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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 865 records · Page 48
All sourcesNASA NTRSDOE OSTI
NASA NTRS2004

Thermodynamic Vent System Test in a Low Earth Orbit Simulation

A thermodynamic vent system for a cryogenic nitrogen tank was tested in a vacuum chamber simulating oxygen storage in low earth orbit. The nitrogen tank was surrounded by a cryo-shroud at -40 F. The tank was insulated with two layers of multi-layer insulation. Heat transfer into cryogenic tanks causes phase change and increases tank pressure which must be controlled. A thermodynamic vent system was used to control pressure as the location of vapor is unknown in low gravity and direct venting would be wasteful. The thermodynamic vent system consists of a Joule-Thomson valve and heat exchanger installed on the inlet side of the tank mixer-pump. The combination is used to extract thermal energy from the tank fluid, reducing temperature and ullage pressure. The system was sized so that the tank mixer-pump operated a small fraction of the time to limit motor heating. Initially the mixer used sub-cooled liquid to cool the liquid-vapor interface inducing condensation and pressure reduction. Later, the thermodynamic vent system was used. Pressure cycles were performed until steady-state operation was demonstrated. Three test runs were conducted at tank fills of 97, 80, and 63 percent. Each test was begun with a boil-off test to determine heat transfer into the tank. The lower tank fills had time averaged vent rates very close to steady-state boil-off rates showing the thermodynamic vent system was nearly as efficient as direct venting in normal gravity.

VanOverbeke, Thomas J.↗
DOE OSTI2013

Determination of temperature-dependent heat conductivity and thermal diffusivity of waste glass melter feed

The cold cap is a layer of reacting glass batch floating on the surface of melt in an all-electric continuous glass melter. The heat needed for the conversion of the melter feed to molten glass must be transferred to and through the cold cap. Since the heat flux into the cold cap determines the rate of melting, the heat conductivity is a key property of the reacting feed. We designed an experimental setup consisting of a large cylindrical crucible with an assembly of thermocouples that monitors the evolution of the temperature field while the crucible is heated at a constant rate. Then we used two methods to calculate the heat conductivity and thermal diffusivity of the reacting feed: the approximation of the temperature field by polynomial functions and the finite-volume method coupled with least-squares analysis. Up to 680°C, the heat conductivity of the reacting melter feed was represented by a linear function of temperature.

Pokorny, Richard↗
DOE OSTI2012

Some Fundamental Experiments on Apparent Dissolution Rate of Gas Phase in the Groundwater Recovery Processes of the Geological Disposal System - 12146

The apparent dissolution rates of gas phase in the co-presence of solid phase were examined by in-room experiments in this study. The apparent dissolution rate of gas phase q (mol/m{sup 3}.s) was generally defined by q=aK{sub L}(γP{sub g}-c), where a (1/m) is specific surface area of the interface between gas and liquid phases, K{sub L} (m/s) is overall mass transfer coefficient, γ (mol/(Pa.m{sup 3})) is reciprocal number of Henry constant, P{sub g} (Pa) is partial pressure of gas phase, and c (mol/m{sup 3}) is the concentration of gas component in liquid phase. As a model gas, CO{sub 2} gas was used. For evaluating the values of K{sub L}, this study monitored pH or the migration rate of the interface between water/gas phases, using some experiments such as the packed beds and the micro channel consisting of granite chip and rubber sheet including a slit. In the results, the values of K{sub L} were distributed in the range from 5.0x10{sup -6} m/s to 5.0x10{sup -7} m/s. These values were small, in comparison with that (7.8x10{sup -4} m/s) obtained from the bubbling test where gas phase was continually injected into deionized water without solid phase. This means that the solid phase limits the local mixing of water phase near gas-liquid interfaces. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2015

