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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
NASA NTRS1978

An improved thermionic power conversion system for space propulsion

A concept of an out-of-core thermionic nuclear electric power conversion system for 400 Kwe power level is being investigated for space propulsion applications. Two key features distinguish the power system design from previous thermionic power conversion concepts. First, the thermionic converters are located outside a nuclear reactor with a neutron shield inserted to reduce the radiation level on the thermionic converter matrix. Second, multiple liquid-metal heat pipes are used exclusively for both thermal power transport (from the nuclear reactor to the thermionic converters) and waste heat removal (from the thermionic converters to the space radiator); no mechanical or electromagnetic pumps are involved. The system characteristics are are compared to those of the in-core thermionic reactor system concept. In many aspects, the system characteristics, including specific weight, lifetime, dynamics control and safety features are found to be more desirable than those of the in-core system concept.

Hsieh, T. M.↗
NASA NTRS1990

Publications of the NASA Controlled Ecological Life Support System (CELSS) Program, 1979-1989

Publications of research sponsored by the NASA Controlled Ecological Life Support System (CELSS) Program from 1979 to 1989 are listed. The CELSS Program encompasses research and technology with the goal of developing an autonomous bioregenerative life support system that continually recycles the solid, liquid, and gaseous materials essential for human life. The bibliography is divided into four major subject areas: food production, nutritional requirements, waste management, and systems management and control.

Wallace, Janice S.↗
DOE OSTI2024

Organic Evaporation, Oxidation, and Hydrolysis Testing in Support of Hanford Sample-and-Send

The Hanford site has approximately 54 to 56 million gallons of radioactive mixed waste stored in 156 unretrieved underground storage tanks. The Hanford Waste Treatment and Immobilization Plant (WTP) is being built to treat and immobilize the tank waste. The baseline method for immobilization of Low Activity Waste (LAW) through the WTP is vitrification, but additional immobilization capacity is needed to supplement the initial LAW melters. An alternative cementitious waste form is being investigated for that future immobilization method. However, one impediment to a cementitious waste form is the presence of Land Disposal Restricted (LDR) organic chemicals in tank waste, which are regulated on a concentration based standard in the final waste form. Hence, if the quantity of organics in LAW is high enough, they must be destroyed or removed to make a waste form compatible with disposal in a mixed low level waste landfill. This work evaluates potential avenues for treatment of LDR organics to eliminate the impediment and permit possible use of a cementitious waste form. Vacuum evaporation testing to remove LDR organics consisted of preparing a non-radioactive LAW simulant, spiking that simulant with organic chemicals, and evaporating the mixture via differential distillation. The apparatus was a laboratory-scale vacuum evaporator operated at 60 ±5 torr absolute (vacuum evaporation). The LAW simulant represented the liquid expected to be retrieved from the Hanford tank farms at approximately 4.0 M [Na+] total sodium ion concentration. The concentration of the organic chemicals added was significantly higher than typically found in the tank waste samples since the higher levels were necessary to assist in analytical measurement and tracking of the spiked species.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2026

Search for Double Beta Decays of Xe134 with EXO-200 Phase II

EXO-200 was a leading double beta decay experiment consisting of a single-phase, enriched liquid xenon time projection chamber filled with an admixture of 80.672% ^{136}Xe and 19.098% ^{134}Xe. The detector operated at the Waste Isolation Pilot Plant between 2010 and 2018 and was designed to search for double beta decay of ^{136}Xe. Data were acquired in two phases separated by a period of detector upgrades. We report on the search for 0νββ and 2νββ decay of ^{134}Xe with Phase II EXO-200 data, with median 90% CL exclusion sensitivity to half-life T_{1/2}^{0ν}≥3.7×10^{23} yr and T_{1/2}^{2ν}≥2.6×10^{21} yr, respectively. No statistically significant signal is observed for either decay mode. We set a world-leading lower limit on the half-life of the neutrinoless decay mode of ^{134}Xe of T_{1/2}^{0ν}≥8.7×10^{23} (90% CL) and the second strongest constraint on the two-neutrino decay of T_{1/2}^{2ν}≥2.9×10^{21} (90% CL), a threefold improvement over the EXO-200 Phase I measurement. New constraints are also set for the 2νββ and 0νββ decays of ^{134}Xe to the lowest excited state of ^{134}Ba.

