Isabella van Rooyen

Profile Information

Name: Dr. Isabella van Rooyen
Institution: Pacific Northwest National Laboratory
Position: Senior Technical Advisor Advanced Material Systems
Affiliation: University of Idaho
h-Index
ORCID: 0000-0001-8524-938X
Biography: Dr. Isabella Van Rooyen is a senior technical advisor for Advanced Material Systems specifically integrating advanced and manufacturing techniques and material development to accelerate technology readiness through advanced characterization techniques and performance testing. She has been PI /co-PI for over 15 government funded projects as a distinguished staff scientist tenured at INL, national technical director for the DOE-NE AMM program (2019-2021), material development technical area lead for the DOE-NE-AMMT program. She published 50+ journal articles, 30+ conference proceeding papers, and 100+ technical/scientific reports. Four patents awarded (2020, 2021, 2021 2022), and six patents pending for ceramic, metallic and gradient components, and corrosion resistant heat management components fuel through AM processes.
Expertise: Additive Manufacturing, Characterization, Cladding, Composites, Fission Products, Grain Boundary, Li-ion, Silicon Carbide (SiC), Uranium Compounds, Zirconium

Publications:

		"Associations of Pd, U and Ag in the SiC layer of neutron-irradiated TRISO fuel" Thomas Lillo, Isabella van Rooyen, Journal of Nuclear Materials Vol. 460 2015 97-106 Link Knowledge of the associations and composition of fission products in the neutron irradiated SiC layer of high-temperature gas reactor TRISO fuel is important to the understanding of various aspects of fuel performance that presently are not well understood. Recently, advanced characterization techniques have been used to examine fuel particles from the Idaho National Laboratory’s AGR-1 experiment. Nano-sized Ag and Pd precipitates were previously identified in grain boundaries and triple points in the SiC layer of irradiated TRISO nuclear fuel. Continuation of this initial research is reported in this paper and consists of the characterization of a relatively large number of nano-sized precipitates in three areas of the SiC layer of a single irradiated TRISO nuclear fuel particle using standardless EDS analysis on focused ion beam-prepared transmission electron microscopy samples. Composition and distribution analyses of these precipitates, which were located on grain boundaries, triple junctions and intragranular precipitates, revealed low levels, generally <10 atomic %, of palladium, silver and/or uranium with palladium being the most common element found. Palladium by itself, or associated with either silver or uranium, was found throughout the SiC layer. A small number of precipitates on grain boundaries and triple junctions were found to contain only silver or silver in association with palladium while uranium was always associated with palladium but never found by itself or in association with silver. Intergranular precipitates containing uranium were found to have migrated ~23 µm along a radial direction through the 35 µm thick SiC coating during the AGR-1 experiment while silver-containing intergranular precipitates were found at depths up to ~24 µm in the SiC layer. Also, Pd-rich, nano-precipitates (~10 nm in diameter), without evidence for the presence of either Ag or U, were revealed in intragranular regions throughout the SiC layer. Because not all grain boundaries and triple junctions contained precipitates with fission products and/or uranium, along with the differences in migration behavior between Pd, Ag and U, it was concluded that crystallographic grain boundary and triple junction parameters likely influence migration behavior.
		"Distribution of fission products palladium, silver, cerium and cesium in the un-corroded areas of the locally corroded SiC layer of a neutron irradiated TRISO fuel particle" Haiming Wen, Isabella van Rooyen, Journal of the European Ceramic Society Vol. 37 (2017) 2017 3271-3284 Link
		"Effect of Neutron Irradiation Damage on Fission Product Transport in the SiC Layer of TRISO Fuel Particles" Isabella van Rooyen, Subhashish Meher, OSTI.gov, Conf. Proceedings Vol. 2018 Link
		"Effect of Sample Preparation Techniques on Grain Boundary Characterization of Annealed TRISO-Coated Particles" Mary Lou Dunzik-Gougar, Isabella van Rooyen, C.M. Hill, T. Trowbridge, J. Madden, J. Burns, Nuclear Technology Vol. 196(1) 2016 111-120 Link
		"Electron Microscopy Study of Pd, Ag, and Cs in Carbon Areas in the Locally Corroded SiC Layer in a Neutron-Irradiated TRISO Fuel Particle" Haiming Wen, Isabella van Rooyen, John Hunn, Tyler Gerczak, Journal of the European Ceramic Society Vol. 38 (2018) 2016 4173-4188 Link
