Funded PhD research projects

Applications are invited from candidates interested in an RWM sponsored PhD project.

As an RWM RSO student you will be conducting world leading, high quality, and relevant research to underpin the RWM geological disposal programme.  Your PhD research will address gaps and uncertainties relevant to the design and development of a Geological Disposal Facility (GDF), potentially the most significant environmental infrastructure project in the UK. Throughout your research project you will be supported by the RWM RSO with professional networking opportunities, support to publish your work and opportunities to present at relevant conferences. If you want to undertake impactful research, consider one of the fully funded PhD projects below. More research projects will be added to this page regularly as funding becomes available. Sign up to our newsletter to be kept up to date.

PhD projects starting in 2021 mark the first cohort of RWM RSO research students. The RWM RSO will offer additional training and support, as well as access to a network of researchers working on all aspects of geological disposal.

If you are interested in one of the fully funded PhD projects below, please get in touch with the supervisor for more information on how to apply.

Advanced characterisation of hydrothermally aged cement

Title: Advanced characterisation of hydrothermally aged cement (10 years old) – Improving the safety case for deep geological disposal of radioactive waste

Description: Nuclear energy provides almost a fifth of the UK’s electricity, generating waste that needs to be managed for safe, long term storage. While most radioactive waste comes from the generation of electricity it is also a by-product of many medical and industrial processes, research and defense activities that make use of radioactivity and radioactive materials. In a Geological Disposal Facility (GDF), higher-activity waste is stored hundreds of metres deep underground and GDF is internationally recognised as the safest long-term solution for this type of waste. There is strong interest in understanding how the cement grout used to contain waste interacts with the backfill cement (called Nirex reference vault backfill) used to stabilise waste containers in the GDF. This project investigates rare, aged samples to determine how microstructural and physical characteristics of the Nirex reference vault backfill (NRVB): Portland cement grout interface will alter over time-scales applicable to deep geological disposal facilities. This project will use a combination of 2D X-ray diffraction and scattering, 3D/2D imaging and supporting analytical measurements to determine how the cements microstructure and porosity/permeability have developed over 10 years of hydrothermal ageing. Beamtime at Diamond Light Source, a national synchrotron facility, will be applied for to access a new small angle X-ray scattering technique called SAXS-Tensor Tomography for high resolution information on the microstructural changes. The results from this project will inform on further (future) work on radionuclide retention and reactive transport in NRVB, which requires a thorough understanding of porosity/permeability (and mineralogy) to support numerical/predictive models on radionuclide mobility. Funded by Radioactive Waste Management (RWM), this project will directly inform on improving and developing the safety case for deep geological disposal of radioactive waste.

 

Institution: The University of Strathclyde

Supervisor(s): Dr Andrea Hamilton, Dr Pieter Bots, Dr Katherine Dobson, Dr Paul Edwards

Sponsor(s): Radioactive Waste Management Ltd

Alteration of vitrified radioactive waste in low temperature natural environments

Title: Alteration of vitrified radioactive waste in low temperature natural environments: a natural analogue approach

Description: The PhD project focuses on determining the long-term (>10,000 yrs) behaviour of nuclear waste glass within a geological disposal facility. The project will utilize ‘natural analogue experiments’, where glasses have been exposed to natural environments with conditions of relevance to radioactive waste disposal for tens to hundreds of years. A key outcome will be to compare glass alteration in these complex low temperature environments, with alteration observed in high temperature, laboratory dissolution tests. The PhD will work towards a detailed mechanistic understanding of glass durability in complex environments taking into account of how groundwater composition, adjacent mineralogy and microbiology affect the glass corrosion process. The successful applicant will work in the Immobilisation Science Laboratory at the University of Sheffield, a world-leaching centre for nuclear waste research, alongside 45 other PhD students. You will have access to the brand new £2M suite of dedicated radiation-controlled laboratory facilities and will have the opportunity to perform experiments using state-of-the-art facilities at the University and worldwide (e.g. Diamond light source, UK; PNNL, USA).

