Saturn_Nuclear_CDT
Legacy nuclear sites such as Sellafield face long-term challenges in managing groundwater contaminated with radionuclides, including strontium-90 and redox-sensitive species like uranium and technetium. Traditional pump-and-treat (PAT) systems, which rely on extracting groundwater, treating it at the surface, and reinjecting or discharging it, often operate inefficiently. A key limitation is poor in situ mixing between contaminants, remediation amendments, and naturally occurring electron donors or acceptors, which inhibits the chemical and biological reactions essential for natural attenuation.
This interdisciplinary PhD project aims to develop a novel remediation strategy that enhances PAT performance through chaotic advection, a mechanism that induces complex, yet controlled, subsurface flow fields to improve mixing. By cycling injection and extraction wells out of phase, the project will test whether mixing and reaction zones can be intensified, thereby accelerating contaminant breakdown or immobilisation. The potential for this approach to improve the performance of permeable reactive barriers (PRBs) will also be considered.
The project is jointly developed by the University of Sheffield, Sellafield Ltd, and the British Geological Survey (BGS), and includes both field-based and modelling components. Field experiments will be carried out at the UK Geoenergy Observatory (UKGEOS) in Cheshire, a state-of-the-art research facility situated in a well-characterised Permo-Triassic sandstone aquifer, with advanced hydraulic and geochemical monitoring capabilities. This unique setting enables full-scale tracer tests under dynamic pumping regimes with high spatial and temporal resolution.
Using these data, the student will build and calibrate numerical models to simulate conservative transport and mixing. A combination of particle-tracking and grid-based reactive transport models will be used to understand how flow variability governs interactions between contaminants and amendments over space and time. The models will then be extended to simulate redox-sensitive radionuclide behaviour, capturing reaction rates, sorption, and immobilisation under enhanced mixing conditions.
The final phase will evaluate how dynamic PAT schemes can be optimised to reduce remediation time and cost. Model-based scenario analysis will compare different pumping protocols across hydrogeological conditions, identifying key sensitivities and performance indicators. While focused on Sellafield, this approach has broad applicability to other legacy nuclear sites facing similar remediation challenges.
Why This Project?
This project is at the frontier of innovation in groundwater remediation, combining physical hydrology, environmental geochemistry, and mathematical modelling in a real-world context. It offers the opportunity to contribute to nationally important goals in nuclear site decommissioning and long-term environmental stewardship. You will work in a multi-partner setting, engaging with leading researchers at the University of Sheffield and BGS, and benefit from access to industrial expertise and infrastructure through Sellafield Ltd.
What Will You Learn?
The successful candidate will gain high-level skills in:
· Groundwater flow and solute transport modelling (e.g. MODFLOW, MT3DMS, RT3D, or Python-based tools)
· Experimental design and field data analysis
· Radionuclide geochemistry and contaminant hydrogeology
· Numerical simulation of reactive transport systems
· Stakeholder engagement and science communication
· Cross-sector collaboration and career development through the Saturn CDT
The skills developed through this project will position the successful candidate extremely well for future employment in the civil nuclear and environmental sectors. A recognised UK-wide shortage of expertise in hydrogeology and groundwater modelling presents a key challenge for the long-term delivery of nuclear decommissioning programmes. By gaining advanced technical, modelling, and communication skills, the candidate will be well equipped to meet this demand. A three-month placement at Sellafield Ltd is expected during the PhD, supporting real-world application of the research and strengthening links with end users. Training and networking opportunities provided through the SATURN CDT will further enhance the candidate’s professional development and cross-sector career prospects.
Supervision and Collaborators
You will be based in the School of Mechanical, Aerospace and Civil Engineering at the University of Sheffield and supervised by:
1. Dr Domenico Baù (Lead Supervisor) – expert in groundwater modelling and subsurface contaminant transport
2. Prof Steve Thornton (Co-supervisor, Emeritus) – internationally recognised leader in contaminant hydrogeology and redox processes
3. Dr John Heneghan (Industrial Supervisor, Sellafield Ltd.) – experienced contaminated land specialist in the UK nuclear sector
Dr Michael Spence and Dr Oliver Kuras (BGS collaborators) – field instrumentation and hydro-geophysical experts at UKGEOS
Before you apply
We strongly recommend that you contact the supervisor(s) for this project before you apply. For informal enquiries, please contact (Dr Domenico Baù ) at (d.bau@sheffield.ac.uk)
The studentship will be run as part of the SATURN Centre for Doctoral Training and thus you will get to interact with a large cohort of students who are studying nuclear science and engineering at six leading UK universities.
Eligibility
Applicants should have, or expect to achieve, at least a 2.1 honours degree or a master’s (or international equivalent) in a relevant science or engineering related discipline
How to apply
Please complete the enquiry form to express your interest.
We strongly recommend you contact the project supervisor after completing the form to speak to them about your suitability for the project. You can find their details on the project listing.
If your qualifications meet our standard entry requirements, the CDT Admissions Team will send your enquiry form and CV to the named project supervisor.
Our application process can also be found on our website: Apply | EPSRC Centre for Doctoral Training in Skills And Training Underpinning a Renaissance in Nuclear | The University of Manchester. If you have any questions, please contact SATURN@manchester.ac.uk
Equality, diversity and inclusion
Equality, diversity and inclusion is fundamental to the success of The University of Manchester, and is at the heart of all of our activities. We know that diversity strengthens our research community, leading to enhanced research creativity, productivity and quality, and societal and economic impact. We actively encourage applicants from diverse career paths and backgrounds and from all sections of the community, regardless of age, disability, ethnicity, gender, gender expression, sexual orientation and transgender status. We also support applications from those returning from a career break or other roles. We consider offering flexible study arrangements (including part-time: 50%, 60% or 80%, depending on the project/funder).