		"Influence of SiC grain boundary character on fission product transport in irradiated TRISO fuel" Thomas Lillo, Isabella van Rooyen, Journal of Nuclear Materials Vol. 473 2016 83-92 Link In this study, the fission product precipitates at silicon carbide grain boundaries from an irradiated TRISO particle were identified and correlated with the associated grain boundary characteristics. Precession electron diffraction in the transmission electron microscope provided the crystallographic information needed to identify grain boundary misorientation and boundary type (i.e., low angle, random high angle or coincident site lattice (CSL)-related). The silicon carbide layer was found to be composed mainly of twin boundaries and small fractions of random high angle and low angle grain boundaries. Most fission products were found at random, high-angle grain boundaries, with small fractions at low-angle and CSL-related grain boundaries. Palladium (Pd) was found at all types of grain boundaries while Pd-uranium and Pd-silver precipitates were only associated with CSL-related and random, high-angle grain boundaries. Precipitates containing only Ag were found only at random, high-angle grain boundaries, but not at low angle or CSL-related grain boundaries.
		"Microstructure and Fission Product Distribution Examination in the UCO kernel of TRISO Fuel Particles" Isabella van Rooyen, Yong Yang, Terry Holesinger, Mukesh Bachhav, OSTI.gov, Conf Proceedings Vol. 2018 Link
		"Precession electron diffraction for SiC grain boundary characterization in unirradiated TRISO fuel" Thomas Lillo, Isabella van Rooyen, Yaqiao Wu, Nuclear Engineering and Design Vol. 305 2016 277-283 Link Precession electron diffraction (PED), a transmission electron microscopy-based technique, has been evaluated for the suitability for evaluating grain boundary character in the SiC layer of tristructural isotropic (TRISO) fuel. This work reports the effect of transmission electron microscope (TEM) lamella thickness on the quality of data and establishes a baseline comparison to SiC grain boundary characteristics, in an unirradiated TRISO particle, determined previously using a conventional electron backscatter diffraction (EBSD) scanning electron microscope (SEM)-based technique. In general, it was determined that the lamella thickness produced using the standard focused ion beam (FIB) fabrication process (∼80 nm), is sufficient to provide reliable PED measurements, although thicker lamellae (∼120 nm) were found to produce higher quality orientation data. Also, analysis of SiC grain boundary character from the TEM-based PED data showed a much lower fraction of low-angle grain boundaries compared to SEM-based EBSD data from the SiC layer of a TRISO-coated particle made using the same fabrication parameters and a SiC layer deposited at a slightly lower temperature from a surrogate TRISO particle. However, the fractions of high-angle and coincident site lattice (CSL)-related grain boundaries determined by PED are similar to those found using SEM-based EBSD. Since the grain size of the SiC layer of TRSIO fuel can be as small as 250 nm (Kirchhofer et al., 2013), depending on the fabrication parameters, and since grain boundary fission product precipitates in irradiated TRISO fuel can be nano-sized, the TEM-based PED orientation data collection method is preferred to determine an accurate representation of the relative fractions of low-angle, high-angle, and CSL-related grain boundaries. It was concluded that although the resolution of the PED data is better by more than an order of magnitude, data acquisition times may be significantly longer or the number of areas analyzed needs to be significantly greater than the SEM-based method to obtain a statistically relevant distribution. Also, grain size could be accurately determined but significantly larger analysis areas would be required than those used in this study.
		"Sample Preparation Techniques for Grain Boundary Characterization of Annealed TRISOCoated Particles" Mary Lou Dunzik-Gougar, Isabella van Rooyen, C. M. Hill, James Madden, Jatuporn Burns, Tammy Trowbridge, Nuclear Technology Vol. 196 2017 111-120 Link Crystallographic information about layers of silicon carbide (SiC) deposited by chemical vapor deposition is essential to understanding layer performance, especially when the the layers are in nonplanar geometries (e.g., spherical). Electron backscatter diffraction (EBSD) was used to analyze spherical SiC layers using a different sampling approach that applied focused ion beam (FIB) milling to avoid the negative impacts of traditional sample polishing and address the need for very small samples of irradiated materials for analysis. The mechanical and chemical grinding and polishing of sample surfaces can introduce lattice strain and result in the unequal removal of SiC and the surrounding layers of different materials due to the hardness differences among these materials. The nature of layer interfaces is thought to play a key role in the performance of SiC; therefore, the analysis of representative samples at these interfacial areas is crucial. In the work reported herein, a FIB was employed in a novel manner to prepare a more representative sample for EBSD analysis from