Al Kharusi, S↗
NASA NTRS1982

A preliminary study of environmental parameters associated with the feasibility of a polygeneration plant at Kennedy Space Center

The feasibility of a polygeneration plant at Kennedy Space Center was studied. Liquid hydrogen and gaseous nitrogen are the two principal products in consideration. Environmental parameters (air quality, water quality, biological diversity and hazardous waste disposal) necessary for the feasibility study were investigated. A National Environmental Policy Act (NEPA) project flow sheet was to be formulated for the environmental impact statement. Water quality criteria for Florida waters were to be established.

Barnes, G. D.↗
NASA NTRS1986

Heat-Pipe Array for Large-Area Cooling

High rates of heat transfer anticipated. Prototype evaporative cold plate gathers waste heat from equipment mounted on it. Plate made by welding together flanges of several sections of heat pipe. Since plate separates liquid and vapor phases at inlet and outlet ports, eliminates complexities and uncertainties of two-phase flow in zero gravity. On earth, inlet valve enables plate to operate at relatively-large height differences with other plates in same system.

Edelstein, F.↗
NASA NTRS2007

Exploration Life Support Technology Development Challenges

The Exploration Life Support project is developing technologies to address the needs for life support during NASA s exploration missions. The focus of development is Air Revitalization, Water Recovery, and Waste Management Systems (ARS, WRS, and WMS). The approach to meeting exploration needs for life support intrinsically involves processing mixtures of gases, liquids and solids; thus the effects of micro or hypo gravity must be considered in developing and verifying the technologies. This paper provides an overview of the ELS project, how ELS technologies are planned to be used in exploration vehicles and the challenges being addressed.

Chambliss Joe↗
NASA NTRS2016

Torrefaction Processing for Human Solid Waste Management

This study involved a torrefaction (mild pyrolysis) processing approach that could be used to sterilize feces and produce a stable, odor-free solid product that can be stored or recycled, and also to simultaneously recover moisture. It was demonstrated that mild heating (200-250 C) in nitrogen or air was adequate for torrefaction of a fecal simulant and an analog of human solid waste (canine feces). The net result was a nearly undetectable odor (for the canine feces), complete recovery of moisture, some additional water production, a modest reduction of the dry solid mass, and the production of small amounts of gas and liquid. The liquid product is mainly water, with a small Total Organic Carbon content. The amount of solid vs gas plus liquid products can be controlled by adjusting the torrefaction conditions (final temperature, holding time), and the current work has shown that the benefits of torrefaction could be achieved in a low temperature range (< 250 C). These temperatures are compatible with the PTFE bag materials historically used by NASA for fecal waste containment and will reduce the energy consumption of the process. The solid product was a dry material that did not support bacterial growth and was hydrophobic relative to the starting material. In the case of canine feces, the solid product was a mechanically friable material that could be easily compacted to a significantly smaller volume (approx. 50%). The proposed Torrefaction Processing Unit (TPU) would be designed to be compatible with the Universal Waste Management System (UWMS), now under development by NASA. A stand-alone TPU could be used to treat the canister from the UWMS, along with other types of wet solid wastes, with either conventional or microwave heating. Over time, a more complete integration of the TPU and the UWMS could be achieved, but will require design changes in both units.