We are seeking an enthusiastic, motivated individual who wishes to learn about radioactive waste management in the UK with a desire to help influence government policy on nuclear waste disposal. We are offering an opportunity for a 4 year, fully-funded PhD sponsored by Radioactive Waste Management Ltd and conducted within the world-leading Immobilisation Science Laboratory in the Department of Materials Science and Engineering.

This project would suit a candidate with a 1st or 2:1 Bachelor or Masters degree in any of the following: materials science, chemistry, chemical engineering, physics, geology or related subjects. To be eligible for a studentship, you must be a U.K. citizen.

Note that the application may be closed prior to the stated date if a suitable candidate is found.

Institution: The University of Sheffield

Supervisor(s): Dr Clare Thorpe

Sponsor(s): Radioactive Waste Management Ltd and the University of Sheffield

Analysis of microseismic data to inform the siting, construction and operation of a geological disposal facility in the UK

Title: Analysis of microseismic data to inform the siting, construction and operation of a geological disposal facility in the UK

Description: A fully-funded 4-year industrial CASE PhD studentship is offered by the Department of Civil and Environmental Engineering at the University of Strathclyde, Glasgow and RWM Ltd., a public organisation established by government and responsible for planning and delivering geological disposal in the UK.

This PhD aims to develop a tool for automated analysis of microseismic events (very tiny earthquakes so small they can’t be felt at the surface) to be used as part of the UK siting process for a geological disposal facility (GDF) for nuclear waste. The UK launched its GDF siting programme in 2020 and, to-date, RWM are consulting with two volunteer communities about the potential for hosting a GDF at their locations. One important criterion for deciding on the preferred location for a GDF will be the local geology.

Microseismic events can help us understand the locations of geological structures in the ground, without the need to drill large numbers of boreholes. Events occur naturally at construction depths for a GDF (200 m to 1 km below ground) and can also be induced by man-made activities during site investigation and construction. Each event corresponds to a rock fracturing, and hence, provides information on open fracture pathways for groundwater flow.

The research challenges in analyzing microseismic data are (1) the difficulty in detecting, locating in 3D, and then analyzing the properties of these very tiny events amongst the background noise and (2) the sheer quantity of data caused by the high sampling frequency (> 500 Hz) which necessitates full automation of all analyses. This PhD will address these challenges and develop a reliable software tool for use in the site investigation and construction phases of a Geological Disposal Facility (GDF). One further use for such a tool is that the frequency of tiny events at any location is related to the likelihood of larger events, thus the PhD will support larger earthquake prediction and seismic hazard assessment, feeding back into GDF design.

Candidate Profile: We are looking for candidates to apply with a background in applied mathematics/physics/computer science/engineering, or related disciplines. Ideally they will have strong computational skills and computer programming experience. Some knowledge of signal processing/Spectral Analysis (e.g. Fourier transforms) is desirable, but not essential. Candidates should have, or be expected to achieve, a Bachelors degree (2:1 or above). Masters students or those with practical experience in research or industry are also encouraged to apply. The successful candidate will benefit from both academic and industrial training (with RWM) and have the opportunity to join the Postgraduate Certificate in Researcher Professional Development (PG Cert RPD) at Strathclyde. The candidate will also gain industrial work experience through a funded 3-month secondment to RWM Ltd, based in Oxfordshire, as part of their PhD programme.

Eligibility: To be eligible for a full award (stipend and fees) applicants must have:

  • Settled status in the UK, meaning they have no restrictions on how long they can stay and
  • Been ‘ordinarily resident’ in the UK for 3 years prior to April 2021. This means they must have been normally residing in the UK (apart from temporary or occasional absences AND
  • Not been residing in the UK wholly or mainly for the purpose of full-time education (This does not apply to UK nationals).

(See: https://epsrc.ukri.org/skills/students/help/eligibility/ for more details)

  • In addition to the EPSRC requirements, please also see https://www.strath.ac.uk/studywithus/postgraduateresearch/yourapplicationoffer/ for entry requirements at Strathclyde University.
  • Full Time programme only
  • Applicant required to start by October 2021.
  • This Studentship will cover tuition fees at the UK rate and provide a generous, tax-free annual stipend (Currently set as £18,667 for 2021/22) for 4 years. In addition to the fees and stipend, a total of £38,000 is available for other research expenses such as conference participation, a workstation, other consumables, and travel and subsistence expenses incurred during the secondment to RWM Ltd.
  • If English is not your first language you will require a valid English certificate equivalent to IELTS 6.5+ overall with a minimum score of 6.0 in Writing and 5.5 in all sections (Reading, Listening, Speaking).

