Indo - UK Civil Nuclear Collaboration on Damage and Radiation Effects in Amorphous Materials (DREAM)

The overarching objective of this proposal is to initiate an India-UK collaboration to lead development of understanding of radiation damage processes in nuclear waste glasses and glass composite materials. UK collaborators will contribute in two principal areas: provision of expertise in application of X-ray spectroscopy methods to radiation damaged materials and application of advanced analytical electron microscopy to glass and glass composite characterisation. Indian collaborators will bring many years of expertise in preparation and characterisation of radionuclide-containing nuclear glasses by electron spin and positron annihilation spectroscopies. This project will access world class central laboratories for materials irradiation and synchrotron radiation in the partner countries. The outcome of this collaboration will be to provide the fundamental understanding required to develop predictive models for performance of radiation damaged glasses in geological disposal facilities.The research programme will systematically investigate the potential for radiation induced phase separation and the impact of alpha-recoil damage on the structure, and speciation of redox active elements, in glass systems of relevance to nuclear waste immobilisation. Electron irradiation and ion beam implantation experiments will be performed to simulate the effects of beta- and alpha-decay, a combination of bulk spectroscopic and nano-scale chemical and imaging probes will be applied to determine the nature of point defects, phase separation and change in network polymerisation induced by different damage modes. We will also investigate the potential deleterious effects of radiation damage on glass dissolution rate through simple but informative alteration experiments. The proposed research is divided into three well defined research packages, with the following aims:Work Package 1: Radiation damage induced phase separation in model nuclear waste glassesThe aim of this WP is to develop an understanding of the mechanism of phase separation in nuclear waste glasses, under the influence of combined electron irradiation and radiogenic heating.Work Package 2: Radiation induced structural modification in model nuclear waste glassesThe aim of this WP is to develop an understanding of the effect of alpha-recoil damage on glass structure, using ion beam implantation combined with XAS and TEM.Work Package 3: Impact of radiation damage on dissolution of model nuclear waste glassesThe aim of this WP is to determine potential deleterious effects of radiation damage on glass dissolution, using internationally standardised short term experiments.

The primary end users of this research may include Sellafield Ltd., the Radioactive Waste Management Directorate (RWMD), the Environment Agency, the Health & Safety Executive, and the National Nuclear Laboratory who are responsible, respectively, for HLW glass production, radioactive waste disposal, regulatory concerns, safety of storage and disposal, and the nuclear skills pipeline. The benefit to these organisations and the public, over the whole grant lifecycle, include: - New scientific understanding and data required to support parameterisation of models for extended interim storage and eventual disposal of HLW glass. - Demonstration of a methodology to asses impact of radiation damage on wasteform performance, guiding more informed use of expensive and hazardous actinide doping experiments. - Potential future reduction of the estimated 18 Bn cost of radioactive waste disposal, through more appropriate design of disposal facility led by an improved understanding and confidence in wasteform behaviour. - Enhanced protection of the UK population from the risk of radioactive migration, achieved by supporting more accurate knowledge of radiation damage on radionuclide release rate. - Improved public confidence in UK radioactive waste disposal strategy, through provision of underpinning scientific understanding and data, which are currently absent. - A highly skilled and knowledgeable scientist for potential recruitment. Our research could be of potential benefit to a wider user base of public and private sector organisations, suchin diverse fields such as radiopharmaceuticals, medical imaging, and homeland security. The benefit to these organisations is likely to be new insight into the design of improved radiation hard or sensitive materials, based on new understanding of the interaction of radiation with solid matter. A further beneficiary of the proposed research is the Department for Business, Innovation & Skills, since the proposed collaboration with BARC will highlight the success of the India-UK Civil Nuclear Collaboration, acting as a catalyst for further collaboration and future trade. The identified benefits will extend over the whole grant life cycle. It is our intention to publish outputs in the open peer reviewed literature, which will be immediately available to our primary user base during the design phase of the geological disposal facility over the next decade or more - assisting in building public confidence. A further near term benefit will be the availability of a highly skilled scientist, for employment in an industry in which there is substantial demand for high calibre scientists. Cost saving and safety benefits, which may be substantial, would be delivered on a timescale of several decades to several decades to several millenia.