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

Lead Research Organisation: University of Birmingham
Department Name: Sch of Geography, Earth & Env Sciences

Abstract

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.

Planned Impact

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).
 
Description We have successfully developed a suite of equations to model colloid migration and attached radionuclide transport, using the general purpose COMSOL finite element equation solver package. These have been successfully applied to simulate colloid migration experiments at the Grimsel Test Site Underground research Laboratory in Switzerland. For the first time we are representing the radionuclide and colloid transport in the two dimensional flow field of two different dipole experiments in a simple fault zone intersection the laboratory tunnels. Common properties characteristic of the hydrogeological and geochemical setting were infered. However, the simulations require many uncertain input parameters posing a challenge to site characterisation. The work is being used to design further experiments to investigate colloid rock interaction models which currently involve parameters that have not been measured directly. A futrther challenge is to understand the role of the pore structure in the fault zone which whilst it is simple geologically, nevertheless incorporates a very complex small scale structure that has had to be simplified for radionuclide migration modelling. These simplifications mean we need to calibrate effective properties and reduces the predictive power of the models. Ongoing work has attempted to directly observe the pore structure of small scale stabilised rock samples cored from the fault zone using X-ray tomography.
This has been followed by demonstration projects undertaken by MSc students to investigate lab scale colloid migration through an artificial fracture and characterisation of a small sample taken from Grimsel Test Site URL. Additional MSc projects following up these investigations are being offered to current MSc students adn a DREAM PhD project (Lauren Dackombe) will repeat the colloid migration experiments making use of well characterised Bentonite colloid sample to investigate evolution of colloid properties during migration.
Exploitation Route The results from our developing understanding at Grimsel, Switzerland could now be extended to the more complex geochemical environment more typical of UK or Korean deep hydrogeological settings that might be considered for hosting a deep Geological Disposal Facility for radioactive waste disposal.
Sectors Energy,Environment

 
Description The research team have left academia and are now working in industry in hydrogeology and radioactive waste management. Dr Kenney work in radioactive waste management with Wood Group plc, a major contractor in the nuclear energy sector. Dr Harvey completed his PhD and is employed by Stantec plc working in hydrogeology for the environmental sector. Dr Herbert has founded Leaton Hydrogeology Limited and works mostly in radioactive waste management as a subcontractor to the UK and Swiss nuclear industries drawing directly on the experience and research of this award. He continues to be engaged in the Grimsel URL and other projects for Nagra. He has developed flexible numerical tools to continue research in the field of coupled processes relevant to the management of radioactive waste and is currently tenering for future projects in the UK and Europe
First Year Of Impact 2018
Sector Energy,Environment
Impact Types Economic,Policy & public services

 
Title COMSOL Colloid migration equations 
Description Development of a suite of equation libraries for coupled colloid and radionuclide migration. 
Type Of Material Computer model/algorithm 
Provided To Others? No  
Impact The suite of equations enables conceptual models of colloid and radionuclide migration processes to be simulated and to be validated by comparison with experiment in the NAGRA Grimsel Test Site (GTS). Our modelling tools are feeding into the experiment design for future experiments at the GTS. It is proposed to offer to share these models with KAERI in future collaboration 
 
Description X-ray tomography of fault zone rock sample 
Organisation Diamond Light Source
Country United Kingdom 
Sector Private 
PI Contribution Ben Harvey (attached PhD student) interpreted x-ray tomography of a small (30cm scale) stabilised sample from the GTS Fault zone used in the project dipole radionuclide migration tracer and colloid migration experiments. This was used to prepare a proposal (unsuccessful at this stage) for more detailed synchrotron x-ray tomography on Diamond beam I12. Preliminary analysis is informing our understanding of the pore structure through which the colloid migration experiments are conducted.
Collaborator Contribution NAGRA provided a rock sample carefully cored from the Fault zone used in the CFM programme, stabilised using resin injection and overcoring. We collaborated with University of Manchester to prepare preliminary x-ray tomographic imaging of the pore space of the fault zone at the 100um-10cm scale. UoM and Diamond provided training to Ben Harvey (attached PhD student ) in image analysis for the sample tomography.
Impact Preliminary analysis is informing our understanding of the pre structure through which the colloid migration experiments are conducted. Presented at the NAGRA CFM Modellers meeting in San Francisco Dec 2015 In discussion with UoM regarding further X-ray tomography whilst I12 Beam is offline due to wiggler failure.
Start Year 2015
 