Outstanding applicants that do not meet the above eligibility criteria will be eligible for full fees and a partial stipend.

For informal enquiries about this position, please contact Prof Rebecca Lunn (rebecca.lunn@strath.ac.uk), or Dr Stella Pytharouli (stella.pytharouli@strath.ac.uk)

 Application Method: To apply for this studentship please follow the instructions detailed on the following webpage:

http://www.strath.ac.uk/admissions/postgraduateresearch/

Applications should be received by Friday 16th April, 2021.

Please be sure to include a reference to ‘2021 EPSRC iCASE CIV-RWM’ to associate your application with this studentship opportunity.

Institution: The University of Strathclyde

Supervisor(s): Professor Rebecca Lunn and Dr Stella Pytharouli

Sponsor(s): Radioactive Waste Management Ltd and EPSRC

Effect of high temperatures on cement backfill (NRVB)

Title: Effect of high temperatures on cement backfill (NRVB) – Improving the safety case for deep geological disposal of radioactive waste

Description: Nuclear energy provides almost a fifth of the UK’s electricity, generating waste that needs to be managed for safe, long term storage. While most of this waste comes from the generation of electricity, it is also a by-product of many medical and industrial processes, research and defense activities that make use of radioactivity and radioactive materials. In a Geological Disposal Facility (GDF), higher-activity waste is stored hundreds of metres deep underground and GDF is internationally recognised as the safest long-term solution for this type of waste. This project focuses on understanding the long term chemical alteration and stability of a cement (NRVB) backfill material used in GDF, at the temperatures reached in the facility. This is important to improving and developing the safety case for deep geological disposal of radioactive waste. The information available on performance of NRVB under sustained exposure to elevated temperatures above 100 oC is very limited and deals largely with mechanical and thermal properties. The aim of this project is to understand the mineralogy and permeability evolution of hydrothermally cured NRVB at T=100-150 oC from 1 day to 1 year. Nanoparticulate calcium (aluminium) silicate hydrates (C-S-H/C-A-S-H), the primary hydration products of NRVB cement, can convert to more crystalline phases such as tobermorite, hillebrandite and afwillite during heating, which involves crystallographic restructuring, altering the micro-structure and affecting fluid flow paths. While some experimental studies exist on hydrothermally cured oilwell cements, the extent and implications of these recrystallisation/restructuring processes are largely unknown/unexplored for NRVB. The results from this project will aid further (future) work on radionuclide retention and reactive transport in NRVB, which requires a thorough understanding of mineralogy (and porosity/permeability) to support numerical/predictive models on radionuclide retention. Funded by Radioactive Waste Management, this project will directly inform on improving and developing the safety case for deep geological disposal of radioactive waste.

 

Institution: The University of Strathclyde

Supervisor(s): Dr Andrea Hamilton, Dr Pieter Bots, Dr Katherine Dobson, Dr Paul Edwards

Sponsor(s): Radioactive Waste Management Ltd

Inducing the resumption of alteration in UK radioactive waste glasses

Title: Inducing the resumption of alteration in UK radioactive waste glasses

Description: The dissolution rate of radioactive waste glasses reduces by approximately a factor of one thousand over the first 1 – 28 days of contact with water. This reduction in dissolution rate, to what is known as the residual rate, is associated with a reduction in the thermodynamic driving force for dissolution and the protective effect on the glass surface of the formation of an altered layer that inhibits transport to and from the unaltered glass surface. A phenomenon that is occasionally observed at long time scales in international (and compositionally different) glass formulations is that glass dissolution resumes at rates approaching the initial dissolution rate. The main objectives of the project will be:
• Distinguish between the relative importance of the two effects thought to cause resumption of alteration.
• Determine the mechanism of the resumption of dissolution and its rate with respect to the initial rate and the rate-drop.
• Determine the sensitivity of the process to pH. This is to cover potential scenarios where groundwaters have become highly alkaline through contact with cementitious material in back-fill or ILW vaults.

