The Project: GeoSafe
One of the rock types that has been identified as a potentially suitable host rock for the location of a GDF are lower-strength sedimentary rocks, known as LSSRs. Siting and construction of a GDF in LSSR will require the development of a quantitative understanding of the physical and biogeochemical properties of the host rocks surrounding the GDF. However, many fundamental gaps still exist in our knowledge of the issues related to the performance of these host rocks as a geological barrier to the transport and migration of radionuclides, which are radioactive forms of elements such as Uranium or Plutonium. Overall, there are key knowledge gaps in three Challenge Areas: geological isolation of the waste, potential contaminant pathways for radioactivity to escape into the biosphere, and new advances in mathematical modelling of the relevant processes. To address these Challenges, we have assembled a multidisciplinary consortium composed of over twenty scientists at seven UK universities and research institutes, many of whom have extensive experience and expertise in various areas related to radioactive waste disposal, and/or in closely related areas of subsurface science and engineering. In addition to these investigators, seven PhD students will be funded by the participating institutions, to further support the objectives of this project. As the ultimate goal of this work is the safe geological disposal of radioactive waste, we have named our project “GeoSafe”.
The GeoSafe research consortium will carry out innovative research that will investigate fundamental behaviour of LSSRs in the context of the three Challenges. We will measure mechanical properties of LSSRs, as well as flow and transport properties of liquids, gases, and radionuclides within LSSR rocks, over a range of time and length scales, with an emphasis on quantifying the effects of heterogeneities such as sedimentary architecture, bedding, laminations, inclusions, and fractures. We will use cutting edge multi-scale imaging techniques, and novel experimental techniques for coupled measurements, that will reconstruct properties of the rocks of interest across scales. We will investigate the effects that chemical and biological changes in LSSR rocks will have on the rock’s permeability and dispersivity, conducting novel radionuclide diffusion and advection experiments paired with dynamic multi-scale imaging. GeoSafe will investigate the effects of possible existing fractures, quantifying whether these are likely to seal, and what their effect on transport may be if they remain open. Numerical simulations will be performed to assess flow and transport of liquids and gases through the rock, as well as reactive radionuclide transport, within the vicinity and in the surrounding region of the GDF. Taken as a whole, GeoSafe will produce and synthesise a unique set of data, and develop state of the art experimental and computational tools and methods, which will be essential in understanding the fundamental behaviour of lower-strength sedimentary rocks in the context of evaluating the performance of a UK Geological Disposal Facility.
Throughout the project, we will work with the NWS-RSO and NWS to ensure that outputs are delivered that underpin the safety case, e.g., developing new claims/arguments and/or providing additional evidence to support claims/arguments. These will be delivered via in-person/virtual secondments of PhDs/PDRAs from each WP, facilitated by the RSO. In addition, a GeoSafe report reviewing impact related to the GDF programme will be developed in Year 4. In particular, we aim to deliver at least ten entries to the ViSI database, in support of the GDF safety case.
Budget: Total budget for this project is £5 million, co-funded by the Natural Environment Research Council (£2M), Nuclear Waste Services (£2M), and the participating institutions (£1M total).
GeoSafe Project 