PNNL

Ramprashad Prabhakaran is a materials scientist at Pacific Northwest National Laboratory (PNNL). He has been actively involved in the nuclear materials R&D for about 25 years. He worked at the University of Nevada, Las Vegas (UNLV) and Idaho National Laboratory (INL) prior to joining PNNL in September 2014.

Prabhakaran has extensive experience in evaluating environment-induced degradations (corrosion and irradiation effects), performing mechanical and microstructural characterizations of nuclear materials (ferritic-martensitic steels, austenitic stainless steels, zirconium alloys, oxide dispersion strengthened [ODS] alloys, friction stir welded/processed alloys) and obtaining structure-property-processing relationships to understand irradiation hardening mechanisms. His research is focused on identifying advanced structural materials to extend the life of existing nuclear reactors and building next-generation nuclear reactors with improved efficiency, economy, and safety.

Prabhakaran also utilizes his corrosion science knowledge and performs electrochemical, immersion, and autoclave corrosion studies to understand the effects of chemical composition, fabrication parameters, surface modifications, coatings, and various processes on the corrosion behavior of various materials, such as U-Mo, Al-6061 and Hf (research reactors), Al and Mg alloys – cold spray, plasma treatment, welding (automotive applications), austenitic stainless steels like 316SS – sensitization studies (reactor applications).

As a principal investigator (PI) (10 projects), co-PI/PNNL PI (7 projects) and task lead (over 15 projects), he has supported multiple programs with the Department of Energy ─ Nuclear Energy (fuel cycle R&D, nuclear energy enabling technologies, advanced materials and manufacturing technologies and nuclear science user facilities programs), Office of Science (high energy physics), National Nuclear Security Administration (international nuclear safety and cooperation, nuclear weapon stockpile), Energy Efficiency & Renewable Energy (vehicle technologies, hydrogen and fuel cells technologies), Nuclear Regulatory Commission (Office of Nuclear Regulatory Research), RaDIATE (Radiation Damage in Accelerator Target Environments), and industry (Electric Power Research Institute, TerraPower).

He has authored over 40 publications with over 330 citations and collaborated with numerous researchers, engineers, and professors from national laboratories, industry, and universities. He has reviewed over 100 manuscripts as a reviewer and guest editor.

• Nuclear fuels and cladding/structural materials
• Lightweight materials for automobiles; friction stir welding (aluminum to aluminum; aluminum to steel)
• Mechanical properties and microstructural characterization
• Environment-induced degradation (stress corrosion cracking [SCC], corrosion, hydrogen embrittlement)
• Irradiation effects, small-scale testing and hot-cell experiments
• Designing experiments and performing failure analysis
• Thermomechanical processing
• Microstructure property-processing correlation

• Corrosion
• Electrochemistry
• Irradiated materials characterization
• Irradiation effects
• Materials science and engineering
• Mechanical properties

• PhD candidate in Materials Science & Engineering, University of Idaho
• MS in Nuclear Engineering, University of Idaho
• MS in Mechanical Engineering, University of Nevada-Las Vegas
• BE in Mechanical Engineering, University of Madras

• Guest editor, TMS JOM journal
• Key reader, Metallurgical and Materials Transactions: A; E journals
• Reviewer, Journal of Materials Engineering & Performance, Metallurgical and Materials Transactions: A; E, Scripta Materialia, Metallography, Microstructure & Analysis, JOM, Journal of Nuclear Materials and Nuclear Technology journals
• Vice-chair (2013-2015), Chair (2015-2017), JOM Advisor (2017-2019), TMS Corrosion and Environmental Effects Committee
• Vice-chair (2011-2013), Chair (2013-2015), JOM Advisor (2015-2017), TMS Nuclear Materials Committee
• Secretary (2016), Vice-Chair (2017), Chair (2018), TMS Young Professional Committee
• TMS Structural Material Division Council Member
• TMS Programming Committee (Board) Member
• TMS Professional Development Committee (Administrative) Member
• TMS Professional Development Committee Representative for the Structural Materials Division
• North American Young Generation in Nuclear (NA-YGN) National Awards Committee Member
• Secretary, NA-YGN Knowledge Transfer and Retention Committee
• Lead Organizer - TMS Annual Meeting (2012, 2013, 2014, 2015, 2016, 2017, 2018) - Symposiums on Nuclear Fuels & Materials

