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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.

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At least 523 records · Page 29
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Micro-Tensile Properties of Irradiated AGR-2 TRISO Fuel Pyrolytic Carbon (PyC) and Silicon Carbide (SiC) Coatings

Tristructural isotropic (TRISO) coated nuclear fuel particles are emerging as a versatile option for new reactor designs, with the silicon carbide (SiC) layer crucial for retaining fission products. However, the mechanical properties of TRISO coating layers, particularly after irradiation, are not fully understood due to their small size and high radioactivity. Recent in situ micro-tensile testing of various TRISO layers aims to better understand the SiC layer's failure mechanisms, advancing TRISO fuel qualification. These micro-tensile results will be presented.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2026

Shake-up and shake-off spectra in the electron capture decay of atomic $^7$Be

The most stringent laboratory-based experimental limits on the existence of sub-MeV sterile neutrinos are currently set by decay spectroscopy of radioactive $^7$Be embedded into superconducting sensors. The systematic uncertainties are dominated by the modeling of the electron shake-up and shake-off spectra that are not based on state-of-the-art atomic theory and do not include electron correlations or relativistic effects. We have used the multiconfiguration Dirac-Fock formalism to obtain correlated wavefunctions ab initio and compute all single and double shake processes in the electron capture decay of atomic $^7$Be. The simulations can explain some but not all of the observed spectral features, likely because the wave functions are modified by the Ta sensor material that the $^7$Be is embedded into. The new models also show that the L/K electron capture ratio of $^7$Be in Ta has previously been slightly underestimated revising the previous value of 0.070(7) to a new value of 0.0756(20).

Atomic Physics (physics.atom-ph)↗
NASA NTRS1972

Study of radioisotope safety devices for electric propulsion system, Volume 1: Summary report

A new reference design was prepared for the 5 kW(e) thermionic power supply. The safety equipment in this design is a passive containment system which does not rely on the operation of any mechanisms such as a launch escape rocket or deployment of parachutes. It includes: (1) a blast shield to protect against the explosion of the launch vehicle; (2) a combination of refractory thermal insulation and heat storage material to protect against a sustained launch pad fire; (3) a reentry body with a spherical nose and a large conical flare at the aft end to stabilize the reentry attitude and lower the terminal velocity in air; (4) composite graphite thermal protection to sustain the reentry heat pulse; (5) crushable honeycomb behind the nose to limit the deceleration of the radioisotope source due to impact on land at terminal velocity; (6) a double-walled secondary containment vessel surrounding the isotopic capsules; (7) neutron shielding to reduce external dose rates; (8) an auxiliary cooling system employing redundant heat pipes to remove the radioactive decay heat from the heat source and reject it to the surroundings or to a forced convection loop.

Bradshaw, G. B.↗
NASA NTRS1997

Fusion Crust and the Measurement of Surface Ages of Antarctic Ordinary Chondrites

Natural thermoluminescence (TL) reflects radiation exposure and storage temperature. Meteorites generally exhibit thermoluminescence acquired during their long exposure to galactic cosmic rays in space. During atmospheric passage, temperatures are high enough to completely drain the TL, in the first mm of material under the fusion crust. We therefore refer to this surface layer as "fusion crust" although it does include some unmelted material just below the crust. When the meteorite lands on earth this drained layer will begin to build up natural TL once again due to radiation from cosmic rays and internal radionuclides. Cosmic ray annual dose is estimated to be between 0.04 and 0.06 rad/yr on the earth's surface in Antarctica while the internal radionuclides contribute only about 0.01 rad/yr. Therefore the total annual dose received by the meteorite while it is on the surface is between 0.05 and 0.07 rad/yr. If the meteorite is buried deeply in the ice it is effectively shielded from most cosmic rays and thus only internal radioactivity contributes to the annual dose.

Akridge, Jannette M. C.↗
DOE OSTI2024

Thermal Conductivity Measurements on Irradiated TRISO Fuel at IMCL

INL is leading the development and testing of accident tolerant fuels: fuels that resist melting down and that contain radioactive byproducts, preventing their release into their environment. One such fuel, called TRi-structural ISOtropic particle fuel (TRISO) See Fig 1. Understanding how heat propagates through a fuel is essential to fuel development and qualification. When irradiated in a reactor the properties that affect heat transport change. Our objective is to quantify the change in thermal properties of TRISO after irradiation.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
NASA NTRS1976

