SUSTAINABILITY AND PROLIFERATION RESISTANCE ASSESSMENT OF OPEN CYCLE THORIUM-FUELLED NUCLEAR ENERGY William J. Nuttall Senior Lecturer Technology Policy University of Cambridge, UK Cambridge Nuclear Energy Centre

Project partners Cambridge Judge Business School (Dr WJ Nuttall) Cambridge University Engineering Department (Dr RA Fenner and Dr GT Parks) National Nuclear Laboratory, UK (Prof A Worrall) Bhabha Atomic Research Centre, India (Prof PD Krishnani)

Goals: Sustainability Assessment Proliferation Assessment Integrated Assessment Work Packages: WP1: Proliferation Resistance Methods WP2: Sustainability Methods WP3: Assess Reactor Concepts WP4: Analysis tools WP5 Open Cycle Th Assessment

Sustainability Assessment A sustainability assessment framework specific to thorium nuclear reactors will be developed, drawing on existing literature. This will be based on the Life Cycle Assessment (LCA) and Multi-Criteria Decision Analysis (MCDA) methodologies. We shall consider a wide system boundary for the assessment going beyond the reactor site to include mining operations for thorium etc. The assessment will focus on two key goals: To compare the thorium full life cycle to that of uranium-fuelled LWRs and To enable the identification of relative differences in sustainability between different thorium reactor concepts.

Proliferation Assessment Drawing upon both qualitative and quantitative experience and expertise from all project collaborators the NNL's Proliferation Resistance Methodology will be applied to open cycle thorium fuelled nuclear energy - meaning that all partners have a contribution to make to the inputs of the analysis if not the actual tools. The relevant tools here include the reactor physics tools to assist in producing the material inventories/isotopics that are relevant, as well as NNL's fuel cycle modelling tools ORION and FCM. Possible Target Systems: Advanced Heavy Water Reactor AHWR-LEU, for which it is possible to increase the utilization of uranium resources by using Th-LEU fuel High Temperature Gas Cooled Graphite moderated reactor

Integrated Assessment Framework (IAF) The Sustainability and Proliferation Assessments will be constructed with a view to producing a quantitative Integrated Assessment Framework The IAF might take the form of a spreadsheet with associated scripted algorithms suitable for public disclosure and discussion.

Team Working The Project Researcher will visit NNL (total time 2 weeks) and be granted appropriate access to software and literature relevant to NNL’s existing Multi-Attribute Utility Analysis (MAUA) tools, fuel cycle modelling tools and reactor physics tools. Members of NNL will teach aspects of these tools and techniques to the Researcher. The Project Researcher will make two extended visits to the BARC laboratory, with the senior UK investigators making shorter visits, as necessary. Researchers at BARC have agreed to provide results from their detailed calculations on thorium fuel burn-up and other relevant studies, such as the required quantity of materials and the radioactivity of ancillary materials (e.g. coolant).

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