Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “nuclear engineering”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 397 records · Page 22
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Intrinsic property of defective β-Ga 2 O 3 to self-heal under ionizing irradiation

Damage evolution and phase stability in defective β-Ga 2 O 3 and an irradiation-converted γ-Ga 2 O 3 layer have been studied under ionizing irradiation at 300 K. By exploring athermal nonequilibrium processes in β-Ga 2 O 3 , we succeed in identifying a self-healing mechanism that enables recovery pre-existing damage, characterized by a recovery cross-section of ~0.17 nm 2 . Remarkably, this study further demonstrates that the crystallinity of the irradiation-converted γ-Ga 2 O 3 layer improves under ionizing irradiation. More importantly, X-ray diffraction analysis reveals that the highly-strained 𝛾 -phase transforms into a highly-crystalline structure without film disintegration, contrasting to that reported for isochronal annealing at 1000 K. The inelastic thermal spike calculations provide insights into the important effects of energy transfer to electrons in reordering the local atomic arrangement of both defective β- Ga 2 O 3 and 𝛾-Ga 2 O 3 . This behavior suggests a pathway for low-temperature crystallization, offering a promising strategy for fabricating ultrahigh-speed non-volatile memory devices.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Pursuing theranostics: a multimodal architecture approach

Theranostics is a field of nuclear medicine which uses the same targeting vector and chelating system for both a diagnostic and therapeutic radionuclide, allowing for uniformity in imaging and treatment.

Bender, Aidan A. [Nuclear Engineering Program, Uni↗
NASA NTRS1963

ADVANCED PROPULSION SYSTEMS

Nuclear and electric propulsion concepts for space systems in terms of weight-power ratios

SPACECRAFT PROPULSION↗
DOE OSTI2026

Structural and Electrocatalytic Studies of Pulsed Laser Deposited Epitaxial RuO 2 Thin Films

Two sets of high-quality epitaxial ruthenium oxide (RuO 2 ) thin films with different thicknesses were synthesized in situ on cost-competitive sapphire substrates by using a pulsed laser deposition technique. The first set of films, with a thickness of 40 nm and a sheet resistance of 15.7 Ω/□, was prepared using 2100 laser pulses, while the second set of films, with a thickness of 87 nm and a sheet resistance of 6.7 Ω/□, was prepared using 4800 laser pulses. All other deposition parameters were kept the same. The post-deposition structural and morphological measurements showed that both sets of films grew at the same growth rate, had the same crystallinity, similar grain boundary density, and slightly different surface roughness. The thicker RuO 2 films achieved an overpotential of 280 mV for the oxygen evolution reaction at a current density of 100 μA/cm 2 , comparable to or exceeding the performance of films grown on more expensive substrates. Comparatively, the thinner RuO 2 films, which have a significantly higher charge transfer resistance (250 Ω versus 100 Ω for thick films), display a higher overpotential of 320 mV. These results indicate that the lower electrical resistance of thicker films promotes charge transfer through the film body, leading to superior electrocatalytic properties.

charge-transfer↗
DOE OSTI2025

The ScIDEP muon radiography project at the Egyptian Pyramid of Khafre

The ScIDEP Collaboration is constructing muon telescopes based on scintillator technology to investigate the internal structure of the Egyptian Pyramid of Khafre at Giza near Cairo using cosmic-ray muons. The collaboration aims to scan the pyramid from multiple viewpoints, both inside the king’s burial chamber that is located centrally at the base of the pyramid, and outside of the pyramid, to potentially identify any new internal structures. An overview of the project is presented, including the development of the data-acquisition system, the simulation framework, and very first detector studies.

47 OTHER INSTRUMENTATION↗
DOE OSTI2025

Barium ion sensing with IPG K + molecular probes

Fluorophores covalently bound to azacrown ether ionophores can be assembled into sensitive turn-on chemosensors. The size specificity and electron-rich nature of the ionophore's binding domain contribute to both selectivity and strong turn-on fluorescence sensing by various mechanisms when properly constructed. Aza-18-crown-6 ethers are quite selective for binding to K + and Ba 2+ , yet the more electron-withdrawing dicationic nature of barium imposes a larger electronic effect on turn-on fluorescent sensors. Barium chemosensors can be important for measuring soluble Ba 2+ in drinking water and have gained recent attention for their potential to enhance the detection of rare events in xenon decay. Here we quantify the capability of three chemosensors, marketed for biologically useful K + sensing, as effective probes for Ba 2+ ions. Here, we present measurements from bulk spectrofluorometry to characterize the system in aqueous solutions and demonstrate the usefulness of these species for low-background single-ion fluorescence microscopy, revealing new candidates for Ba 2+ sensing.

