Inhibiting laser oxidation of UO2 via Th substitution

JOURNAL OF NUCLEAR MATERIALS

卷:517

Article

Rickert, K.^1,2  Prusnick, T. A.^1,2  Hunt, E.¹  Kimani, M. M.¹  Chastang, S.^1,2  Brooks, D. L.¹  Moore, E. A.^1,2  Petrosky, J. C.³  Mann, J. M.¹ 

[1] US Air Force, Res Lab, Sensors Directorate, Wright Patterson AFB, OH 45433 USA

[2] KBRwyle, Dayton, OH 45431 USA

[3] US Air Force, Inst Technol, Dept Engn Phys, 2950 Hobson Way, Wright Patterson AFB, OH 45433 USA

关键词: Oxidation;    Raman spectroscopy;    Single crystal;    Spent nuclear fuel;    ThO2;    Thorium dioxide;    UO2;    Uranium dioxide;    (U,Th)O-2;    UxTh1-xO2;   

DOI  :  10.1016/j.jnucmat.2019.02.005

来源: Elsevier

【 摘 要 】

UO2, a major component of nuclear fuels, undergoes volume-changing oxidation reactions that make its long-term storage challenging. The impact of substituting Th, which has a stable oxidation state of 4 + as opposed to the stable 6+, 5+, or 4 + states of U, into UO2 on the oxidation potential of the resulting isostructural solid solution is investigated. Hydrothermally grown single crystals of UxTh1-xO2, with x = 0.1, 0.5, 0.75, 0.9, or 1.0 are subjected to a damaging 532 nm laser whose power is tuned at > 3.04 mW to be simultaneously used as a driving force for oxidation and as an excitation source for mu-Raman spectroscopy. In so doing, the oxidation of UxTh1-xO2 to UxTh1-xO2+delta when x = 0.9 or 0.75 can be tracked by the evolution of a peak near 630 cm(-1), which is indicative of the formation of oxygen interstitials. Higher Th contents disable this oxidation reaction and engender increased laser damage resistance. The oxidation of UO2 to U3O8 is found to be completely inhibited by all Th contents studied. (C) 2019 Published by Elsevier B.V.

【 授权许可】

Free