tristructural-isotropic layers that are free of effects introduced by mechanical and chemical preparation methods. In addition, the difficulty of handling neutron-irradiated microscopic samples (such as those analyzed in this work) has been simplified using pretilted mounting stages. The results showed that while the average grain sizes of samples may be similar, the grain boundary characteristics can differ significantly. Furthermore, low-angle grain boundaries comprised 25% of all boundaries in the FIB-prepared sample compared to only 1% to 2% in the polished sample from the same particle. This study demonstrated that the characterization results from FIB-prepared samples provide more repeatable results due to the elimination of the effects of sample preparation.
		"SiC Grain Boundary Character and Fission Product Transport in Irradiated TRISO Fuel Particles" Isabella van Rooyen, Thomas Lillo, Nuclear Fuels & Material Spotlight Vol. 5 2016 31-38 Link
		"Silicon carbide grain boundary distributions, irradiation conditions, and silver retention in irradiated AGR-1 TRISO fuel particles" Jeffery Aguiar, Thomas Lillo, Isabella van Rooyen, Nuclear Engineering and Design Vol. 329 2018 46-52 Link Distributions of silicon carbide grain boundary types (random high angle, low angle, and coincident site lattice-related boundaries), were compared in irradiated tristructural isotropic-coated fuel particles from the Advanced Gas Reactor-1 experiment exhibiting high (>80%) and low (<19%) Ag-110m retention. Grain orientation from transmission electron microscope-based precession electron diffraction data, and, ultimately, grain boundary distributions, indicate irradiated particles with high Ag-110m retention correlate with lower relative fractions of random, high-angle grain boundaries. An inverse relationship between the random, high-angle grain boundary fraction and Ag-110m retention was found and is consistent with grain boundary percolation theory. Also, the SiC grain boundary distribution in an irradiated, low Ag-110m retention, Variant 1 particle was virtually identical to that of a previously reported as-fabricated (unirradiated) Variant 1 TRISO particle. Thus, SiC layers with grain boundary distributions associated with low Ag-110m retention may have developed during fabrication and were present prior to irradiation, assuming significant microstructural evolution did not occur during irradiation. Finally, irradiation levels up to 3.6 × 1025 n/m2 and 16.7% fissions per initial metal atom were found to have little effect on association of fission product precipitates with specific grain boundary types in particles exhibiting between 19% and 80% Ag-110m retention.
		"STEM-EDS Analysis of Fission Products in Neutron-Irradated TRISO Fuel Particles from AGR-1 Experiment" bin leng, Kumar Sridharan, Izabela Szlufarska, Yaqiao Wu, Isabella van Rooyen, Journal of Nuclear Materials Vol. 475 2016 62-70 Link Historic and recent post-irradiation-examination from the German AVR and Advanced Gas Reactor Fuel Development and Qualification Project have shown that 110 m Ag is released from intact tristructural isotropic (TRISO) fuel. Although TRISO fuel particle research has been performed over the last few decades, little is known about how metallic fission products are transported through the SiC layer, and it was not until March 2013 that Ag was first identified in the SiC layer of a neutron-irradiated TRISO fuel particle. The existence of Pd- and Ag-rich grain boundary precipitates, triple junction precipitates, and Pd nano-sized intragranular precipitates in neutron-irradiated TRISO particle coatings was investigated using Scanning Transmission Electron Microscopy and Energy Dispersive Spectroscopy analysis to obtain more information on the chemical composition of the fission product precipitates. A U-rich fission product honeycomb shape precipitate network was found near a micron-sized precipitate in a SiC grain about ∼5 μm from the SiC-inner pyrolytic carbon interlayer, indicating a possible intragranular transport path for uranium. A single Ag-Pd nano-sized precipitate was found inside a SiC grain, and this is the first research showing such finding in irradiated SiC. This finding may possibly suggest a possible Pd-assisted intragranular transport mechanism for Ag and may be related to void or dislocation networks inside SiC grains. Preliminary semi-quantitative analysis indicated the micron-sized precipitates to be Pd2Si2U with carbon existing inside these precipitates. However, the results of such analysis for nano-sized precipitates may be influenced by the SiC matrix. The results reported in this paper confirm the co-existence of Cd with Ag in triple points reported previously.
		"The Effect of High-Temperature Annealing on the Grain Characteristics of a Thin Chemical Vapor Deposition Silicon Carbide Layer" Isabella van Rooyen, Philippus van Rooyen, Mary Lou Dunzik-Gougar, Microscopy and Microanalysis, 19 (Supplement 2) Vol. 19 2013 1948-1949 Link