Miller, R. L. [Department of Chemistry and Biochem↗
DOE OSTI2025

Revealing a Pathway for Low-Temperature Recrystallization in Germanium

Thermally activated annealing in semiconductors faces inherent limitations, such as dopant diffusion. Here, a nonthermal pathway is demonstrated for a complete structural restoration in predamaged germanium via ionization-induced recovery. By combining experiments and modeling, this study reveals that the energy transfer of only 2.4 keV nm −1 from incident ions to target electrons can effectively annihilate pre-existing defects and restore the original crystalline structure at room temperature. Moreover, it is revealed that the irradiation-induced crystalline-to-amorphous (c/a) transformation in Ge is reversible, a phenomenon previously considered unattainable without additional thermal energy imposed during irradiation. For partially damaged Ge, the overall damage fraction decreases exponentially with increasing fluence. Surprisingly, the recovery process in preamorphized Ge starts with defect recovery outside the amorphous layer and a shrinkage of the amorphous thickness. After this initial stage, the remaining damage decreases slowly with increasing fluence, but full restoration of the pristine state is not achieved. These differences in recovery are interpreted in the framework of structural differences in the initial defective layers that affect recovery kinetics. This study provides new insights on reversing the c/a transformation in Ge using highly-ionizing irradiation and has broad implications across materials science, radiation damage mitigation, and fabrication of Ge-based devices.

athermal recovery↗
DOE OSTI2024

On the convergence of the fixed point method for solving neutron transport alpha eigenvalue problems

It was shown that the Fixed Point Method (also known as the Rayleigh Quotient Method) is several times faster than the Critical Search Method for solving neutron transport alpha eigenvalue problems. It was also shown that the Fixed Point Method is able to determine the alpha eigenvalues of sub-critical systems that are beyond the reach of the Critical Search Method. Despite these significant advances, the Fixed Point Method remains an unproven algorithm. Here, this report provides a proof.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2021

Package Review Guide for Reviewing Safety Analysis Reports for Packages (Revision 4)

This Package Review Guide (PRG) provides guidance for Department of Energy (DOE) review and approval of packages to transport fissile and Type B quantities of radioactive material. It fulfills, in part, the requirements of DOE Order 460.1D for the Headquarters Certifying Official to establish standards and to provide guidance for the preparation of Safety Analysis Reports for Packages (SARP). This Package Review Guide is intended for use by the United States Department of Energy Headquarters Certifying Official and their staff, DOE Secretarial offices, operations/field offices, and applicants for Department of Energy package approval. This Package Review Guide is generally organized at the chapter-level in a format similar to that recommended in United States Nuclear Regulatory Commission Regulatory Guide 7.9. One notable exception is the addition of Chapter 9 Quality Assurance, which is not included as a separate chapter in Regulatory Guide 7.9. Within each chapter, this Package Review Guide addresses the technical and regulatory bases for the review, the manner in which the review is accomplished, and findings that are generally applicable for a package that meets the approval standards.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
NASA NTRS2006

A Programmatic and Engineering Approach to the Development of a Nuclear Thermal Rocket for Space Exploration

With the announcement of the Vision for Space Exploration on January 14, 2004, there has been a renewed interest in nuclear thermal propulsion. Nuclear thermal propulsion is a leading candidate for in-space propulsion for human Mars missions; however, the cost to develop a nuclear thermal rocket engine system is uncertain. Key to determining the engine development cost will be the engine requirements, the technology used in the development and the development approach. The engine requirements and technology selection have not been defined and are awaiting definition of the Mars architecture and vehicle definitions. The paper discusses an engine development approach in light of top-level strategic questions and considerations for nuclear thermal propulsion and provides a suggested approach based on work conducted at the NASA Marshall Space Flight Center to support planning and requirements for the Prometheus Power and Propulsion Office. This work is intended to help support the development of a comprehensive strategy for nuclear thermal propulsion, to help reduce the uncertainty in the development cost estimate, and to help assess the potential value of and need for nuclear thermal propulsion for a human Mars mission.