Viking labeled release biology experiment - Interim results

All results of the labeled-release life-detection experiment conducted on Mars prior to conjunction are summarized. Tests at both landing sites provide remarkably similar evolution of radioactive gas upon addition of a radioactive nutrient to the Mars sample. The 'active' agent in the sample is stable to 18 C, but is substantially inactivated by heat treatment for 3 hours at 50 C and completely inactivated at 160 C, as would be anticipated if the active response were caused by microorganisms. Results from test and heat-sterilized control samples are compared with those obtained from terrestrial soils and a lunar sample. Possible nonbiological explanations of the Mars data are reviewed. Although such explanations of the labeled-release data depend on UV irradiation, the labeled-release response does not appear to depend on recent direct UV activation of surface material. Available facts do not yet permit a conclusion regarding the existence of life on Mars.

Levin, G. V.↗
NASA NTRS1977

Gaseous-fuel nuclear reactor research for multimegawatt power in space

In the gaseous-fuel reactor concept, the fissile material is contained in a moderator-reflector cavity and exists in the form of a flowing gas or plasma separated from the cavity walls by means of fluid mechanical forces. Temperatures in excess of structural limitations are possible for low-specific-mass power and high-specific-impulse propulsion in space. Experiments have been conducted with a canister filled with enriched UF6 inserted into a beryllium-reflected cavity. A theoretically predicted critical mass of 6 kg was measured. The UF6 was also circulated through this cavity, demonstrating stable reactor operation with the fuel in motion. Because the flowing gaseous fuel can be continuously processed, the radioactive waste in this type of reactor can be kept small. Another potential of fissioning gases is the possibility of converting the kinetic energy of fission fragments directly into coherent electromagnetic radiation, the nuclear pumping of lasers. Numerous nuclear laser experiments indicate the possibility of transmitting power in space directly from fission energy. The estimated specific mass of a multimegawatt gaseous-fuel reactor power system is from 1 to 5 kg/kW while the companion laser-power receiver station would be much lower in specific mass.

Thom, K.↗
NASA NTRS2011

Mono Lake Analog Mars Sample Return Expedition for AMASE

We explored the performance of one robotic prototype for sample acquisition and caching of martian materials that has been developed at the Jet Propulsion Laboratory for potential use in the proposed MAX-C Mars Sample Return architecture in an environment, rich in chemical diversity with a variety of mineralogical textures. Mono Lake State Tufa Reserve in Mono County, CA possesses a variety of minerals including a variety of evaporites, volcanic glass and lava, and sand and mudstones. The lake itself is an interesting chemical system: the water is highly alkaline (pH is approximately 10) and contains concentrations of Cl, K, B, with lesser amounts of S Ca Mg, F, As, Li, I and Wand generally enriched HREEs. There are also traces of radioactive elements U, Th, Pl.

Conrad, P. G.↗
NASA NTRS1988

Isotopic investigations in the area of the Tunguska catastrophe in 1908 year

The hypotheses of the annihilation and thermonuclear character of the Tunguska explosion have been tested by measuring inductive Ar-39 radioactivity from K and Ca in rocks and soil under the explosion epicentrum. Ar-39 was not detected though its estimated radioactivity was expected to be 100 times higher than the radio-metrical plant sensitivity. These results testify against the nuclear nature of the Tunguska explosion. The contents of 11 elements in the ultrasmall quantity of matter of the silicate microspherules isolated from catastrophe peat layer at the explosion site were measured by method of neutron activation analysis. It was demonstrated that the enrichment of microspherules by light and volatile elements (Al, Na, Zn, Cs) and the impoverishment by more heavy and hard volatile ones (Fe, Co, Sc). It was shown that the microspherules were not the product of differentiation of the terrestrial soil or of an ordinary meteorite material. It was demonstrated that Pb isotopic content in catastrophe peat layer had more Pb-204, Pb-207, Pb-208 than Pb-206 as compared with Pb isotopic content of other peat layers and common Pb in this area. In the peat column taken at the Ostraya hill area in three nearcatastrophe layers, small increases of isotopic C-13 was determined. Isotopic C effect in the peat layer is confirmed also for the North peatbog. Observed isotopic changes are not accounted for by climatic changes or other physico-chemical reasons. They seem to be related to preservation in the peat of matter resembling carbonaceous chrondrites of the Cl type or more probably of cometary matter enriched much more in volatile elements.

