Assessment of D-MOx Manufacturing Parameters on Product Microstructure: The Impact of Powder Processing, Neutron Poisons and Contaminants

About Us

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 UK’s 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 Institutes, the UK’s centre for advanced materials science, giving access to and training on leading materials science and engineering techniques.

This 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 UK’s inventory of plutonium and this will permit exchange of your work directly to the industry partners to maximise the impact. 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 (DLS) or the European Synchrotron Radiation Facility (ESRF).

 About the Project

The UK reprocessed spent nuclear fuel between 1960’s until the early 2020’s, separating plutonium which was stored as plutonium oxide (PuO₂) powders. During storage, some of these powders have been contaminated with impurities such as Cl from storage in PVC bags as well as some batches containing high levels of C and Fe from processing routes. To date, there is a lack of systematic understanding of the effect of these impurities on the manufacturability and microstructure of the resultant ceramic products that can be obtained with them. Furthermore, there are two potential manufacturing routes based on industrial scale powder processing routes, the micronized master blend (MIMAS) utilised in the Orano MELOX fuel fabrication facility and the Short Binderless Route (SBR) developed in the UK which leads to variations in the homogeneity and characteristics of the pellets. To inform on the manufacturing route and the effect of powder feedstock, impurity and sintering conditions on the resultant pellet quality, this project will undertake a parametric study utilising in-situ sintering techniques to perform a manufacturing sensitivity analysis. The project will assess the effect of impurities on the MIMAS and SBR fabrication routes and sinter simulant MOx pellets under a range of conditions (temperature, partial pressure of oxygen). The results obtained from the in-situ sintering technique will be used to develop models such as master sintering curves and analysis of the sintering activation energy and kinetics for each system which will be used to understand any effects on the final product quality.

As part of this project, you will be based at the University of Manchester in the Nuclear Fuels group with access to state-of-the-art nuclear laboratories within the Henry Royce Institute and National Nuclear User Facilities (NNUF). You will utilise (where necessary), radioactive materials handling facilities, in-situ materials manufacturing techniques and characterisation techniques such as scanning electron microscopy (SEM), Transmission electron microscopy (TEM) and X-ray diffraction (XRD) to study the materials at the microscale and nanoscale and analytical techniques such as mass spectrometry (MS) as well as access to National and International facilities, for example for synchrotron based experiments.

More information on these facilities can be found;

–       Henry Royce Institute Nuclear Facilities

–       https://www.nnuf.ac.uk/simfuel-and-alpha-active-material-manufacturing-and-characterisation-facility

Expectations and Rewards:

During this PhD you will be expected to:

–         Work with and support the PUMaS Hub, nuclear fuels research groups

–         Have a sound work ethic allowing you to manage your project with an independence.

–         Provide regular updates and technical outcomes to your industry supervisor at NDA, SL or NWS and present updates at annual NDA and NWS conferences

–         Attend and present at both local and international conferences.

–         Partake in graduate teaching, supervision or training of Masters students

–         Able to obtain baseline security vetting (BPSS)

There will be many rewards:

–         Working as part of a large and experienced team across the cohorts will ensure a supportive environment and that you will always have someone to help.

–         Opportunities to develop training and skills in a range of technical areas including radioactive materials handling, state of the art materials manufacturing, characterisation and testing equipment

–         Flexible and hybrid working is supported.

–         Receipt of a competitive, tax-free stipend.

–         Numerous opportunities for local and international collaboration and travel.

–         Opportunities to develop a range of non-technical skills (presentation, organisation, leadership) through bespoke training programme of the Hub, mentoring and a broad range of university training and development courses.