Description X-ray tomography of fault zone rock sample 
Organisation National Centre for the Replacement, Refinement and Reduction of Animals in Research (NC3Rs)
Country United Kingdom 
Sector Charity/Non Profit 
PI Contribution Ben Harvey (attached PhD student) interpreted x-ray tomography of a small (30cm scale) stabilised sample from the GTS Fault zone used in the project dipole radionuclide migration tracer and colloid migration experiments. This was used to prepare a proposal (unsuccessful at this stage) for more detailed synchrotron x-ray tomography on Diamond beam I12. Preliminary analysis is informing our understanding of the pore structure through which the colloid migration experiments are conducted.
Collaborator Contribution NAGRA provided a rock sample carefully cored from the Fault zone used in the CFM programme, stabilised using resin injection and overcoring. We collaborated with University of Manchester to prepare preliminary x-ray tomographic imaging of the pore space of the fault zone at the 100um-10cm scale. UoM and Diamond provided training to Ben Harvey (attached PhD student ) in image analysis for the sample tomography.
Impact Preliminary analysis is informing our understanding of the pre structure through which the colloid migration experiments are conducted. Presented at the NAGRA CFM Modellers meeting in San Francisco Dec 2015 In discussion with UoM regarding further X-ray tomography whilst I12 Beam is offline due to wiggler failure.
Start Year 2015
 
Description X-ray tomography of fault zone rock sample 
Organisation University of Manchester
Country United Kingdom 
Sector Academic/University 
PI Contribution Ben Harvey (attached PhD student) interpreted x-ray tomography of a small (30cm scale) stabilised sample from the GTS Fault zone used in the project dipole radionuclide migration tracer and colloid migration experiments. This was used to prepare a proposal (unsuccessful at this stage) for more detailed synchrotron x-ray tomography on Diamond beam I12. Preliminary analysis is informing our understanding of the pore structure through which the colloid migration experiments are conducted.
Collaborator Contribution NAGRA provided a rock sample carefully cored from the Fault zone used in the CFM programme, stabilised using resin injection and overcoring. We collaborated with University of Manchester to prepare preliminary x-ray tomographic imaging of the pore space of the fault zone at the 100um-10cm scale. UoM and Diamond provided training to Ben Harvey (attached PhD student ) in image analysis for the sample tomography.
Impact Preliminary analysis is informing our understanding of the pre structure through which the colloid migration experiments are conducted. Presented at the NAGRA CFM Modellers meeting in San Francisco Dec 2015 In discussion with UoM regarding further X-ray tomography whilst I12 Beam is offline due to wiggler failure.
Start Year 2015
 
Description AGU Chapman Conference 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact L McMillan presented Inverse flow and transport modelling to understand contaminant transport experiments in a highly heterogeneous shear zone at the Grimsel Test Site in Switzerland, Lindsay A Mcmillan, Alan W Herbert and Michael S Riley, University of Birmingham, School of Geography, Earth and Environmental Sciences, Birmingham, United Kingdom at the AGU Chapman Conference 'The MADE Challenge for Groundwater Transport in Highly Heterogeneous Aquifers: Insights from 30 Years of Modeling and Characterization at the Field Scale and Promising Future Directions' Valencia Oct 2015
Year(s) Of Engagement Activity 2015
 
Description Attend CFM Partner meeting at Kahlsruhe Institute of Technology 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Attended CFM NAGRA International collaboration Partner meeting to help define forward programme and represent the interests of RWM on behalf of UK
Year(s) Of Engagement Activity 2016
 
Description CFM Modellers Meeting 2014 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? Yes
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Meeting resulted in forward plan for the CFM project and HYDROFRAME involvement. Initiated discussion on new experimental programme within the project for 2015

Led to collaboration with KAERI and preparation of a submission to EPSRC UK-Republic of Korea Civil Nuclear Research Programme call.
Year(s) Of Engagement Activity 2014
 
Description Display presentation on geological settings for radioactive waste disposal 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Policymakers/politicians
Results and Impact A display of geological samples presenting stable geological settings for radioactive waste disposal. The display was intended to inform debate to other members of the RATE programme and attendees to the RATE Final meeting including NERC, RWM, and Government, together with researchers from other RATE consortia
Year(s) Of Engagement Activity 2018
 
