NSUF - Nuclear Science User Facilities

David Frazer

Profile Information
Name
Dr. David Frazer
Institution
General Atomics
Position
Staff member
h-Index
ORCID
0000-0001-5139-858X
Expertise
Cladding, Mechanical Properties, Nanoindentation, Nuclear Fuel
Publications:
"Comparing structure-property evolution for PM-HIP and forged Alloy 625 irradiated with neutrons to 1 " Janelle Wharry, Caleb Clement, Sri Sowmya Panuganti, Patrick Warren, Yangyang Zhao, Yu Lu, Katelyn (Wheeler) Baird, David Frazer, Donna Guillen, David Gandy, Materials Science & Engineering A Vol. 857 2022 144058 Link
"Comparing structure-property evolution for PM-HIP and forged alloy 625 irradiated with neutrons to 1 dpa" Patrick Warren, Caleb Clement, Yangyang Zhao, Yu Lu, David Frazer, Donna Guillen, David Gandy, Janelle Wharry, Materials Science and Engineering: A Vol. 857 [unknown] Link
The nuclear power industry has growing interest in qualifying powder metallurgy with hot isostatic pressing (PM-HIP) to replace traditional alloy fabrication methods for reactor structural components. But there is little known about the response of PM-HIP alloys to reactor conditions. This study directly compares the response of PM-HIP to forged Ni-base Alloy 625 under neutron irradiation doses ∼0.5–1 displacements per atom (dpa) at temperatures ranging ∼321–385 °C. Post-irradiation examination involves microstructure characterization, ASTM E8 uniaxial tensile testing, and fractography. Up through 1 dpa, PM-HIP Alloy 625 appears more resistant to irradiation-induced cavity nucleation than its forged counterpart, and consequently experiences significantly less hardening. This observed difference in performance can be explained by the higher initial dislocation density of the forged material, which represents an interstitial-biased sink that leaves a vacancy supersaturation to nucleate cavities. These findings show promise for qualification of PM-HIP Alloy 625 for nuclear applications, although higher dose studies are needed to assess the steady-state irradiated microstructure.
"High-Temperature Nanoindentation of SiC/SiC Composites" David Frazer, JOM Vol. 72 2020
The results of high-temperature nanoindentation testing on both a control and a neutron-irradiated silicon carbide matrix silicon carbide fiber composite sample are presented. The mechanical properties of the chemical vapor-infiltrated matrix were observed to have slightly increased in hardness and slightly decreased in elastic modulus after irradiation. Tyranno SA3 fiber behavior results are inconclusive, possibly because residual graphite in the fibers resulting from the manufacturing process produced a large scatter in the data. This work also demonstrates the capability to measure the individual components of fabricated composites at elevated temperature, which should provide inputs for modeling the macro-scale behavior of the composites.
"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.
"Mechanical testing data from neutron irradiations of PM-HIP and conventionally manufactured nuclear structural alloys" Donna Guillen, Janelle Wharry, Caleb Clement, Yangyang Zhao, Katelyn Wachs, David Frazer, Jatuporn Burns, Yu Lu, Yaqiao Wu, Collin Knight, David Gandy, Data in Brief Vol. 48 2023 109092 Link
This article presents the comprehensive mechanical testing data archive from a neutron irradiation campaign of nuclear structural alloys fabricated by powder metallurgy with hot isostatic pressing (PM-HIP). The irradiation campaign was designed to facilitate a direct comparison of PM-HIP to conventional casting or forging. Five common nuclear structural alloys were included in the campaign: 316L stainless steel, SA508 pressure vessel steel, Grade 91 ferritic steel, and Ni-base alloys 625 and 690. Irradiations were carried out in the Advanced Test Reactor (ATR) at Idaho National Laboratory (INL) to target doses of 1 and 3 displacements per atom (dpa) at target temperatures of 300 and 400 °C. This article contains the data collected from post-irradiation uniaxial tensile tests following ASTM E8 specifications, fractography of these tensile bars, and nanoindentation. By making this systematic and valuable neutron irradiated mechanical behavior dataset openly available to the nuclear materials research community, researchers may now use this data to populate material performance databases, validate material performance and hardening models, design follow-on experiments, and enable future nuclear code-qualification of PM-HIP techniques.
