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NASA NTRS2019

Assessment of Airframe Noise Reduction Technologies Based on EPNL from Flight Tests

The acoustic performance of various airframe noise reduction technologies – Adaptive Compliant Trailing Edge flap, main landing gear fairings, and gear cavity treatments – was determined, individually and in combination, using the Effective Perceived Noise Level metric. These noise measurements and calculations closely follow the Federal Aviation Administration aircraft noise certification standards, specifically for the approach noise measurement point. The flyover data correspond to pole-mounted, single-microphone measurements obtained during a series of flight tests, conducted under the NASA Flight Demonstrations and Capabilities project, that evaluated flap and landing gear noise reduction technologies. To minimize contributions from the propulsion system, the aircraft was flown along the approach path with engine thrust set at ground idle. Although contamination from engine, background, and secondary airframe noise sources partially masked the true performance of the tested technologies, the resulting acoustic data clearly showed substantial noise reductions relative to baseline levels. The acoustic benefits measured by the single microphones are consistent with previously reported trends in acoustic levels obtained from phased microphone array data.

Ravetta, Patricio A.↗

NASA NTRSDate not supplied

Evaluation of Variable Facesheet Liner Configurations for Broadband Noise Reduction

This paper investigates the broadband noise reduction properties of a distributed (variable) facesheet liner. Candidate uniform samples are selected using the Wave Propagation Model and Two-Parameter Model developed at the NASA Langley Research Center. Three uniform and one distributed facesheet samples are tested in the Normal Incidence Tube (NIT) at NASA Langley. Initial results show that the distributed facesheet sample possesses broadband noise reduction properties. Acoustic impedances educed from these NIT tests are used as inputs into the Convected Helmholtz Equation (CHE) propagation code developed at NASA Langley to synthesize the acoustic pressure field in the Grazing Flow Impedance Tube (GFIT) with no flow. Three uniform, one distributed, as well as one three-zone liner, oriented in two different directions, are investigated. Preliminary results showed the distributed facesheet and three-zone liners exhibit broadband noise reduction properties.

M C Brown↗

NASA NTRSDate not supplied

Hydrogen Plasma Reduction of Silicates for Lunar Oxygen Liberation

As crewed missions to the moon become closer, the focus on in-situ resource utilization efforts has increased. Since lunar soil has abundant oxygen on the surface of the moon, work has been done to process this resource in an efficient manner. Hydrogen reduction of lunar regolith has emerged as a method of liberating oxygen that can be used for fuel and water production. Traditional reduction techniques require high temperatures and increased complexity when dealing with high amounts of silicates. Plasma can reduce silicates efficiently and thus has become of high interest for use in the lunar highlands where silicates exist in high quantities. NASA’s Kennedy Space Center is exploring the use of low temperature plasmas for the reduction of silicates. This work shows that exposing silicates to a hydrogen plasma produces water. Residual gas analysis and optical emission spectroscopy were used to measure the relative quantities of water vapor production and OH (A-X) emission for hydrogen plasma interactions with lunar highland simulant and silica. X-ray photo-electron spectroscopy and scanning electron microscopy/energy-dispersive X-ray spectroscopy were also used to observe surface modifications to the silicates that reflect the key chemical reactions that occurred. From this data, plasma has emerged as a promising solution to produce oxygen on the lunar surface. *Work supported by NASA's Science Technology Mission Directorate Center Innovation Fund.

R. P. Gott↗

NASA NTRSDate not supplied

Plasma Reduction of Regolith for Oxygen Liberation

Ryan Gott↗

NASA NTRSDate not supplied

Carbothermal Reduction Demonstration: Laser Driven Reaction in a Thermal-Vacuum Environment and Project Status

Introduction: Lunar regolith is approximately 45% oxygen by mass. The majority of the oxygen is bound in silicate minerals. The carbothermal reduction process has been proven to be effective at removing oxygen from lunar regolith simulants [1]. The Carbothermal Reduction Demonstration (CaRD) project aims to increase the Technology Readiness Level (TRL) of a combined solar concentrator and carbothermal reduction systemin order to demonstrate this technology on the lunar surface. The CaRD project is divided into two design cycles, a brass board and prototype. The status of both design cycles will be discussed, as well as concepts for how this technology can be applied to the Artemis program in the future. Brassboard Vacuum Test: For the brassboard demonstration, a 2 kW Nd-YAG laser was used to heat lunar regolith simulant within a carbothermal reactor developed by Sierra Space. The reactor was placed inside of a 15 ft thermal vacuum chamber at the Johnson Space Center. The resulting reaction products were analyzed using both a gas chromotograph and mass spectrometer provided by Kennedy Space Center. Thermal data was also collected. Prototype Design: For the prototype, the CaRD team will perform another thermal vacuum test at JSC using the same interfaces and assets developed for the brassboard but will test a new carbothermal reactor design that Sierra Space is developing through the Carbothermal Oxygen Production Reactor (COPR) Tipping Point project that will include a means to autonomously move regolith in and out of the reactor. In addition, a deployable solar concentrator is being developed by Glenn Research Center using mirrors produced by Carbon Mirror Applications. The solar concentrator will be used to deliver solar energy into a carbothermal reactor to melt regolith and extract oxygen. Avionics and software for the concentrator are being developed by Kennedy Space Center. Future Concepts: An ongoing task within the CaRD project is to update models that can be used to determine the mass, power, and size of In-Situ Resource Utilization concepts at various scales. These models can now be used to analyze alternatives for future applications based on the latest available data.

