Nuclear Waste Services (NWS) has been carrying out studies to understand the geology of the Theddlethorpe area to see whether it is suitable to host a Geological Disposal Facility (GDF).
Here they explain the local geology and the work carried out so far.
Rock formed over 150 million years ago
The rock formation of interest is called the Ancholme Group which is Upper Jurassic aged and formed over 150 million years ago. It was formed from sediments that have been deeply buried for a long period of time, under great pressure, turning them into rock.
Why the rock might be suitable
These types of rocks have several key features which make them potentially suitable for hosting a GDF. One of these is that they have very low permeability, and this means they can act as a highly effective natural barrier to the flow of liquid. The Ancholme Group is very similar to the rocks that are being considered to host GDFs in France and Switzerland.
Large data gathering exercise
In the UK, geological data has been collected over many decades, to support industries including oil, gas and mineral exploration, construction, tunnelling, and mining.
Data from these past activities including seismic surveys and boreholes are stored in national archives such as the National Data Repository, the UK Onshore Geophysical Library, and the National Geological Repository. Over the last two years NWS has undertaken a large data gathering activity and has obtained the following.
- over 200 historical borehole records
- more than 4,000 line kilometres of 2D seismic data
- approximately 350 square kilometres of 3D seismic data
Each of these items has been carefully checked for quality, before being included into the NWS geological database. Much of this data has required additional work to be undertaken on them to bring them up to a suitable standard and quality.
NWS has used these data items to develop an understanding of the subsurface and they are being used to support initial engineering and safety case feasibility studies.
Further information about the geology will be made available by NWS.
Read about the work involved in the siting process to find a suitable site for a GDF