Serio, Michael A.↗
DOE OSTI2025

Conductive Liquid Metal Vitrimer Composites for Reconfigurable and Recyclable Flexible Electronics

Liquid metal (LM) elastomer composites exhibit excellent functionality for stretchable electronics and wearables, but limited recycling and reuse pathways constrain their sustainable use. Here, to address these challenges amid growing concerns over electronic waste, a conductive LM–vitrimer composite is presented that enables recyclable and reconfigurable electronics. This soft and stretchable composite features uniformly distributed LM inclusions that enhance thermal conductivity by 6.53× and enable the formation of conductive traces with electrical self-healing, while the vitrimer provides structural restoration. The dynamic covalent bonds of the vitrimer matrix are leveraged for both reprocessing the composite and chemically recovering 94% of the LM. This liquid-state filler slightly reduces the vitrimer's stiffness to 2.63 MPa (≈20% lower), while maintaining its high stretchability (>135% strain) and thermal stability. It is further examined how ultrasonicated LM inclusions interact with the vitrimer matrix and demonstrate the composite's self-healing and recyclability through two distinct approaches: 1) thermomechanical reprocessing, which restores fragmented composites under heat and compression for circuit reconfiguration; and 2) chemical recycling, which recovers the embedded LM for reuse in fabricating new composites and redesigned circuitry. With the integration of recyclability and diverse functional capabilities, LM–vitrimer composites emerge as a promising material platform for sustainable, flexible electronics.

Han, Youngshang [Univ. of Washington, Seattle, WA ↗
DOE OSTI2024

Exploring the Nature of f-Element Soft Donor Interactions Using Electronically Tunable Azolate Ionic Liquids

This project was undertaken to advance the understanding of how f-elements interact with moderately soft donors, a heavily investigated yet open question which is of prime importance in spent nuclear fuel processing and fundamental inorganic chemistry. During the course of the project, based on exciting results, a stretch goal was developed to study the hydrolysis products of transuranic actinide metals, a somewhat understudied field even with its significance in nuclear fuel cycle and impacts in environmental chemistry. The stretch goal was to take our serendipitous discovery of an easy route to isolation of crystalline multinuclear ƒ-element hydrolysis products, and apply it to gaining a mechanistic understanding of Pu(III/IV) colloid formation. The simplicity of our techniques should lend themselves to the remote handling required for study of many transuranic elements. We developed several methodologies using azolium azolate chemistry to overcome ƒ-element hydrolysis problems that prohibit the isolation of ƒ-element soft donor complexes and to build a crystallographic library of ƒ-element N-donor complexes as a means to understand the fundamental differences between actinide and lanthanide interactions with moderately soft donor ligands. Our next major endeavor will be to transfer this chemistry from 4ƒ elements to transuranic elements, particularly in the study of hydrolysis of Pu(III/IV). While our work is fundamental in nature, applications of the knowledge we are generating should be felt in such diverse fields as catalysis, separations in general, nuclear waste remediation specifically, and many other applications in f-element magnetic and luminescent properties. The potential ramifications of the consistent and robust formation of hydrolysis controlled hexanuclear lanthanide structures are enormous, with future uses being catalyst formation, higher-nuclearity structure synthesis using our hexanuclear motif as a fundamental building block, Pu waste remediation, separations, and many other potential applications resulting from characteristic magnetic and luminescent properties of lanthanide polynuclear structures. Three synthetic methodologies (direct mixing with variable stoichiometries, use of volatile solvent, metathesis) were developed starting with 7 acidic and 6 basic azoles to obtain ionic liquids suitable for f-element coordination. Proton transfer by acidic/basic azole combination led to suitable low melting salts and two cocrystals. Acid/base reaction of azoles with soft-donor permanent cations of ([X 4444 ][OH] (where [X 4444 ] + = tetrabutylammonium [N 4444 ] + or tetrabutylphosphonium [P 4444 ] + ) with weakly acidic azoles including imidazole, 1,2,3-triazole, 1,2,4-triazole, 5-aminotetrazole, 4,5-dicyanoimidazole, and 2-amino-4,5-dicyanoimidazole) revealed several suitable low-melting salts. Metathesis reactions of Na(azolate) were conducted by first using weakly acidic azoles including 4,5-dicyanoimidazole, 2-amino-4,5-dicyanoimidazole, 5-aminotetrazole, and 1,2,4-triazole to form sodium or lithium salts using group(I) hydroxides in methanolic solutions. The best results were obtained by reacting the basic and acidic azoles directly in 1:1 or 3:1 ratios at elevated temperatures. Twenty-two azole mixtures were identified which are either low melting solids or room temperature liquids. Each of the low melting solids was confirmed to be a new solid phase, each of which is being further characterized. The liquids and solids are anticipated to be ILs, eutectics, or partially ionized systems, all of which will be suitable for the dissolution of f-element salts. Five new synthetic methodologies were developed to finding suitable crystallization conditions for f-element complexation with the goal of finding simple one pot reaction syntheses and crystallization strategies that could be used under the demanding conditions of transuranic chemistries. These synthetic methods yield many new crystalline phases which were studied by single crystal X-ray diffraction.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2022