Presentations:

	"Advanced Electron Microscopic Examination Aided in the Identification of Silver and Palladium in Irradiated TRISO Coted Particles" Isabella van Rooyen, TMS 2014 February 16-20, (2014)
	"Effect of Neutron Irradiation Damage on Fission Product Transport in the SiC Layer of TRISO Fuel Particles" Isabella van Rooyen, Subhashish Meher, HTR 2018 October 8-10, (2018)
	"Microstructure and Fission Product Distribution Examination in the UCO Kernel of TRISO Fuel Particles" Isabella van Rooyen, Yong Yang, Terry Holesinger, , HTR 2018 October 8-10, (2018)

NSUF Articles:

DOE awards 39 RTE Projects - Projects total approximately $1.3 million Thursday, February 1, 2018 - Calls and Awards

Additional Publications:

	"Friction surface layer deposition of triple-phase Al10Cr12Fe35Mn23Ni20 high entropy alloy: Process optimization and microstructural evolution" David Garcia, Subhashish Meher, Tianhao Wang, Jorge F. Dos Santos, Isabella Van Rooyen, Mohan Sai Kiran Kumar Yadav Nartu, [2025] Materials Science and Engineering: A · DOI: 10.1016/j.msea.2025.148019
	"Analysis of surface roughness in metal directed energy deposition" Calvin M. Downey, Isabella J. van Rooyen, Indrajit Charit, Michael R. Maughan, Luis Nuñez, [2024] The International Journal of Advanced Manufacturing Technology · DOI: 10.1007/s00170-024-13587-8
	"Determining the tensile strength of fuel surrogate TRISO-coated particle buffer, IPyC, and buffer-IPyC interlayer regions" Mary Lou Dunzik-Gougar, Subhashish Meher, Isabella J van Rooyen, Tanner Mauseth, [2023] Journal of Nuclear Materials · DOI: 10.1016/j.jnucmat.2023.154540
	"In situ embedment of type K sheathed thermocouples with directed energy deposition" Piyush Sabharwall, Isabella J. van Rooyen, Luis Nuñez, [2023] The International Journal of Advanced Manufacturing Technology · DOI: 10.1007/s00170-023-11624-6
	"Microstructure and fission products in the UCO kernel of an AGR-1 TRISO fuel particle after post irradiation safety testing" Isabella J. van Rooyen, Mukesh Bachhav, Yong Yang, Zhenyu Fu, [2020] Journal of Nuclear Materials · DOI: 10.1016/j.jnucmat.2019.151884
	"Ab initio study and thermodynamic modeling of the Pd-Si-C system" Isabella J. van Rooyen, Subhashish Meher, Chao Jiang, [2020] Computational Materials Science · DOI: 10.1016/j.commatsci.2019.109238 · EID: 2-s2.0-85071558361
	"Analytical bond-order potential for silver, palladium, ruthenium and iodine bulk diffusion in silicon carbide" Qing Peng, Zhijie Jiao, Isabella van Rooyen, William F Skerjanc, Fei Gao, Nanjun Chen, [2020] Journal of physics. Condensed matter : an Institute of Physics journal · DOI: 10.1088/1361-648x/ab5465 · EID: 2-s2.0-85075814082
	"Characterizing surrogates to develop an additive manufacturing process for U 3 Si 2 nuclear fuel" Isabella J. van Rooyen, Clemente J. Parga, Jhonathan Rosales, [2019] Journal of Nuclear Materials · DOI: 10.1016/j.jnucmat.2019.02.026 · EID: 2-s2.0-85062551837
	"Oxidation behavior of Zirconium, Zircaloy-3, Zircaloy-4, Zr-1Nb, and Zr-2.5Nb in air and oxygen" Patrick M. Price, John-Paul Stroud, Clemente J. Parga, Isabella J. Van Rooyen, Brian J. Jaques, Darryl P. Butt, Jordan L. Vandegrift, [2019] Nuclear Materials and Energy · DOI: 10.1016/j.nme.2019.100692 · EID: 2-s2.0-85070370173
	"Reveal the fast and charge-insensitive lattice diffusion of silver in cubic silicon carbide via first-principles calculations" Nanjun Chen, Zhijie Jiao, Isabella J. van Rooyen, William F. Skerjanc, Fei Gao, Qing Peng, [2019] Computational Materials Science · DOI: 10.1016/j.commatsci.2019.109190 · EID: 2-s2.0-85070538734
	"Understanding of fission products transport in SiC layer of TRISO fuels by nanoscale characterization and modeling" I.J. van Rooyen, C. Jiang, S. Meher, [2019] Journal of Nuclear Materials · DOI: 10.1016/j.jnucmat.2019.151793 · EID: 2-s2.0-85071986575
