Funded PhD research projects

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

As an NWS RSO student you will be conducting world leading, high quality, and relevant research to underpin the NWS 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 NWS 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 2022 mark the second cohort of NWS RSO research students. The NWS 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, click on the title of the project to get further details. Please get in touch with the supervisor for more information on how to apply.

Advanced characterisation of hydrothermally aged cement (10 years old)

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.

The successful candidate will be trained in and use techniques such as micro-(X-ray diffraction), electron probe micro-analysis, X-ray computed tomography and access national facilities such as Diamond Light Source, to determine how mineralogy, micro-strain, porosity and permeability of the NRVB:cement grout interface have altered over 10 years. The candidate has a unique opportunity to gain some industrial experience at Radioactive Waste Management (Oxfordshire) to understand their working environment first hand and make an impact on an important problem, while learning high-level and cutting-edge scientific techniques at Strathclyde. The student will be based in the Faculty of Engineering, one of the largest and most successful engineering faculties in the UK, and the largest in Scotland. The student will be supervised by an interdisciplinary team, including Drs Andrea Hamilton, Pieter Bots and Kate Dobson in Civil and Environmental Engineering (CEE) and Dr Paul Edwards in the Physics Department.

We are looking for a highly motivated person to undertake multi-disciplinary research. Applicants should have an excellent undergraduate degree (MSc/MEng/BSc/BEng) in Physics/Chemistry/Chemical Engineering/Materials, Science, or related subjects, and be comfortable working in physics, chemistry and engineering laboratories. Any previous experience using Matlab or similar is advantageous.

To apply, please Dr Andrea Hamilton () as soon as possible, indicating your motivation to apply, your CV and outline any experience you have working in a laboratory.

Institution: University of Strathclyde

Supervisor(s): Dr Andrea Hamilton and Dr Katherine Dobson

Sponsor(s): Nuclear Waste Services

Colloidal Silica for Well Stabilisation during Borehole Sealing

Title: Colloidal Silica for Well Stabilisation during Borehole Sealing

Description: This project is investigating the use of colloidal silica grout (which forms a hydrogel) in the long-term sealing of boreholes in the ground, to prevent subsequent upward fluid migration from rocks at depth to the surface. Successful borehole sealing is vital in many industries, including: deep borehole disposal of radioactive waste; oil and gas production and well decommissioning; carbon capture and storage; and hydrogen storage. For UK radioactive waste disposal, the preferred option for borehole sealing is backfilling with compacted bentonite, a clay which swells to form a tight, strong seal upon wetting. Prior to bentonite emplacement, it is necessary for the steel borehole casing to be removed. Recent field trials have exposed a problem with this method in weak or damaged rocks, where the borehole walls can collapse before the compacted bentonite is emplaced. This PhD project will investigate the potential for colloidal silica grout to provide short-term stabilisation of these weak rocks, prior to the bentonite emplacement. Figure 1 shows an example of a weak cracked material, into which colloidal silica has been injected to recover its strength. This PhD will use similar silica injection and imaging techniques. The final repaired rock will be investigated to optimise strength and durability.

The project will be largely experimental, using equipment in the University of Strathclyde’s geotechnical laboratories. Colloidal silica will be injected into samples of damaged mudstone and the resulting material will be tested for shear strength, erosion resistance and unconfined compressive strength. The chemical and physical interactions between the colloidal silica and the bentonite will also be investigated to determine any long-term impacts on seal performance. Investigations will make use of the University of Strathclyde’s Advanced Materials Research Laboratory, which hosts equipment such as Scanning Electron Microscopy, X-Ray Diffraction facilities and Micro X-Ray Computer Tomography. 

 

Institution: University of Strathclyde

Supervisor(s): Prof Rebecca Lunn and Dr Gea Pagano

Sponsor(s): Nuclear Waste Services, EPSRC

Geological Fate and Impact of Isosaccharinic acid (Geo-FISA)

Title: Geological Fate and Impact of Isosaccharinic acid (Geo-FISA) 

Description:

The nuclear fuel cycle has generated higher-level radioactive wastes that will be disposed of in a deep geological facility (GDF) that will provide multiple barriers to the migration of radionuclides to the surface over prolonged timescales (tens of thousands of years). Isosaccharinic acid (ISA) is an organic ligand that is produced from the abiotic hydrolysis of cellulosic material found in Low Heat Generating (Intermediate Level Radioactive) Wastes (LHGW) [1]. Our studies showed that microbes can degrade ISA under GDF-relevant conditions [2] and this process can lead to the precipitation of priority radionuclides [3].

