Pollution by anthropogenic radionuclides is ubiquitous in the environment. In particular, Wales and the southwest of England have experienced the legacy of the atomic age from the spread of toxic radionuclides from a range of now-decommissioned nuclear power plants (e.g. Berkeley, Wylfa) and the proximity to the Sellafield nuclear processing plant. Yet, the ultimate toxicity of radionuclides as a pollutant to life is directly linked to their relative abundances in the environment. Thus, direct monitoring of specific radionuclide abundance and understanding their mobility under different environmental conditions is paramount. However, given a range of these radionuclides are man-made (e.g. plutonium), their specific characteristic behaviour and mobility in nature is not well established. It is therefore necessary to further our understanding of these processes through monitoring in natural sediment and soil settings, as well as in controlled laboratory experiments.
The primary aim is to improve the understanding of the mobility of both natural and anthropogenic radionuclides in the environment, studying the geochemistry of sediment and soils. A major focus is on actinides, where natural uranium and thorium isotopes (parent 238U/235U ratios, uranium-series daughter products) provide a means to study actinide mobility from different natural processes (e.g. weathering rates and deposition environments, redox conditions and organic binding properties). The study of the mobility of natural actinides can be directly linked to the behaviour of anthropogenic radionuclides, in particular, plutonium. Here nuclear forensics from plutonium isotopes provide a fingerprint of specific source origins. Targeted samples will be a range of shallow marine and estuary sediments as well as terrestrial soils taken in the vicinity of decommissioned nuclear powerplants in Wales and the Southwest. These studies will be combined with controlled laboratory experiments to further understand the mobility of the actinides under changing environmental conditions (e.g. Eh, pH) directly related to expected environmental changes that are linked to future climate change. There is an option for involvement in project design or choice of research direction, with the overall aim being to deepen the understanding of sources and mobility of radionuclides in the environment and their toxicity.
A strong background and interest in (geo)chemistry is highly advantageous. Isotope work and/or clean laboratory experience would be useful.
The main training aspects for the student involve 1) environmental sampling, 2) laboratory experiments and 3) analytical isotope geochemistry. The student would be trained in fieldwork, sampling of soil and sediments and the set up and conducting of laboratory experiments at Cardiff University, supervised by the PI. Specific analytical purification techniques and mass spectrometric measurements (238U/235U, U-series decay products, plutonium isotope ratios and other radionuclides 138Cs, 210Pb) would be conducted in Cardiff (CELTIC) and Bristol (BIG) isotope laboratories trained by the PI and co-I Richards. Further engagement and outreach opportunities related to the impact of anthropogenic radionuclides in the environment will be achieved through the Southwest Nuclear hub (co-I Richards).
UK Research Council eligibility conditions apply
Open to UK and EU students. All EU applicants must have been ordinarily resident in the EU for at least 3 years prior to the start of their proposed programme of study.
Applicants from EU countries who do not meet the residency requirements may still be eligible for a fees-only award.
How to apply
You should apply to the Doctor of Philosophy in Earth and Ocean Sciences with a start date of October 2020.
two references (applicants are recommended to have a third academic referee, if the two academic referees are within the same department/school)
current academic transcripts.
In the research proposal section of your application, please specify the project title and supervisors of this project and copy the project description in the text box provided. In the funding section, please select ’I will be applying for a scholarship/grant’ and specify that you are applying for advertised funding from NERC GW4+ DTP.
If you wish to apply for more than one project please email [email protected]
The deadline for applications is 16:00 on 6 January 2020.
Shortlisting for interview will be conducted by 31 January 2020.
Shortlisted candidates will then be invited to an institutional interview. Interviews will be held in Cardiff University between 10 February and 21 February 2020.
References / Background reading list
Lindahl, P., Worsfold, P., Keith-Roach, M., Andersen, M.B., Kershaw, P., Leonard, K., Choi, M.S., Boust, D. and Lesueur, P., 2011. Temporal record of Pu isotopes in inter-tidal sediments from the northeastern Irish Sea. Science of the Total Environment, 409(23), pp.5020-5025.
Andersen, M.B., Stirling, C.H. and Weyer, S., 2017. Uranium isotope fractionation. Reviews in Mineralogy and Geochemistry, 82(1), pp.799-850.
Andersen, M.B., Vance, D., Keech, A.R., Rickli, J. and Hudson, G., 2013. Estimating U fluxes in a high-latitude, boreal post-glacial setting using U-series isotopes in soils and rivers. Chemical Geology, 354, pp.22-32.