Kolesnikov, E. M.↗
NASA NTRS1990

Experiment K-6-18. Study of muscarinic and gaba (benzodiazepine) receptors in the sensory-motor cortex, hippcampus and spinal code

Frontal lobe samples of rat brains flown aboard Cosmos 1887 were processed for the study of muscarinic (cholinergic) and GABA (benzodiazepine) receptors and for immunocytochemical localization of the neurotransmitter gamma-aminobutyric acid (GABA) and glial fibrillary acidic protein (GFAP). Although radioactive labeling of both muscarinic cholinergic and GABA (benzodiazepine) receptors proved to be successful with the techniques employed, distinct receptor localization of individual laminae of the frontal neocortex was not possible since the sampling of the area was different in the various groups of animals. In spite of efforts made for proper orientation and regional identification of laminae, it was found that a densitometric (quantitation of autoradiograms) analysis of the tissue did not contribute to the final interpretation of the effects of weightlessness on these receptors. As to the immunocytochemical studies the use of both markers, GFAP and GABA antiserum, confirmed the suitability of the techniques for use in frozen material. However, similar problems to those encountered in the receptor studies prevented an adequate interpretation of the effects of micro-G exposure on the localization and distribution of GABA and GFAP. This study did, however, confirm the feasibility of investigating neurotransmitters and their receptors in future space flight experiments.

Daunton, N.↗
NASA NTRS2005

Lunar and Planetary Science XXXVI, Part 22

The Lunar and Planetary Science XXXVI, Part 22 is presented. The topics include: 1) Pressure Histories from Thin and Thick Shock-induced Melt Veins in Meteorites; 2) Nano-structured Minerals as Signature of Microbial Activity; 3) The Insoluble Carbonaceous Material of CM Chondrites as Possible Source of Discrete Organics During the Asteroidal Aqueous Phase; 4) Discovery of Abundant Presolar Silicates in Subgroups of Antarctic Micrometeorites; 5) Characteristics of a Seismometer for the LUNAR-A Penetrator; 6) Heating Experiments of the HaH 262 Eucrite and Implication for the Metamorphic History of Highly Metamorphosed Eucrites; 7) Measurements of Ejecta Velocity Distribution by a High-Speed Video Camera; 8) Petrological Comparison of Mongolian Jalanash Ureilite and Twelve Antarctic Ureilites; 9) Metallographic Cooling Rate of IVA Irons Revisited; 10) Inhomogeneous Temperature Distribution in Chondrules in Shock-Wave Heating Model; 11) Subsurface Weathering of Rocks and Soils at Gusev Crater; 12) Extinct Radioactivities in the Early Solar System and the Mean Age of the Galaxy; 13) Correlation of Rock Spectra with Quantitative Morphologic Indices: Evidence for a Single Rock Type at the Mars Pathfinder Landing Site; 14) Silicon Isotopic Ratios of Presolar Grains from Supernovae; 15) Current Status and Readiness on In-Situ Exploration of Asteroid Surface by MINERVA Rover in Hayabusa Mission; 16) Long Formation Period of Single CAI: Combination of O and Mg Isotope Distribution; 17) Supra-Canonical Initial 26Al/27Al Indicate a 105 Year Residence Time for CAIs in the Solar Proto-Planetary Disk; 18) Evolution of Mercury's Obliquity; 19) First Results from the Huygens Surface Science Package; 20) Polyhedral Serpentine Grains in CM Chondrites; 21) Mountainous Units in the Martian Gusev Highland Region: Volcanic, Tectonic, or Impact Related? 22) Petrography of Lunar Meteorite MET 01210, A New Basaltic Regolith Breccia; 23) Earth-Moon Impacts at ~300 Ma and ~500 Ma Ago; 24) Chemical and Isotopic Analyses of Apollo 16 Glasses: An Integrated Approach; 25) Measuring the Surfaces on Mars; 26) Melting in Martian Snowbanks; 27) The Effect of Ni on Fe-FeS Phase Relations: Implications for the Chemistry of the Martian Core; 28) Shorelines in the Western United States as Analogs for Hypothesized Shoreline Features on Mars; 29) Al and Ti Isotopic Ratios of Presolar SiC Grains of Type Z; 30) Physicochemical Conditions of Clinopyroxene Crystallization in the Parental Bodies of Ordinary Chondrites; 31) Metamorphosed CM and CI Carbonaceous Chondrites Could be from the Breakup of the Same Earth-crossing Asteroid; 32) Aqueous Alteration and Hydrogen Generation on Parent Bodies of Unequilibrated Ordinary Chondrites: Thermodynamic Modeling for the Semarkona Composition; and 33) Preliminary Analysis of Relative Abundances of Hydrothermal Alteration Products in the C1-N10, Y6-N19, and Yax-1_863.51 Impact Melt Samples, Chicxulub Structure, Mexico

