Formulation of engineering design principles for the treatment of irradiated fuel and associated radioactive waste

The industrial scale treatment of irradiated fuel in the UK has resulted in BNFL developing extensive experience of the process design, build, commissioning, and operation necessary for successful nuclear processing plant. Much of the design experience now resides in Nexia Solutions (formally BNFL Research and Development Division) who have always defined and undertaken the extensive development programmes necessary to underpin the design at all stages of the project life-cycle. Since the 1990's, Nexia Solutions has built up a large portfolio of plant designs for a range of spent fuel applications, from fuel conditioning to partitioning and transmutation. In addition, by investigation of a large and diverse portfolio of technologies Nexia Solutions has developed innovative concepts for plant design that could present significant economic savings on conventional approaches. Using this experience and the lessons learned, we have developed and refined our own engineering design principles necessary for the successful design of commercial spent fuel and waste treatment plant. Our approach is to advocate an integral concept, with both science and engineering designs working in parallel during development. 4 foundation principles for success have been identified: -) understand the strategic objective, -) adopt a risk driven programme, -) engage in engineering activities early, and -) timely application of appropriate engineering methodologies. 2 Case studies presented in this paper: first, the BNFL segregated effluent treatment plant and secondly, the selection of a pyrochemical process for recycle of fast reactor, demonstrate how this approach has been adopted and the benefits that have been gained