U-gas +Cool GTL™ - A New Integrated Process for Direct Biomass Conversion to Liquid Fuels

The U-Gas gasification technology, marketed by Sungas, is a proven fluid bed gasification technology for biomass conversion. U-Gas has been tested on a wide variety of biomass feeds including wood and waste streams. The U-Gas Technology has successfully converted wood for more than 20 years in a gasification plant in Skive Denmark at the 150t/d size. GTI has also recently developed the Cool GTL process for converting biogas to high quality gasoline, jet, and diesel fuels. The technoeconomics and LCA for the combination of the two technologies results an integrated optimized process, which will be discussed. The Cool GTL process is still in development and the development should be complete by 2023. Cool GTL converts high CO2 content feeds to synthesis gas with a 2-2.4/1 H2/CO ratio suitable for fuels synthesis. The process is based on a novel, highly stabile CO2/steam reforming catalyst. The 2.0-2.4/1 H2/CO synthesis gas ratio is always achieved, independently of feed CO2 content, by adjusting the amount of water added according to the amount of CO2 in the feed. The reformer catalyst has been tested for 500 hours and shows no measurable deactivation. The product from the reformer then goes directly to a low temperature slurry bed Fischer Tropsch reactor with an integrated finishing hydroisomerization reactor which makes hydrocarbon liquids from the synthesis gas. With this configuration no wax is produced. The technoeconomics and carbon intensity for the integration of UGas and the Cool GTL processes will be compared to other biomass conversion approaches. The use of electrolysis to boost H2 in the feed and increase liquid production will also be analyzed as a potential process improvement with sensitivities to the cost of electricity and the use of renewable electricity.

09 BIOMASS FUELS↗
DOE OSTI2021

Nitrate and Nitrite Incompatibility with Hydroxide Ions in Concentrated NaOH Solutions: Implications for Hydroxide and Gibbsite Reactivity in Alkaline Nuclear Waste

Electrolyte solutions in alkaline nuclear waste contain aluminate, hydroxide, nitrate and nitrite with sodium as the predominant counterion. The salts of these ions are highly soluble, so the liquids are highly concentrated. This study found that there is a substantial incompatibility between the hydroxide and nitrate and/or nitrate ions. This was determined by the observations that adding just one molal of NaNO2 or NaNO3 to saturated NaOH solution precipitation of 12 moles of NaOH·H2O salt, whereas the common ion effect would have expected only about 1 mole to precipitate. Further analysis indicates that the presence of nitrate and nitrite drastically increases the reactivity of sodium hydroxide ions in solution, which likely influences the reactivity of other hydroxide-mediated reactions. This enhanced reactivity is likely because it disrupts large Na+-OH- ion networks because nitrate and nitrite do not fit in those ion networks similarly to how some ions cannot substitute into a foreign crystal lattice. In contrast, the aluminate ion did not have the same large incompatibility with hydroxide.

Nitrite, Nitrate, Aluminate, NaOH*H2O, Ion-aggrega↗
NASA NTRS1984

Liquid-Droplet Radiative Cooler

Large-area, low-mass radiative cooler applicable to industrial processes requiring non-contacting cooling of process fluids. Droplet-stream radiators are used to radiate away waste heat. Extensive development required to produce practical system for terrestrial use. Effects of gravity and atmosphere are to be evaluated.