Source record↗
NASA NTRS2017

Measuring Surface Bulk Elemental Composition on Venus

The extreme surface environment (462 C, 93 bars pressure) of Venus makes subsurface measurements of its bulk elemental composition extremely challenging. Instruments landed on the surface of Venus must be enclosed in a pressure vessel. The high surface temperatures also require a thermal control system to keep the instrumentation temperatures within their operational range for as long as possible. Since Venus surface probes can currently operate for only a few hours, it is crucial that the lander instrumentation be able to make statistically significant measurements in a short time. An instrument is described that can achieve such a measurement over a volume of thousands of cubic centimeters of material by using high energy penetrating neutron and gamma radiation. The instrument consists of a Pulsed Neutron Generator (PNG) and a Gamma-Ray Spectrometer (GRS). The PNG emits isotropic pulses of 14.1 MeV neutrons that penetrate the pressure vessel walls, the dense atmosphere and the surface rock. The neutrons induce nuclear reactions in the rock to produce gamma rays with energies specific to the element and nuclear process involved. Thus the energies of the detected gamma rays identify the elements present and their intensities provide the abundance of each element. The GRS spectra are analyzed to determine the Venus elemental composition from the spectral signature of individual major, minor, and trace radioactive elements. As a test of such an instrument, a Schlumberger Litho Scanner oil well logging tool was used in a series of experiments at NASA's Goddard Space Flight Center. The Litho Scanner tool was mounted above large (1.8 m x 1.8 m x.9 m) granite and basalt monuments and made a series of one-hour elemental composition measurements in a planar geometry more similar to a planetary lander measurement. Initial analysis of the results shows good agreement with target elemental assays

Venus↗
DOE OSTI2026

Improbability of Post-Closure Criticality in Compacted Criticality Control Overpacks after Room Closure at Waste Isolation Pilot Plant

As part of its periodic re-certification of the Waste Isolation Pilot Plant (WIPP), an operating repository in bedded salt for the disposal of transuranic (TRU) waste from atomic energy defense activities, the United States Environmental Protection Agency expects a re-evaluation of features, events, and processes, such as post-closure nuclear criticality. Although salt creep beneficially encapsulates the TRU waste in the closed WIPP repository, the spacing between an array of waste packages is disrupted as the salt creep closes disposal rooms and containers lose structural integrity. For most TRU waste, the possibility of post-closure criticality is exceedingly small either because the salt neutronically isolates TRU waste canisters or because closure of a disposal room from salt creep does not sufficiently compact the low mass of fissile material. The criticality evaluation was updated, however, because of the introduction of criticality control overpack (CCO) containers, which may dispose up to 380 fissile gram equivalent plutonium-239 in each container. The criticality potential is evaluated through high-fidelity geomechanical modeling of a disposal room filled with CCO containers during two representative conditions: (1) large salt block fall, and (2) gradual disposal room closure from salt creep. Geomechanical models of roof fall demonstrate three tiers of CCO containers are not greatly disrupted. Geomechanical models of gradual room closure from salt creep (without brine seepage and subsequent gas generation to permit maximum room closure) were used to predict irregular arrays of closely packed CCOs after 1000 years, when room closure has asymptotically approached maximum compaction. Models of spheres or cylinders with 380 fissile gram equivalent of plutonium (as oxide) at the predicted irregular compacted spacing demonstrate that an array of CCO containers is not critical when surrounded by salt and magnesium oxide, provided the mass of hydrogenous material shipped in CCO containers (usually plastics) is controlled or boron carbide (a neutron poison) is mixed with the fissile contents.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
NASA NTRS1994

Plasma Heating: An Advanced Technology

The Mercury and Apollo spacecraft shields were designed to protect astronauts from high friction temperatures (well over 2,000 degrees Fahrenheit) when re-entering the Earth's atmosphere. It was necessary to test and verify the heat shield materials on Earth before space flight. After exhaustive research and testing, NASA decided to use plasma heating as a heat source. This technique involves passing a strong electric current through a rarefied gas to create a plasma (ionized gas) that produces an intensely hot flame. Although NASA did not invent the concept, its work expanded the market for commercial plasma heating systems. One company, Plasma Technology Corporation (PTC), was founded by a member of the team that developed the Re-entry Heating Simulator at Ames Research Center (ARC). Dr. Camacho, President of PTC, believes the technology has significant environmental applications. These include toxic waste disposal, hydrocarbon, decomposition, medical waste disposal, asbestos waste destruction, and chemical and radioactive waste disposal.

