This project will for the first time resolve the reaction mechanisms, rate of reaction and structure of cement-based wasteforms for safe and sustainable disposal of radioactive waste. In the UK alone, approximately 150,000m3 of radioactive waste (enough to fill 60 Olympic size swimming pools) has been produced to date and 75% will require processing and storing in a secure facility to ensure the safety of society and the environment. Radioactive waste streams are often immobilised in cements to limit leaching of the radioactive material to the environment. Due to poor compatibility of radioactive wastes with Portland cement, modern alternatives such as ‘geopolymer cements’ are being investigated. The long-term performance of geopolymer cement wasteforms is controlled by the transport, solubility and incorporation processes. However, this is still not well understood. The project aims to understand these factors by using advanced characterisation techniques to monitor the reaction and wasteform formation at the atomic level, as it happens in real time. This will be assessed at a range of temperatures which mimic the waste disposal conditions. Particular focus will be on advanced spectroscopic and microstructural techniques revealing the atomic/nanostructure and dynamics of these wasteforms. This includes solid state nuclear magnetic resonance (NMR) spectroscopy and synchrotron-based techniques, with which the Sustainable Materials at Sheffield (SMASH) research group has unique and world-leading expertise. This has never been done before and will yield new insight which is vital to understand the suitability and performance of geopolymer wasteforms for disposal of radioactive waste.
The successful applicant will have the opportunity to apply chemical/materials/environmental engineering principles to a real-world, globally significant industrial challenge. They will receive training in the production and characterisation of radionuclide-loaded geopolymer cement wasteforms, assessing their performance and durability under industrially relevant conditions. The candidate will gain expertise in advanced spectroscopic and microstructural techniques revealing the atomic/nanostructure and dynamics of materials, including solid state NMR spectroscopy, in which the SMASH research group at The University of Sheffield possess unique, world-leading expertise and facilities. The successful applicant will develop multidisciplinary skills in geopolymer/cement chemistry and engineering. They will be familiarised with Good Laboratory Practice regulations, COSHH, research ethics, confidentiality and development of generic transferable skills including IT, critical evaluation, problem solving, data collection and analysis, team working, time management, written and communications skills will be ensured. The successful applicant will also get a chance to interact and work closely with a world-leading and friendly research community The University of Sheffield, including research members of the [email protected]
and Immobilisation Science Laboratory (ISL) research groups at the Department of Materials Science and Engineering, The University of Sheffield, as well as the Grantham Centre for Sustainable Futures at The University of Sheffield, and the wider cement chemistry and immobilisation science research communities within and outside Sheffield, in addition to relevant industries.
The project will provide the necessary interdisciplinary skills for the successful applicant to pursue research and development in the sustainable use of materials for infrastructure, clean energy and manufacturing sectors, as example sectors.
All the methodology, instrumentation and characterisation equipment required to achieve the objectives of the proposal are available in the applicant’s laboratory and through University-wide facilities. These will be available for the successful applicant during the duration of the project.
This includes the newly appointed laboratories of the Sustainable Materials at Sheffield (SMASH) research group in the Department of Chemical and Biological Engineering, The University of Sheffield, as well as the facilities of the Immobilisation Science Laboratory (ISL) group at the University of Sheffield, including a fully refurbished cements laboratory facility, and the ISL-hosted MIDAS user facility for nuclear materials science analytical instrumentation.