Knapp, K. K.↗
DOE OSTI1989

Nuclear Safety [Vol. 30, No. 1, January-March 1989]

Nuclear Safety is a review journal that covers significant developments in the field of nuclear safety. Its scope includes the analysis and control of hazards associated with nuclear energy, operations involving fissionable materials, and the products of nuclear fission and their effects on the environment. Primary emphasis is on safety in reactor design, construction, and operation; however, the safety aspects of the entire fuel cycle, including fuel fabrication, spent-fuel processing, nuclear waste disposal, handling of radioisotopes, and environmental effects of these operations, are also treated. Table of Contents for this issue follows. GENERAL SAFETY CONSIDERATIONS: 1 International Conference on Thermal Reactor Safety: NUCSAFE 88 by A. P. Malinauskas and J. G. Pruett; ACCIDENT ANALYSIS: 18 Chernobyl Today: State of Research by A. Yu. Gagarinskii; CONTROL AND INSTRUMENTATION: 23 Problems Associated with Routine In-Plant Radioactive Effluent Monitoring Systems at U.S. Light-Water Reactors by Barry G. Wahlig, David M. Walker, Mahmoud R. Ghavi, and John M. Palms; DESIGN FEATURES: 34 Twentieth DOE/NRC Nuclear Air-Cleaning Conference by R. R. Bellamy, D. W. Moeller, and M. W. First, 46 Design Options for the Core Support Structure for Liquid-Metal-Cooled Reactor Plants by J. P. Burelbach, W. J. Kann, J. G. Saiveau, and R. W. Seidensticker; ENVIRONMENTAL EFFECTS: 53 The Radiological Consequences of the Chernobyl Accident by L. V. Konstantinov and A. J. González; WASTE AND SPENT FUEL MANAGEMENT: 70 Activities Related to Waste Management Compiled by E. G. Silver; OPERATING EXPERIENCES: 80 Fuel Performance Annual Report for 1986 by W. J. Bailey, 103 Safety Considerations Related to 12-Hour Shift Schedules by S. Gould, 105 Reactor Shutdown Experience Compiled by J. W. Cletcher, 108 Operating U.S. Power Reactors Compiled by E. G. Silver; RECENT DEVELOPMENTS: 130 General Administrative Activities Compiled by E. G. Silver, 140 Reports, Standards, and Safety Guides by D. S. Queener, 145 Status of Power-Reactor Licensing Activities Compiled by E. G. Silver, 153 Proposed Rule Changes as of Sept. 30, 1988; ANNOUNCEMENTS: 69 Northwestern University Short Course on Radiation Safety, 79 International Seminar on Fission Product Transport Processes in Reactor Accidents, 129 Harvard School of Public Health Offers Short Courses, 152 MIT Offers Summer Short Courses on Reactor Safety and Nodal Analysis, 152 Seminar on Use of PCs in Probabilistic Safety Analysis, 157 The Authors, 160 Indexes to Nuclear Safety, Volume 29.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
NASA NTRS1980

Some advantages of methane in an aircraft gas turbine

Because liquid methane may be obtained from existing natural gas sources or produced synthetically from a range of other hydrocarbon sources (coal, biomass, shale, organic waste), it is considered as an aviation fuel in a simplified cycle analysis of the performance of a turboprop engine intended for operation at Mach 0.8 and 10,688 m altitude. Performance comparisons are given for four cases in which the turbine cooling air is either not cooled or cooled to -111, -222, and -333 K, and the advantages and problems that may be expected from direct use of the cryogenic fuel in turbine cooling are discussed. It is shown that while (1) methane combustion characteristics are appreciably different from those of Jet A fuel and will require the development of different combustor designs, and (2) the safe integration of methane cryotanks into transport aircraft structures poses a major design problem, a highly fuel-efficient turboprop engine fueled by methane appears to be feasible.