	"Ab initio study of the stability of intrinsic and extrinsic Ag point defects in 3C SiC" Qing Peng, Zhijie Jiao, Isabella van Rooyen, William F. Skerjanc, Fei Gao, Nanjun Chen, [2018] Journal of Nuclear Materials · DOI: 10.1016/j.jnucmat.2018.08.053
	"Ab initio study of the stability of intrinsic and extrinsic Ag point defects in 3C–SiC" Qing Peng, Zhijie Jiao, Isabella van Rooyen, William F. Skerjanc, Fei Gao, Nanjun Chen, [2018] Journal of Nuclear Materials · DOI: 10.1016/j.jnucmat.2018.08.053 · EID: 2-s2.0-85052761358
	"A Novel Dual-Step Nucleation Pathway in Crystalline Solids under Neutron Irradiation" Isabella J. van Rooyen, Thomas M. Lillo, Subhashish Meher, [2018] Scientific Reports · DOI: 10.1038/s41598-017-18548-8 Abstract Innovations in nanostructuring of inorganic crystalline solids are often limited by prerequisite critical nucleation energy and solute supersaturation for formation of a phase. This research provides direct evidence supporting the viability of an unconventional irradiation-induced nanostructuring process, via transmission electron microscopy, that circumvents these preconditions. Using polymorphic silicon carbide (SiC) as a prototype, a surprising two-step nucleation route is demonstrated through which nanoscale distribution of the second phase is achieved by reaction of solutes with neutron irradiation-induced precursors. In the first step, nanoscale α–SiC precipitates in a β–SiC matrix unexpectedly nucleate heterogeneously at structural defects. This occurs at significantly lower temperatures compared with the usual β→α transition temperature. Subsequently, α–SiC precipitate acts as a surrogate template for its structural and compositional transition into a fission product precipitate, palladium silicide. These discoveries provide a modern view of irradiation engineering in polymorphic ceramics for advanced applications.
	"Effect of High Si Content on U3Si2 Fuel Microstructure" Isabella J. van Rooyen, Subhashish Meher, Rita Hoggan, Clemente Parga, Jason Harp, Jhonathan Rosales, [2018] Jom · DOI: 10.1007/s11837-017-2654-6
	"Effect of High Si Content on U3Si2 Fuel Microstructure" Isabella J. van Rooyen, Subhashish Meher, Rita Hoggan, Clemente Parga, Jason Harp, Jhonathan Rosales, [2018] JOM · DOI: 10.1007/s11837-017-2654-6 · EID: 2-s2.0-85034271827
	"Electron microscopy study of Pd, Ag, and Cs in carbon areas in the locally corroded SiC layer in a neutron-irradiated TRISO fuel particle" Isabella J. van Rooyen, John D. Hunn, Tyler J. Gerczak, Haiming Wen, [2018] Journal of the European Ceramic Society · DOI: 10.1016/j.jeurceramsoc.2018.05.003 · EID: 2-s2.0-85047200416
	"Fission product transport in TRISO fuel: A computational study" [2018] Transactions of the American Nuclear Society · EID: 2-s2.0-85060858808
	"Fuel – clad chemical interaction evaluation of the TREAT reactor conceptual low-enriched-uranium fuel element" I.J. van Rooyen, E.P. Luther, C.J. Parga, [2018] Journal of Nuclear Materials · DOI: 10.1016/j.jnucmat.2018.10.028 · EID: 2-s2.0-85055127830
	"Silicon carbide grain boundary distributions, irradiation conditions, and silver retention in irradiated AGR-1 TRISO fuel particles" I.J. van Rooyen, J.A. Aguiar, T.M. Lillo, [2018] Nuclear Engineering and Design · DOI: 10.1016/j.nucengdes.2017.11.048 · EID: 2-s2.0-85044369332
	"Report on technical activities and technical plan for university advanced manufacturing work for in-pile sensors" G. Ilevbare, I. Van Rooyen, M. D. McMurtrey, [2017] · DOI: 10.2172/1473593
	"Characterization of U3Si2 surrogates along the development of an additive manufacturing process" [2017] Transactions of the American Nuclear Society · EID: 2-s2.0-85062024778
	"Distribution of fission products palladium, silver, cerium and cesium in the un-corroded areas of the locally corroded SiC layer of a neutron irradiated TRISO fuel particle" Isabella J. van Rooyen, Haiming Wen, [2017] Journal of the European Ceramic Society · DOI: 10.1016/j.jeurceramsoc.2017.04.012
