Laser repair welding of irradiated alloy 182

Jian Chen; Jonathan Tatman; Zhili Feng; Roger Miller; Greg Frederick

doi:10.1016/j.jnucmat.2025.156321

Laser repair welding of irradiated alloy 182

Jian Chen
, Jonathan Tatman
, Zhili Feng
, Roger Miller
, Greg Frederick

Materials Joining

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

Abstract

Welding repair of irradiated nickel-based alloys, such as Alloy 182, poses a significant challenge due to helium-induced cracking (HeIC) and grain boundary degradation (GBD) in the heat affected zone, driven by helium accumulation at grain boundaries and welding-induced tensile stresses. This study investigates the weldability of irradiated Alloy 182 up to 15 wppm doped boron using both conventional laser welding and the Auxiliary Beam Stress Improved (ABSI) laser welding technique. While HeIC was observed at the weld toe of the entry pass in both methods due to the higher effective heat input associated with the initial pass directly on the base metal, no additional cracking occurred elsewhere, even at elevated helium concentrations. Optical and scanning electron microscopy analysis revealed that the ABSI technique, which introduces additional compressive stresses to counteract solidification-induced tensile stresses, significantly reduced GBD formation, lowering its total count from 1,230 to 339 and decreasing both average and maximum GBD lengths. These results demonstrate that the ABSI technique is a promising approach to mitigate helium-induced damage and improve the weldability of irradiated Alloy 182, offering a viable solution for structural repairs for long-term operation of existing nuclear reactors.

Original language	English
Article number	156321
Journal	Journal of Nuclear Materials
Volume	620
DOIs	https://doi.org/10.1016/j.jnucmat.2025.156321
State	Published - Jan 2026

Funding

This research was sponsored by the U.S. Department of Energy (DOE), Office of Nuclear Energy - Light Water Reactor Sustainability Program Materials Research Pathway and the EPRI Long Term Operations Program. The manuscript is co-authored by UT-Battelle, LLC under Contract DE-AC05-00OR22725 with the U.S. Department of Energy. The authors would like to thank Donald Caverly, Clay Morris, Stephanie Curlin, Yiyu Wang and Amy Godfrey for their valuable assistance with welding, sample preparation, and microstructural characterization. Notice : This manuscript has been authored by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the US Department of Energy (DOE). 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 ).

Keywords

Grain boundary degradation
Helium induced cracking
Irradiated materials
Nickel-based alloys
laser repair welding

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10.1016/j.jnucmat.2025.156321

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@article{884816effd8a442691463a79f3893246,

title = "Laser repair welding of irradiated alloy 182",

abstract = "Welding repair of irradiated nickel-based alloys, such as Alloy 182, poses a significant challenge due to helium-induced cracking (HeIC) and grain boundary degradation (GBD) in the heat affected zone, driven by helium accumulation at grain boundaries and welding-induced tensile stresses. This study investigates the weldability of irradiated Alloy 182 up to 15 wppm doped boron using both conventional laser welding and the Auxiliary Beam Stress Improved (ABSI) laser welding technique. While HeIC was observed at the weld toe of the entry pass in both methods due to the higher effective heat input associated with the initial pass directly on the base metal, no additional cracking occurred elsewhere, even at elevated helium concentrations. Optical and scanning electron microscopy analysis revealed that the ABSI technique, which introduces additional compressive stresses to counteract solidification-induced tensile stresses, significantly reduced GBD formation, lowering its total count from 1,230 to 339 and decreasing both average and maximum GBD lengths. These results demonstrate that the ABSI technique is a promising approach to mitigate helium-induced damage and improve the weldability of irradiated Alloy 182, offering a viable solution for structural repairs for long-term operation of existing nuclear reactors.",

keywords = "Grain boundary degradation, Helium induced cracking, Irradiated materials, Nickel-based alloys, laser repair welding",

author = "Jian Chen and Jonathan Tatman and Zhili Feng and Roger Miller and Greg Frederick",

note = "Publisher Copyright: Copyright {\textcopyright} 2025. Published by Elsevier B.V.",

year = "2026",

month = jan,

doi = "10.1016/j.jnucmat.2025.156321",

language = "English",

volume = "620",

journal = "Journal of Nuclear Materials",

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TY - JOUR

T1 - Laser repair welding of irradiated alloy 182

AU - Chen, Jian

AU - Tatman, Jonathan

AU - Feng, Zhili

AU - Miller, Roger

AU - Frederick, Greg

PY - 2026/1

Y1 - 2026/1

N2 - Welding repair of irradiated nickel-based alloys, such as Alloy 182, poses a significant challenge due to helium-induced cracking (HeIC) and grain boundary degradation (GBD) in the heat affected zone, driven by helium accumulation at grain boundaries and welding-induced tensile stresses. This study investigates the weldability of irradiated Alloy 182 up to 15 wppm doped boron using both conventional laser welding and the Auxiliary Beam Stress Improved (ABSI) laser welding technique. While HeIC was observed at the weld toe of the entry pass in both methods due to the higher effective heat input associated with the initial pass directly on the base metal, no additional cracking occurred elsewhere, even at elevated helium concentrations. Optical and scanning electron microscopy analysis revealed that the ABSI technique, which introduces additional compressive stresses to counteract solidification-induced tensile stresses, significantly reduced GBD formation, lowering its total count from 1,230 to 339 and decreasing both average and maximum GBD lengths. These results demonstrate that the ABSI technique is a promising approach to mitigate helium-induced damage and improve the weldability of irradiated Alloy 182, offering a viable solution for structural repairs for long-term operation of existing nuclear reactors.

AB - Welding repair of irradiated nickel-based alloys, such as Alloy 182, poses a significant challenge due to helium-induced cracking (HeIC) and grain boundary degradation (GBD) in the heat affected zone, driven by helium accumulation at grain boundaries and welding-induced tensile stresses. This study investigates the weldability of irradiated Alloy 182 up to 15 wppm doped boron using both conventional laser welding and the Auxiliary Beam Stress Improved (ABSI) laser welding technique. While HeIC was observed at the weld toe of the entry pass in both methods due to the higher effective heat input associated with the initial pass directly on the base metal, no additional cracking occurred elsewhere, even at elevated helium concentrations. Optical and scanning electron microscopy analysis revealed that the ABSI technique, which introduces additional compressive stresses to counteract solidification-induced tensile stresses, significantly reduced GBD formation, lowering its total count from 1,230 to 339 and decreasing both average and maximum GBD lengths. These results demonstrate that the ABSI technique is a promising approach to mitigate helium-induced damage and improve the weldability of irradiated Alloy 182, offering a viable solution for structural repairs for long-term operation of existing nuclear reactors.

KW - Grain boundary degradation

KW - Helium induced cracking

KW - Irradiated materials

KW - Nickel-based alloys

KW - laser repair welding

UR - https://www.scopus.com/pages/publications/105023574718

U2 - 10.1016/j.jnucmat.2025.156321

DO - 10.1016/j.jnucmat.2025.156321

M3 - Article

AN - SCOPUS:105023574718

SN - 0022-3115

VL - 620

JO - Journal of Nuclear Materials

JF - Journal of Nuclear Materials

M1 - 156321

ER -

Laser repair welding of irradiated alloy 182

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