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

Application deadline: 31/03/2026
Research theme: Nuclear Materials
Hoe to apply: https://uom.link/pgr-apply-2425

UK only

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.

The Nuclear Decommissioning Authority (NDA) has established the Plutonium Cerams 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.

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.

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.

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

To apply, please email the main supervisor, Dr Robert Harrison - r.w.harrison@manchester.ac.uk. 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.

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