α-U and ω-UZr2 in neutron irradiated U-10Zr annular metallic fuel

Tiankai Yao; Luca Capriotti; Jason M. Harp; Xiang Liu; Yachun Wang; Fei Teng; Daniel J. Murray; Alex J. Winston; Jian Gan; Michael T. Benson; Lingfeng He

doi:10.1016/j.jnucmat.2020.152536

α-U and ω-UZr₂ in neutron irradiated U-10Zr annular metallic fuel

Tiankai Yao, Luca Capriotti, Jason M. Harp, Xiang Liu, Yachun Wang, Fei Teng, Daniel J. Murray, Alex J. Winston, Jian Gan, Michael T. Benson, Lingfeng He

Nuclear Fuel Element Performance

Idaho National Laboratory

Research output: Contribution to journal › Article › peer-review

27 Scopus citations

Abstract

To develop metallic fuel with ultra-high burnup of 30%-40%, an annular U-10Zr fuel with 55% smear density was fabricated through a casting route and irradiated at the Advanced Test Reactor at Idaho National Laboratory. The annular fuel design also serves as a demonstration of the feasibility to replace the sodium bond with a helium bond to benefit the geological disposal of irradiated fuel, cut the cost of fuel fabrication, and boosts the overall metallic fuel economy. This paper reports the results from transmission electron microscopy (TEM) based post-irradiation examination of this fuel type irradiated to a burnup of 3.3% fissions per initial heavy metal atoms. The low burnup was planned for initial screening of this fuel design. After irradiation, the initial U-10Zr microstructure separated into an α-U annular region and an UZr_2+x center region with a nanoscale spinodal decomposed microstructure. Because of the large amount of interface areas created in this microstructure, the fission gas atoms and vacancies generated in the UZr_2+x phase are possibly pinned at the interface areas, leading to ~20 times smaller fission gas bubbles than those in the neighboring α-U. The large bubbles in α-U become connected and merged into large pores that provide fast paths for fission gas release into capsule plenum which prevents further swelling of fuel slug. The fuel slug center still has open space to accommodate further fuel swelling from solid fission products at higher burnup. Other neutron irradiation induced phase and microstructure change are also characterized and compared with traditional solid fuel designs.

Original language	English
Article number	152536
Journal	Journal of Nuclear Materials
Volume	542
DOIs	https://doi.org/10.1016/j.jnucmat.2020.152536
State	Published - Dec 15 2020

Bibliographical note

Publisher Copyright:
© 2020 Elsevier B.V.

Funding

This work was financially supported by the Center for Thermal Energy Transport under Irradiation, an Energy Frontier Research Center funded by the Office of Science, Basic Energy Sciences. This research used resources of the Irradiated Materials Characterization Laboratory, which is supported by U.S. Department of Energy, Office of Nuclear Energy under DOE Idaho Operations Office Contract DE-AC07-051D14517. This manuscript has been authored in part by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy. The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (http://energy.gov/downloads/doe-public-access-plan). This work was financially supported by the Center for Thermal Energy Transport under Irradiation, an Energy Frontier Research Center funded by the Office of Science, Basic Energy Sciences. This research used resources of the Irradiated Materials Characterization Laboratory, which is supported by U.S. Department of Energy , Office of Nuclear Energy under DOE Idaho Operations Office Contract DE-AC07-051D14517 . This manuscript has been authored in part by UT-Battelle, LLC under Contract No. DE-AC05-00OR22725 with the U.S. Department of Energy . The United States Government retains and the publisher, by accepting the article for publication, acknowledges that the United States Government retains a non-exclusive, paid-up, irrevocable, world-wide license to publish or reproduce the published form of this manuscript, or allow others to do so, for United States Government purposes. The Department of Energy will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan ( http://energy.gov/downloads/doe-public-access-plan ).

Funders	Funder number
Center for Thermal Energy Transport
DOE Public Access Plan
United States Government
U.S. Department of Energy	DE-AC05-00OR22725, DE-AC07-051D14517
Office of Science
Office of Nuclear Energy
Basic Energy Sciences

Keywords

Annular fuel
Metallic fuel
Microstructure
Radiation damage
Spinodal decomposition
Swelling

UN SDGs

This output contributes to the following UN Sustainable Development Goals (SDGs)