A J Paz↗

NASA NTRSDate not supplied

Carbothermal Reduction Demonstration (CaRD)

Introduction: Lunar regolith is approximately 45% oxygen by mass. The majority of the oxygen is bound in silicate minerals. The carbothermal reduction process has been proven to be effective at removing oxygen from lunar regolith simulants. The Carbothermal Reduction Demonstration (CaRD) project aims to increase the Technology Readiness Level (TRL) of a combined solar concentrator and carbothermal reduction systemin order to demonstrate this technology on the lunar surface. The CaRD project is divided into two design cycles, a brass board and prototype. The status of both design cycles will be discussed, as well as concepts for how this technology can be applied to the Artemis program in the future. Brassboard Vacuum Test: For the brassboard demonstration, a 2 kW Nd-YAG laser was used to heat lunar regolith simulant within a carbothermal reactor developed by Sierra Space. The reactor was placed inside of a 15 ft thermal vacuum chamber at the Johnson Space Center. The resulting reaction products were analyzed using both a gas chromotograph and mass spectrometer provided by Kennedy Space Center. Thermal data was also collected. Prototype Design: For the prototype, the CaRD team will perform another thermal vacuum test at JSC using the same interfaces and assets developed for the brassboard but will test a new carbothermal reactor design that Sierra Space is developing through the Carbothermal Oxygen Production Reactor (COPR) Tipping Point project that will include a means to autonomously move regolith in and out of the reactor. In addition, a deployable solar concentrator is being developed by Glenn Research Center using mirrors produced by Carbon Mirror Applications. The solar concentrator will be used to deliver solar energy into a carbothermal reactor to melt regolith and extract oxygen. Avionics and software for the concentrator are being developed by Kennedy Space Center. Future Concepts: An ongoing task within the CaRD project is to update models that can be used to determine the mass, power, and size of In-Situ Resource Utilization concepts at various scales. These models can now be used to analyze alternatives for future applications based on the latest available data.

Aaron Paz↗

DOE OSTI2014

Method and apparatus for monitoring a hydrocarbon-selective catalytic reduction device

A method for monitoring a hydrocarbon-selective catalytic reactor device of an exhaust aftertreatment system of an internal combustion engine operating lean of stoichiometry includes injecting a reductant into an exhaust gas feedstream upstream of the hydrocarbon-selective catalytic reactor device at a predetermined mass flowrate of the reductant, and determining a space velocity associated with a predetermined forward portion of the hydrocarbon-selective catalytic reactor device. When the space velocity exceeds a predetermined threshold space velocity, a temperature differential across the predetermined forward portion of the hydrocarbon-selective catalytic reactor device is determined, and a threshold temperature as a function of the space velocity and the mass flowrate of the reductant is determined. If the temperature differential across the predetermined forward portion of the hydrocarbon-selective catalytic reactor device is below the threshold temperature, operation of the engine is controlled to regenerate the hydrocarbon-selective catalytic reactor device.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗

DOE OSTI2014

Accelerating Data Acquisition, Reduction, and Analysis at the Spallation Neutron Source

ORNL operates the world's brightest neutron source, the Spallation Neutron Source (SNS). Funded by the US DOE Office of Basic Energy Science, this national user facility hosts hundreds of scientists from around the world, providing a platform to enable break-through research in materials science, sustainable energy, and basic science. While the SNS provides scientists with advanced experimental instruments, the deluge of data generated from these instruments represents both a big data challenge and a big data opportunity. For example, instruments at the SNS can now generate multiple millions of neutron events per second providing unprecedented experiment fidelity but leaving the user with a dataset that cannot be processed and analyzed in a timely fashion using legacy techniques. To address this big data challenge, ORNL has developed a near real-time streaming data reduction and analysis infrastructure. The Accelerating Data Acquisition, Reduction, and Analysis (ADARA) system provides a live streaming data infrastructure based on a high-performance publish subscribe system, in situ data reduction, visualization, and analysis tools, and integration with a high-performance computing and data storage infrastructure. ADARA allows users of the SNS instruments to analyze their experiment as it is run and make changes to the experiment in real-time and visualize the results of these changes. In this paper we describe ADARA, provide a high-level architectural overview of the system, and present a set of use-cases and real-world demonstrations of the technology.

