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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 1,351 records · Page 75
All sourcesNASA NTRSDOE OSTI
NASA NTRSDate not supplied

Mirror Surface Contamination Specification Derived from Coronagraphy Scatter Error Budget Allocation

Near-Angle Scatter (NAS) of the host star’s light may limit the ability of a potential Habitable Worlds Observatory (HWO) to detect and characterize an Earth-like planet around a Sun-like star via coronagraphy. NAS from each optical surface before the coronagraph’s focal plane mask produces an E-field across the dark hole that is coherent. These E-fields sum and could be as large or larger than the coronagraph mask leakage E-field. This paper assumes an error budget allocation for scatter of 20 ppt. NAS E-fields contribute to the dark hole noise floor via both shot noise and heterodyne amplification of the wavefront instability. While previous papers have developed specifications for scatter from surface scatter, this paper develops specifications for scatter from surface contamination and micrometeoroid impacts. The development process utilizes an expression that predicts scatter throughput into the dark hole based on surface BRDF. Analysis does not include scatter from coating columnar structure, edges, contamination, micrometeoroid impacts, or polarization.

near angle scatter↗
DOE OSTI2014

Minimizing electrode contamination in an electrochemical cell

An electrochemical cell assembly that is expected to prevent or at least minimize electrode contamination includes one or more getters that trap a component or components leached from a first electrode and prevents or at least minimizes them from contaminating a second electrode.

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2015

Using ASCEM Modeling and Visualization to Inform Stakeholders of Contaminant Plume Evolution and Remediation Efficacy at F-Basin Savannah River, SC – 15156

Communication with stakeholders, regulatory agencies, and the public is an essential part of implementing different remediation and monitoring activities, and developing site closure strategies at contaminated sites. Modeling of contaminant plume evolution plays a critical role in estimating the benefit, cost, and risk of particular options. At the same time, effective visualization of monitoring data and modeling results are particularly important for conveying the significance of the results and observations. In this paper, we present the results of the Advanced Simulation Capability for Environmental Management (ASCEM) project, including the discussion of the capabilities of newly developed ASCEM software package, along with its application to the F-Area Seepage Basins located in the U.S. Department of Energy Savannah River Site (SRS). ASCEM software includes state-of-the-art numerical methods for simulating complex flow and reactive transport, as well as various toolsets such as a graphical user interface (GUI), visualization, data management, uncertainty quantification, and parameter estimation. Using this software, we have developed an advanced visualization of tritium plume migration coupled with a data management system, and simulated a three-dimensional model of flow and plume evolution on a high-performance computing platform. We evaluated the effect of engineered flow barriers on a nonreactive tritium plume, through advanced plume visualization and modeling of tritium plume migration. In addition, we developed a geochemical reaction network to describe complex geochemical processes at the site, and evaluated the impact of coupled hydrological and geochemical heterogeneity. These results are expected to support SRS’s monitoring activities and operational decisions.

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

Fogging formulations for fixation of particulate contamination in ductwork and enclosures

A method and an apparatus using aqueous fixatives for fogging of ventilation ductwork, enclosures, or buildings containing dust, lint, and particulates that may be contaminated by radionuclides and other dangerous or unsafe particulate contaminants, which method and apparatus are capable of (1) obtaining full coverage within the ductwork and (2) penetrating and fixing the lint, dust and large particles present in the ductwork so that no airborne particles are released during or after the application of the fixative. New aqueous fogging solutions outperform conventional glycerin-based solutions. These aqueous solutions will fog using conventional methods of application and contain a surfactant to aid wetting and penetration of the lint and dust, a binder to stabilize loose or respirable particles, and an agent to aid in fogging and enhance adhesiveness. The solutions are safe and easy to use.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2018

Chemical, biological, and radioactive contamination remediation with lasers

A laser is used to clean surfaces contaminated with chemical, biological, or radioactive substances. The laser directs a laser beam onto the surfaces and the ejecta is collected by a getter which can be a version of vacuum cleaner. A mobile system includes a laser transporting arm and collection system used in cleanup of metal and concrete surfaces contaminated with chemical, biological, or radioactive substances.

