Hydromechanical and Biogeochemical Processes in Fractured Rock Masses in the Vicinity of a Geological Disposal Facility for Radioactive Waste

The main goal of this project is to build up expertise and capability in modelling hydromechanical and biogeochemical processes that occur in fractured rock masses in the vicinity of a geological disposal facility for radioactive waste. A consortium of three UK universities will carry out the research, with the expectation of creating durable teams that will continue to collaborate in the future on other radioactive waste projects. The project will bring together researchers with extensive experience in radioactive waste research, as well as others who will bring in key expertise and technologies that were developed in other research fields, such as mining, petroleum engineering, geophysics, or biogeochemistry but are now key to tackling the interdisciplinary problems involved in nuclear waste. The project will also benefit form interactions with leading researchers worldwide, as well as international facilities such as the underground research lab at Grimsel, Switzerland.

The overall project comprises six work packages. Work Package 1 will develop improved methods for estimating the repository-scale hydraulic conductivity of a fractured rock mass, based on geologically realistic fracture network geometries. Work Package 2 will explore and evaluate suitable seismic monitoring strategies, and develop data processing techniques, for the characterisation of potential repository sites. Work Package 3 will examine the key seismic attributes for identifying fracture properties (e.g., fracture density, orientation and stiffness) that play a critical role in repository performance. Work Package 4 will develop coupled thermo-hydro-mechanical models for the behaviour of fractured rock masses. Work Package 5 will model colloid and tracer transport experiments that have been conducted at the Grimsel test site in Switzerland. Work Package 6 will test the importance of biogeochemical processes involving microbes and natural organic matter on actinide mobility in the near-field environment of a nuclear waste repository.

The six work packages are complementary, but are linked to each other in some cases through shared data between, overlapping supervision of PhD students, etc., as described in more detail below. Overall, the project addresses two scientific areas prioritised in the RATE call: Technological innovation for rock mass characterisation at a range of spatial scales, and Biogeochemical coupling, including deep multiphase transport processes. The project involves three UK universities (Imperial College, University of Birmingham, University of Leeds), as well as collaborators from several institutions in the US and Europe.

The main outcomes of this project will be a set of new and/or improved methodologies, codes and protocols for analysing various processes that occur during the lifetime of a repository, or during the site characterisation phase. These methods and tools will be sufficiently flexible and generic to be used in any fractured geological formation that might be investigated as a potential location of a geological repository in the UK. The results and findings of this project will be published in peer-reviewed journals, and presented at appropriate national and international scientific conferences and workshops. Throughout the project, close contact will be maintained, through frequent meetings and visits, with the Nuclear Decommissioning Authority, which is the governmental agency responsible for the safe disposal of nuclear waste.

The main aim of this consortium is to aid in the capacity building and technology delivery of nuclear storage within the UK, with emphasis on hydromechanics and biogeochemical processes. Thus, it is crucial that the developed knowledge and new technology be made accessible to industry and government. To facilitate this, we will engage with those industries currently working on radioactive waste storage, by making in-house presentations, providing access to white papers and research results, fostering collaboration within and across business sectors, and convening workshops.

The consortium will engage directly with government organisations (e.g., DECC) early on and throughout the project, to identify and define what information is required for policy and regulation, and work with these organisations to help shape new policy and regulations. The outputs of this study will be of direct and lasting benefit to a wide community of regulatory bodies such as EA, SEPA, HSE, FSA, research councils including EPSRC and BBSRC, and NERC Centres including BGS, CEH, and advisory groups such as CoRWM, COMARE, and HPA.

A more comprehensive understanding of hydro-mechanical and biogeochemical processes, and the ability to model these accurately, will be of interest to all the above-listed groups of end-users, because both are fundamental to the safe storage of radioactive waste. Any future accidents and leakage of radioactive contaminants in the groundwater may have a fundamental impact on natural resources, the economy, the standard of living, and the environment.

Societal impact will furthermore be achieved through the numerous collaborations in which the consortium members are involved. The codes that are developed and deployed by the groups will not only be used for studies of nuclear safety, but also for general research into fluid flow, microbes-metal interactions, and rock mechanics. Hence, our methods will have a direct impact in research fields that go far beyond the classical applications of radioactive waste science.

Conferences and Papers: The various research groups will present results every year on key conferences in their fields (e.g., American and British Chemical Society, International Society for Rock Mechanics, etc.) and deliver seminars at academic institutions. We aim to organise special sessions within these conferences. We aim to write comprehensive review articles during the consortium period, to be submitted to high-impact journals, preferably Nature and Science.

Public Outreach: To reach the general public, we will give Nature Live talks at the Natural History Museum (www.nhm.ac.uk/nature-live). We plan to participate in science fairs (Imperial College London and the Royal Society). Via the Imperial Volunteering Centre, we will visit secondary schools in England, and educate high schools about the problems associated with radioactive waste. To reach the wider adult public, we will - in collaboration with the NHM publishing team - create a public science book on the topic Nuclear Waste.

Press and Internet Presence: A primary mechanism of dissemination, throughout the project and beyond, will be through websites. We will use the Imperial Science Press to communicate to the public via the Internet and i-Tunes U.

Scholarship: We plan to incorporate undergraduate students into the project by offering defined MSci projects.

Workshop: We plan to organise two scientific workshops. The theme of the first one will be entitled 'The Hydromechanics of Nuclear Waste in the Near Field' in year 3 and 'The Biogeochemistry of a Nuclear Waste in the Near Field' in year 4. We will invite the various research groups working in the respective research areas and in special nuclear research programs in the United Kingdom (e.g., EPSRC-sponsored Diamond) or Europe (e.g., Euratom) as well as key stakeholders in industry and public service (i.e., Environmental Agency, NDA, Defra).