Irradiation effects on thermal properties of LWR hydride fuel

• Published in: Journal of nuclear materials Vol. 486; no. C; pp. 381 - 390
• Main Authors: Terrani, Kurt, Balooch, Mehdi, Carpenter, David, Kohse, Gordon, Keiser, Dennis, Meyer, Mitchell, Olander, Donald
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.04.2017; Elsevier BV; Elsevier
• Subjects: Bismuth base alloys; Cladding; Fuel irradiation; Fuels; Heat transfer; Irradiation; Light water reactors; Nuclear fuel elements; Nuclear fuels; Radiation; Rods; Temperature effects; Thermal conductivity; Thermal properties; Thermocouples; Thermodynamic properties; Tips; Uranium; Uranium-zirconium hydride fuel; Zircaloys (trademark); Zirconium; Fuel irradiation; Uranium-zirconium hydride fuel
• ISSN: 0022-3115; 1873-4820
• DOI: 10.1016/j.jnucmat.2017.01.030

Three hydride mini-fuel rods were fabricated and irradiated at the MIT nuclear reactor with a maximum burnup of 0.31% FIMA or ∼5 MWd/kgU equivalent oxide fuel burnup. Fuel rods consisted of uranium-zirconium hydride (U (30 wt%)ZrH1.6) pellets clad inside a LWR Zircaloy-2 tubing. The gap between the fuel and the cladding was filled with lead-bismuth eutectic alloy to eliminate the gas gap and the large temperature drop across it. Each mini-fuel rod was instrumented with two thermocouples with tips that are axially located halfway through the fuel centerline and cladding surface. In-pile temperature measurements enabled calculation of thermal conductivity in this fuel as a function of temperature and burnup. In-pile thermal conductivity at the beginning of test agreed well with out-of-pile measurements on unirradiated fuel and decreased rapidly with burnup.