Bubble evolution in Kr-irradiated UO₂ during annealing

Journal Article · 27 September 2017 · Journal of Nuclear Materials

DOI: https://doi.org/10.1016/j.jnucmat.2017.09.036 · OSTI ID:1396012

He, L.  ^[1]; Bai, X. M. ^[2]; Pakarinen, J. ^[3]; Jaques, B. J.  ^[4]; Gan, J.  ^[1]; Nelson, A. T.  ^[5]; El-Azab, A. ^[6]; Allen, T. R. ^[7]

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1. Idaho National Lab. (INL), Idaho Falls, ID (United States)
2. Virginia Polytechnic Inst. and State Univ. (Virginia Tech), Blacksburg, VA (United States). Dept. of Materials Science and Engineering
3. Belgian Nuclear Research Center (SCK-CEN), Mol (Belgium)
4. Boise State Univ., ID (United States). Dept. of Materials Science and Engineering
5. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
6. Purdue Univ., West Lafayette, IN (United States). School of Materials Engineering
7. Univ. of Wisconsin, Madison, WI (United States). Dept. of Engineering Physics

Transmission electron microscopy observation of Kr bubble evolution in polycrystalline UO₂ annealed at high temperature was conducted in order to understand the inert gas behavior in oxide nuclear fuel. The average size of intragranular bubbles increased gradually from 0.8 nm in as-irradiated sample at room temperature to 2.6 nm at 1600 °C and the bubble size distribution changed from a uniform distribution to a bimodal distribution above 1300 °C. The size of intergranular bubbles increased more rapidly than intragranular ones and bubble denude zones near grain boundaries formed in all the annealed samples. It was found that high-angle grain boundaries held bigger bubbles than low angle grain boundaries. Complementary atomistic modeling was conducted to interpret the effects of grain boundary character on the Kr segregation. Lastly, the area density of strong segregation sites in the high-angle grain boundaries is much higher than that in the low angle grain boundaries.

• Research Organization: Idaho National Laboratory, Idaho Falls, ID (United States)
• Sponsoring Organization: USDOE Office of Nuclear Energy (NE); USDOE Laboratory Directed Research and Development (LDRD) Program
• Grant/Contract Number: AC07-05ID14517
• OSTI ID: 1396012
• Report Number(s): INL/JOU--17-42658; PII: S0022311514006163
• Journal Information: Journal of Nuclear Materials, Journal Name: Journal of Nuclear Materials Journal Issue: C Vol. 496; ISSN 0022-3115
• Publisher: ElsevierCopyright Statement
• Country of Publication: United States
• Language: English