Source record↗
NASA NTRS1994

A new material for removing heavy metals from water

The NASA Lewis Research Center developed and is patenting a new high capacity ion exchange material (IEM) that removes toxic metals from contaminated water in laboratory tests. The IEM can be made into many forms, such as thin films, coatings, pellets, and fibers. As a result, it can be adapted to many applications to purify contaminated water wherever it is found, be it in waste water treatment systems, lakes, ponds, industrial plants, or in homes. Laboratory tests have been conducted on aqueous solutions containing only one of the following metal cations: lead, copper, mercury, cadmium, silver, chromium (III), nickel, zinc, and yttrium. Tests were also conducted with: (1) calcium present to determine its effects on the uptake of cadmium and copper, and (2) uranium and lanthanides which are stand-ins for other radioactive elements, (3) drinking water for the removal of copper and lead, and (3) others compositions. The results revealed that the IEM removes all these cations, even in the presence of the calcium. Of particular interest are the results of the tests with the drinking water: the lead concentration was reduced from 142 ppb down to 2.8 ppb (well below the accepted EPA standard).

Philipp, Warren H., Jr.↗
DOE OSTI2025

LDR Inorganic Spiked Simulants in Pozzolan-Substituted Cast Stone for Hanford Pretreated Low-Activity Tank Waste

Pretreated Low Activity Waste (PTW/LAW) at the Hanford Site, is currently projected for disposition through a cementitious waste form. The current standard formulation, Cast Stone, uses Class F fly ash, blast furnace slag, and Portland cement. However, the future availability of Class F fly ash is uncertain, as many coal-fired power plants—the source of this byproduct—are being decommissioned or converted to natural gas. This issue has prompted research into identifying and evaluating suitable alternative materials to replace fly ash in the cementitious waste forms used by the Department of Energy (DOE). The Savannah River National Laboratory (SRNL) successfully identified four natural pozzolans for the replacement of Class F fly ash in the current Savannah River Site (SRS) low-level waste (LLW) form, Saltstone.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2025

Temperature dependence of uranium and thorium partitioning in igneous zircons

Zircon is a key mineral in geochronology because of its chemical and physical durability and tendency to incorporate radioactive trace elements such as U and Th. Quantifying the partitioning of the actinide elements is critical to constrain initial non-secular equilibrium amounts of 230 Th in zircon. An excess or deficit of 206 Pb will be produced from such an initial excess/deficit of 230 Th from the secular equilibrium condition, which influences the calculated 206 Pb/ 238 U age (Schärer, 1984, Mattinson, 1973). However, there is no standard way to calculate Th/U partitioning ratios when applying age corrections to young igneous zircon, making uncertainties hard to estimate. To better understand U and Th partitioning of zircon/melt that is the cornerstone of the secular disequilibrium correction, zircon was synthesized in one-atmosphere experiments using basaltic andesite, andesite, and rhyolite starting materials, doped with Zr, U, and Th. Different experimental temperatures and oxygen fugacity conditions (ΔQFM−4 to ΔQFM+4) were explored to examine their effects on U and Th partitioning. In addition, we specifically quantify the effects of sector zoning, fractional crystallization, and melt composition on U and Th partitioning. By combining experimental and natural zircon data, we find that temperature has the primary control on the partitioning of U and Th in the zircon and calibrate an inverse relationship between these partition coefficients and crystallization temperatures. The calibrated equation can be applied to the 230 Th correction for an improvement in the accuracy of Th-corrected 206 Pb/ 238 U dates when the zircon crystallization temperature is known.

206Pb/238U dating↗
DOE OSTI2025

Tank 48H Phase 1 Initial Testing Using Sodium Permanganate to Decompose Tetraphenylborate: Simulant Studies with Shaker Oven and 2-L Vessel

Tank 48H currently holds legacy material including organic tetraphenylborate (TPB) compounds from the operation of the In-Tank Precipitation process. The large quantity of TPB is not compatible with the waste treatment facilities at SRS and must be removed or undergo treatment to oxidize the organic compounds before the tank can be returned to routine Tank Farm service. Tank 48H currently holds approximately 270,000 gallons of legacy material comprised of decontaminated salt solution, approximately 20,000 kilograms of TPB solids, 3,400 kilograms of sludge solids, and 1,800 kilograms of monosodium titanate (MST).

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