Thermal properties of U-Mo alloys irradiated under high fission power density

JOURNAL OF NUCLEAR MATERIALS

卷:547

Article

Burkes, Douglas E.¹  Schwerdt, Ian J.¹  Huber, Tanja K.²  Breitkreutz, Harald²  Reiter, Christian²  Petry, Winfried²  Schulthess, Jason L.³  Casella, Andrew M.¹  Casella, Amanda J.¹  Buck, Edgar C.¹  Pool, Karl N.¹  MacFarlan, Paul J.¹  Edwards, Matthew K.¹  Smith, Frances N.¹ 

[1] Pacific Northwest Natl Lab, POB 999, Richland, WA 99352 USA

[2] Tech Univ Munich, Forsch Neutronenquelle Heinz Maier Leibnitz, Lichtenbergstr 1, D-85748 Garching, Germany

[3] Idaho Natl Lab, 1955 N Fremont Ave, Idaho Falls, ID 83415 USA

关键词: Uranium;    Molybdenum;    Nuclear fuel;    Research reactor;    Thermal properties;   

DOI  :  10.1016/j.jnucmat.2021.152823

来源: Elsevier

【 摘 要 】

A variety of physical and thermal property measurements made on irradiated U-Mo alloy monolithic fuel samples with a Zr diffusion barrier and clad in Al alloy 6061 are reported. These properties form the basis for additional investigations in thermal behavior of U-Mo fuel under high performance research reactor irradiation conditions. Measurements were performed on samples harvested from fuel plates irradiated under high fission power density and surface heat flux and complement previous measurements on samples subjected to moderate fission power density and surface heat flux. Sample measurements reported in this work represented fission density ranging from 2.42 - 4.81 x 10(27) fissions.m(-3) (20.8 - 36.5 U-235 depletion) and average plate surface temperatures from 355 - 414 K. Specific heat capacity of irradiated monolithic U-Mo increases with increasing temperature and fission density, but carries large uncertainties associated with thickness measurements used to determine the mass fraction of the layer constituents for extraction of the U-Mo specific heat capacity, specifically the very thin and nonuniform Zr diffusion barrier. Density of irradiated monolithic U-Mo decreases with increasing fission density resulting from fission gas swelling and porosity formation. Thermal diffusivity of irradiated monolithic U-Mo increased with increasing temperature and decreased with increasing fission density. Thermal conductivity of irradiated monolithic U-Mo increased with increasing temperature, and in general, appeared to decrease and become less sensitive to temperature with increasing fission density. Thermal conductivity measurements compared to a semi-empirical model agreed within +/- 30%. It is suspected that the main driver in deviation between model calculations and measurements is the fission gas swelling determination, which does not account for fission power density or irradiation temperature. (C) 2021 Elsevier B.V. All rights reserved.

【 授权许可】

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