47 OTHER INSTRUMENTATION↗
DOE OSTI2019

Identifying specific cryomodule and cleanroom particulate contamination: understanding legacy issues and providing new feedback standards

While the techniques used to provide "UHV clean" and "particle-free" beamline components, including SRF cavities, continue to evolve, "real-world" operating machines must deal with actual accumulated and latent contamination issues that produce non-trivial cryogenic heatload, radiation, activation, and degradation via field emission. We have developed a standardized and automated particulate contamination assay method for use in characterizing particulates found on beamline components and in cleanroom assembly environments. We present results from using this system to analyze samples taken from reworked cryomodules from CEBAF. Particle sizes are much larger than anticipated. Utility for feedback on sources to enable improved source reduction is explored.

Reece, C. E.↗
DOE OSTI2020

Exploring the Next Generation of Low-Carbon Technologies for Deployment on Contaminated Lands

Low-carbon energy technologies and industries can reduce or avoid pollution, create economic development benefits (e.g. job creation), enhance local tax revenues, and support supply chain businesses. Many communities have vacant or underutilized and contaminated land that presents an opportunity cost for the economy and a blight on neighborhoods. This paper identifies a research agenda and funding proposal to support the next generation of low carbon technologies to deploy on contaminated lands.

brownfield sites↗
DOE OSTI2015

Using ASCEM modeling and visualization to inform stakeholders of contaminant plume evolution and remediation efficacy at F-Basin Savannah river, SC - 15156

Communication with stakeholders, regulatory agencies, and the public is an essential part of implementing different remediation and monitoring activities, and developing site closure strategies at contaminated sites. Modeling of contaminant plume evolution plays a critical role in estimating the benefit, cost, and risk of particular options. At the same time, effective visualization of monitoring data and modeling results are particularly important for conveying the significance of the results and observations. In this paper, we present the results of the Advanced Simulation Capability for Environmental Management (ASCEM) project, including the discussion of the capabilities of newly developed ASCEM software package, along the its application to the F-Area Seepage Basins located in the U.S. Department of Energy Savannah River Site (SRS). ASCEM software includes state-of-the-art numerical methods for simulating complex flow and reactive transport, as well as various tool-sets such as a graphical user interface (GUI), visualization, data management, uncertainty quantification, and parameter estimation. Using this software, we have developed an advanced visualization of tritium plume migration coupled with a data management system, and simulated a three-dimensional model of flow and plume evolution on a high-performance computing platform. We evaluated the effect of engineered flow barriers on a nonreactive tritium plume, through advanced plume visualization and modeling of tritium plume migration. In addition, we developed a geochemical reaction network to describe complex geochemical processes at the site, and evaluated the impact of coupled hydrological and geochemical heterogeneity. These results are expected to support SRS's monitoring activities and operational decisions. (authors)

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

Management of technetium contaminated demolition debris from the gaseous diffusion plants at the east Tennessee Technology Park - 15422

The demolition of the final section of the gaseous diffusion plant (GDP) facility formerly known as K-25 at the East Tennessee Technology Park was completed in December of 2013, with the final shipment of waste completed only six months later in June 2014. While most of the radioactive waste shipments would be considered 'routine' by today's standards (lower activity waste was disposed onsite at the Environmental Management Waste Management Facility [EMWMF] and at some offsite commercial disposal facilities with higher activity waste making its way across country to the Nevada National Security Site [NNSS] disposal facility) the final section of K-25, consisting of six cascade 'units', presented some unique technical and stakeholder challenges. Portions of this final section of K-25 were presumed to be heavily contaminated with Technetium-99 (Tc-99) based on sampling and analysis activities conducted during facility deactivation. Tc-99 is known to be highly mobile under a variety of environmental conditions, and is suspected to be potentially mobile in unmitigated landfill conditions, resulting in the need to implement additional engineered controls during facility demolition as well as throughout the management of the resultant waste. A variety of controls were implemented to ensure Tc-99 mobility was controlled and possible consequences mitigated, including isolation and offsite shipment of highest Tc-99 concentration components, as well as construction of a 'cell within a cell' at the EMWMF. This paper will examine the process utilized to develop the controls for management of Tc-99 contaminated waste and will describe those controls. Additionally, it will describe the stakeholder involvement and approval process as well as examining and documenting the efficacy of the controls that were implemented. Finally, this paper will discuss lessons learned from this first of a kind demolition effort and how this experience can be utilized to further refine the Tc-99 waste management approach for the remaining GDPs at ETTP. (authors)