• PNNL Outstanding Performance Award for performing electrochemical corrosion research ─ National Nuclear Security Administration’s (NNSA’s) uranium-molybdenum (U-Mo) program (March 2022)
• PNNL Outstanding Performance Award for attention to detail to improve laboratory safety and security (October 2021)
• NSsD Core Value: Collaboration Award, PNNL Nuclear Sciences Division, PNNL (December 2020)
• NSsD STEM Award, Nuclear Sciences Division, PNNL (December 2020)
• PNNL Outstanding Performance Award ─ DOE-NE’s Used Fuel Disposition program (September 2020)
• PNNL Director’s Award for Outstanding Contribution to STEM education (September 2019)
• PNNL Outstanding Performance Award for Task Leadership - NNSA’s U-Mo program (October 2018)
• Battelle Community Spirit Award for volunteering in local schools (August 2018)
• TMS Young Professional Highlight ─ an article was published about his professional accomplishments (JOM November issue, 2017)
• TMS Structural Materials Division Young Professional Best Poster Award (March 2017)
• TMS Structural Materials Division Young Leader Professional Development Award (March 2015)
• TMS Rising Professional selected to attend the Emerging Leaders Alliance Conference (November 2015)
• JOM guest editor/journal advisor (2015-2017), TMS Nuclear Materials Committe
• JOM guest editor/journal advisor (2018-2021), TMS Corrosion and Environmental Effects Committee
• TMS Nuclear Materials Committee ─ Chair (2013-2015), Vice-chair (2011-2013)
• TMS Corrosion and Environmental Effects Committee ─ Chair (2017-2019), Vice-Chair (2015-2017)
• TMS Young Professionals Committee ─ Chair (2018), Vice-Chair (2017), Secretary (2016)
• TMS Structural Material Division Council Member (2011-2019)
• TMS Membership and Student Development Committee Representative
• TMS Professional Development Committee Representative for the Structural Materials Division (2016-2020)
• TMS Program Committee Representative for the Structural Materials Division (2015-2018)
• Lead Organizer ─ TMS (2012-2018) ─ Symposia on Nuclear Fuels & Materials
• Lead Organizer ─ TMS 2016 Annual Meeting “Meet the Candidate” interactive poster session
• Co-organizer ─ MS&T (2010-2012) and TMS 2012 (symposia on nuclear materials)
• Session chair: Over 15 sessions at TMS and MS&T conferences
• Guest editor: JOM, Metallurgical and Materials Transactions A and E journals
• Reviewer of journals Metallurgical and Materials Transactions A, Metallurgical and Materials Transactions E, JOM, Scripta Materialia, Metallography, Microstructure & Analysis, Journal of Materials Engineering & Performance, Corrosion Reviews, Corrosion Science, Materials Today Communications, Journal of Nuclear Materials and Nuclear Technology. Invited to review over 125 manuscripts and reviewed over 100 manuscripts
• Member of Tau Beta Pi (Engineering Honor Society) and Phi Kappa Phi (National Honor Society)
• NA-YGN National Awards Committee Member
• Secretary of NA-YGN Knowledge Transfer and Retention Committee
• Invited Mentor, 2016 MeV Summer School (Host: Oak Ridge National Laboratory), July 24-29, 2016, Oak Ridge, Tennessee
• Received travel scholarships from the Oak Ridge Associated Universities, DOE, ASME, EPI, ANS and TMS (twice) to attend/present papers at the SNS-JINS-NICEST 2003 Conference, Oak Ridge, Tennessee (March 2003), IYNC, Canada (May 2004), 12^th ICONE Conference, Arlington, Virginia (April 2004), First Annual Energy Policy Institute Summit, Boise, Idaho (March 2009), ANS 2010 Annual Meeting, San Diego, California (June 2010), TMS 2011 Annual Meeting, San Diego, California (February 2011), and TMS 2015 Annual Meeting, Orlando, Florida (March 2015), respectively
• Received scholarship from the Los Alamos Neutron Science Center to attend the LANSCE Neutron School 2010, August 5-13, 2010, Los Alamos, New Mexico

