Irradiation creep measurement and microstructural analysis of chromium nitride–coated zirconium alloy using pressurized tubes

Padhraic L. Mulligan; Andrew T. Nelson; Chad M. Parish; Patrick A. Champlin; Xiang Chen; Daniel Morrall; Jason M. Harp

doi:10.1016/j.jnucmat.2023.154808

Irradiation creep measurement and microstructural analysis of chromium nitride–coated zirconium alloy using pressurized tubes

Padhraic L. Mulligan, Andrew T. Nelson, Chad M. Parish, Patrick A. Champlin, Xiang Chen, Daniel Morrall, Jason M. Harp

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

1 Scopus citations

Abstract

Environmental barrier coatings for Zr-based materials are currently under development to reduce oxidation and embrittlement in light-water reactors. Chromium nitride is one such candidate for this application, particularly as accident-tolerant fuel cladding. However, quantifying the impact of coatings on the irradiation-induced creep of zircaloy (Zry) is critical as this mechanism often exceeds thermal creep rates under light-water reactor operating conditions and can be a limiting design characteristic. Additionally, examining irradiation effects in the microstructure at the coating interface is key to understanding the compatibility of the material system. To accelerate the experimental measurement of irradiation creep and microstructure evolution in CrN-Zry, compact, pressurized creep tubes were fabricated and irradiated in the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory. Miniature, thin-walled rodlets fabricated from annealed Zr-Sn barstock were coated with CrN using physical vapor deposition (PVD) to nominal thicknesses of 4 and 8 μm. Coated and uncoated rodlet specimens were internally pressurized and welded, generating nominal circumferential hoop stresses of 0, 90, or 180 MPa under 300 ^∘C irradiation conditions. Twelve specimens were measured diametrically prior to irradiation using a low-cost, automated, contactless laser profilometer developed for this work. Specimens were irradiated in sealed capsules for one 25-day HFIR cycle, accumulating approximately 1.8×10²¹n/cm² fast fluence (E_n>1.0MeV). The irradiated samples were retrieved and remeasured using the same profilometry system in a shielded hot cell facility. Irradiation creep between specimens was compared using standard statistical tests and showed that both thicknesses of CrN coating had a negligible effect on the irradiation creep strain of the Zry material. Microstructure characterization of pre- and post-irradiated CrN-Zry specimens showed minimal changes due to irradiation but did show a substantial O-rich region at the Zry-CrN interface.

Original language	English
Article number	154808
Journal	Journal of Nuclear Materials
Volume	588
DOIs	https://doi.org/10.1016/j.jnucmat.2023.154808
State	Published - Jan 2024

Funding

Notice: This manuscript has been authored by UT-Battelle, LLC under contract DE-AC05-00OR22725 with the US Department of Energy (DOE). The US government retains and the publisher, by accepting the article for publication, acknowledges that the US 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 US government purposes. DOE 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 ). Research performed at Oak Ridge National Laboratory was supported by the US Department of Energy Office of Nuclear Energy Advanced Fuels Campaign under contract no. DE-AC05–00OR22725 with UT Battelle, LLC. The authors would like to thank Scarlet Clark, Annabelle Le Coq, Clay Morrison, and Stephanie Curlin for their assistance in performing this work and Candace Brakewood, Brandon Wilson, and Jacob Gorton for reviewing this manuscript. The selected area electron diffraction patterns were simulated using SingleCrystal: a diffraction program for Mac and Windows. CrystalMaker Software Ltd, Oxford, England ( www.crystalmaker.com ). Notice: This manuscript has been authored by UT-Battelle, LLC under contract DE-AC05-00OR22725 with the US Department of Energy (DOE). The US government retains and the publisher, by accepting the article for publication, acknowledges that the US 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 US government purposes. DOE 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).Research performed at Oak Ridge National Laboratory was supported by the US Department of Energy Office of Nuclear Energy Advanced Fuels Campaign under contract no. DE-AC05–00OR22725 with UT Battelle, LLC. The authors would like to thank Scarlet Clark, Annabelle Le Coq, Clay Morrison, and Stephanie Curlin for their assistance in performing this work and Candace Brakewood, Brandon Wilson, and Jacob Gorton for reviewing this manuscript. The selected area electron diffraction patterns were simulated using SingleCrystal: a diffraction program for Mac and Windows. CrystalMaker Software Ltd, Oxford, England (www.crystalmaker.com).

