This PhD project addresses a critical challenge in nuclear decommissioning: the behaviour and distribution of chlorine-36 (Cl-36) in graphite reactor systems. Cl-36 is a long-lived radionuclide with significant implications for radiological safety assessments, particularly in the context of geological disposal facilities (GDFs), low-level waste repositories, and long-term on-site storage.
There is currently conflicting evidence regarding the total inventory of Cl-36 in graphite reactors, with large discrepancies between trepanned sample analyses and modelling predictions. The mobility of Cl-36 during reactor operation means that it can redistribute within the system, yet this is not accounted for in the UK Radioactive Waste Inventory (UKRWI), due to limited understanding. This uncertainty forces safety assessments to adopt conservative assumptions, which may lead to overly cautious predictions and potentially exclude viable disposal options.
Key Research Areas
This PhD will explore several interconnected research themes:
Behaviour of Cl-36 in Reactor Graphite
Investigate the distribution of Cl-36 precursors within graphite blocks.
Use neutron flux modelling to estimate remaining Cl-36 inventory, accounting for mobilisation mechanisms during reactor operation.
Examine Cl-36 release from graphite under innovative processing conditions and GDF-relevant temperature and pH environments.
Determine the release rate, releasable fraction, and chemical speciation of Cl-36 under these scenarios.
Redistribution of Mobilised Cl-36
Assess the extent to which mobilised Cl-36 is taken up by other reactor components such as metal pipework, bioshield concrete, and steel structures.
Characterise the chemical form of redistributed Cl-36, distinguishing it from Cl-36 formed by direct activation of non-graphite materials.
Investigate the release behaviour of Cl-36 from these non-graphite components during processing and under disposal conditions.
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
Funding
This 4 year PhD project is fully funded and home students, and EU students with settled status, are eligible to apply. The successful candidate will receive an annual tax-free stipend set at the UKRI rate (£20,780 for 2025/26) and tuition fees will be paid. We expect the stipend to increase each year.
Before you apply
We strongly recommend that you contact the supervisor(s) for this project before you apply. Please include details of your current level of study, academic background and any relevant experience and include a paragraph about your motivation to study this PhD project.
How to apply
Apply online through our website: https://uom.link/pgr-apply-2425
When applying, you’ll need to specify the full name of this project, the name of your supervisor, if you already having funding or if you wish to be considered for available funding through the university, details of your previous study, and names and contact details of two referees.
Your application will not be processed without all of the required documents submitted at the time of application, and we cannot accept responsibility for late or missed deadlines. Incomplete applications will not be considered.
After you have applied you will be asked to upload the following supporting documents:
- Final Transcript and certificates of all awarded university level qualifications
- Interim Transcript of any university level qualifications in progress
- CV
- Supporting statement: A one or two page statement outlining your motivation to pursue postgraduate research and why you want to undertake postgraduate research at Manchester, any relevant research or work experience, the key findings of your previous research experience, and techniques and skills you’ve developed. (This is mandatory for all applicants and the application will be put on hold without it).
- Contact details for two referees (please make sure that the contact email you provide is an official university/work email address as we may need to verify the reference)
- English Language certificate (if applicable)
If you have any questions about making an application, please contact our admissions team by emailing FSE.doctoralacademy.admissions@manchester.ac.uk.
We recommend that you apply early as the advert might be removed once the position has been filled.
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).
