PhD Studentship - Liquid-liquid Extraction of Plutonium: Third Phase, Molecular Modelling and Molecular Theory

Research theme: Multiscale modelling

How to apply: uom.link/pgr-apply-2425

This 4-year PhD project is fully funded; students who are eligible to pay tuition fees at the Home rate are eligible to apply (more details can be found here). The successful candidate will receive an annual tax-free stipend set at the UKRI rate (£21,805 for 2026/27) plus an uplift of £5000 per annum and tuition fees will be paid. We expect the stipend to increase each year. The Research and Training Grant will be £2,500 per annum.

The start date is October 2026. 

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

This project concerns the liquid-liquid of extraction of plutonium, which is important to energy, defence, space power and waste disposal. For example, closing the nuclear fuel cycle by reprocessing spent nuclear fuel to remove plutonium reduces the volume and heat load of high-level waste, improves the efficiency of uranium reserves and may enable the future use of mixed oxide fuel. The extraction process involves the transfer of plutonium ions, dissolved in nitric acid, to plutonium complexes in an organic phase. The plutonium may then be isolated from this organic phase. At high loadings, these plutonium complexes stick together to form an extended gel-like phase, called the third phase. Why this happens is both unknown and intriguing, but from a practical viewpoint, third phase formation is a processing disaster! This project will involve the use of atomistic Molecular Dynamics simulation to shed light on how and why this third phase forms and then, building on the insights gained, to investigate a range of organic solutes to identify the characteristics that would reduce the propensity for third phase formation. In addition to the computational work, we will also develop new molecular thermodynamic models, based on those proposed for aqueous systems by Nagarajan et al. and Danov et al., to provide a theoretical framework that describes aggregate and third phase formation, which can then be fed into future process-level flowsheet models.

This project is part of the Nuclear Doctoral Focal Award in Radiation Protection, Nuclear Safety and Environmental Sustainability (RAPTOR). The successful candidate will be part of a cohort of PhD students across four universities (Manchester, Liverpool, Surrey, Suffolk) working in a national programme with 18 industrial partners. During the first months of this PhD, training will be provided UK experts in radiation protection, environmental assessment and radioactive waste management, nuclear safety and security, and social value and societal impact.

Applicants should have, or expect to achieve, at least a 2.1 honours degree or a master’s (or international equivalent) in Chemical Engineering or a related science/engineering discipline. Only UK students are eligible for this PhD scholarship.

We strongly recommend that you contact the main supervisor, Prof Andrew Masters - andrew.masters@manchester.ac.uk, 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.

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