Bordelon, Wayne J., Jr.↗
DOE OSTI2026

Exploration of Neutron-Rich Isotopes around N = 50 via the In-Flight Fission of a 345 MeV/Nucleon 238 U Beam

A search for new neutron-rich isotopes beyond $Z=28$ and $N=50$ was performed using a 345 MeV/nucleon $^{238}$U beam at RI Beam Factory in RIKEN Nishina Center. The BigRIPS separator and state-of-the-art radiation detectors were used to efficiently separate and identify the produced nuclei. For the first time, we have observed and determined the production cross sections for eight neutron-rich isotopes $^{72}$Cr, $^{74,75}$Mn, $^{77}$Fe, $^{79,80}$Co, $^{85}$Cu, and $^{90}$Ga. This study broadens our understanding of nuclear existence and paves the way for investigating the properties of neutron-rich medium-mass nuclei.

Shimizu, Yohei [RIKEN, Saitama (Japan); et al.]↗
DOE OSTI2025

Quantifying mining requirement and waste for energy sustainability

This study demonstrates the life-cycle assessment of different energy sources-coal, natural gas, solar, wind, nuclear, and hydro-particularly focused on mining activities and waste per given electricity capacity and generation.

Ermakova, Dinara [Department of Nuclear Engineerin↗
DOE OSTI2026

A Benchmarking Framework for Evaluating Large Language Model Capabilities in Nuclear Reactor Safety Applications

Large language models (LLMs) are increasingly capable of answering technical questions, synthesizing domain knowledge, and supporting engineering workflows. For nuclear science and engineering, these capabilities require careful, domain-specific evaluation before they can be credibly incorporated into safety-related activities, regulatory review, or technical decision support. This paper presents preliminary results from benchmarking framework for evaluating LLM capabilities in nuclear contexts. The framework is organized into three evaluation categories: nuclear fundamentals, general dual-use knowledge, and plant specific knowledge. These categories are intended to distinguish general nuclear engineering competence from broader technical reasoning and more context-dependent nuclear knowledge. Initial evaluations focus on nuclear fundamentals using questions representative of the knowledge expected of a nuclear professional engineer. Results indicate that contemporary frontier models perform at a high level and substantially exceed the performance of older model generations, with some models approaching saturation of the current benchmark. These findings suggest both the rapid improvement of LLM capabilities in specialized technical domains and the need for more discriminating evaluation methods. The paper presents the benchmark structure, preliminary model-comparison results, and ongoing work. This work supports development of verifiable, responsible, and safety-conscious methods for assessing AI systems in nuclear engineering applications.

21 - SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLAN↗
NASA NTRS1961

Systems Engineering of a Nuclear-Electric Spacecraft

Studies have shown that nuclear-electric propulsion systems will provide superior payload capability and unique advantages over chemical systems for high-energy deep-space missions. Conceptual design studies of unmanned spacecraft employing nuclear-electric propulsion systems have been undertaken to determine some of the major integration problems. Early recognition of these problems will help to stimulate the development effort that will be required to bring these systems into fruitful utilization. Typical designs under consideration for interplanetary missions for the next decade employ a nuclear reactor providing thermal energy to a turbogeneration system which, in turn, supplies electrical power to an ion engine for primary propulsion and additional utility power for guidance and control, powered-flight radio transmission, instrumentation, et cetera. The major systems and components which form a complete spacecraft are listed in this Report, and a review of the significant physical and operational characteristics of these various systems and components which affect spacecraft integration is made. Conceptual.configurations and detailed weight studies for a 60-kilowatts-electric Venus-capture spacecraft and a 1-megawattelectric Jupiter-capture spacecraft are shown to illustrate typical physical arrangements based on the various hardware constraints. From these configurations, the major development goals are ascertained and summarized.

SPACECRAFT↗