Thak Sang Byun

Profile Information
Name
Dr. Thak Sang Byun
Institution
Oak Ridge National Laboratory
Position
Distinguished R&D
h-Index
ORCID
0000-0003-0860-4936
Expertise
Alloy Processing, Fuel Cladding, Mechanical Behavior Of Materials, Nuclear Structural Materials
Publications:
"Correlative STEM-APT characterization of radiation-induced segregation and precipitation of in-service BWR 304 stainless steel" Timothy Lach, Kayla Yano, Danny Edwards, Thak Sang Byun, Peter Chou, Journal of Nuclear Materials Vol. 549 2021 Link
Radiation induced segregation and precipitation phenomena in an in-service boiling water reactor 304 stainless steel component were investigated using directly correlated 3D-atom probe tomography and scanning transmission electron microscopy. Significant quantitative differences in measured segregation at grain boundaries were found between the atom probe and energy dispersive spectroscopy measurements of the exact same locations. In particular, a much stronger Si segregation (~10 atomic% via atom probe versus ~4 atomic% via electron microscopy) and different Cr profile shapes were detected that are critical to models of radiation induced segregation and stress corrosion cracking behavior. These quantitative differences highlight the need for comparative microscopy and critical evaluation of limitations in each analytical method. Elemental segregation to dislocations and conjoined-clusters were also highlighted by atom probe; confirming and expanding upon what has been observed in test reactor neutron and accelerator-based ion irradiations.
"Mechanical characteristics of SiC coating layer in TRISO fuel particles" Thak Sang Byun, David Frazer, Peter Hosemann, John Hunn, Maria Okuniewski, Kurt Terrani, Gokul Vasudevamurthy, J. N. Matros, Brian Jolly, Journal of Nuclear Materials Vol. 442 2013 133-142 Link
Tristructural isotropic (TRISO) particles are considered as advanced fuel forms for a variety of fission platforms. While these fuel structures have been tested and deployed in reactors, the mechanical properties of these structures as a function of production parameters need to be investigated in order to ensure their reliability during service. Nanoindentation techniques, indentation crack testing, and half sphere crush testing were utilized in order to evaluate the integrity of the SiC coating layer that is meant to prevent fission product release in the coated particle fuel form. The results are complimented by scanning electron microscopy (SEM) of the grain structure that is subject to change as a function of processing parameters and can alter the mechanical properties such as hardness, elastic modulus, fracture toughness and fracture strength. Through utilization of these advanced techniques, subtle differences in mechanical properties that can be important for in-pile fuel performance can be distinguished and optimized in iteration with processing science of coated fuel particle production.
"Stability of MX-type strengthening nanoprecipitates in ferritic steels under thermal aging, stress and ion irradiation" Yutai Katoh, Lizhen Tan, Lance Snead, Thak Sang Byun, Acta Materialia Vol. 71 2014 11–19 Link
The stability of MX-type precipitates is critical to retain mechanical properties of both reduced activation ferritic–martensitic (RAFM) and conventional FM steels at elevated temperatures above 500 C. The stability of TaC, TaN and VN nanoprecipitates under thermal aging (600 and 700 C), creep (600 C) and ion irradiation (Fe ion, 500 C) conditions was systematically studied in this work. The statistical particle evolution in density and size was characterized using transmission electron microscopy. Nanoprecipitate stability under the studied conditions manifested differently through either dissolution, reprecipitation, growth or fragmentation, with TaC exhibiting the greatest stability followed by VN and TaN in sequence. Nanoprecipitate evolution phenomena and mechanisms and the apparent disagreement of this interpretation with published literature on the subject are discussed. These findings not only help understanding the degradation mechanisms of RAFM and conventional FM steels at elevated temperatures and under stress and irradiation, but should also prove beneficial to the development of advanced RAFM steels.
