of geological isolation of radioactive material such as at Cigar Lake, in Canada (see below), which provide confidence in the long-term safety of this type of disposal.

cigar lake example.png

Image: Comparison between the components of Cigar Lake natural uranium deposit and a designed geological disposal facility. Source: Geological Disposal Generic Environmental Safety Case, NDA, 2010.

The siting process is ongoing and RWM invite interested parties to get in touch for further information. If you are interested learning more about what hosting a GDF would mean for your community, read the Community Guidance document before getting in touch.

The Geological Society of London will continue to host its long standing Public Lecture Series throughout 2019. These monthly public lectures are free and held at the Geological Society, Burlington House, Piccadilly.  Live webcasts of the lectures are available on the day, and details of how to view can be found on the individual event pages.

Join us for the next Public Lecture on 27th March 2019 where Kate Kiseeva will give a talk entitled ‘Diamond windows into the deep Earth‘.

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