Institution: University of Cambridge

This project is in collaboration with the Nuclear Energy Futures Centre for Doctoral Training. The successful applicant will be part of this exciting CDT, in addition to the Research Support Office community.

Supervisor(s): Prof Ian Farnan (Camb) and Dr Michelle Cowley (Radioactive Waste Management)

Sponsor(s): EPSRC and Radioactive Waste Management

 

LHGW GDFs in the Circular Economy: Utilising waste rocks as Engineered Barrier System material

Title: LHGW GDFs in the Circular Economy: Utilising waste rocks as Engineered Barrier System material

Description: Nuclear energy supplies approximately 20% of the UK’s energy. While this power is greenhouse-gas free, reactor components and waste materials represent long term radiation hazards. To address this hazard the permanent disposal of wastes is planned in a Geological Disposal Facility (GDF). GDF’s are designed to contain and prevent the release of radionuclides into the environment. Ensuring that GDF components will safely contain radionuclides during long-term disposal is a priority. As a result, understanding the environmental processes, especially the fate and management of produced gases, that could occur over the GDF’s life span, and the implications of those processes on containment is critically important. Both projects focus on gas management from Low Heat Generating Wastes (LHGW). LHGW include intermediate level waste (ILW) arising from the operation and decommissioning of reactors and other nuclear facilities, and a small amount of low level waste (LLW) unsuitable for near surface disposal.

The Engineered Barrier System (EBS) is a key component for GDF safety. The EBS slows the flow of water to limit corrosion, protects the structural integrity of the container, and prevents radionuclides from being released into the environment. The EBS is intended to manage gases that are produced during container corrosion and waste degradation, through providing pore-space to passively control gas release by storage and to limit pressures.

This project explores use of waste rocks from quarries, excavated GDF rocks and re-use of other materials (e.g., concrete waste from NDA sites) for the EBS. Their use as an EBS material would lower the environmental footprint and prevent these materials from filling landfills.

We will assess whether waste rock/bentonite mixtures meet criteria for EBS usage, including mechanical strength, fluid/gas permeability, microbial activity for gas consumption and the long term performance of these re-used materials. 

Candidate Requirements: Minimum entry qualification – an Honours degree at 2:1 or above (or International equivalent) in a relevant science or engineering discipline.

Applications are welcome from students with backgrounds in chemistry, earth and geosciences, civil and environmental engineering, microbiology or other closely related disciplines.

Start date is October 2021.

Institution: The University of Edinburgh

Supervisor(s): Dr Ian Molnar

Sponsor(s): Radioactive Waste Management Ltd

Mechanisms of radionuclide retention in aged cements

Title: Mechanisms of radionuclide retention in aged cements

Description: Radionuclide sorption on potential backfill materials is a topic of continued research and development in geological disposal of intermediate level waste. Prior work has employed hydrothermal ageing to accelerate the chemical evolution of Nirex Reference Vault Backfill (NRVB) and understand the consequent changes in cement mineralogy. To date, limited research into radionuclide interactions with aged cements has been undertaken. This project will focus on a mechanistic study on aged cement phases and radionuclides of importance to the safety case for a Geological Disposal Facility. The successful applicant will focus on understanding the composition of cementitious materials and their aged forms to validate them as representative of aged NRVB. Secondly, the researcher will examine bulk and molecular scale interactions of select radionuclides on their reaction with these phases. Finally, the impact of further ageing on radionuclide speciation and fate will be considered.

Our experimental research programme will exploit the new NNUF Facilities due to open in 2021 including the NNUF RADER Labs hosted within the Research Centre for Radwaste Disposal at the University of Manchester as well as the new Diamond Light Source Active Materials Laboratory and will utilise state-of-the-art STFC facilities which allow for a mechanistic understanding at multiple scales.

Institution: The University of Manchester

This project is in collaboration with the GREEN Centre for Doctoral Training. The successful applicant will be part of this exciting CDT, in addition to the Research Support Office community. 