Chooz-A steam generators characterization - 15205

EDF nuclear waste management requires a deep understanding of characterization, classification and waste sorting operations. In fact, French nuclear waste management defines several classes with specific management, treatment and storage facilities. Based on particular criteria, the more the radiological risk of the nuclear waste is important, the more its management will be complex and expensive. During the dismantling of the first French pressurized reactor Chooz-A, decontamination of the primary water circuits (not including the reactor vessel), the steam generators and the pressurizer have been carried out in order to reduce their activity levels. Thanks to these decontamination operations, and a specific characterization methodology, EDF was able to de-classify the 4 steam generators and store them in one piece at the ANDRA Very Low Level Activity disposal facilities instead of the Low and Intermediate Level activity one. This de-classification allowed EDF to avoid important cutting and packaging processes. Therefore, significant dose reductions for the operators and financial gain have been made. To characterize and declare Chooz-A SG activity, EDF-CIDEN uses a methodology defined by the French institute of atomic energy, CEA. The method is based on external gamma spectrometry measurements performed with NaI collimated detectors, associated with MERCURAD simulations providing the transfer functions for the detectors and activity sources. Internal measurements are carried out with a CZT (CdZnTe) probe inside the SG tubes to refine the 3D model. In fact, the primary side represents the main source of activity, and understanding its contamination distribution is important to reduce the model and calculation uncertainties. Measurements eventually provide SG {sup 60}Co global activity, from which the activities of other radionuclides of the spectrum are determined using scaling factors. The final activity declaration takes into account the standard deviation of the measurements in order to cover the uncertainties of the methodology. Thereby, the declaration is 'slightly over-estimative', enough to meet the waste storage facility acceptance criteria. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2017

Knowledge Management in the Field of Nuclear Energy - How to Bridge the Gap between Retiring Workforce and Next Generations - 17101

The current phase-out decision of the German Federal Government and the 'Energiewende' - resulting from the Fukushima Daiichi Accident in 2011 - changed the nuclear market significantly. Together with the change in political and social attitude towards nuclear energy since 2002 it has contributed to a decline in technical expertise. This as well as the generation change in the nuclear technology lead to the risk of losing accumulated knowledge and experience which still are essential for the future - not only in Germany but in other countries - even though the focus in Germany will shift from operating to decommissioning, dismantling and radioactive waste management. A long-term strategy in order to preserve technical expertise to solve the forthcoming tasks in Germany was required. This strategy should include e.g. the implementation of technical programs not only for internal training of the staff but also for authorities. Together with authorities TUV NORD developed individual training concepts for a broad range of customers to preserve a transfer of know-how with the state-of-the-art in science and technology and even support international projects, especially in countries with less experience in the nuclear fields. Additionally, special data bases were developed in order to ensure the accessibility of long-term nuclear data storage. Furthermore technical conferences in different fields like decommissioning and radioactive waste disposal were established as an opportunity for knowledge exchange. Based on given examples it is being demonstrated how technical expertise can be preserved even though the field of nuclear energy in Germany has changed. (authors)

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2023

Radionuclide Waste Disposal: Development of Multi-scale Experimental and Modeling Capabilities (Final Report)