Campbell, Stuart I↗

DOE OSTI2015

Modular anode assemblies and methods of using the same for electrochemical reduction

Modular anode assemblies are used in electrolytic oxide reduction systems for scalable reduced metal production via electrolysis. Assemblies include a channel frame connected to several anode rods extending into an electrolyte. An electrical system powers the rods while being insulated from the channel frame. A cooling system removes heat from anode rods and the electrical system. An anode guard attaches to the channel frame to prevent accidental electrocution or damage during handling or repositioning. Each anode rod may be divided into upper and lower sections to permit easy repair and swapping out of lower sections. The modular assemblies may have standardized components to permit placement at multiple points within a reducing system. Example methods may operate an electrolytic oxide reduction system by positioning the modular anode assemblies in the reduction system and applying electrical power to the plurality of anode assemblies.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2015

Selective Catalytic Reduction of Oxides of Nitrogen with Ethanol/Gasoline Blends over a Silver/Alumina Catalyst on Lean Gasoline Engine

Ethanol is a very effective reductant of nitrogen oxides (NOX) over silver/alumina (Ag/Al2O3) catalysts in lean exhaust environment. With the widespread availability of ethanol/gasoline-blended fuel in the USA, lean gasoline engines equipped with an Ag/Al2O3 catalyst have the potential to deliver higher fuel economy than stoichiometric gasoline engines and to increase biofuel utilization while meeting exhaust emissions regulations. In this work a pre-commercial 2 wt% Ag/Al2O3 catalyst was evaluated on a 2.0-liter BMW lean burn gasoline direct injection engine for the selective catalytic reduction (SCR) of NOX with ethanol/gasoline blends. The ethanol/gasoline blends were delivered via in-pipe injection upstream of the Ag/Al2O3 catalyst with the engine operating under lean conditions. A number of engine conditions were chosen to provide a range of temperatures and space velocities for the catalyst performance evaluations. High NOX conversions were achieved with ethanol/gasoline blends containing at least 50% ethanol; however, higher C1/N ratio was needed to achieve greater than 90% NOX conversion, which also resulted in significant HC slip. Temperature and HC dosing were important in controlling selectivity to NH3 and N2O. At high temperatures, NH3 and N2O yields increased with increased HC dosing. At low temperatures, NH3 yield was very low, however, N2O levels became significant. The ability to generate NH3 under lean conditions has potential for application of a dual SCR approach (HC SCR + NH3 SCR) to reduce fuel consumption needed for NOX reduction and/or increased NOX conversion, which is discussed in this work.

Prikhodko, Vitaly Y↗

DOE OSTI2016

Reductant injection and mixing system

A gaseous reductant injection and mixing system is described herein. The system includes an injector for injecting a gaseous reductant into an exhaust gas stream, and a mixer attached to a surface of the injector. The injector includes a plurality of apertures through which the gaseous reductant is injected into an exhaust gas stream. The mixer includes a plurality of fluid deflecting elements.

02 PETROLEUM↗

DOE OSTI2015

Reduction-oxidation Enabled Glass-ceramics to Stainless Steel Bonding Part I: screening of doping oxidants

Lithium silicate-based glass-ceramics with high coefficients of thermal expansion, designed to form matched hermetic seals in 304L stainless steel housing, show little evidence of interfacial chemical bonding, despite extensive inter-diffusion at the glass-ceramic-stainless steel (GC-SS) interface. A series of glass-ceramic compositions modified with a variety of oxidants, AgO, FeO, NiO, PbO, SnO, CuO, CoO, MoO 3 and WO 3 , are examined for the feasibility of forming bonding oxides through reduction-oxidation (redox) at the GC-SS interface. The oxidants were selected according to their Gibbs free energy to allow for oxidation of Cr/Mn/Si from stainless steel, and yet to prevent a reduction of P2O5 in the glass-ceramic where the P 2 O 5 is to form Li 3 PO 4 nuclei for growth of high expansion crystalline SiO 2 phases. Other than the CuO and CoO modified glass-ceramics, bonding from interfacial redox reactions were not achieved in the modified glass-ceramics, either because of poor wetting on the stainless steel or a reduction of the oxidants at the surface of glass-ceramic specimens rather than the GC-SS interface.

