TY - JOUR
T1 - Transmission electron microscopy characterization of the fuel-cladding chemical interactions in HT9 cladded U-10Zr fuel
AU - Wang, Yachun
AU - Miller, Brandon D.
AU - Harp, Jason M.
AU - Salvato, Daniele
AU - Capriotti, Luca
AU - Yao, Tiankai
N1 - Funding Information:
The authors acknowledge the financial support of the U.S. Department of Energy, Advanced Fuels Campaign of the Fuel Cycle R&D program in the Office of Nuclear Energy for sample preparation and irradiation experiments. The microstructure characterization and phase identification were supported by a Laboratory Directed Research and Development Project (22A1059-094FP) under the U.S. Department of Energy , Office of Nuclear Energy, Idaho Operations Office Contract DE-AC07-051D14517 . Accordingly, the U.S. Government retains and the publisher, by accepting the article for publication, acknowledges that the U.S. Government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript or allow others to do so, for U.S. Government purposes.
Funding Information:
The authors acknowledge the financial support of the U.S. Department of Energy, Advanced Fuels Campaign of the Fuel Cycle R&D program in the Office of Nuclear Energy for sample preparation and irradiation experiments. The microstructure characterization and phase identification were supported by a Laboratory Directed Research and Development Project (22A1059-094FP) under the U.S. Department of Energy, Office of Nuclear Energy, Idaho Operations Office Contract DE-AC07-051D14517. Accordingly, the U.S. Government retains and the publisher, by accepting the article for publication, acknowledges that the U.S. Government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript or allow others to do so, for U.S. Government purposes.
Publisher Copyright:
© 2022
PY - 2022/12/15
Y1 - 2022/12/15
N2 - Fuel cladding chemical interaction (FCCI) is a key phenomenon needs to be better understood to establish the design basis for U-10Zr metallic fuel performance. Characterizing the microstructure and chemical composition of FCCI at micron and sub-micron scale is critically important toward a more mechanistic understanding of FCCI phenomenon and its potential effects on cladding integrity and metallic fuel performance. This paper, by using transmission electron microscopy, investigated the FCCI region in HT9 cladded U-10Zr fuel irradiated to 5.7% FIMA burnup at a peak inner cladding temperature of 615 °C in Fast Flux Test Facility (FFTF). Four distinct layers are identified in the FCCI region. The migration of Fe into the fuel side leads to the formation of several U-Zr-Fe ternary phases, including χ-Fe0.5Zr0.32U0.18, ε-Fe0.3Zr0.4U0.3, and λ-Fe0.06Zr0.23U0.71, mingled with UFe2, U6Fe, and U phase at various Fe penetration depth up to ∼ 150 µm. On the cladding side, grain coarsening and significant lanthanides infiltration along grain boundaries are observed. Laves phase, (Fe,Cr)2(Mo,W), which typically does not exist in fresh HT9, is identified in a wide radial range in the cladding. The typical HT9 martensitic lath structure and pre-existing M23C6 precipitates disappear, partially or completely, depending on the radial distance from the fuel-cladding interface. Those microstructural and compositional changes could cause mechanical degradation in the HT9 cladding. The present characterization results will improve the understanding of FCCI phenomenon and facilitate the development of microstructure-informed FCCI modeling for metallic fuel.
AB - Fuel cladding chemical interaction (FCCI) is a key phenomenon needs to be better understood to establish the design basis for U-10Zr metallic fuel performance. Characterizing the microstructure and chemical composition of FCCI at micron and sub-micron scale is critically important toward a more mechanistic understanding of FCCI phenomenon and its potential effects on cladding integrity and metallic fuel performance. This paper, by using transmission electron microscopy, investigated the FCCI region in HT9 cladded U-10Zr fuel irradiated to 5.7% FIMA burnup at a peak inner cladding temperature of 615 °C in Fast Flux Test Facility (FFTF). Four distinct layers are identified in the FCCI region. The migration of Fe into the fuel side leads to the formation of several U-Zr-Fe ternary phases, including χ-Fe0.5Zr0.32U0.18, ε-Fe0.3Zr0.4U0.3, and λ-Fe0.06Zr0.23U0.71, mingled with UFe2, U6Fe, and U phase at various Fe penetration depth up to ∼ 150 µm. On the cladding side, grain coarsening and significant lanthanides infiltration along grain boundaries are observed. Laves phase, (Fe,Cr)2(Mo,W), which typically does not exist in fresh HT9, is identified in a wide radial range in the cladding. The typical HT9 martensitic lath structure and pre-existing M23C6 precipitates disappear, partially or completely, depending on the radial distance from the fuel-cladding interface. Those microstructural and compositional changes could cause mechanical degradation in the HT9 cladding. The present characterization results will improve the understanding of FCCI phenomenon and facilitate the development of microstructure-informed FCCI modeling for metallic fuel.
KW - Fuel-cladding chemical interaction (FCCI)
KW - HT9 cladding
KW - Laves phase
KW - Transmission electron microscopy
KW - U-10Zr metallic fuel
KW - U-Zr-Fe ternary phase
UR - https://www.scopus.com/pages/publications/85138453325
UR - https://www.mendeley.com/catalogue/a262dceb-088b-32bb-a312-c895f3a922fb/
U2 - 10.1016/j.jnucmat.2022.153990
DO - 10.1016/j.jnucmat.2022.153990
M3 - Article
AN - SCOPUS:85138453325
SN - 0022-3115
VL - 572
JO - Journal of Nuclear Materials
JF - Journal of Nuclear Materials
M1 - 153990
ER -