This is an interdisciplinary research project combining geomicrobiology, microbial genomics, radiochemistry and mineralogy, and will study ISA degradation in dynamic flowthrough systems using state of the art techniques including shotgun metagenomics, XRF, XAS, confocal microscopy, ESEM, and TEM. The successful applicant will join a welcoming cohort of 40+ interdisciplinary researchers working in two recently refurbished and co-located centres in the Dept of Earth and Environmental Sciences, co-directed by the PI and co-supervisors (Lloyd, Morris and Shaw).  The student will have access to a large suite of dedicated laboratories within the Williamson Research Centre for Molecular Environmental Sciences (WRC; directed by Lloyd), which houses state of the art equipment for molecular environmental studies and sits alongside the new £4M NNUF RADER labs (https://www.nnuf.ac.uk/rader) directed by Morris, offering unique complementary facilities for handling and analysing radionuclides in nuclear environmental systems.

Academic background of candidates

Applicants are expected to hold, or about to obtain, a minimum upper second class undergraduate degree (or equivalent) in Chemistry, Environmental Chemistry, Geosciences, Microbiology or a closely related discipline. A Masters degree in a relevant subject is highly desirable and experience in handling and analysis of environmental samples is also desirable.

Application Enquiries

To apply please send a cover letter and CV to Jonathan Lloyd (Jon.lloyd@manchester.ac.uk), Naji Bassil (Naji.bassil@manchester.ac.uk)

To apply please visit: https://www.ees.manchester.ac.uk/study/postgraduate-research/how-to-apply/

Please search and select Environmental Science (academic programme) and PhD Environmental Science (academic plan)

Institution:  University of Manchester

Supervisor(s): Jonathan Lloyd, Naji Bassil, Sam Shaw, Katherine Morris, Tom Neill

Sponsor(s): Nuclear Waste Services, GREEN CDT

 

1. Glaus MA, Van Loon, LR. 2008. Degradation of cellulose under alkaline conditions: New insights from a 12 years degradation study. Sci. Technol. 42:2906-2911

2. Bassil NM, Bryan N, Lloyd JR. 2014. Microbial degradation of isosaccharinic acid at high pH. ISME J. 9:310-320

3. Kuippers G, Morris K, Townsend LT, Bots P, Kvashnina K, Bryan ND, Lloyd JR. 2021. Biomineralization of uranium-phosphates fueled by microbial degradation of isosaccharinic acid (ISA). Sci. Technol. 55:4597-4606

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): Nuclear Waste Services

Ventilation of Hydrogen in a Geological Disposal Facility

Title: Hydrogen Ventilation in a Geological Disposal Facility

Description: One of the biggest engineering challenges in safeguarding the UK from the legacy of half a century of nuclear power generation may be found in the design of long-term storage for spent fuel. Plans are being developed for a Geological Disposal Facility, deep underground, where spent fuel can safely be allowed to decay.  During this process, small quantities of hydrogen gas may be released.  While not especially dangerous in small quantities, any long-term accumulation of a flammable gas could be dangerous, so understanding how quickly gasses might accumulate and in what concentration is essential to ensure that adequate ventilation is designed into the facility, and to understand the risk in the event of a failure of mechanical ventilation.

To address these questions of design and risk, in this project a scientific study into slow leakage flows will be carried out in a desktop-scale laboratory model, using density differences between fresh and salt water as a scale representation of the buoyancy of hydrogen gas leaking into air.  In the Hele-Shaw laboratory we use non-invasive techniques, usually marking a fluid with dye and video-recording the flows for quantitative analysis.  For this study of leakage over long timescales, the measurements will need to be automated.  Leaking gas will mix with its surroundings, though how quickly is not yet known, and this strongly affects the combustibility of hydrogen accumulations and hence the risks associated with ventilation failure. Furthermore, the vault environment will be filled with heat sources that will cause its atmosphere to become density-stratified, and this raises further challenges over predicting the rate of mixing of ascending hydrogen gas.  A network of sensors to detect hydrogen need to be positioned within the vault so that a leaking package of spent fuel can be identified and removed.  Back-tracing the leakage flow is a challenging inverse problem that draws together modelling, sensitivity analysis and experimental calibration.  This project will suit a student with a practical mindset for designing and building their own automated experiment, and who also has an interest in developing models to deepen their understanding of an extremely important engineering problem.

Candidate Requirements: Applicants must hold/achieve a minimum of a master’s degree (or international equivalent) in a relevant discipline: Aerospace Engineering, Physical Sciences, Mechanical Engineering, Chemical/Process Engineering, Applied Mathematics. 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