2025

• Edwards D.J., A.L. Schemer-Kohrn, M.J. Olszta, R. Prabhakaran, Y. Zhu, J. Wang, and J.V. Haag, et al. 2025. "Understanding and Removing FIB Artifacts in Metallic TEM Samples Using Flash Electropolishing." Journal of Nuclear Materials 606:Art. No. 155618. PNNL-SA-202068. doi:10.1016/j.jnucmat.2025.155618

2024

• Agrawal P., A. Dhal, Z. Hu, M. Dubey, L. Shao, R. Prabhakaran, and R.S. Mishra. 2024. "Irradiation-induced shift in the thermodynamic stability of phases and the self-healing effect in transformative high entropy alloys." Journal of Nuclear Materials 597, no. _:Art. No. 155093. PNNL-SA-182838. doi:10.1016/j.jnucmat.2024.155093
• Agrawal P., C. Shiau, A. Sharma, Z. Hu, M. Dubey, Y. Lu, and L. Shao, et al. 2024. "Ion Irradiation and Examination of Additive Friction Stir Deposited 316 Stainless Steel." Materials & Design 238. PNNL-SA-192675. doi:10.1016/j.matdes.2024.112730
• van Rooyen I.J., M. Komarasamy, C.M. Silva, T. Ajantiwalay, Q.R. Miller, R. Prabhakaran, and S. Tripathi, et al. 2024. Preliminary Characterization and Evaluation on ShAPE Manufactured 316H and ODS Steels. PNNL-36737. Richland, WA: Pacific Northwest National Laboratory. Preliminary Characterization and Evaluation on ShAPE Manufactured 316H and ODS Steels
• Wang X., D. Zhang, J.T. Darsell, K.A. Ross, X. Ma, J. Liu, and T. Liu, et al. 2024. "Manufacturing Oxide Dispersion Strengthened (ODS) steel plate via cold spray and friction stir processing." Journal of Nuclear Materials 596, no. _:Art. No. 155076. PNNL-SA-184484. doi:10.1016/j.jnucmat.2024.155076
• Wang X., J.T. Darsell, X. Ma, J. Liu, T. Liu, R. Prabhakaran, and I.E. Anderson, et al. 2024. "Manufacturing ODS Steels from GARS Powders by Friction Consolidation and Extrusion." JOM. The Journal of the Minerals, Metals and Materials Society 76, no. _:2899-2913. PNNL-SA-200089. doi:10.1007/s11837-024-06584-5

2023

• Agrawal P., S. Gupta, A. Dhal, R. Prabhakaran, L. Shao, and R.S. Mishra. 2023. "Irradiation response of innovatively engineered metastable TRIP high entropy alloy." Journal of Nuclear Materials 574. PNNL-SA-178941. doi:10.1016/j.jnucmat.2022.154217
• Guillen D., M.B. Toloczko, R. Prabhakaran, Y. Zhu, Y. Lu, and Y. Wu. 2023. "Thermomechanical Properties of Neutron Irradiated Al3Hf-Al Thermal Neutron Absorber Materials." Materials 16, no. 16:Art. No. 5518. PNNL-SA-131070. doi:10.3390/ma16165518
• Kautz E.J., M. Song, S.L. Riechers, A.M. Koziol, S.A. Briggs, K.H. Yano, and R. Prabhakaran, et al. 2023. "Influence of processing on secondary phase formation and microstructural evolution at U-10Mo alloy and Zr interlayer interfaces." Journal of Alloys and Compounds 969. PNNL-SA-182384
• Lu Y., Y. Wu, R. Prabhakaran, M. Dubey, and L. Shao. 2023. "Microstructural Characterization of Ion Irradiated ODS MA956 Alloy." Microscopy and Microanalysis 29, no. Suppl 1:1563-1564. PNNL-SA-182254. doi:10.1093/micmic/ozad067.804
• van Rooyen I., S. Meher, J. Fernandez dos Santos, M. Komarasamy, M. Nartu, J.B. Wierschke, and R. Prabhakaran, et al. 2023. Feasibility Evaluation of a Solid Phase Scalable HEA Cladding Manufacturing Route. PNNL-35499. Richland, WA: Pacific Northwest National Laboratory. Feasibility Evaluation of a Solid Phase Scalable HEA Cladding Manufacturing Route

