The AREVA HTR fuel cycle: An analysis of technical issues and potential industrial solutions

摘要

The AREVA high temperature reactor (HTR) is a modular 600 MWt high temperature gas-cooled reactor that provides up to 950℃ process helium for power generation and/or hydrogen production. Energy facilities based on this technology will consist of up to four AREVA HTR modules achieving high thermodynamic efficiency with a total possible electrical generation capability of 1200 MWe. At the heart of the AREVA HTR is the TRISO-coated low-enriched uranium (LEU) fuel which is assembled into fuel compacts that are inserted into prismatic graphite fuel elements. The intent of this paper is to examine the AREVA HTR fuel and fuel cycle from two perspectives. First, from the "front-end" perspective, the available fuel cycle-related options are examined along with the basis for the subsequent choice of fuel type and cycle. Second, from the "back-end" perspective, the generation and management of spent fuel and graphite waste is examined along with the strategies and options available for disposition or disposal. The AREVA HTR has the inherent flexibility to accommodate many fuel types and to permit full cost-effective optimization. The reasons for this flexibility are presented and the main advantages and disadvantages of the various fuels cycle are discussed. The reference fuel cycle for the AREVA HTR is then introduced and its main features are given. Additionally, non-proliferation attributes of the AREVA HTR technology are also examined. The amount of spent fuel and graphite waste generated by the AREVA HTR is governed by the burn-up capability of the fuel and the longevity of the adjacent graphite reflector blocks. As currently envisioned, the AREVA HTR will need to be refueled every 18 months, with 50% of the core being replaced. Additionally, the graphite reflector blocks will need to be replaced at regular intervals. Given a 60-year design life, approximately 20,000 spent fuel elements and 10,000 graphite reflectors blocks will be generated. The near-term and long-term options for dealing with these waste streams are examined and, as with the front end of the fuel cycle, a reference strategy for spent fuel and graphite waste proposed.