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

Development of ion specific media to treat Sr-contaminated water at Fukushima Daiichi Nuclear Power Plant - 15486

Since April of 2011, Kurion, Inc. contracted with the Tokyo Electric Power Company (TEPCO) to remediate cooling water using Ion Specific Media targeting cesium (Cs). The effluent of the Cs-sorption systems routed into a reverse osmosis (RO) system. While the RO permeate was recirculated into the cooling loop, the RO reject was captured in carbon-steel tanks. However, the cesium-extracted tank water at Fukushima Daiichi also has a high strontium (Sr) activity (∼4 x 10{sup 5} Bq/mL) and needs to be reduced to lower the onsite and boundary doses. To treat this highly contaminated water, Kurion developed the Kurion Mobile Processing System (KMPS). The KMPS uses a powder batch-contact addition step in concert with a series of ion exchange vessels to decontaminate the high Sr-activity water. Kurion tested and developed several ion specific media to treat the water. Several inorganic media were evaluated in the down-select for the system. Equilibrium batch tests, shortened contact time batch tests and column tests were performed to assess the media depending on water conditions. Two media were selected for KMPS: FAS-P (a powdered zeolite) to reduce Ca{sup 2+} and Sr{sup 2+} concentrations and TS-G (a synthetic titanosilicate) to polish the Sr{sup 2+} downstream. The results of these laboratory tests and their performance in the field will be discussed. The operation of the system has led to the continued reduction of dose at the Fukushima Daiichi nuclear power plant. This system and these media can be applied to other difficult wastewater solutions involving high levels of contaminants and salinity. (authors)

21 SPECIFIC NUCLEAR REACTORS AND ASSOCIATED PLANTS↗
DOE OSTI2016

High Angle Remediation of Legacy Mercury Contaminated Soil at LANL - 16276

Mercury contaminated soil was left behind by The Manhattan Project and early Cold War era operations at Los Alamos National Laboratory (LANL) in Los Alamos, NM. TerranearPMC (TPMC) was the subcontractor that successfully completed this high-angle, legacy cleanup project on a steep, difficult-to-access canyon wall in Upper Los Alamos Canyon Aggregate Area south of a busy shopping center parking lot. A Menzi Muck (spider excavator) was used in concert with a high capacity telescoping crane to remove approximately 158 cubic yards of contaminated rock and soil from the steep slope. The crane was also used to safely move personnel and equipment into and off of the site, as well as to retrieve packaged waste. All soil excavated from the site was containerised in soft-sided 1.77 cubic yard IP-1 containers and shipped to an approved, licensed, off-site disposal facility. Once excavation was completed, sampling confirmed that human health concerns and environmental risk issues had been mitigated. This proven technical approach will become the preferred method for cleaning up other similar, difficult-to access/steep legacy waste sites across the Upper Los Alamos Canyon Aggregate Area. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2018

Extremely Highly Volume Reduction of r-Cs Contaminated Wastes by Using Ion Exchanging Chromatography - 18248