Additional Publications:
"Strength and ductility of additively manufactured 316L stainless steel: Impact of neutron irradiation and data variability" Jesse W. Werden, Timothy G. Lach, Nick G. Russell, Annabelle.G. Le Coq, Kory D. Linton, Thak Snag Byun, [2025] Journal of Nuclear Materials · DOI: 10.1016/j.jnucmat.2025.155956
"Assessing the viability of a new subsize tensile specimen geometry for evaluation of structural nuclear and additively manufactured materials" Maxim Gussev, Stephen Taller, T.S. Byun, Caleb Massey, David Collins, [2025] Journal of Nuclear Materials · DOI: 10.1016/j.jnucmat.2025.155831
"Mechanical Characteristics of Additively Manufactured ODS 316L and 316H Alloys with and Without Post-build Processing" Yan-Ru Lin, David A. Collins, Holden C. Hyer, Kelsey Epps, Kara Krogh, Thak Sang Byun, [2025] JOM · DOI: 10.1007/s11837-025-07336-9
"Post-irradiation Examination of Eurofer-97 Steel Irradiated to 20 dpa at 200–400°C in HFIR under the EUROfusion (ORNL-KIT) Collaboration Program" Josina Geringer, Xiang Chen, Tim Seibert, Yukinori Yamamoto, Anthony Guajardo, T. Byun, [2024] · DOI: 10.2172/2480019
"Mechanical Performance of Additively Manufactured ODS 316L and 316H Stainless Steels" David Collins, Holden Hyer, Yan-Ru Lin, Kelsey Epps, Kara Krogh, TS Byun, [2024] · DOI: 10.2172/2441053
"Characteristics of oxide-dispersion strengthened alloys produced by high-temperature severe deformation" Timothy G. Lach, Yan-Ru Lin, David A. Collins, Kelsey Epps, David T. Hoelzer, Thak Sang Byun, [2024] Journal of Nuclear Materials · DOI: 10.1016/j.jnucmat.2024.155129
"Deformation and Fracture Behavior of Additively Manufactured 316L Stainless Steel" Maxim N. Gussev, Timothy G. Lach, Thak Sang Byun, [2024] JOM · DOI: 10.1007/s11837-023-06224-4
"Feasibility Studies and Downselection of New Materials and Manufacturing Technologies for Nuclear Applications" David Collins, Yan-Ru Lin, Kevin Hanson, Bryant Kanies, Robin Montoya, Michael Brand, Erofili Kardoulaki, Miles Beaux II, A. Andersson, Mohan Nartu, Subhashish Meher, Isabella van Rooyen, Shalini Tripathi, Nathan Canfield, TS Byun, [2023] · DOI: 10.2172/2007713
"Oak Ridge National Laboratory Compilation of AMMT Quality Assurance Procedures" Thomas Butcher, Christian Petrie, TS Byun, Chase Joslin, Andres Marquez Rossy, Ryan Duncan, Ryan Dehoff, Holden Hyer, Michael Russell, [2023] · DOI: 10.2172/2000347
"Progress on Producing an ODS Ferritic Alloy by High Deformation Processing of Reactive Powders" Caleb Massey, Thak Byun, Holden Hyer, David Hoelzer, [2023] · DOI: 10.2172/2006917
"AMMT FY23 HFIR Irradiation Test Matrix – Supported by the Design of a Miniature Bend Bar Irradiation Vehicle" Caleb Massey, Annabelle Le Coq, Stephen Taller, T. Byun, Kory Linton, Patrick Champlin, [2023] · DOI: 10.2172/1996657
"Downselection and Basic Properties of Additively Manufactured ODS Alloys" David Collins, K. Fillingim, Thomas Feldhausen, Holden Hyer, Yan-Ru Lin, David Hoelzer, Kevin Hanson, T. Byun, [2023] · DOI: 10.2172/1997696