The DOE EPSCoR Implementation project “Radioactive waste management: Development of multi-scale experimental and modeling capabilities” helped to develop a team of scientists and engineers from Clemson University, South Carolina State University, and the University of South Carolina to address the disposition of nuclear wastes and study the transport of radioisotopes from a waste repository in the near and far field. The project involved 20 faculty from the three institutions as well as 13 postdoctoral fellows, 32 graduate students, and 32 undergraduate students and was active from 2014-2019. Additionally, we forged new collaborations with nine researchers from DOE laboratories SRNL, LLNL, and ANL as well as the University of Manchester and the China Academy of Engineering Physics. The overarching goal of the project was to understand the conditions under which important classes of co-reactants, ranging from counter ions in crystal lattices to dissolved oxygen in pores, control the chemistry and transport characteristics of radionuclides in engineered waste forms and natural soils. Our approach was to characterize the time and length scales over which non-equilibrium states are maintained by rate-limiting, or rate-enhancing, reactions between radionuclides and co-reactants due to interactions between physical mass-transfer processes (i.e., advection, diffusion) and (biogeo) chemical reactions. We have focused our project on three specific classes of reactions relevant to radionuclide transport at DOE legacy sites: ion exchange/substitution, ligand complexation, and redox-mediated reactions. Understanding radionuclide migration requires detailed knowledge of how changes to a system – whether engineered or natural – drive the behavior of co-reactants, which in turn provide the geochemical context controlling radionuclide transport. Student engagement and training were a primary focus of the project in order to create a pipeline of researchers who could work in the area of nuclear waste disposition to support the state and the nation. Over the duration of the project we worked with 32 undergraduate, graduated 18 M.S. students and 14 Ph.D. students, and advised 13 postdoctoral fellows. The Ph.D students and postdocs have primarily taken positions at DOE laboratories, academia, and industry. Through our collaborative team, numerous follow on projects have been started with over $5M in sponsored research. Additionally, thus far the team has published 53 peer reviewed papers and given over 75 technical presentations.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2024

Uranium Solubility and Supernate Enrichment Testing for Accelerated Basin De-Inventory Discards to Concentration, Storage, and Transfer Facilities

After future Accelerated Basin De-inventory (ABD) enriched uranium discards into sludge batches (SB), portions of supernate decants during SB preparation will be blended into salt batches (StB) and the resulting feeds must meet the nuclear safety requirements for the Salt Waste Processing Facility (SWPF). During previous SB10 sampling and testing, which involved H-Canyon material containing enriched uranium being mixed with Tank 51 sludge shortly after the H-Canyon stream was neutralized, it was identified that the uranium isotopic enrichment in the supernate deviated from the uranium isotopic enrichment in the slurry. The higher uranium isotopic enrichment in the supernate introduced the risk of challenging the feed requirements of SWPF. The ABD material added to SB11 was isotopically diluted with depleted uranium, mitigating any downstream impacts. However, H-Canyon desires to eliminate or minimize future depleted uranium additions in order to meet the mission schedule.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2013

Effect of Feeding Rate on the Cold Cap Configuration in a Laboratory-Scale Melter

High level waste melter feed is converted into glass in a joule heated melter, where it forms a floating layer of reacting feed, called the cold cap. After the glass-forming phase becomes connected, evolving gases produce bubbles that form a foam layer under the cold cap. The bubbles coalesce into cavities that escape around the edges of the cold cap. The foam layer insulates the cold cap from the heat transferred from the molten glass below. More information is needed about the formation and behavior of the foam layer to control, limit and possibly avoid foaming, thus allowing for a higher rate of melting. The cold cap behavior was investigated in a laboratory scale assembly with a sealed silica-glass crucible. A high alumina waste simulant was fed into the crucible and the feed charging rate was varied from 3 to 7 mL min-1. After a fixed amount of time (35 min), feed charging was stopped and the crucible was removed from the furnace and quenched on a copper block to preserve the structure of the cold cap and foam during cooling. During the rapid quenching, thermal cracking of the glass and cold cap allowed it to be broken up into sections for analysis. The effect of the charging rate on the height, area and volume of the cold cap was determined. The size of the bubbles collected in the foam layer under the cold cap increased as the cold cap expanded. Under the cold cap, the bubbles coalesced into oblong cavities. These cavities allowed the evolved gases to escape around the edges of the cold cap through the molten glass into the melter plenum.