Calcination or melting processes remove radio-Cs from contaminated soil and incineration ashes when appropriate amounts of CaO and CaCl{sub 2} are added. The byproducts from the heat treatment system are concentrated water-soluble alkali chlorides, mainly composed of KCl with small amounts of CsCl contaminated with radio-Cs. These methods may effectively reduce the volume of wastes to as much as 1/100. the initial volume in the best condition. Further volume reduction from the concentrated salts is investigated by using ion-exchange chromatography of transitional metal ferrocyanides. Copper ferrocyanide (CuFeCN) is chosen as the optimum salt as it has a high ion selectivity coefficient of 2.75 x 10{sup 4} and ion-exchange capacity of 0.29 mmol/g. This CuFeCN is supported by porous silica gel carrier and is used in the ion-exchange column. A solution containing 1.34 M of KCl and 1.34 mM of CsCl labelled with Cs-137 is flowed through the column. A maximum of 80% absorbing capacity of CuFeCN and 99.9% removal efficiency of radio-Cs are achieved. Because the used adsorbent contains a high concentration of radio-Cs, it must be solidified and scattering or leaching out must be prevented. Therefore, 10 g of the used adsorbent is mixed with 20 g of meta-kaolin, 7 g of NaOH, and 18 g of water and the 'geopolymer' mixture is solidified under room temperature. No ratio-Cs release is detected from this solidified material when it is immersed in sea water or pure water for a month at 40 deg. C. Using the proposed method, the final volume of the waste could be reduced to approximately 1/10,000. the initial volume. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2019

The Development of Legacy Waste Scaling Factors for Radioactively Contaminated Soils at Chalk River Laboratories - 19333

The Chalk River Laboratories (CRL) began nuclear operations in 1947. Beginning in 1952 after the NRX accident, the management of excess contaminated liquids from the accident, and later in 1953, other waste liquids, were intermittently dispersed to trenches and pits in the local sand. The local sands proved effective at immobilization of actinides, and most activation and fission products. However there was very limited retention of some more commonly mobile radionuclides. Sand filtration performance and radionuclide migration was studied beginning in 1952. Monitoring data indicated slow migration of most radioactive contaminants away from the trenches and pits due to the adsorbing capacity of the sand substrate. The radionuclide migration continues to be studied today in frequent plume monitoring studies. Because many hard-to measure (HTM) radionuclides may also present as long term dose contributors in post remediation scenarios, or in disposal site performance assessments, the quantification of these HTM radionuclides is important. The use of scaling factors between HTM radionuclides and easy-to-measure (ETM) radionuclides (gamma emitters) for packaged soil wastes would alleviate significant effort in sampling individual waste containers. As part of plume monitoring studies and the environmental remediation process, significant characterization of soils have been performed at the site. The soil sample data from multiple historic waste management areas across site is combined and relationships between HTM radionuclides and ETM or key radionuclides are examined. Additional (secondary) relationships between ETM key nuclides are also explored to evaluate secondary scaling relationships between ETM key radionuclides (e.g., Co- 60/Cs-137), because of the significant decay of the activation product key radionuclide Co-60, (predominantly 10-20 half-lives). The evaluation is yielding consistent scaling factors for legacy soil wastes in the historic waste management areas. Given the hydrogeology of the site, a sandy shallow unconfined aquifer, and the annual precipitation of about 0.85 m/a, this evaluation reveals some expected relationships between fission products and actinides and some unanticipated relationships between more mobile radionuclides and key gamma emitters. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2019

Geochemical Reactions Controlling Contaminant Transport in Groundwater at a Former Uranium Mill Site - 19576

The historical operation of a uranium mill near Tuba City, Arizona, contaminated the underlying groundwater. Initial characterization led to a compliance strategy using groundwater extraction and treatment, which operated from 2002 through 2014. Remediation progress was inhibited primarily by aquifer productivity. Geochemical testing was undertaken to better understand future potential for contaminant plume migration. Results indicated the presence of solid-phase uranium in the subsurface, which can continue to feed the groundwater plume, along with limited uranium sorption on uncontaminated material. Future transport modeling will incorporate the laboratory-quantified geochemical reactions and be used to evaluate site compliance strategies. (authors)