Supervisor(s): Prof Sam Shaw

Sponsor(s): EPSRC and Radioactive Waste Management Ltd

Microbial Consumption of GDF Gases and Implications for Long-Term GDF Performance

Title: Microbial Consumption of GDF Gases and Implications for Long-Term GDF Performance

Description: Nuclear energy supplies approximately 20% of the UK’s energy. While this power is greenhouse-gas free, reactor components and waste materials represent long term radiation hazards. To address this hazard the permanent disposal of wastes is planned in a Geological Disposal Facility (GDF). GDF’s are designed to contain and prevent the release of radionuclides into the environment. Ensuring that GDF components will safely contain radionuclides during long-term disposal is a priority. As a result, understanding the environmental processes, especially the fate and management of produced gases, that could occur over the GDF’s life span, and the implications of those processes on containment is critically important. Both projects focus on gas management from Low Heat Generating Wastes (LHGW). LHGW include intermediate level waste (ILW) arising from the operation and decommissioning of reactors and other nuclear facilities, and a small amount of low level waste (LLW) unsuitable for near surface disposal.

Gases will be produced during container corrosion and may overpressurize the GDF, but the ultimate fate of GDF gases remains uncertain. This project will investigate the role of microbiological activity in consuming produced gases and its impacts on GDF components to ensure Engineered Barrier System (EBS) performance over the planned lifespan.

Experiments will re-create GDF conditions predicted to be dominant over the one million year safety assessment timeframe, assess how microbial processes are consuming gases, and identify by-products and geochemical reactions from gas consumption. An emphasis of the work will  be testing how these by-products and geochemical reactions impact the performance of each GDF component. Computer modelling will be used to predict the implications of experimental results for long-term GDF performance.

Candidate Requirements: Minimum entry qualification – an Honours degree at 2:1 or above (or International equivalent) in a relevant science or engineering discipline.

Applications are welcome from students with backgrounds in chemistry, earth and geosciences, civil and environmental engineering, microbiology or other closely related disciplines.

Start date is October 2021.

Institution: The University of Edinburgh

Supervisor(s): Dr Ian Molnar

Sponsor(s): Radioactive Waste Management Ltd

Modelling the behaviour of compacted bentonite at high temperatures

Title: Modelling the behaviour of compacted bentonite at high temperatures – Optimisation of geological disposal facilities

Description: Compacted bentonite clay is part of engineered barrier systems (EBS) developed for nuclear waste storage in geological disposal facilities (GDF). No such facilities have yet been constructed but Governments around the world, including the UK, are committed to delivering GDFs as the most efficient and sustainable long-term solution for managing the existing and newly-produced nuclear waste. These will be substantial environmental projects, comprising the construction of vaults / access tunnels and EBS emplacement up to 1km below the ground surface, in competent ground conditions. The GDF underground footprint is envisaged to take an area of 10km2 on average, under the current constraint of the bentonite clay being exposed to a maximum temperature of 100 deg C from the nuclear waste canister. Placed as a buffer between the canister and the host rock, bentonite will be subjected to hydration from the host rock and to high temperature from the canister. The objective of the EBS design is for the hydration to promote the swelling of bentonite and sealing of construction voids, thus preventing and retarding the possible escape of radionuclides into the natural host environment.

Institution: Imperial College London

This project is in collaboration with the Nuclear Energy Futures Centre for Doctoral Training. The successful applicant will be part of this exciting CDT, in addition to the Research Support Office community.

Supervisor(s): Prof Lidija Zdravkovic, Prof David Potts

Sponsor(s): EPSRC and Radioactive Waste Management Ltd

Performance of aged cement grouts for encapsulating radioactive wastes

Title: Performance of aged cement grouts for encapsulating radioactive wastes

Description: The UK Geological Disposal Facility concept for low and intermediate level radioactive wastes is based on encapsulating the wastes in a cementitious matrix, typically a BFS/OPC or PFA/OPC grout, and surrounding the wasteform packages with a specialist high-alkalinity backfill grout known as the Nirex Reference Vault Backfill (NRVB). The overarching aim of this PhD project is to develop a deep understanding of the chemical, microstructural and physical changes that occur due to long-term interactions between NRVB and wasteform grouts under repository relevant conditions. We will achieve this via a novel approach that combines thermodynamic modelling with quantitative microstructural analysis and mass transport characterisation. Ultimately, the new knowledge generated will inform and strengthen the post-closure safety case of the UK Geological Disposal Facility.