Funders	Funder number
DOE Public Access Plan
Jacob Gorton
US Department of Energy Office of Nuclear Energy Advanced Fuels Campaign	DE-AC05-00OR22725
U.S. Department of Energy

Keywords

Accident-tolerant fuel
Chromium nitride (CrN)
Cladding
Irradiation creep
Zircaloy

Access to Document

10.1016/j.jnucmat.2023.154808

Cite this

@article{f38df4eb64714447951d23d565f10d49,

title = "Irradiation creep measurement and microstructural analysis of chromium nitride–coated zirconium alloy using pressurized tubes",

abstract = "Environmental barrier coatings for Zr-based materials are currently under development to reduce oxidation and embrittlement in light-water reactors. Chromium nitride is one such candidate for this application, particularly as accident-tolerant fuel cladding. However, quantifying the impact of coatings on the irradiation-induced creep of zircaloy (Zry) is critical as this mechanism often exceeds thermal creep rates under light-water reactor operating conditions and can be a limiting design characteristic. Additionally, examining irradiation effects in the microstructure at the coating interface is key to understanding the compatibility of the material system. To accelerate the experimental measurement of irradiation creep and microstructure evolution in CrN-Zry, compact, pressurized creep tubes were fabricated and irradiated in the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory. Miniature, thin-walled rodlets fabricated from annealed Zr-Sn barstock were coated with CrN using physical vapor deposition (PVD) to nominal thicknesses of 4 and 8 μm. Coated and uncoated rodlet specimens were internally pressurized and welded, generating nominal circumferential hoop stresses of 0, 90, or 180 MPa under 300 ∘C irradiation conditions. Twelve specimens were measured diametrically prior to irradiation using a low-cost, automated, contactless laser profilometer developed for this work. Specimens were irradiated in sealed capsules for one 25-day HFIR cycle, accumulating approximately 1.8×1021n/cm2 fast fluence (En>1.0MeV). The irradiated samples were retrieved and remeasured using the same profilometry system in a shielded hot cell facility. Irradiation creep between specimens was compared using standard statistical tests and showed that both thicknesses of CrN coating had a negligible effect on the irradiation creep strain of the Zry material. Microstructure characterization of pre- and post-irradiated CrN-Zry specimens showed minimal changes due to irradiation but did show a substantial O-rich region at the Zry-CrN interface.",

keywords = "Accident-tolerant fuel, Chromium nitride (CrN), Cladding, Irradiation creep, Zircaloy",

author = "Mulligan, {Padhraic L.} and Nelson, {Andrew T.} and Parish, {Chad M.} and Champlin, {Patrick A.} and Xiang Chen and Daniel Morrall and Harp, {Jason M.}",

note = "Publisher Copyright: {\textcopyright} 2023 Elsevier B.V.",

year = "2024",

month = jan,

doi = "10.1016/j.jnucmat.2023.154808",

language = "English",

volume = "588",

journal = "Journal of Nuclear Materials",

issn = "0022-3115",

publisher = "Elsevier",

}

TY - JOUR

T1 - Irradiation creep measurement and microstructural analysis of chromium nitride–coated zirconium alloy using pressurized tubes

AU - Mulligan, Padhraic L.

AU - Nelson, Andrew T.

AU - Parish, Chad M.

AU - Champlin, Patrick A.

AU - Chen, Xiang

AU - Morrall, Daniel

AU - Harp, Jason M.