2022

• Prabhakaran R., et al., “Understanding localized corrosion on metal surfaces using scanning electrochemical cell impedance microscopy (SECCIM)”, J. Phys. Chem. C; accepted; https://doi.org/10.1021/acs.jpcc.2c03807 
• Prabhakaran R., G.W. Coffey, O.A. Marina, J.S. Hardy, D.J. Edwards, and A.M. Casella. 2022. Final Report: Improved Understanding of Zircaloy Hydrogen Pickup Mechanisms in BWRs. NSUF Report. PNNL-32984. Richland, WA: Pacific Northwest National Laboratory. Final Report: Improved Understanding of Zircaloy Hydrogen Pickup Mechanisms in BWRs. NSUF Report
• Strange L.E., V. Shutthanandan, M. Song, M.E. Bowden, Q. Miller, R. Prabhakaran, and R.W. Shimskey, et al. 2022. "Multimodal Analysis and Characterization of the Boehmite Layer formed on AA6061 Before and After Alkaline Etching." Journal of Materials Research and Technology 21. PNNL-SA-174631. doi:10.1016/j.jmrt.2022.09.125

2021

• Prabhakaran R., et al., “Status of the elevated temperature mechanical test facility setup at PNNL”, PNNL-SA-170069, In Fusion Materials Semiannual Progress Report for period ending December 31, 2021, DOE/ER-0313/71, Department of Energy, 2021.
• Wang J., et al., “Progress report on re-starting hot-rolling and continued characterization of tungsten heavy alloy at PNNL”, PNNL-SA-170335, In Fusion Materials Semiannual Progress Report for period ending December 31, 2021, Department of Energy, 2021.
• Prabhakaran R., et al., “Progress report: The effect of neutron irradiation on conventional and nanocrystalline nickel”, PNNL-32024, Pacific Northwest National Laboratory, Richland, WA, 2021.
• Wang J., et al., “Quantifying microstructure-mechanical property correlation in ductile phase toughened W-NiFe heavy alloy” PNNL-SA-165617, In Fusion Materials Semiannual Progress Report for the period ending June 30, 2021, Department of Energy, 2021.
• Wang J., et al., “Microstructure-mechanical property correlation in ductile phase toughened W-NiFe heavy alloys”, PNNL-SA-159767, In Fusion Materials Semiannual Progress Report for the period ending December 31, 2020, DOE-ER-0313/69, pp. 117-131, 2021.
• Kalsar R., et al. “Characterization report for the MP-1 experiment fabrication campaign. PNNL-30372 Rev. 1, Pacific Northwest National Laboratory, WA, 2021.

2020

• Ishida T., E. Wakai, S. Makimura, A.M. Casella, D.J. Edwards, R. Prabhakaran, and D.J. Senor, et al. 2020. "Tensile behavior of dual-phase titanium alloys under high-intensity proton beam exposure: radiation-induced omega phase transformation in Ti-6Al-4V." Journal of Nuclear Materials 541. PNNL-SA-152944. doi:10.1016/j.jnucmat.2020.152413
• Kalsar R., F.G. Di Lemma, T. Trowbridge, E. Tegtmeier, R. McCabe, R. Prabhakaran, and N.R. Overman, et al. 2020. Characterization Report for the MP-1 Experiment Fabrication Campaign. PNNL-30372. Richland, WA: Pacific Northwest National Laboratory. Characterization Report for the MP-1 Experiment Fabrication Campaign 
• R. Prabhakaran, et al., “FY20 report: Improved understanding of Zr-2 hydrogen pickup mechanisms in BWRs”, PNNL-30477, Pacific Northwest National Laboratory, Richland, WA, 2020.
• R. Prabhakaran, “Mechanical properties of proton irradiated Ti grades (DS-Ti2 and US-Ti)”, PNNL-SA-154380, Pacific Northwest National Laboratory, Richland, WA, 2020.

