The effect of ion irradiation on the dissolution of UO2 and UO2-based simulant fuel

JOURNAL OF ALLOYS AND COMPOUNDS

卷:735

Article

Popel, Aleksej J.^1,2  Wietsma, Thomas W.³  Engelhard, Mark H.³  Lea, Alan S.³  Qafoku, Odeta⁴  Grygiel, Clara⁵  Monnet, Isabelle⁵  Ilton, Eugene S.⁴  Bowden, Mark E.³  Farnan, Ian¹ 

[1] Univ Cambridge, Dept Earth Sci, Downing St, Cambridge CB2 3EQ, England

[2] Imperial Coll London, Dept Mat, London SW7 2AZ, England

[3] Pacific Northwest Natl Lab, EMSL, Richland, WA 99352 USA

[4] Pacific Northwest Natl Lab, Richland, WA 99352 USA

[5] Univ Caen, ENSICAEN, CNRS, CIMAP,CEA, BP 5133, F-14070 Caen 5, France

关键词: UO2;    Simfuel;    Ion irradiation;    Radiation damage;    Dissolution;    Secondary phases;   

DOI  :  10.1016/j.jallcom.2017.11.216

来源: Elsevier

【 摘 要 】

The aim of this work was to study the separate effect of fission fragment damage on the dissolution of simulant UK advanced gas-cooled reactor nuclear fuel in water. Plain UO2 and UO2 samples, doped with inactive fission products to simulate 43 GWd/tU of burn-up, were fabricated. A set of these samples were then irradiated with 92 MeV Xe-129(23+) ions to a fluence of 4.8 x 10(15) ions/cm(2) to simulate the fission damage that occurs within nuclear fuels. The primary effect of the irradiation on the UO2 samples, observed by scanning electron microscopy, was to induce a smoothening of the surface features and formation of hollow blisters, which was attributed to multiple overlap of ion tracks. Dissolution experiments were conducted in single-pass flow-through (SPFT) mode under anoxic conditions (<0.1 O-2 ppm in Ar) to study the effect of the induced irradiation damage on the dissolution of the UO2 matrix with data collection capturing six minute intervals for several hours. These time-resolved data showed that the irradiated samples showed a higher initial release of uranium than unirradiated samples, but that the uranium concentrations converged towards similar to 10(-9) mol/l after a few hours. Apart from the initial spike in uranium concentration, attributed to irradiation induced surficial micro-structural changes, no noticeable difference in uranium chemistry as measured by X-ray electron spectroscopy or 'effective solubility' was observed between the irradiated, doped and undoped samples in this work. Some secondary phase formation was observed on the surface of UO2 samples after the dissolution experiment. (C) 2017 The Authors. Published by Elsevier B.V.

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