Dai, Steve Xunhu↗

DOE OSTI2020

Flow-based anode for the electrocatalytic oxidation of a fuel or other reductant

Anode half-cells for the electrocatalytic oxidation of a liquid or gaseous fuel or other reductant are disclosed, along with electrochemical cells that include such half-cells. The anode half-cells include redox mediator/heterogeneous redox catalyst pairs within an electrolyte solution that is also in contact with an electrode. The electrode is not in direct contact with the heterogeneous catalyst. The redox mediator must include at least one carbon atom and be capable of transferring or accepting electrons and protons while undergoing reduction or oxidation.In operation, the fuel or other reductant is oxidized and the redox mediator is reduced at the heterogeneous catalyst. The reduced form of the redox mediator can then migrate to the electrode, where it is converted back to its oxidized form, which can then migrate back to the heterogeneous catalyst, where the cycle is repeated. The disclosed anode half-cells can be used in electrochemical cells, such as in fuel cells that produce electricity, or in electrosynthetic cells that produce one or more desired chemical products.

30 DIRECT ENERGY CONVERSION↗

DOE OSTI2013

Fringe biasing: A variance reduction technique for optically thick meshes

Fringe biasing is a stratified sampling scheme applicable to Monte Carlo thermal radiation transport codes. The thermal emission source in optically thick cells is partitioned into separate contributions from the cell interiors (where the likelihood of the particles escaping the cells is virtually zero) and the 'fringe' regions close to the cell boundaries. Thermal emission in the cell interiors can now be modelled with fewer particles, the remaining particles being concentrated in the fringes so that they are more likely to contribute to the energy exchange between cells. Unlike other techniques for improving the efficiency in optically thick regions (such as random walk and discrete diffusion treatments), fringe biasing has the benefit of simplicity, as the associated changes are restricted to the sourcing routines with the particle tracking routines being unaffected. This paper presents an analysis of the potential for variance reduction achieved from employing the fringe biasing technique. The aim of this analysis is to guide the implementation of this technique in Monte Carlo thermal radiation codes, specifically in order to aid the choice of the fringe width and the proportion of particles allocated to the fringe (which are interrelated) in multi-dimensional simulations, and to confirm that the significant levels of variance reduction achieved in simulations can be understood by studying the behaviour for simple test cases. The variance reduction properties are studied for a single cell in a slab geometry purely absorbing medium, investigating the accuracy of the scalar flux and current tallies on one of the interfaces with the surrounding medium. (authors)

97 MATHEMATICS AND COMPUTING↗

DOE OSTI2013

Savannah River Site Footprint Reduction Results under the American Recovery and Reinvestment Act - 13302

The Savannah River Site (SRS) is an 802 square-kilometer United States Department of Energy (US DOE) nuclear facility located along the Savannah River near Aiken, South Carolina, managed and operated by Savannah River Nuclear Solutions. Construction of SRS began in the early 1950's to enhance the nation's nuclear weapons capability. Nuclear weapons material production began in the early 1950's, eventually utilizing five production reactors constructed to support the national defense mission. Past operations have resulted in releases of hazardous constituents and substances to soil and groundwater, resulting in 515 waste sites with contamination exceeding regulatory thresholds. More than 1,000 facilities were constructed onsite with approximately 300 of them considered radiological, nuclear or industrial in nature. In 2003, SRS entered into a Memorandum of Agreement with its regulators to accelerate the cleanup using an Area Completion strategy. The strategy was designed to focus cleanup efforts on the 14 large industrial areas of the site to realize efficiencies of scale in the characterization, assessment, and remediation activities. This strategy focuses on addressing the contaminated surface units and the vadose zone and addressing groundwater plumes subsequently. This approach streamlines characterization and remediation efforts as well as the required regulatory documentation, while enhancing the ability to make large-scale cleanup decisions. In February 2009, Congress approved the American Reinvestment and Recovery Act (ARRA) to create jobs and promote economic recovery. At SRS, ARRA funding was established in part to accelerate the completion of environmental remediation and facility deactivation and decommissioning (D and D). By late 2012, SRS achieved 85 percent footprint reduction utilizing ARRA funding by accelerating and coupling waste unit remediation with D and D of remnant facilities. Facility D and D activities were sequenced and permitted with waste unit remediation activities to streamline regulatory approval and execution. Achieving footprint reduction fulfills the Government's responsibility to address legacy contamination; allows earlier completion of legally enforceable compliance agreement milestones; and enables future potential reuse of DOE resources, including land and infrastructure for other missions. Over the last 3.5 years significant achievements were met that contributed to footprint reduction, including the closure of 41 waste units (including 20 miles of radiologically contaminated stream) and decommissioning of 30 facilities (including the precedent setting in situ closure of two former production reactors, the first in the DOE Complex). Other notable achievements included the removal of over 39,750 cubic meters of debris and 68,810 cubic meters of contaminated soils, including 9175 cubic meters of lead-contaminated soil from a former site small arms testing range and treatment of 1,262 cubic meters of tritium-laden soils and concrete using a thermal treatment system. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2013

