Effect of Sintering Atmosphere on Diposal Mixed Oxide Manufacturability For Nuclear Wasteform Applications

About the Project

The Nuclear Decommissioning Authority (NDA) has established the Plutonium Ceramics Academic Hub at the Universities of Manchester and Sheffield (PUMaS), focused on underpinning the development of ceramic materials and technologies for the safe and secure disposition of the UK’s inventory of plutonium. This represents one of the most significant challenges facing the UKs programme of remediation and restoration of the Sellafield site, expected to be complete in the 2100s.

The PUMaS hub will support ~20 PhD students along with research staff, creating a vibrant and dynamic research environment with PhD cohort training, skills and networking events built into the PhD programmes. As a member of the PUMaS hub you will be based within state-of-the-art facilities such as the Henry Royce Institute, the UKs centre for advanced materials science, giving access to and training on leading materials science and engineering techniques.

Your PhD will include industrial supervision from either NDA, Sellafield Ltd. or Nuclear Waste Services (NWS) to provide focus on tackling industrially significant issues with regards to the safe and secure disposition of the UKs inventory of plutonium and this will permit exchange of your work directly to the industry partners. Furthermore, there will be extensive opportunities to travel and attend conferences and meetings within the UK and internationally as well as collaborate with our academic and industry partners – accessing national or international facilities, for example at the UK National Nuclear Laboratory (UKNNL), Diamond Light Source.

Disposal mixed uranium and plutonium oxide (DMOX) is a potential candidate for disposal of the UKs Pu inventory. Historically, two industrial scale powder processing routes have been used to manufacture MOx fuel materials, the micronized master blend (MIMAS) developed by Belgonucleaire and utilised in the Orano MELOX fuel fabrication facility and the Short Binderless Route (SBR) developed in the UK which was utilised at the Sellafield MOx plant (SMP). In each process, the sintering atmosphere is controlled to certain partial pressures of oxygen (p(O2) to ensure a near-stoichiometric product to meet the fuel specification. However, increasing the p(O2) through addition of humidity or CO2 may have beneficial effects on sintering kinetics and atomic diffusion leading to better mixing of U, Pu and neutron absorbers within the pellet which may result in improved performance as a wasteform.

Thus, to inform DMOx manufacturing processes and understanding sintering atmosphere parameters on the final pellet quality this project will aim to;

• Develop gas mixing and measurement capability on dilatometers in the NFCE facility to undertake in-situ sintering studies as a function of p(O2)
• Assess the impact of sintering atmosphere on sintering kinetics and final pellet quality
• Undertake detailed characterisation of stoichiometry and oxidation states of materials to develop thorough understanding of Oxygen/Metal ratio and charge balancing mechanisms.
• Generate library of highly characterised samples for future performance testing (i.e. aqueous durability vs. stoichiometry).

For this project, you will be based at the University of Manchester within the Nuclear Fuels and Radioactive Waste and Environment research groups. You will have access to state-of-the-art nuclear laboratories within the Henry Royce Institute and National Nuclear User Facilities (NNUF) for Radioactive waste managing and environmental remediation (RADER). You will utilise (where necessary), radioactive materials handling facilities, advanced materials characterisation techniques such as scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and X-ray diffraction (XRD) to study the materials at the micro and as well as access to national and international facilities for example synchrotron based experiments.

Eligibility

Applicants should have, or expect to have a MSc or integrated Masters degree in Materials Science, Engineering, Chemistry or related subject

Before you apply

We strongly recommend that you contact the supervisors 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.

Funding Notes

This 4-year PhD project is fully funded by the Nuclear Decommissioning Authority (NDA) and home students 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. The start date is October 2026.

We recommend that you apply early as the advert may be removed before the deadline.