"Microstructural and nanomechanical characterization of in-situ He implanted and irradiated fcc materials" David Frazer, Peter Hosemann, Djamel Kaoumi, Ce Zheng, Microscopy & Microanalysis Vol. 23 (Suppl 1) 2017 756-757 Link
"Nano- and micro-indentation testing of sintered UO2 fuel pellets with controlled microstructure and stoichiometry" David Frazer, Journal of Nuclear Materials Vol. 516 2019 169-177 Link
Dense nanocrystalline and microcrystalline UO2 samples with controlled grain structure and stoichiometry were prepared by high energy ball milling and spark plasma sintering (SPS). Nano-indentation and micro-indentation testing were performed at different temperatures of 25 °C, 300 °C, and 600 °C in order to study the mechanical properties of the sintered fuels as functions of grain structure and temperature. Nanocrystalline UO2 display higher hardness than microcrystalline counterpart, consistent with the Hall-Petch strengthening mechanism. Greater Young's modulus and fracture toughness are also identified for the nanocrystalline UO2, and hardness and Young's modulus decrease with temperature, suggesting better ductility of oxide fuels at high temperature and small length scale. Hyper-stoichiometric UO2 specimen displays higher hardness and fracture toughness than stoichiometric UO2, due to the impediment of the crack propagation by the oxygen interstitial atoms. These results are useful in understanding the mechanical properties of the high burn-up structure (HBS) formed in nuclear fuels during reactor operation, and also provide critical experimental data as the input for the development and validation of the MARMOT fracture model of nuclear fuels.
"Role of low-level void swelling on plasticity and failure in a 33 dpa neutron-irradiated 304 stainless steel, International Journal of Plasticity " Frank Garner, Hi Vo, David Frazer, Aaron Kohnert, Sebastien Teysseyre, Saryu Fensin, Peter Hosemann, International Journal of Plasticity Vol. 164 2023 Link
"Twin boundary-accelerated ferritization of austenitic stainless steels in liquid lead–bismuth eutectic" David Frazer, Peter Hosemann, Konstantina Lambrinou, Erich Stergar, Scripta Materialia Vol. 118 2016 37-40 Link
Exposure of austenitic stainless steels to liquid lead-bismuth eutectic with low concentration of dissolved oxygen typically results in selective leaching of highly-soluble alloying elements and ferritization of the dissolution-affected zone. In this work, focused ion beam, transmission electron backscatter diffraction and scanning transmission electron microscopy were utilised to elucidate early-stage aspects of the dissolution corrosion process of cold-worked austenitic stainless steels exposed to static, oxygen-poor liquid lead-bismuth eutectic at 450C for 1000 hours. It was found that deformation-induced twin boundaries in the cold-worked steel bulk provide paths of accelerated penetration of the liquid metal into the steel bulk.
NSUF Articles:
DOE Awards 33 Rapid Turnaround Experiment Research Proposals - Projects total approximately $1.5 million These projects will continue to advance the understanding of irradiation effects in nuclear fuels and materials in support of the mission of the DOE Office of Nuclear Energy. Monday, May 14, 2018 - Calls and Awards
RTE 1st Call Awards Announced - Projects total approximately $1.4 million These projects will continue to advance the understanding of irradiation effects in nuclear fuels and materials in support of the mission of the DOE-NE. Friday, February 8, 2019 - Calls and Awards
DOE awards 39 RTE Projects - Projects total approximately $1.3 million Thursday, February 1, 2018 - Calls and Awards
RTE 2nd Call Awards Announced - Projects total approximately $1.6 million These project awards went to principal investigators from 26 U.S. universities, eight national laboratories, two British universities, and one Canadian laboratory. Tuesday, May 14, 2019 - Calls and Awards

About Us

The Nuclear Science User Facilities (NSUF) is the U.S. Department of Energy Office of Nuclear Energy's only designated nuclear energy user facility. Through peer-reviewed proposal processes, the NSUF provides researchers access to neutron, ion, and gamma irradiations, post-irradiation examination and beamline capabilities at Idaho National Laboratory and a diverse mix of university, national laboratory and industry partner institutions.

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