	"Room temperature mechanical properties of electron beam welded zircaloy-4 sheet" I.J. van Rooyen, B.D. Coryell, W.R. Lloyd, L.N. Valenti, H. Usman, C.J. Parga, [2017] Journal of Materials Processing Technology · DOI: 10.1016/j.jmatprotec.2016.11.001
	"STEM/EELS Study of Fission Product Transport in Neutron Irradiated TRISO Fuel Particles (NSUF report)" Haiming Wen, Isabella J. van Rooyen, [2016] · DOI: 10.2172/1483612
	"Electron probe microanalysis of irradiated and 1600°C safety-tested AGR-1 TRISO fuel particles with low and high retained ^110mAg" [2016] International Topical Meeting on High Temperature Reactor Technology, HTR 2016 · EID: 2-s2.0-85026320183
	"Evaluating quantitative 3-D image analysis as a design tool for low enriched uranium fuel compacts for the transient reactor test facility: A preliminary study" I.J. van Rooyen, A.E. Craft, T.J. Roney, S.R. Morrell, J.J. Kane, [2016] Nuclear Engineering and Design · DOI: 10.1016/j.nucengdes.2016.01.005
	"Fission products silver, palladium, and cadmium identification in neutron-irradiated SiC TRISO particles using a Cs-Corrected HRTEM" E.J. Olivier, J.H. Neethling, I.J. van Rooyen, [2016] Journal of Nuclear Materials · DOI: 10.1016/j.jnucmat.2016.04.010
	"Influence of SiC grain boundary character on fission product transport in irradiated TRISO fuel" I.J. van Rooyen, T.M. Lillo, [2016] Journal of Nuclear Materials · DOI: 10.1016/j.jnucmat.2016.01.040
	"Micro/nano-structural examination and fission product identification in neutron irradiated agr-1 TRISO fuel" [2016] International Topical Meeting on High Temperature Reactor Technology, HTR 2016 · EID: 2-s2.0-85026301486
	"Precession electron diffraction for SiC grain boundary characterization in unirradiated TRISO fuel" I.J. van Rooyen, Y.Q. Wu, T.M. Lillo, [2016] Nuclear Engineering and Design · DOI: 10.1016/j.nucengdes.2016.05.027
	"STEM-EDS analysis of fission products in neutron-irradiated TRISO fuel particles from AGR-1 experiment" I.J. van Rooyen, Y.Q. Wu, I. Szlufarska, K. Sridharan, B. Leng, [2016] Journal of Nuclear Materials · DOI: 10.1016/j.jnucmat.2016.03.008
	"Sample Preparation Techniques for Grain Boundary Characterization of Annealed TRISO-Coated Particles" I. J. van Rooyen, C. M. Hill, T. Trowbridge, J. Madden, J. Burns, M. L. Dunzik-Gougar, [2016] Nuclear Technology · DOI: 10.13182/nt15-129
	"TREAT reactor LEU fuel-clad chemical interaction empirical modeling analysis" [2016] Top Fuel 2016: LWR Fuels with Enhanced Safety and Performance · EID: 2-s2.0-85019051531
	"Assessment of neutron-irradiated 3C-SiC implanted at 800℃" G. Deyzel, E. G. Minnaar, W. E. Goosen, I. J. Van Rooyen, J. A. A. Engelbrecht, [2015] Journal of Applied Optics · DOI: 10.5768/jao201536.0604001 · EID: 2-s2.0-84948760699
	"Associations of Pd, U and Ag in the SIC layer of neutron-irradiated TRISO fuel" I.J. van Rooyen, T.M. Lillo, [2015] Journal of Nuclear Materials · DOI: 10.1016/j.jnucmat.2015.02.010
	"Fission products distribution in triso coated fuel particles irradiated to 3.22 x 1021 n/cm² fast fluence at 1092°c" [2015] ASME 2015 Nuclear Forum, NUCLRF 2015, collocated with the ASME 2015 Power Conference, the ASME 2015 9th International Conference on Energy Sustainability, and the ASME 2015 13th International Conference on Fuel Cell Science, Engineering and Technology · DOI: 10.1115/nuclrf201549695 · EID: 2-s2.0-84962132660
	"Grain boundary character and fission product precipitation in SiC" [2015] Transactions of the American Nuclear Society · EID: 2-s2.0-84988908484
	"Notes on the plasma resonance peak employed to determine doping in SiC" I.J. van Rooyen, A. Henry, E. Janzén, B. Sephton, J.A.A. Engelbrecht, [2015] Infrared Physics & Technology · DOI: 10.1016/j.infrared.2015.07.007
	"Spatial distribution of Pd, Ag & U in the SiC layer of an irradiated TRISO fuel particle" Isabella J. van Rooyen Idaho, Thomas M. Lillo, [2014] Microscopy and Microanalysis · DOI: 10.1017/s1431927614010782 · EID: 2-s2.0-84923226658
