Project highlights

  • Novel and sustainable preparation of nuclear materials surrogates/mimics 
  • Assessment of a new proposed method against current processes for civil terrestrial nuclear fuel production to understand if waste aspects can be improved    
  • Recycling nuclear material for space exploration and Earth applications 
  • Experimental project with an opportunity to gain expertise in multiple analytical instruments 
  • Supervised by a multi-disciplinary team across Physics, Chemistry and Space Park Leicester 

Overview

The UK Government is investing in nuclear for NET-Zero [1]. For an effective and resilient nuclear strategy, our society needs to address every aspect of the nuclear fuel cycle and, crucially, legacy nuclear waste. Therefore, it is paramount that we train and build the skill set and knowledge in the next generation of nuclear scientists to address the long-term, such as americium-241 (241Am), and near-term nuclear legacy materials for environmental and health reasons. The UK has historically reprocessed Mixed Oxide Fuel, namely, uranium-plutonium (U-Pu) oxides, which has resulted in a large stockpile of civil plutonium oxide (PuO2) that is gradually accumulating 241Am due to the beta-decay of plutonium-241 (241Pu). Minor actinides, such as 241Am have a 432 year half-life. To address the nuclear legacy, the tonnes of ingrown 241Am should be extracted and used for other purposes or transmuted into shorter-lived isotopes. 

Members of our team at The University of Leicester are already involved in a multidisciplinary project, together with partners, that will be utilising the 241Am to create americium-uranium (Am-U) oxides for radioisotope electrical and thermal power systems for space exploration to Mars, which is a prime example of repurposing legacy nuclear material [4]. The processing of nuclear materials often requires time-consuming multi-step processes, producing significant volumes of chemical and radioactive waste that needs to be carefully managed to reduce environmental impact. This PhD project proposes producing Lanthanide Mixed Oxides (Ln-MOX) materials as surrogates for U-Pu, U-Am and U-Pu-Am oxides using a novel methodology with the aim to improve efficiency of MOX production. The new method will involve the use of lanthanide nitrate precursors and will be combined with ‘dry’ mechanochemical synthesis methods (i.e. use of mechanical forces to promote chemical reactions) [5], with the goal to reduce manipulations, improve efficiency and minimise waste. The overall aim of the project will be to assess the method’s suitability to recycle/re-use the nuclear legacy material with a reduced environmental impact. An assessment of the waste streams of the current methods for nuclear reactor fuel production and the new proposed method will be made. Their environmental impacts will be assessed and compared.  

A scientific diagram representing a chemical pathway for synthesis of nuclear material mimics, with chemical formulae.

Figure 1: New method for the synthesis of Ln-MOX materials as nuclear material mimics.  

Host

University of Leicester

Theme

  • Climate and Environmental Sustainability

Supervisors

Project investigator

Co-investigators

How to apply

Methodology

The Workplan: 

Methodology development and synthesis of lanthanide (Ln) Mixed Oxides (Ln-MOX). Ln-MOX will be prepared by mixing selected lanthanide nitrates (e.g. Ce(NO3)4, Nd(NO3)3, Pr(NO3)3) using mechanochemical methods, followed by calcination to form target MOX compositions. Synthetic work will be supported by state-of-the-art anaerobic techniques (Schlenk line and glovebox). 

Physical characterisation. This work on new Ln-MOX (working alongside collaborators) will use: 

  1. powder X-ray diffraction to check Ln-MOX crystalline phases. 
  2. scanning electron microscopy with energy-dispersive X-ray spectroscopy to establish homogeneity/heterogeneity of lanthanide atoms in MOX. 
  3. X-ray absorption spectroscopy techniques to probe the valency and oxidation state of metal cations in the new Ln-MOX.  

These results will inform the methodology development in a two-way feedback loop. 

Waste Stream Assessment. Project results and literature will be used to assess the waste streams of current reactor fuel production routes and the new proposed route. Their Environmental Impact will be compared.  

Training and skills

DRs will be awarded CENTA Training Credits (CTCs) for participation in CENTA-provided and ‘free choice’ external training. One CTC can be earned per 3 hours training, and DRs must accrue 100 CTCs across the three and a half years of their PhD.  

The student will be trained in modern solid-state synthesis. Additionally, the student will be trained to perform and interpret every analytical and spectroscopic technique involved in the project (e.g. PXRD, SEM, XAS). 

The student will work within a stimulating multidisciplinary team, and we will encourage them to develop communication and interpersonal skills by participating at research meetings, conferences and outreach activities. This project is closely related to applications in the nuclear sector and space exploration. Therefore, the student will develop a holistic scientific training encompassing multiple topics of vital importance for the scientific community and modern society.  

Further details

Potential applicants are welcome to discuss the project informally with the project supervisors : Emily Jane Watkinson ([email protected]) and Fabrizio Ortu ([email protected]) 

To apply to this project: 

  • You must include a CV with the names of at least two referees (preferably three) who can comment on your academic abilities.  
  • Please submit your application and complete the host institution application process via: CENTA PhD Studentships | Postgraduate research | University of Leicester.  Please scroll to the bottom of the page and click on the “Apply Now” button.  The “How to apply” tab at the bottom of the page gives instructions on how to submit your completed CENTA Studentship Application Form 2025, your CV and your other supporting documents to your University of Leicester application. Please quote CENTA 2025-L19when completing the application form.  

Applications must be submitted by 23:59 GMT on Wednesday 8th January 2025.  

Possible timeline

Year 1

Preparation of first generation of Ln-MOX and first round of physical measurements and testing. 

Year 2

Rationalisation of methodology criteria applied to Ln-MOX synthesis and preparation of second materials. Additional physical measurements with external collaborators.

Year 3

Publication of results with student as named first author (methodology and Ln-MOX characterisation). Extension of methodology to various combinations of lanthanide elements and oxides.

This PhD project will generate new insight into new methodologies related to the nuclear fuel cycle, aimed at reducing the environmental impact of nuclear waste reprocessing, together with improving efficiency of current methods. Additionally, these new methods will be highly relevant to the production of nuclear materials used for technologies in support of space exploration. 

Further reading

  1. HM Government, “Net Zero Strategy: Build Back Greener”, Policy paper, 2021. 
  2. HM Government, “Powering our Net Zero Future”, White Paper, December 2020.  
  3. HM Government, “The Ten Point Plan for a Green Industrial Revolution”, November 2020. 
  4. Gibney, Mars rover mission will use pioneering nuclear power source, Nature, https://www.nature.com/articles/d41586-024-01487-6 Last accessed 16th August 2024. 
  5. Do, J.-L., Friščić, T. (2017) ‘Mechanochemistry: A Force of Synthesis’, ACS Central Science, 3(1), pp. 13–19.