Bio
Dr. Ragai Altamimi is a nuclear engineer with approximately 15 years of international research and engineering experience in advanced nuclear energy systems, reactor design and safety, thermal-hydraulics, multiphysics simulation, and space nuclear power technologies.
Before joining Oak Ridge National Laboratory, Dr. Altamimi held research and engineering roles at the Korea Atomic Energy Research Institute, the Jordan Atomic Energy Commission, and the University of New Mexico’s Institute for Space and Nuclear Power Studies. Through his work with KAERI and JAEC, he contributed to the design, construction, commissioning, and early operation of the Jordan Research and Training Reactor, with particular emphasis on reactor core design, cooling-system performance, thermal-hydraulic evaluations, and reactor safety analyses.
His research experience includes experimental and analytical investigations of material test reactor fuel behavior and transient thermal-hydraulic response. He has also contributed to advanced heat-rejection technologies for space nuclear power systems under a NASA Early Stage Innovation project, liquid-metal systems for advanced reactor testing environments, and nuclear safety and cybersecurity modeling efforts conducted in collaboration with Sandia National Laboratories.
At Oak Ridge National Laboratory, Dr. Altamimi applies his multidisciplinary experience to advanced fission and fusion energy systems, reactor irradiation experiments, uncertainty quantification, integrated safety and security, and energy-intensive industrial processes.
Selected ongoing and completed projects at ORNL:
- Nested Pebble Bed Fusion Blanket Development
Neutronics modeling, experiment design, and performance evaluation of advanced pebble-bed-based fusion blanket concepts. - FREDA – Fusion REactor Design & Assessment
System-level thermal-hydraulic modeling of fusion balance-of-plant configurations to evaluate operational performance and transient behavior. - Hybrid Next-Generation Cement Materials Initiative
Energy management, process-intensity analysis, and CO₂ emissions modeling to support development of low-carbon cement technologies. - Integration of Safety, Security, and Operations for Advanced Nuclear Facilities
Development of integrated frameworks that couple nuclear safety, security, and operational considerations for advanced nuclear systems. - Open-Source Uncertainty Quantification Framework for Reactor Irradiation Experiments
Development of an open-source computational framework for quantifying and propagating uncertainties in reactor irradiation experiments, supporting experiment design, analysis, interpretation, and characterization of irradiation conditions and associated response parameters. - Technical Review of Radioisotope Production Experiment Designs at HFIR
Independent thermal-hydraulic technical assessment of irradiation experiment configurations, analytical methods, and safety considerations for radioisotope production campaigns.
Awards
Science and Engineering Excellence Award, Korea Atomic Energy Research Institute (KAERI), 2014
IAEA’s Nuclear Research Reactors Fellowship, International Atomic Energy Agency (IAEA), 2015
Alpha Nu Sigma National Honor Society, American Nuclear Society (ANS), 2021
Outstanding Graduate Student Award, School of Engineering, UNM, 2022
Supplemental Performance Award , ORNL, 2025
Education
Ph.D. Nuclear Engineering, University of New Mexico
M.S. Nuclear Engineering, Korea University of Science and Technology
B.A. Nuclear Engineering, Jordan University of Science and Technology