"Metal forming and working of stabilized nanocrystalline Cu-Ta for electrical contacts" T.S. Byun, A.J. Roberts, T.L. Luckenbaugh, S.J. Fudger, VH Hammond, K.A. Darling, D.T. Hoelzer, [2023] Journal of Alloys and Compounds · DOI: 10.1016/j.jallcom.2023.169749
"Mechanical Properties of Additively Manufactured 316L Stainless Steel Before and After Neutron Irradiation–FY23" Annabelle Le Coq, Jesse Werden, Tim Lach, Kory Linton, T. Byun, [2023] · DOI: 10.2172/1974316
"Two-step deformation-induced martensitic transformation in additively manufactured High-Si stainless steel" Maxim N. Gussev, Thak Sang Byun, Nitish Bibhanshu, [2022] Materials Science and Engineering: A · DOI: 10.1016/j.msea.2022.144341
"Deformation Mechanism Transition in Additively Manufactured Compositionally Graded Fe-Base Alloys" Maxim N. Gussev, Nitish Bibhanshu, Timothy G. Lach, Thak Sang Byun, [2022] JOM · DOI: 10.1007/s11837-022-05401-1
"Mechanical Properties of Additively Manufactured 316L Stainless Steel Before and After Neutron Irradiation (FY21)" David Collins, Annabelle Le Coq, Tim Lach, Kory Linton, Maxim Gussev, Jesse Werden, Michael Mcalister, Xiang Chen, Chase Joslin, J. Carver, Fred List, III, T. Byun, [2021] · DOI: 10.2172/1828253
"Mechanical and Thermophysical Properties of 3D-Printed SiC before and after Neutron Irradiation – FY21" Tim Lach, Chad Parish, Hsin Wang, Artem Trofimov, David Collins, Annabelle Le Coq, Kory Linton, M. Richardson, Brian Jolly, Michael Trammell, Austin Schumacher, Gokul Vasudevamurthy, Takaaki Koyanagi, Kurt Terrani, T. Byun, [2021] · DOI: 10.2172/1814305
"Creep behavior of 316 L stainless steel manufactured by laser powder bed fusion" Xuan Zhang, Wei-Ying Chen, T.S. Byun, Meimei Li, [2021] Journal of Nuclear Materials · DOI: 10.1016/j.jnucmat.2021.152847
"Mechanical behavior of additively manufactured and wrought 316L stainless steels before and after neutron irradiation" B.E. Garrison, M.R. McAlister, X. Chen, M.N. Gussev, T.G. Lach, A. Le Coq, K. Linton, C.B. Joslin, J.K. Carver, F.A. List, R.R. Dehoff, K.A. Terrani, T.S. Byun, [2021] Journal of Nuclear Materials · DOI: 10.1016/j.jnucmat.2021.152849
"Precipitation-site competition in duplex stainless steels: Cu clusters vs spinodal decomposition interfaces as nucleation sites during thermal aging" William E. Frazier, Jing Wang, Arun Devaraj, Thak Sang Byun, Timothy G. Lach, [2020] Acta Materialia · DOI: 10.1016/j.actamat.2020.05.017
"Monte Carlo simulations of Cu/Ni–Si–Mn co-precipitation in duplex stainless steels" Timothy G. Lach, Thak Sang Byun, William E. Frazier, [2020] Acta Materialia · DOI: 10.1016/j.actamat.2020.03.053
"Fracture Toughness of High-Cr Steels after Various Thermomechanical Treatments" David Collins, Timothy Lach, Jung-Pyung Choi, Emily Barkley, Thak Byun, [2019] · DOI: 10.2172/2352288
"Fabrication and Characterization of Sixteen SiC Variants Deposited on the Same IPyC Substrate for Fracture Strength Testing" thak Byun, James Miller, Kevin Cooley, Gokul Vasudevamurthy, Jeoung Kim, Ivan Dunbar, Chinthaka Silva, Andrew Kercher, Dixie Barker, Paul Menchhofer, Stewart Voit, John Hunn, [2009] · DOI: 10.2172/1798589
Source: ORCID/CrossRef using DOI