Access to Document

10.1016/j.jnucmat.2020.152536

Cite this

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title = "α-U and ω-UZr2 in neutron irradiated U-10Zr annular metallic fuel",

abstract = "To develop metallic fuel with ultra-high burnup of 30%-40%, an annular U-10Zr fuel with 55% smear density was fabricated through a casting route and irradiated at the Advanced Test Reactor at Idaho National Laboratory. The annular fuel design also serves as a demonstration of the feasibility to replace the sodium bond with a helium bond to benefit the geological disposal of irradiated fuel, cut the cost of fuel fabrication, and boosts the overall metallic fuel economy. This paper reports the results from transmission electron microscopy (TEM) based post-irradiation examination of this fuel type irradiated to a burnup of 3.3% fissions per initial heavy metal atoms. The low burnup was planned for initial screening of this fuel design. After irradiation, the initial U-10Zr microstructure separated into an α-U annular region and an UZr2+x center region with a nanoscale spinodal decomposed microstructure. Because of the large amount of interface areas created in this microstructure, the fission gas atoms and vacancies generated in the UZr2+x phase are possibly pinned at the interface areas, leading to ~20 times smaller fission gas bubbles than those in the neighboring α-U. The large bubbles in α-U become connected and merged into large pores that provide fast paths for fission gas release into capsule plenum which prevents further swelling of fuel slug. The fuel slug center still has open space to accommodate further fuel swelling from solid fission products at higher burnup. Other neutron irradiation induced phase and microstructure change are also characterized and compared with traditional solid fuel designs.",

keywords = "Annular fuel, Metallic fuel, Microstructure, Radiation damage, Spinodal decomposition, Swelling",

author = "Tiankai Yao and Luca Capriotti and Harp, {Jason M.} and Xiang Liu and Yachun Wang and Fei Teng and Murray, {Daniel J.} and Winston, {Alex J.} and Jian Gan and Benson, {Michael T.} and Lingfeng He",

note = "Publisher Copyright: {\textcopyright} 2020 Elsevier B.V.",

year = "2020",

month = dec,

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doi = "10.1016/j.jnucmat.2020.152536",

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AU - Yao, Tiankai

AU - Capriotti, Luca

AU - Harp, Jason M.

AU - Liu, Xiang

AU - Wang, Yachun

AU - Teng, Fei

AU - Murray, Daniel J.

AU - Winston, Alex J.

AU - Gan, Jian

AU - Benson, Michael T.

AU - He, Lingfeng

PY - 2020/12/15

Y1 - 2020/12/15

N2 - To develop metallic fuel with ultra-high burnup of 30%-40%, an annular U-10Zr fuel with 55% smear density was fabricated through a casting route and irradiated at the Advanced Test Reactor at Idaho National Laboratory. The annular fuel design also serves as a demonstration of the feasibility to replace the sodium bond with a helium bond to benefit the geological disposal of irradiated fuel, cut the cost of fuel fabrication, and boosts the overall metallic fuel economy. This paper reports the results from transmission electron microscopy (TEM) based post-irradiation examination of this fuel type irradiated to a burnup of 3.3% fissions per initial heavy metal atoms. The low burnup was planned for initial screening of this fuel design. After irradiation, the initial U-10Zr microstructure separated into an α-U annular region and an UZr2+x center region with a nanoscale spinodal decomposed microstructure. Because of the large amount of interface areas created in this microstructure, the fission gas atoms and vacancies generated in the UZr2+x phase are possibly pinned at the interface areas, leading to ~20 times smaller fission gas bubbles than those in the neighboring α-U. The large bubbles in α-U become connected and merged into large pores that provide fast paths for fission gas release into capsule plenum which prevents further swelling of fuel slug. The fuel slug center still has open space to accommodate further fuel swelling from solid fission products at higher burnup. Other neutron irradiation induced phase and microstructure change are also characterized and compared with traditional solid fuel designs.

AB - To develop metallic fuel with ultra-high burnup of 30%-40%, an annular U-10Zr fuel with 55% smear density was fabricated through a casting route and irradiated at the Advanced Test Reactor at Idaho National Laboratory. The annular fuel design also serves as a demonstration of the feasibility to replace the sodium bond with a helium bond to benefit the geological disposal of irradiated fuel, cut the cost of fuel fabrication, and boosts the overall metallic fuel economy. This paper reports the results from transmission electron microscopy (TEM) based post-irradiation examination of this fuel type irradiated to a burnup of 3.3% fissions per initial heavy metal atoms. The low burnup was planned for initial screening of this fuel design. After irradiation, the initial U-10Zr microstructure separated into an α-U annular region and an UZr2+x center region with a nanoscale spinodal decomposed microstructure. Because of the large amount of interface areas created in this microstructure, the fission gas atoms and vacancies generated in the UZr2+x phase are possibly pinned at the interface areas, leading to ~20 times smaller fission gas bubbles than those in the neighboring α-U. The large bubbles in α-U become connected and merged into large pores that provide fast paths for fission gas release into capsule plenum which prevents further swelling of fuel slug. The fuel slug center still has open space to accommodate further fuel swelling from solid fission products at higher burnup. Other neutron irradiation induced phase and microstructure change are also characterized and compared with traditional solid fuel designs.

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