Institution: Imperial College London

This project is in collaboration with the Nuclear Energy Futures Centre for Doctoral Training. The successful applicant will be part of this exciting CDT, in addition to the Research Support Office community. 

Supervisor(s): Dr Hong Wong (IC) and Dr Rupert Myers (IC)

Sponsor(s): EPSRC and Radioactive Waste Management Ltd

Understanding the consequences of steam formation for the sealing performance of barrier bentonites

Title: Understanding the consequences of steam formation for the sealing performance of barrier bentonites

Description: This project will investigate the effects of steam formation within partially saturated bentonite and its subsequent performance on the engineered barrier system. Maintaining and demonstrating an adequate Engineered Barrier System sealing performance will be of fundamental importance to safety assessments for the disposal of HHGWs. This PhD will specifically address two key questions: (i) whether the interaction between partially saturated bentonite and steam results in a marked reduction in the bentonite swelling capacity, and (ii) whether the bentonite permeability is increased as a consequence.

The PhD will answer these questions by conducting a series of experiments in bespoke testing apparatus at the British Geological Survey (BGS) to establish the swelling capacity and permeability of steam treated bentonites under a range of repository conditions. Laboratory experimentation will be conducted both within the Transport Properties Research Laboratories at the BGS and using the state-of-the-art facilities at the University of Bristol Interface Analysis Centre, at which the student will have membership.

Institution: British Geological Survey and University of Bristol

Supervisor(s): Dr Katherine Daniels and Prof Tom Scott

Sponsor(s): Radioactive Waste Management Ltd

Ventilation of Hydrogen in a Geological Disposal Facility

Title: Ventilation of Hydrogen in a Geological Disposal Facility

Description: The aim of this project is to predict the behaviour of slowly-released buoyant gasses in a Geological Disposal Facility (GDF) and inform the design of ventilation for such facilities. Geological disposal involves isolating radioactive waste in a vault deep inside suitable bedrock to ensure that no harmful quantities of radioactivity ever reach the surface environment. A GDF will be a highly engineered structure consisting of multiple barriers designed to provide protection over hundreds of thousands of years.

Hydrogen gas – which is potentially flammable – can arise from the corrosion and degradation of certain types of radioactive waste. Ventilation of hydrogen is a significant engineering challenge for a GDF; new research is required to inform the design of the vaults themselves and size the mechanical ventilation for them. Passive safety in the event of a loss of power is a further consideration.

The release of dense and buoyant gases has been extensively studied, including several recently by the project supervisor (Dr Andrew Lawrie) on determining scaling laws for particular geometries. Here our focus will be to migrate existing understanding of special cases into the more general GDF context to predict the likely evolution of hydrogen concentrations. The key scientific challenge lies in estimating the rate of molecular mixing in a vault environment that will have thermal sources and may become density-stratified.

Laboratory experiments measuring vault circulation and release concentrations directly (primarily using non-invasive optical methods) will provide validation for Computational Fluid Dynamics models that will inform the design of GDF vaults and ventilation structures. A sensitivity analysis of the flow will guide suitable locations for a network of hydrogen leak sensors designed to solve the inverse problem of leak source-finding amongst the many individual radioactive waste packages that will be stored in the vault.

Candidate Requirements: Applicants must hold/achieve a minimum of a Masters degree (or international equivalent) in one of the following: Aerospace Engineering, Physical Sciences, Mechanical Engineering, Chemical/Process Engineering. Applicants without a Masters qualification may be considered on an exceptional basis, provided they hold a first-class undergraduate degree.

Some experience in programming in a compiled language relevant to the design of numerically intensive simulation is essential.

Institution: The University of Bristol

Supervisor(s): Dr Andrew Lawrie

Sponsor(s): Radioactive Waste Management Ltd