2019

• Prabhakaran R., L. Gardner, V.V. Joshi, D. Burkes, and C.A. Lavender. "Effect of homogenization and hot rolling on the mechanical properties, microstructure and corrosion behavior of U-10Mo monolithic fuel”, Journal of Nuclear Materials , 527, 2019. doi:10.1016/j.jnucmat.2019.151804
• W. Frazier, et al., “Recrystallization kinetics of cold-rolled U-10wt%Mo”, Journal of Nuclear Materials, January 2019, Vol. 513, pp. 56-61.
• R. Prabhakaran, et al., “Progress report on improved understanding of Zr-2 hydrogen pickup mechanisms in BWRs”, PNNL-28573, Pacific Northwest National Laboratory, Richland, WA, 2019.
• R. Prabhakaran, “Mechanical properties of irradiated beryllium grades (PF-60 and S-65F)”, PNNL-SA-147992, Pacific Northwest National Laboratory, Richland, WA, 2019.
• J. Wang, M. Toloczko, and R. Prabhakaran, “Ion and neutron irradiation effects studies of ferritic/martensitic steels”, PNNL-29224, Pacific Northwest National Laboratory, Richland, WA, 2019.
• R. Kalsar, et al., “PNNL’s intermediate characterization summary for the MP-1 experiment”, PNNL-28543, Pacific Northwest National Laboratory, Richland, WA, 2019. 

2018

• Ishida T., et al. 2018. "Study of the radiation damage effect on Titanium metastable beta alloy by high intensity proton beam." Nuclear Materials and Energy 15. doi:10.1016/j.nme.2018.04.006
• J. Wang, et al., “Summary of neutron irradiation microstructures and barrier hardening determinations”, PNNL-28360, Pacific Northwest National Laboratory, Richland, WA, 2018.
• J. Wang, et al., “Microstructure and mechanical property characterization of three new 9Cr steels”, PNNL-27590, Pacific Northwest National Laboratory, Richland, WA, 2018.
• V. Joshi and R. Prabhakaran, “Density of bare LEU-10wt%Mo”, PNNL-SA-138487, Pacific Northwest National Laboratory, Richland, WA, 2018.
• V. Joshi, et al., “MP-1 qualification: DU/LEU mini-plate characterization”, PNNL-27516, Pacific Northwest National Laboratory, Richland, WA, 2018.

2017

• Prabhakaran R. 2017. "U-Mo Monolithic Fuel for Nuclear Research and Test Reactors." JOM. The Journal of the Minerals, Metals and Materials Society 69, no. 12:2529-2531. doi:10.1007/s11837-017-2612-3
• M. Toloczko, et al., “Report on characterization of materials ion irradiated to 100-150 dpa”, PNNL-26956, Pacific Northwest National Laboratory, Richland, WA, 2017. 
• Y. Zhu, et al., “FY17 annual report on techniques for characterizing the irradiation response of nuclear reactor structural materials”, PNNL-27190, Pacific Northwest National Laboratory, Richland, WA, 2017.
• R. Prabhakaran, et al., “Three-point bend testing of unirradiated U-Mo fuel foils”, PNNL-26662, Pacific Northwest National Laboratory, Richland, WA, 2017.
• M. Toloczko, et al., “Tensile and hardness testing of unirradiated and neutron irradiated Al-Al₃Hf alloys” PNNL-26128, Pacific Northwest National Laboratory, Richland, WA, 2017.
• D. Edwards, et al., “Microstructural characterization of irradiated Ti-15-3-3 OTR foil”, PNNL-26274, Pacific Northwest National Laboratory, Richland, WA, 2017.

2016

• Prabhakaran R., J. Choi, E.V. Stephens, D. Catalini, C.A. Lavender, and A. Rohatgi. 2016. "Mechanical Characterization and Corrosion Testing of X608 Al Alloy." In Light Metals 2016, edited by E. Williams. 145-150. Hoboken, New Jersey:John Wiley & Sons, Inc. PNNL-SA-113866. doi: 10.1002/9781119274780.ch25
• Devaraj A., R. Prabhakaran, V.V. Joshi, S.Y. Hu, E.J. McGarrah, and C.A. Lavender. 2016. Theoretical Model for Volume Fraction of UC, ²³⁵U Enrichment, and Effective Density of Final U 10Mo Alloy. PNNL-SA-117284. Richland, WA: Pacific Northwest National Laboratory. Theoretical Model for Volume Fraction of UC, 235U Enrichment, and Effective Density of Final U 10Mo Alloy 
• Prabhakaran R., V.V. Joshi, M.A. Rhodes, A.L. Schemer-Kohrn, A.D. Guzman, and C.A. Lavender. 2016. U-10Mo Sample Preparation and Examination using Optical and Scanning Electron Microscopy. PNNL-25308 Rev. 1. Richland, WA: Pacific Northwest National Laboratory. U-10Mo Sample Preparation and Examination using Optical and Scanning Electron Microscopy