Dixon, Derek R.↗
DOE OSTI2019

Cesium Removal from AP-105 Hanford Tank Waste Using Spherical Resorcinol Formaldehyde Resin

Spherical resorcinol formaldehyde (SRF) resin is planned to be used to remove cesium (137Cs) from the aqueous phases of Hanford tank wastes in preparation for their vitrification at the Waste Treatment and Immobilization Plant. SRF is an elutable organic ion exchanger that is projected to be used in up to 30multiple process cycles (load/elute/regeneration) before being disposal . Only two full process cycles have been tested using SRF on Hanford tank waste. This paper describes the test results of six complete load/elute cycles using the SRF in a lead/lag column format with 12 liters of Hanford tank waste supernatant collected from Tank AP-105. The testing exposed the SRF to the combined sources of degradation: chemical attack from dissolved oxygen, nitric acid, and tank waste components; physical stress from resin expansion and contraction; and beta and gamma radiolytic exposure. Process conditions, dictated by Washington River Protection Solutions, featured loading until the lag column effluent reached 10% of the waste acceptance criteria (a Cs decontamination factor of 6,000). Under these conditions the lead column was nearly fully loaded and the lag column was loaded with about 20% of the input Cs. Variations in process flowrates and elution volumes were investigated as part of the testing. Characteristics examined included degradation with cycling, mass transfer zones as a function of flowrate, Cs leakage into the ensuing process cycle, and analyte mass fractionation.

spherical resorcincol formaldehyde, ion exchange, ↗
DOE OSTI2012

Fine Tuning of Redox Networks on Multiheme Cytochromes from Geobacter sulfurreducens Drives Physiological Electron/Proton Energy Transduction

The bacterium Geobacter sulfurreducens (Gs) can grow in the presence of extracellular terminal acceptors, a property that is currently explored to harvest electricity from aquatic sediments and waste organic matter into microbial fuel cells. A family composed of five triheme cytochromes (PpcA-E) was identified in Gs . These cytochromes play a crucial role by bridging the electron transfer from oxidation of cytoplasmic donors to the cell exterior and assisting the reduction of extracellular terminal acceptors. The detailed thermodynamic characterization of such proteins showed that PpcA and PpcD have an important redox-Bohr effect that might implicate these proteins in the e - /H + coupling mechanisms to sustain cellular growth. The physiological relevance of the redox-Bohr effect in these proteins was studied by determining the fractional contribution of each individual redox-microstate at different pH values. For both proteins, oxidation progresses from a particular protonated microstate to a particular deprotonated one, over specific pH ranges. The preferred e - /H + transfer pathway established by the selected microstates indicates that both proteins are functionally designed to couple e - /H + transfer at the physiological pH range for cellular growth.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2023

Interseismic Strain Accumulation between the Colorado Plateau and the Eastern California Shear Zone: Implications for the Seismic Hazard near Las Vegas, Nevada

ABSTRACT Crustal deformation in the central Basin and Range between the Colorado plateau and the Eastern California Shear Zone is active but slow, making it a challenge to assess how strain is distributed and crustal motion transferred. However, knowledge of strain rates is very important, particularly for addressing the seismic hazard for both the Las Vegas urban area and the site of the proposed Yucca Mountain nuclear waste repository, in southern Nevada. Global Positioning System (GPS) data provide important constraints, particularly now that the GPS network in the area has substantially expanded in recent years. However, because deformation is slow, it is important to mitigate any transient tectonic and nontectonic signals to obtain the most accurate long-term interseismic motion and robust estimation of strain rates. We use data from all GPS stations in the region including both long-running continuous and semicontinuous stations. We model and remove postseismic displacements at these stations using source parameters for 41 events, dating back to the 1700 Cascadia megathrust earthquake, which contribute significantly to the deformation field within the central Basin and Range. We also remove correlated noise from the time series with the common-mode component imaging technique. We find that removal of both the postseismic transients and common-mode noise substantially reduces the uncertainties and spatial variation in the velocities. We find east–west extension across the Las Vegas Valley of 0.5–0.6 mm/yr. The interseismic strain rate field, calculated with the final velocities, reveals higher strain rates through southern Nevada than in previous studies, with rates within Las Vegas Valley of 8.5±2.4×10−9 yr−1. Our results also confirm shear along the Pahranagat shear zone, but the estimated amplitude is strongly affected by postseismic relaxation.