Graham, R. W.↗
DOE OSTI2022

In-Situ Liquid Cell Transmission Electron Microscopy of Nanoparticles from Spent Nuclear Fuel

Noble Metal Particles (NMP) that are present in SNF play an important role in the Fuel Matrix Degradation (FMD) Model that is being considered for predicting the release rate of radionuclides from a waste package. Previous characterization of chemically separated NMP from SNF showed that these were well-crystallized nanoparticles containing Mo, Tc, Ru, Rh, and Pd with some evidence of actinides. These same chemically separated particles were re-characterized following 10 years of storage as the separated material in water. Scanning Transmission Electron Microscopy (STEM) analysis revealed that significant alteration had occurred in this material during storage, resulting in the almost complete degradation of the NMP. We hypothesized that radiolytic damaged had occurred in the material. To support these concepts, we synthesized a mixed Ru-Pd nanoparticle and subjected it to irradiation in the electron microscope in an in-situ liquid cell. We demonstrated that intense radiation can lead to the decomposition of these metallic particles.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
NASA NTRSDate not supplied

Design of a Jettison System For Space Transit Vehicles

Many options to re-use waste are currently being developed by NASA. These include combustion, compaction, torrefaction, and converting waste materials to an easily stored base polymer for future use. Human exploration missions require large amounts of supplies such as food, clothing and spare parts. A many-month journey to Mars will result in the generation of a substantial amount of problematic waste products. It is thought that this waste must be discarded to enable a Mars transit mission. The most cost-effective, reliable, and safest method to address this problem may be to simply jettison these materials from the spacecraft. The ability to jettison requires a multi-component integrated system design. Major components include a launcher, airlocks, trash bags, and tracking system. Depending upon mission requirements, a jettison dedicated airlock may be necessary. In other cases, the crew airlock might be all that’s needed. Examples of what to jettison include food waste, fecal containers, broken equipment, foam, expendables, hygiene products, health items, wipes, and clothing. The most important design factor is always crew safety. Other features to consider are loss of air due to the inefficiencies of vacuum pumps in the airlock, outgassing from the bags, and liquids condensing on the airlock that result in unwanted coatings. The launching system design must consider many different features: while in planetary orbit, a minimum exit velocity is necessary so the jettisoned material will not complete an orbit only to return and strike the ship. Also, for planetary protection issues, enabling waste to be sent to distant non-critical locations is highly desirable. When the space craft is in planetary transit to say, Mars, the jettison exit velocity should be low if the material is not released along the direction of travel. This is to minimize trajectory perturbations due to jettison-imposed torque on the spacecraft. Design considerations for the launcher include exit velocity, power consumption, volume and mass of material jettisoned, and frequency of jettison. Finally, the launcher must be able to handle many different types and shapes of waste products. This paper will discuss these design issues and give guidance to a pathway forward.

Steve Sepka↗
DOE OSTI2022

Index tests for geosynthetic clay liners containing bentonite–polymer composites

The hydraulic conductivity of geosynthetic clay liners (GCLs) containing bentonite–polymer composites (BPCs) is controlled by a pore clogging mechanism related to the swelling of sodium bentonite (NaB) granules and formation of polymer gel in the pore space. Three index testing procedures that are influenced by bentonite swelling and rheology of the polymer gel were evaluated in this study for screening BPC GCLs for hydraulic conductivity: viscosity, liquid limit by fall-cone penetration and active water content. Experiments were conducted using polyacrylamide (PAM) polymer, dry-blended mixtures of PAM and NaB and a BPC from a commercially available GCL. These materials were contacted with inorganic solutions representing leachates from a range of waste containment scenarios. For the BPC that was evaluated, hydraulic conductivities less than 10 -10 m/s were obtained when the viscosity exceeded 220 mPa s and the active water content exceeded 300%. Hydraulic conductivities less than 10 -11 m/s were achieved for viscosity exceeding 350 mPa s, fall-cone liquid limit exceeding 190 and active water content exceeding 300%. Additional testing is needed to assess the generality of these index tests and the identified thresholds when applied to other BPC GCLs and other permeant liquids.

Engineering↗