Nuclear Fuel Cycles for Mid-Century Deployment by Etienne Parent B. Eng. – Mechanical Engineering (2000) McGill University – Canada Submitted to the Department of Nuclear Engineering in partial fulfillment of the requirements for the degree of Master of Science in Nuclear Engineering at the MASSACHUSETTS INSTITUTE OF TECHNOLOGY September 2003 © MIT, 2003, All rights reserved Author .................................................................................................................................... Department of Nuclear Engineering August 18, 2003 Certified by ............................................................................................................................ Neil E. Todreas KEPCO Professor of Nuclear Engineering Thesis Supervisor Certified by ............................................................................................................................ Michael J. Driscoll Professor Emeritus of Nuclear Engineering Thesis Reader Accepted by ........................................................................................................................... Jeffrey A. Coderre Associate Professor of Nuclear Engineering Chairman, Department Committee on Graduate Students Nuclear Fuel Cycles for Mid-century Deployment by Etienne Parent Submitted to the Department of Nuclear Engineering on August 18, 2003, in partial fulfillment of the requirements for the degree of Master of Science in Nuclear Engineering Abstract A comparative analysis of nuclear fuel cycles was carried out. Fuel cycles reviewed include: once-through fuel cycles in LWRs, PHWRs, HTGRs, and fast gas cooled breed and burn reactors; single-pass recycle schemes: plutonium recycle in LWRs and direct- use of spent PWR fuel in CANDU reactors (DUPIC); multi-pass recycle schemes: transmutation of transuranics in LWRs, fast reactors, double strata systems, and molten salt reactors. Mass flow calculations for the fuel cycles at equilibrium were carried out based on data available in the open literature, and results were used to compare the performance of the fuel cycles with respect to uranium utilization, waste management, proliferation resistance, and economics. Potential for mid-century deployment was assessed based on these results. Once-through fuel cycles based on solid fuel thermal reactors are found to be the best candidates for mid-century deployment because the substantial increase in electricity costs entailed by reprocessing schemes is unlikely to be justified by the afforded reductions in long-term proliferation and waste management risks. Furthermore, once-through cycles present lower proliferation and waste management risks in the short-term and their inefficient use of uranium is not likely to become an important issue before the middle of the century even under a high growth scenario. Thesis Supervisor: Neil E. Todreas Title: KEPCO Professor of Nuclear Engineering 2 Acknowledgements This thesis benefited from the work and input of several individuals. I am grateful to my advisor Neil Todreas and to Michael Driscoll for their review and comments. I must also thank several PhD students in the Department of Nuclear Engineering who have allowed me to benefit from their work, in particular Zhiwen Xu, Eugene Shwageraus, Antonino Romano, and Dean Wang. Finally, I learned a great deal from my involvement in the MIT Study on the Future of Nuclear Power. My interactions with the members of this project were extremely valuable in helping me develop an insight into the many technical, economic, and policy issues in nuclear energy. 3 TABLE OF CONTENTS 1 Introduction................................................................................................................. 5 2 Evaluation Metrics...................................................................................................... 6 2.1 Resource Utilization............................................................................................ 6 2.2 Waste................................................................................................................... 6 2.3 Proliferation ........................................................................................................ 7 2.4 Economics........................................................................................................... 8 2.5 Table of Metrics................................................................................................ 11 3 Analysis of Fuel Cycles ............................................................................................ 12 3.1 Once-Through................................................................................................... 12 3.1.1 Light Water Reactor.................................................................................. 12 3.1.2 Pressurized Heavy Water Reactor ............................................................ 20 3.1.3 High Temperature Gas Reactor ................................................................ 23 3.1.4 Seed and Blanket Thorium Reactor .......................................................... 29 3.1.5 Breed and Burn in Fast Reactor................................................................ 33 3.2 Closed Fuel Cycles ........................................................................................... 37 3.2.1 Plutonium Recycle in Light Water Reactor.............................................. 37 3.2.2 DUPIC Fuel Cycle .................................................................................... 42 3.2.3 Actinide recycle in Light Water Reactor .................................................. 46 3.2.4 Actinide Recycle in Fast Reactor.............................................................. 53 3.2.5 Double Strata Strategy .............................................................................. 56 3.2.6 Actinide Recycle in Molten Salt Reactor.................................................. 67 4 Outlook for Mid-Century Deployment ..................................................................... 74 4.1 Assessment of fuel cycles ................................................................................. 74 4.1.1 Uranium utilization ................................................................................... 74 4.1.2 Waste......................................................................................................... 75 4.1.3 Proliferation .............................................................................................. 76 4.1.4 Economics................................................................................................. 78 4.2 Outlook for mid-century deployment ............................................................... 80 5 Future Work.............................................................................................................. 86 References......................................................................................................................... 88 Appendices........................................................................................................................ 91 A Uranium Resources................................................................................................... 92 B Physics of Transmutation.......................................................................................... 99 B.1 Actinide Transmutation .................................................................................... 99 B.2 Fission Product Transmutation ....................................................................... 107 C Fuel Cycle Cost: Once-through vs. Pu Recycle...................................................... 112 4 1 Introduction The current nuclear industry is based predominantly on light water reactors (LWR), which account for almost 90% of installed capacity, with pressurized heavy water reactors (PHWR) also making a significant contribution with 5% of installed capacity. Most of these reactors operate on the once-through fuel cycle, where natural uranium is enriched to make uranium oxide (UOX) fuel, and, after irradiation, the spent fuel is encapsulated and disposed of directly in the repository. On the other hand, several countries choose to reprocess their spent fuel. Worldwide, a sizable fraction (>10%) of spent LWR fuel is reprocessed in order to extract plutonium1, which is recycled and used to make mixed oxide (MOX) fuel. The mixed oxide fuel is irradiated in conventional PWRs and then sent to the repository2. This fuel cycle is usually referred to as single-pass plutonium recycling. The reactors and fuel cycles identified above, which dominate today’s nuclear electricity industry, represent only a small subset of possibilities. Researchers in the field of nuclear energy have devoted much time and effort to devise fuel cycles that improve on today’s technology. Proposals for innovative reactors and fuel cycles abound in the open literature but none has emerged as a clear winner, as each one has its particular strengths and weaknesses. This situation has spurred efforts to review, evaluate, and compare fuel cycles on a methodical basis. The present study is one such effort, where the emphasis is placed on identifying fuel cycles that constitute viable options for mid-century deployment, meaning that their characteristics must match the needs of the nuclear electricity industry in the coming decades and that a significant deployment is feasible on this time scale. A literature review was conducted to identify