Geochemistry & Geophysics↗
DOE OSTI2025

"Mining" for Critical Minerals: Critical Minerals from Fossil Energy Waste Byproducts

NETL researcher Mengling Stuckman is an invited speaker for the panel discussion session of "Mining for Critical Minerals" at the Marcellus Shale Coalition event, "Shale 2.0: Learn the Facts about Upstream, Midstream and Downstream". Recent studies from DOE have shown that produced water and drill cuttings from the development of unconventional shale in Appalachia has a significant source of valuable critical minerals and will support bolstering America's supply chain security, putting Pennsylvania in a unique position to capitalize. The panel discussion facilitates obtaining an overview of pipeline capacity needs, downstream users for natural gas and effectively educating and engaging the public relevant to the Marcellus Shale community. The event also offers opportunities for local oil and gas industries, water and waste management companies to work with NETL and participate in FECM’s Critical Mineral program. Industrial feedbacks and participation as outcomes of this invited talk will accelerate the technology and knowledge transfer for the DOE’s Critical Mineral program and for DOE’s mission to unleash American Energy and lead in energy innovation.

critical minerals↗
NASA NTRS1982

Preliminary risk assessment for nuclear waste disposal in space, volume 2

Safety guidelines are presented. Waste form, waste processing and payload fabrication facilities, shipping casks and ground transport vehicles, payload primary container/core, radiation shield, reentry systems, launch site facilities, uprooted space shuttle launch vehicle, Earth packing orbits, orbit transfer systems, and space destination are discussed. Disposed concepts and risks are then discussed.

Rice, E. E.↗
DOE OSTI2020

The Industry's Long-term, Yet Near-term, Issues: The Need for Radiation Protection Professionals - 20266

Since the discovery of X-rays and radioactivity, the civil use of nuclear technology has thrived for more than a half-century and has matured to be safer and more efficient. A balance between radiological and non-radiological knowledge and experience has been gained and retained through the years. Nevertheless, a slowly developing gap has emerged during the past few decades. National and international data show a declining trend in the existence of health physics programs and associated enrollment and training, which directly impact the pipeline of radiation professionals (i.e., educators, technicians, researchers, and regulators). This decline can be attributed to many factors including the lack of scientific inquisitiveness, declining funding, and the perception that existing protocols are sufficiently protective. Decommissioning and dismantling nuclear facilities is a complex and multi-phased process that generates large quantities of various levels of radioactive waste. With multiple facilities reaching their end of operational life, and others being shut down for economic reasons, the current pipeline for radiation protection experts cannot meet the future's need. Consequently, international organizations have proposed a variety of programs to transfer knowledge of radiation protection principles and practice. While many change-oriented efforts to counteract this trend aim to promote mobility, this is just a partial solution to the actual issue: long-term availability. This paper suggests multidisciplinary collaborations with modern technologies as a path forward to educate young professionals on the diversity of radiation-related applications to retain expert knowledge and foster innovation. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2016

Enhanced Passive Cooling for Waterless-Power Production Technologies

Recent advances in the literature and at SNL indicate the strong potential for passive, specialized surfaces to significantly enhance power production output. Our exploratory computational and experimental research indicates that fractal and swirl surfaces can help enable waterless-power production by increasing the amount of heat transfer and turbulence, when compared with conventional surfaces. Small modular reactors, advanced reactors, and non-nuclear plants (e.g., solar and coal) are ideally suited for sCO2 coolant loops. The sCO2 loop converts the thermal heat into electricity, while the specialized surfaces passively and securely reject the waste process heat in an environmentally benign manner. The resultant, integrated energy systems are highly suitable for small grids, rural areas, and arid regions.