	"Electron microscopic evaluation and fission product identification of irradiated TRISO coated particles from the AGR-1 experiment: A preliminary review" D.E. Janney, B.D. Miller, P.A. Demkowicz, J. Riesterer, I.J. van Rooyen, [2014] Nuclear Engineering and Design · DOI: 10.1016/j.nucengdes.2013.11.019
	"Identification of silver and palladium in irradiated TRISO coated particles of the AGR-1 experiment" T.M. Lillo, Y.Q. Wu, I.J. van Rooyen, [2014] Journal of Nuclear Materials · DOI: 10.1016/j.jnucmat.2013.11.028
	"Impact of dielectric parameters on the reflectivity of 3C-SiC wafers with a rough surface morphology in the reststrahlen region" E. Janzén, A. Henry, I.J. van Rooyen, J.A.A. Engelbrecht, [2014] Physica B-Condensed Matter · DOI: 10.1016/j.physb.2013.10.058
	"The influence of neutron-irradiation at low temperatures on the dielectric parameters of 3C-SiC" G. Deyzel, E.G. Minnaar, W.E. Goosen, I.J. van Rooyen, J.A.A. Engelbrecht, [2014] Physica B-Condensed Matter · DOI: 10.1016/j.physb.2013.10.059
	"Advanced electron microscopic techniques applied to the characterization of irradiation effects and fission product identification of irradiated TRISO coated particles from the AGR-1 experiment" [2013] International Nuclear Fuel Cycle Conference, GLOBAL 2013: Nuclear Energy at a Crossroads · EID: 2-s2.0-84903120683
	"SiC-CMC-Zircaloy-4 nuclear fuel cladding performance during 4-point tubular bend testing" [2013] LWR Fuel Performance Meeting, Top Fuel 2013 · EID: 2-s2.0-84902316818
	"Studying silicon carbide for nuclear fuel cladding" [2013] Nuclear Engineering International
	"The effect of grain size and phosphorous-doping of polycrystalline 3C-SiC on infrared reflectance spectra" J.A.A. Engelbrecht, A. Henry, E. Janzén, J.H. Neethling, P.M. van Rooyen, I.J. van Rooyen, [2012] Journal of Nuclear Materials · DOI: 10.1016/j.jnucmat.2011.12.003 · EID: 2-s2.0-84855813814
	"Applications of Nd:YAG laser micromanufacturing in high temperature gas reactor research" C.A. Smal, J. Steyn, I.J. van Rooyen, [2012] Journal of Nuclear Materials · DOI: 10.1016/j.jnucmat.2012.04.028
	"Effects of phosphorous-doping and high temperature annealing on CVD grown 3C-SiC" J.H. Neethling, A. Henry, E. Janzén, S.M. Mokoduwe, A. Janse van Vuuren, E. Olivier, I.J. van Rooyen, [2012] Nuclear Engineering and Design · DOI: 10.1016/j.nucengdes.2011.09.066
	"Engineering challenges of LWR advanced fuel cladding technology in preparation for in-reactor demonstrations, invited" [2012] Transactions of the American Nuclear Society · EID: 2-s2.0-84876557120
	"The origin of a peak in the reststrahlen region of SiC" I.J. van Rooyen, A. Henry, E. Janzén, E.J. Olivier, J.A.A. Engelbrecht, [2012] Physica B-Condensed Matter · DOI: 10.1016/j.physb.2011.09.077
	"The influence of various dielectric parameters on the reststrahlen region of SiC" I.J. van Rooyen, J.A.A. Engelbrecht, [2011] Physica B-Condensed Matter · DOI: 10.1016/j.physb.2010.11.050
	"Femtosecond laser induced breakdown spectroscopy of silver within surrogate high temperature gas reactor fuel coated particles" A. du Plessis, J. Steyn, L.R. Botha, C.A. Strydom, I.J. van Rooyen, D.E. Roberts, [2010] Spectrochimica Acta Part B-Atomic Spectroscopy · DOI: 10.1016/j.sab.2010.09.001
	"Nano-indentation hardness measurements as a characterization technique of SiC- and pyrolytic carbon layers of experimental PBMR coated particles" [2010] Ceramic Engineering and Science Proceedings · EID: 2-s2.0-79952383918
	"INFLUENCE OF TEMPERATURE ON THE MICRO- AND NANOSTRUCTURES OF EXPERIMENTAL PBMR TRISO COATED PARTICLES: A COMPARATIVE STUDY" [2009] Proceedings of the 4th International Topical Meeting on High Temperature Reactor Technology, Vol 1
	"Influence of temperature on the micro-and nanostructures of experimental PBMR TRISO coated particles: A comparative study" [2009] 2008 Proceedings of the 4th International Topical Meeting on High Temperature Reactor Technology, HTR 2008 · EID: 2-s2.0-70349850788
Source: ORCID/CrossRef using DOI