Description GSL Early Career Hydrogeologists Meeting 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Postgraduate students
Results and Impact Poster presentation at the Geological Society Early Career Hydrogeologists' conference titled: 'Developing models for coupled colloid-radionuclide transport in the deep geological disposal of radioactive waste in fractured granite'. This poster won the prize for best poster at the conference. The poster sparked interesting discussion about modelling for radioactive waste disposal.
Year(s) Of Engagement Activity 2015
 
Description NAGRA CFM Modellers meeting San Francisco 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Industry/Business
Results and Impact Ben Harvey and Lindsay McMillan presented progress developing and applying models to predict the outcome of radionuclide migration experiments in the Swiss national Underground Research Laboratory at Grimsel (GTS). The workshop evaluated progress in predicting colloid migration and the implications for a Geological Disposal Facility, and planned the design of future research tasks at the URL
Year(s) Of Engagement Activity 2015
 
Description NERC RATE - LORISE meeting at Loughborough University 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Postgraduate students
Results and Impact Ben Harvey (attached PhD student) presented poster 'Model development of coupled colloid-radionuclide migration in fractured granite for deep geological disposal of radioactive waste'.
Year(s) Of Engagement Activity 2015
 
Description News Article for RWM Ltd/NDA 
Form Of Engagement Activity A magazine, newsletter or online publication
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Industry/Business
Results and Impact A non technical summary of progress in this project was presented for the RWM news magazine
Year(s) Of Engagement Activity 2015
 
Description Presentation to CFM Partner Meeting 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Study participants or study members
Results and Impact Gave a presentation to the international CFM Partner Meeting in Tokyo, Japan in May 2017. The presentation was titled: "Modelling Colloid Facilitated Radionuclide Transport Experiments" and gave an update on modelling work, including some predictions of an experiment to help with experimental design.
Year(s) Of Engagement Activity 2017
 
Description Presentation to ESI Ltd 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Industry/Business
Results and Impact Ben Harvey presented invited seminar to leading hydrogeology specialist consultancy company ESI Ltd titled 'Modelling Bentonite colloid migration experiments using COMSOL Multiphysics'. This lead increased interest on the research within the company.
Year(s) Of Engagement Activity 2015
 
Description Presentation to Groundwater- our hidden assest. Geological Society of London/IAH joint meeting Birmingham 2016 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact Presentation on inverse modelling complex flow systems in very heterogeneous fault zones structures. It was shown that the small scale heterogeneity at scales below the resolution of modelling can affect the correlation between flow and transport effective apertures within the fault zone. Once these are accounted for, the relationship between flow and transport properties, described in terms of multiple parallel flow conduits, is reconciled with observations, and allowing the results to be seen as consistent with the conceptual model. These are then taken forward to model colloid and radionuclide migration through the fault zone.
Year(s) Of Engagement Activity 2016
 
Description Presentation to RATE Final Meeting 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Gave a presentation and poster to the NERC RATE final meeting in London, January 2018. The presentation was titled "Modelling the processes behind field colloid-facilitated radionuclide migration", and the poster was titled "Characterising the hydrogeology of a deep underground research laboratory in fractured hard rocks"
Year(s) Of Engagement Activity 2018
 
Description Presentations at American Nuclear Society IHLRWM Conference 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Gave a presentation to the American Nuclear Society International High Level Radioactive Waste Management conference in Charlotte, NC in April 2017, presenting a paper titled "Modelling Colloid-Facilitated Americium Transport at Grimsel Test Site, Switzerland". I also appeared on a student panel in a special session on radioactive waste disposal.
Year(s) Of Engagement Activity 2017
URL http://ihlrwm.ans.org/
 
Description RATE summer school and NAGRA field trip 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Postgraduate students
Results and Impact Presentation to summer school on the role of an Underground Research Laboratory in developing the case for disposal of radioactive waste, followed by field trip to NAGRA researchg site at the Grimsel Test Site organised by this project
Year(s) Of Engagement Activity 2016
 
Description Slides for Natural History Museum NatureLive Talk by Imperial College London 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Public/other audiences
Results and Impact Provided some slides for Prof. Weiss from Imperial College London for his NatureLive talk at the Natural History Museum, which detailed the research as part of the main talk which detailed the research of the HydroFrame consortium, which was delivered to members of the public in February 2017 and was titled 'Managing Radioactive Waste Safely'.
Year(s) Of Engagement Activity 2017