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

Enhanced Monte Carlo Simulation of the Voxel Phantom Lattice Submersed in a Contaminated Air Environment

External dose coefficient calculations reported for submersions in semi-infinite clouds, as in the Environmental Protection Agency: Federal Guidance Report 12, assume a person standing on the ground submerged in a radioactive cloud. In the scope of the work presented here, Oak Ridge National Laboratory's Center for Radiation Protection Knowledge has computed dose coefficients for monoenergetic photons, electrons, and positrons for worker exposures in three rooms of finite sizes representing an office, laboratory, and warehouse. In the process of simulating these exposures, International Commission on Radiological Protection (ICRP) Publication 110 reference adult male and female voxel phantom lattices were placed in the rooms filled with contaminated air. It was apparent that additional simulations were need to treat the non-tissue voxels surrounding the phantoms as containing the contaminated air. Dose coefficients for three room sizes representing an office, laboratory, and warehouse were computed. The coefficients for electrons exhibit little dependence on room size for most energies. However, for organs within the range of electron transport, the dose from source activity within the non-tissue voxels of the lattice surrounding the phantom becomes increasingly important. The photon dose coefficients vary based on room size because of longer mean free paths. It is important to include the air surrounding the voxel phantom within the voxel lattice in the calculations, when simulating a voxel phantom submersed in air for source particle energies below 200-300 keV, otherwise, the organ dose coefficient would be underestimated. Organ and effective dose coefficients for each gender, energy, and room size will be tabulated on the Oak Ridge National Laboratory - Center for Radiation Protection Knowledge website: http://ornl.gov/crpk.

61 RADIATION PROTECTION AND DOSIMETRY↗
DOE OSTI2023

Monolayer organic thin films as particle-contamination–resistant coatings

Abstract Three organic monolayers coatings were developed and tested for their effectiveness to increase cleaning efficiency of attached microscale particles by air flows. The experiments were performed using silica substrates coated with these organic thin films and subsequently exposed to stainless-steel and silica microparticles as a model of contamination. Laser-induced–damage tests confirmed that the coatings do not affect the laser-induced–damage threshold values. The particle exposure results suggest that although the accumulation of particles is not significantly affected under the experimental conditions used in this work, the coated substrates exhibit significantly improved cleaning efficiency with a gas flow. A size-distribution analysis was conducted to study the adsorption and cleaning efficiency of particles of different sizes. It was observed that larger size (> 5-μm) particles can be removed from coated substrates with almost 100% efficiency. It was also determined that the coatings improve the cleaning efficiency of the smaller particles (≤ 5 μm) by 17% to 30% for the stainless steel metal and 19% to 38% for the silica particles.

36 MATERIALS SCIENCE↗
DOE OSTI2017

Determinants of the use of alternatives to arsenic-contaminated shallow groundwater: an exploratory study in rural West Bengal, India

Shallow groundwater containing toxic concentrations of arsenic is the primary source of drinking water for millions of households in rural West Bengal, India. Often, this water also contains unpleasant levels of iron and non-negligible fecal contamination. Alternatives to shallow groundwater are increasingly available, including government-built deep tubewells, water purchased from independent providers, municipal piped water, and household filters. We conducted a survey of 501 households in Murshidabad district in 2014 to explore what influenced the use of available alternatives. Socioeconomic status and the perceived likelihood of gastrointestinal (GI) illness (which was associated with dissatisfaction with iron in groundwater) were the primary determinants of the use of alternatives. Arsenic knowledge was limited. The choice amongst alternatives was influenced by economic, social, and aesthetic factors, but not by health risk perceptions. The use of purchased water was rarely exclusive and was strongly associated with socioeconomic status, suggesting that this form of market-based water provision does not ensure universal access. Demand for purchased water appeared to decrease significantly shortly after free piped water became available at public taps. Finally, our results suggest that arsenic mitigation interventions that also address co-occurring water problems (iron, GI illness) could be more effective than a focus on arsenic alone.

54 ENVIRONMENTAL SCIENCES↗