PACIFIC - Providing a Nuclear Fuel Cycle in the UK for Implementing Carbon Reductions

PACIFIC is a multi-discipline programme, across 12 UK universities, that supports a future nuclear fuel cycle in the UK. We aim to provide a world-class programme of relevant research into the manufacture, performance, and recycle of current and advanced nuclear fuels. For the first time in a major UK academic research programme, we will integrate the two Themes of Nuclear Fuel and Separations Technology into a single programme with a common goal. In the Fuels Theme, our aim is to provide a scientific and technological underpinning to understanding the damage mechanisms that occur in nuclear fuel and cladding materials throughout their operational life and during storage. Our objectives are to: 1. extend molecular dynamics models to predict key properties of advanced fuels; 2. identify promising single component and composite materials for advanced fuels and to develop appropriate manufacturing routes.; 3. investigate the potential for improved TRISO coated fuel particles by employing a duel SiC/ZrC layer; 4. assess the performance of advanced fuels and coatings under a range of conditions; and 5. investigate the mechanism of Pellet-Cladding Interaction failures in LWRs. The first Fuels project addresses advanced fuels and coatings. This Project will employ a combination of advanced modelling and experimental techniques to identify promising new fuel materials, and to explore the mechanisms and effects of radiation damage in both current and advanced fuel materials, including coated fuel particles. Specific Tasks include: - Fuel Modelling - Advanced Fuel Manufacture - Advanced TRISO Coated Fuel Particles - Materials Characterisation and Irradiation The second Fuels project concerns a failure mechanism known as Pellet-Cladding Interaction (PCI). This project will focus on developing a mechanistic understanding of PCI by bringing together metallurgical, mechanical engineering, chemical and radiation aspects; by a combination of experimental investigations and underpinned by computer simulation. In the Separations theme, the projects aim to provide a proof of concept for an integrated flowsheet capable of providing a product suitable for fast reactor fuels from a thermal fuel feed. Our objectives are to: 1. Prove that U, Pu and MAs can be separated to the required purities and in a mixed product for conversion to fast reactor fuel. 2. Prove that the liquid product from a hydrometallurgical separation process can be converted to the required form for fast reactor fuel manufacture. 3. Prove that a new hydrometallurgical separation process can operate within current solvent extraction technologies. 4. Prove that new technologies are available that will offer benefits over current solvent extraction technologies. The project on Minor Actinide Separations will investigate new hydrophobic extractants use in separation of MAs from lanthanides, group actinide separations and Am/Cm separations. Specific Tasks include: - Direct Monitoring of Speciation in Minor Actinide Separations - Optimising Interfacial Transfer Kinetics during Minor Actinide Separations - Actinide Behaviour and Radiolysis Effects of Complexants in Minor Actinide Separations - Ligand Structure-Activity Relationship Development The project on Advanced Separations Technology includes the following tasks: - Develop a better understanding of conventional solvent extraction technology - High efficiency extractions using intensified processes - Continuous Chromatographic Separation of Actinides and Fission Products The final project concerns Product Conversion to Fuel, and will develop the fundamental molten salt technology to take the product from a PUREX plant and convert it efficiently through direct reduction to metal, considering proliferation resistance and waste minimisation. Tasks include: - Establishment and optimisation of the process for direct reduction of spent fuel - Decontamination and immobilisation of pyroprocessing wastes.