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Title: Alternative Applications of Homogeneous Thoria-Urania Fuel in Light Water Reactors to Enhance the Economics of the Thorium Fuel Cycle

Journal Article · · Nuclear Technology
DOI:https://doi.org/10.13182/NT03-30· OSTI ID:20837865

Since the thorium-based fuel has many incentives including the reduction of plutonium generation and long-lived radiotoxic isotope production, the research on the use of thorium as a nuclear fuel for nuclear power reactors has been performed and will last for a long time. Focus is on the fuel economics of the thorium-based cycle for light water reactors (LWRs). Analyses show that the neutronic behavior of a mixed thorium and uranium dioxide (Th + U)O{sub 2} core in a pressurized water reactor (PWR) will not be significantly different from that of a UO{sub 2} core. This implies that homogeneous (Th + U)O{sub 2} fuel can be used in PWRs instead of the current UO{sub 2} fuel without any significant mechanical modification of the fuel design and without any change in the nuclear design limits. However, homogeneous (Th + U)O{sub 2} has not shown any economic advantage over UO{sub 2} fuel when current fuel management strategies are used. Thus, alternative applications of homogeneous (Th + U)O{sub 2} fuel in LWRs have been investigated to enhance the economics of the thorium fuel cycle. Specifically, thorium-uranium fuel with a {sup 235}U enrichment significantly <19.5 wt%, mixed cores of both duplex (Th + U)O{sub 2} and UO{sub 2} fuel assemblies, and use of homogeneous thorium-uranium fuel in small-to-medium PWRs with a 5-yr cycle length have been investigated. The proposed alternatives result in far better fuel economics than the homogeneous thorium-uranium fuel cycle. However, the proposed alternatives do not show the economic merit of thorium-based fuel options for existing LWRs as compared to the UO{sub 2} fuel option. However, the inclusion of spent-fuel disposal costs in the fuel cost estimate makes (Th + U)O{sub 2} fuel competitive with UO{sub 2} fuel. In the case of a spent-fuel disposal cost higher than 700 US$/kg HM, the long-lived core with better economic potential than the UO{sub 2}-fueled core may be realized with the homogeneous (Th + U)O{sub 2} fuel.

OSTI ID:
20837865
Journal Information:
Nuclear Technology, Vol. 147, Issue 1; Other Information: Copyright (c) 2006 American Nuclear Society (ANS), United States, All rights reserved. http://epubs.ans.org/; Country of input: International Atomic Energy Agency (IAEA); ISSN 0029-5450
Country of Publication:
United States
Language:
English