14 SOLAR ENERGY↗
DOE OSTI2019

Fault Stability Perturbation by Thermal Pressurization and Stress Transfer Around a Deep Geological Repository in a Clay Formation

The increase of temperature of a low-permeability, fluid-saturated media may trigger significant thermal pressurization, where the expansion of pore fluid cannot be accommodated by the thermal expansion of the pore space. With the aid of a coupled thermohydromechanical numerical simulator, we investigate the possible impact of thermal pressurization during the life of a deep geological repository (DGR) for high-level radioactive waste, characterized by the emplacement of radioactive material-filled canisters in a series of parallel tunnels, excavated in a low-permeability clay formation. We represent the fault as a planar structure embedded in a thermoporoelastic material and shear activation evaluated by a strain-softening Mohr-Coulomb failure criterion. The results show that stress changes caused by temperature and thermal pressurization of a rock mass around the emplacement tunnels may trigger a slip event on a fault plane in proximity of the geological disposal site: Rupture nucleates at depth, hundreds of meters below the DGR. Stress transfer plays a key role, while a direct hydraulic connection between the repository and the nucleation zone is not necessary in order to trigger rupture. A low stress ratio may favor the occurrence of slip up to a distance of 600 m of the fault from the outermost tunnel. Furthermore, these results highlight the need of investigating hydromechanical properties and local stress conditions at depth to characterize the geomechanical response of weak planes located in the surroundings of a high-level radioactive waste repository and to provide sufficient knowledge for the safe development of the DGR site.

58 GEOSCIENCES↗
DOE OSTI2016

Modeling Analysis for Nuclear Material Transport Package

This paper describes the computational models for the thermal analyses for 9975 nuclear material package under the Normal Conditions of Transport (NCT) and the Hypothetical Accident Conditions (HAC). The package 9975 is a DOE certified package that has been used in the DOE complex for transportation and long term storage of radioactive material. The NCT and HAC thermal analyses for the 9975 package were performed here by taking a computational heat transfer method. The HAC thermal models described here are identical to the models in the current DOE certified 9975 package. Thermal models in this work are for an undamaged package to meet all the regulatory requirements during an HAC thermal event. The model was created using modified shielding where the lead was encapsulated in a 0.036 inches stainless steel casing. The impact of this casing was studied earlier when the modification was proposed and it was found to have minimal impact on the component temperatures. Therefore, the analyses in this paper are good for packages with or without the shielding modifications. Analytical studies show that the realistic value for the solar absorptivity for the stainless steel surface fabricated from the rolling operation is about 0.5. The NCT analyses documented in this report use an absorptivity value of 0.5 to get more realistic component temperature results. Sensitivity studies were also performed to assess the impact of variability in the solar absorptivity for drum surface in the previous work for the NRC certification. The analysis in this paper is based on PuO{sub 2} in a food can. The food can is considered uncredited convenience containers inside the Primary Containment Vessel (PCV) of the 9975 package. PCV is located inside Secondary Containment Vessel (SCV). PuO{sub 2} has a density of 2 g/cc and a heat generation rate of 19 watts. This calculation evaluates the thermal performance for 9975 package with food can configuration during NCT and HAC per NRC regulations in 10 CFR Part 71. The objective of the calculation is to demonstrate that the maximum component temperatures are below their design limits. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2024

Analysis of the Sludge Batch 9 (Macrobatch 11) DWPF Pour Stream Glass Sample Collected During the Nitric-Glycolic Acid Flowsheet Transition

A pour stream (PS) sample taken near the end of processing of Sludge Batch 9 (SB9, Macrobatch 11) during the transition to the nitric-glycolic acid (NGA) flowsheet was analyzed by the Savannah River National Laboratory (SRNL). The SB9 NGA PS sample was taken on 12/18/2022 during Melter Feed Batch 823 associated with glass canister S04773 and was transferred to SRNL in Primary Container PC0139 in February 2023.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