Overview of reductants utilized in nuclear fuel reprocessing/recycling

The most widely used reductant to partition plutonium from uranium in the Purex process was ferrous sulfamate, other alternates were proposed such as hydrazine-stabilized ferrous nitrate or uranous nitrate, platinum catalyzed hydrogen, and hydrazine, hydroxylamine salts. New candidates to replace hydrazine or hydroxylamine nitrate (HAN) are pursued worldwide. They may improve the performance of the industrial Purex process towards different operations such as de-extraction of plutonium and reduction of the amount of hydrazine which will limit the formation of hydrazoic acid. When looking at future recycling technologies using hydroxamic ligands, neither acetohydroxamic acid (AHA) nor formohydroxamic acid (FHA) seem promising because they hydrolyze to give hydroxylamine and the parent carboxylic acid. Hydroxyethylhydrazine, HOC{sub 2}H{sub 4}N{sub 2}H{sub 3} (HEH) is a promising non-salt-forming reductant of Np and Pu ions because it is selective to neptunium and plutonium ions at room temperature and at relatively low acidity, it could serve as a replacement of HAN or AHA for the development of a novel used nuclear fuel recycling process.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

DOE OSTI2015

Laser size reduction of contaminated Magnox Pond skips - 15166

The Magnox Pond Program Team at Hinkley Point A Power Station have successfully demonstrated the use of an automated Computer Numeric Controlled (CNC) dry milling process to efficiently decontaminate radioactive pond skips that were once used to store and transport Magnox spent fuel assemblies between reactor sites and Sellafield for reprocessing. This decontamination process has ensured ILW skips meet metal melt recycling criteria, and even Out of Scope levels, while at the same time producing dry swarf that is easily disposed of as ILW. However, the dry milling method requires the skips to be size reduced to a very simple flat geometry to simplify the milling operation. Several size reduction techniques (mechanical and thermal) have been evaluated. Based on the advantages of remote handling, high cutting speed, flexibility with complex geometries, reduced secondary waste production and significantly reduced worker exposure, robotically operated fibre delivered laser cutting was chosen. This paper describes the development, installation and operation of an automated laser cutting system commissioned at Hinkley Point A to size reduce contaminated skips in to five flat sections. It was demonstrated that a complete skip can be remotely size reduced in less than 60 minutes. This successful demonstration, coupled with CNC milling, has the potential to save an estimated British Pounds 30 million across the Magnox sites alone, with much higher saving potentials for skips stored at Sellafield, enabling this new size reduction process to meet cost reduction objectives of the UK's Nuclear Decommissioning Authority. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2016

Size Reduction of Contaminated Magnox Pond Skips Using Laser Cutting - 16192

Magnox and TWI Ltd (TWI) have recently developed a first-of-a-kind automated remote laser cutting facility. The facility has been commissioned at Hinkley Point 'A' (HPA) nuclear power station and used to successfully demonstrate the capability of TWI's laser cutting technology to remotely size reduce contaminated Intermediate Level Waste (ILW) Magnox pond skips. The benefits of the facility include reduced cutting times, significantly reduced dose uptake, and significant cost savings. The facility has been designed with a 'plug-and-play' approach such that it could be de-planted and re-mobilised to another nuclear site for other applications. Three contaminated ILW Magnox pond skips with activities of 10.3, 25.1 and 218 GBq/t have been successfully size reduced with this facility; with less than 2.5 hours required to size reduce one skip, and the elapsed laser cutting time being less than 40 minutes. Subsequent radiological assessment showed that the surface contamination and airborne activity were confined within a specifically designed modular containment unit. Continuous real-time air monitoring results indicated a rapid rise and fall of airborne activity. The largest proportion of the airborne activity was removed from the modular containment within 10 minutes by local HEPA ventilation, with the residual activity taking approximately one hour to settle out entirely. The measured dose uptakes were mostly associated with manual handling of the skips to and from the size reduction facility, thus indicating the significance of an automated remote skip size reduction facility. This paper describes the design and performance of the laser skip size reduction facility and presents results of the radiological assessment for three contaminated skips with varying activities. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