Accomplishments

Accomplished Author

Authored 10+ NSUF-supported publications

Top 5% Collaborator

Top 5% of all RTE Proposal collaborations

Top 5% Reviewer

Top 5% of all RTE Proposals reviewed

NSUF Supported Research

In-situ High Temperature Ion Irradiation Transmission Electron Microscopy to Understand Fission Product Transport in Silicon Carbide of TRISO Fuel - FY 2018 RTE 1st Call, #18-1282

Development of advanced crystallographic analysis techniques for localised fission product transport in irradiated SiC. - FY 2014 RTE 1st Call, #14-460

Correlating SiC grain size and grain boundary orientation with strength and SiC layer growth conditions - FY 2012 RTE Solicitation, #12-363

NSUF Research Collaborations

An evaluation of effects of ion irradiation on crystal, mechanical, and microstructural properties of Alloy 709 - FY 2024 RTE 1st Call, #24-4797

Ion Irradiation and Post Characterization on Additively Manufactured High Entropy Alloys for Nuclear Applications - FY 2023 RTE 3rd Call, #23-4765

Understand the Fission Products Behavior and Irradiation Effects in UCO Fuel Kernels of Irradiated AGR-1 and AGR-2 TRISO Fuel Particles by Using Atom Probe Tomography - FY 2020 RTE 2nd Call, #20-4217

Enhancing irradiation tolerance of steels via nanostructuring by innovative manufacturing techniques - FY 2016 CINR, #16-10537

Understand the Fission Products Behavior in UCO Fuel Kernels of safety tested AGR2 TRISO Fuel Particles by Using Titan Themis 200 with ChemiSTEM Capability - FY 2019 RTE 3rd Call, #19-2893

Performance and Structural Damage Analysis of Chalcogenide Glass Phase Change Temperature Sensors Under Ion Irradiation - FY 2019 RTE 3rd Call, #19-2832

Microstructural characterization of in-situ ion irradiated SiC layer of TRISO fuel - FY 2019 RTE 2nd Call, #19-1810

Understand the atomic positions of the metallic fission product in UCO Fuel Kernels and Determine the exact stoichiometry of UC, UO phase of Irradiated TRISO Fuel Particles by Using Titan Themis 200 with EELS characterization Capability - FY 2019 RTE 2nd Call, #19-1779

Investigation of Ag, Pd, I, Ru, and Sr fission products in bulk and grain boundaries of neutron irradiated SiC - FY 2018 RTE 3rd Call, #18-1600

Understand the Fission Products Behavior and Irradiation Effects in UCO Fuel Kernels of Irradiated AGR-1 and AGR-2 TRISO Fuel Particles by Using Atom Probe Tomography - FY 2018 RTE 3rd Call, #18-1593

Understand the Fission Products Behavior and Irradiation Effects in UCO Fuel Kernels of Irradiated AGR-1 and AGR-2 TRISO Fuel Particles Using Titan Themis 200 with ChemiSTEM Capability - FY 2018 RTE 1st Call, #18-1257

Fission Product Distribution Comparison in Irradiated and Safety Tested AGR-1 and AGR-2 TRISO Fuel Particles - FY 2018 RTE 1st Call, #18-1256

Electron Tomography for Three-Dimensional Characterization of Intragranular Fission Product Transport in Neutron-Irradiated Silicon Carbide in TRISO Fuel - FY 2018 RTE 1st Call, #18-1151

Characterize the Irradiated Microstructure and Understand the Fission Product Behavior in an Irradiated and Safety Tested AGR-1 TRISO Fuel Particle New Proposal - FY 2017 RTE 3rd Call, #17-1091

The in-situ observation of radiation resistance mechanism in metal-1D/2D nanocomposites for structural material and fuel cladding of next generation reactors - FY 2017 RTE 2nd Call, #17-971

STEM/EELS Study of Fission Product Transport in Neutron Irradiated TRISO Fuel Particles - FY 2015 RTE 3rd Call, #15-581

APT Study of Fission Product Transport in Unirradiated/Neutron Irradiated TRISO Fuel Particles - FY 2015 RTE 1st Call, #15-541

Characterization and correlation of SiC layer grain size/grain boundary orientation with strength/layer growth conditions - Lite - FY 2013 RTE Solicitation, #13-410

STEM/LEAP Study of Fission Product Transportation in Neutron Irradiated TRISO Fuel Particles - FY 2013 RTE Solicitation, #13-412

Isabella van Rooyen

NSUF Profile

Accomplished Author

NSUF Presenter

Accomplished Researcher

Top 5% Collaborator

Top 5% Reviewer

About Us