Minor actinide transmutation in thorium and uranium matrices in heavy water moderated reactors

Conference · Mon Jul 01 00:00:00 EDT 2013

OSTI ID:22257885

Bhatti, Zaki; Hyland, B.; Edwards, G. W.R. ^[1]

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1. Atomic Energy of Canada Limited, Chalk River Laboratories, 1 Plant Road, Chalk River, Ontario, K0J 1J0 (Canada)

The irradiation of Th{sup 232} breeds fewer of the problematic minor actinides (Np, Am, Cm) than the irradiation of U{sup 238}. This characteristic makes thorium an attractive potential matrix for the transmutation of these minor actinides, as these species can be transmuted without the creation of new actinides as is the case with a uranium fuel matrix. Minor actinides are the main contributors to long term decay heat and radiotoxicity of spent fuel, so reducing their concentration can greatly increase the capacity of a long term deep geological repository. Mixing minor actinides with thorium, three times more common in the Earth's crust than natural uranium, has the additional advantage of improving the sustainability of the fuel cycle. In this work, lattice cell calculations have been performed to determine the results of transmuting minor actinides from light water reactor spent fuel in a thorium matrix. 15-year-cooled group-extracted transuranic elements (Np, Pu, Am, Cm) from light water reactor (LWR) spent fuel were used as the fissile component in a thorium-based fuel in a heavy water moderated reactor (HWR). The minor actinide (MA) transmutation rates, spent fuel activity, decay heat and radiotoxicity, are compared with those obtained when the MA were mixed instead with natural uranium and taken to the same burnup. Each bundle contained a central pin containing a burnable neutron absorber whose initial concentration was adjusted to have the same reactivity response (in units of the delayed neutron fraction β) for coolant voiding as standard NU fuel. (authors)

• Research Organization: American Nuclear Society, 555 North Kensington Avenue, La Grange Park, IL 60526 (United States)
• OSTI ID: 22257885
• Resource Relation: Conference: GLOBAL 2013: International Nuclear Fuel Cycle Conference - Nuclear Energy at a Crossroads, Salt Lake City, UT (United States), 29 Sep - 3 Oct 2013; Other Information: Country of input: France; 11 refs.; Related Information: In: Proceedings of GLOBAL 2013: International Nuclear Fuel Cycle Conference - Nuclear Energy at a Crossroads| 1633 p.
• Country of Publication: United States
• Language: English

Related Subjects

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
AFTER-HEAT
BURNUP
COMPARATIVE EVALUATIONS
DELAYED NEUTRON FRACTION
FUEL CYCLE
HEAVY WATER MODERATED REACTORS
IRRADIATION
MIXING
NATURAL URANIUM
NEUTRON ABSORBERS
SPENT FUELS
THORIUM
THORIUM 232
TRANSMUTATION
TRANSURANIUM ELEMENTS
URANIUM 238
WATER COOLED REACTORS
WATER MODERATED REACTORS