PY - 2024/1

Y1 - 2024/1

N2 - Environmental barrier coatings for Zr-based materials are currently under development to reduce oxidation and embrittlement in light-water reactors. Chromium nitride is one such candidate for this application, particularly as accident-tolerant fuel cladding. However, quantifying the impact of coatings on the irradiation-induced creep of zircaloy (Zry) is critical as this mechanism often exceeds thermal creep rates under light-water reactor operating conditions and can be a limiting design characteristic. Additionally, examining irradiation effects in the microstructure at the coating interface is key to understanding the compatibility of the material system. To accelerate the experimental measurement of irradiation creep and microstructure evolution in CrN-Zry, compact, pressurized creep tubes were fabricated and irradiated in the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory. Miniature, thin-walled rodlets fabricated from annealed Zr-Sn barstock were coated with CrN using physical vapor deposition (PVD) to nominal thicknesses of 4 and 8 μm. Coated and uncoated rodlet specimens were internally pressurized and welded, generating nominal circumferential hoop stresses of 0, 90, or 180 MPa under 300 ∘C irradiation conditions. Twelve specimens were measured diametrically prior to irradiation using a low-cost, automated, contactless laser profilometer developed for this work. Specimens were irradiated in sealed capsules for one 25-day HFIR cycle, accumulating approximately 1.8×1021n/cm2 fast fluence (En>1.0MeV). The irradiated samples were retrieved and remeasured using the same profilometry system in a shielded hot cell facility. Irradiation creep between specimens was compared using standard statistical tests and showed that both thicknesses of CrN coating had a negligible effect on the irradiation creep strain of the Zry material. Microstructure characterization of pre- and post-irradiated CrN-Zry specimens showed minimal changes due to irradiation but did show a substantial O-rich region at the Zry-CrN interface.

AB - Environmental barrier coatings for Zr-based materials are currently under development to reduce oxidation and embrittlement in light-water reactors. Chromium nitride is one such candidate for this application, particularly as accident-tolerant fuel cladding. However, quantifying the impact of coatings on the irradiation-induced creep of zircaloy (Zry) is critical as this mechanism often exceeds thermal creep rates under light-water reactor operating conditions and can be a limiting design characteristic. Additionally, examining irradiation effects in the microstructure at the coating interface is key to understanding the compatibility of the material system. To accelerate the experimental measurement of irradiation creep and microstructure evolution in CrN-Zry, compact, pressurized creep tubes were fabricated and irradiated in the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory. Miniature, thin-walled rodlets fabricated from annealed Zr-Sn barstock were coated with CrN using physical vapor deposition (PVD) to nominal thicknesses of 4 and 8 μm. Coated and uncoated rodlet specimens were internally pressurized and welded, generating nominal circumferential hoop stresses of 0, 90, or 180 MPa under 300 ∘C irradiation conditions. Twelve specimens were measured diametrically prior to irradiation using a low-cost, automated, contactless laser profilometer developed for this work. Specimens were irradiated in sealed capsules for one 25-day HFIR cycle, accumulating approximately 1.8×1021n/cm2 fast fluence (En>1.0MeV). The irradiated samples were retrieved and remeasured using the same profilometry system in a shielded hot cell facility. Irradiation creep between specimens was compared using standard statistical tests and showed that both thicknesses of CrN coating had a negligible effect on the irradiation creep strain of the Zry material. Microstructure characterization of pre- and post-irradiated CrN-Zry specimens showed minimal changes due to irradiation but did show a substantial O-rich region at the Zry-CrN interface.

KW - Accident-tolerant fuel

KW - Chromium nitride (CrN)

KW - Cladding

KW - Irradiation creep

KW - Zircaloy

UR - http://www.scopus.com/inward/record.url?scp=85181689620&partnerID=8YFLogxK

U2 - 10.1016/j.jnucmat.2023.154808

DO - 10.1016/j.jnucmat.2023.154808

M3 - Article

AN - SCOPUS:85181689620

SN - 0022-3115

VL - 588

JO - Journal of Nuclear Materials

JF - Journal of Nuclear Materials

M1 - 154808

ER -

Irradiation creep measurement and microstructural analysis of chromium nitride–coated zirconium alloy using pressurized tubes

Abstract

Funding

Keywords

Access to Document

Other files and links

Fingerprint

Cite this