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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 1,603 records · Page 89
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

What's the big deal with TA-55's trash?

There's a beast of hazardous waste, and we're learning how to tame it. Plutonium and production activities are ongoing at TA-55, which means the beast of hazardous waste is always looming around the corner. The Laboratory must dispose of this delicate type of waste properly and swiftly. Learning from previous snags and pitfalls in an incredibly complex process, TA-55 leadership and staff have worked together to greatly improve and streamline waste processes. The result: As of the last week of fiscal year 2020, 42 shipments containing 1,275 containers of transuranic (TRU) waste were sent to the Waste Isolation Pilot Plant (WIPP) in southern New Mexico, the nation’s only repository for defense-generated TRU waste. In FY 2019, we shipped less than half that amount.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2020

Applying Improved Optical Recognition with Machine Learning on Sorting Cu Impurities in Steel Scrap

Annually, 20–55 million tons of electronic waste (e-waste) is produced worldwide (5% of all municipal solid waste). Although e-waste embodies only 2% of America’s municipal waste, it accounts for a significantly larger proportion of the heavy metals and flame retardants present in the waste stream. Currently, less than 20% of all e-waste is recycled in the United States because the heterogeneity of the feedstock limits the opportunity for reuse in high value products and processing of the waste itself is often too costly to justify handling. To address this concern, the aims of this study are: 1) to identify the major plastic and metal compositions within electronic shredder residue (ESR), 2) to formulate solvents and processing conditions to separate 90% of the plastics targeted from consumer shred ESR, and 3) to develop a process design model to estimate the cost and energy efficiency of the proposed solvent-based processing. In this study, a pre-sorted heterogeneous ESR feedstock (one where aluminum, magnetic components, and hazardous battery materials removed by an e-waste recycling facility) was used, with the major compositions of the ESR characterized. It was found that 25 wt.% of the feedstock was composed of plastics, 6 wt.% rubber, 27 wt.% printed circuit boards, 23% wire, and the remainder metals and capacitors. Within the plastic portion, polystyrene (PS, 40 wt.%), acrylonitrile butadiene styrene (ABS, 25 wt.%), and styrene-acrylonitrile (SAN, 9wt.%) were identified to compose the majority of the screened plastics using Fourier transform infrared spectroscopy (FTIR). Next, selective solvents were screened using Hansen Solubility Parameter Theory (HSP) for dissolving PS and ABS. The pre-screening results show that methylene chloride (dichloromethane, DCM) and tetrahydrofuran (THF) are capable of dissolving the most PS and ABS, while methanol (MeOH) and ethylene glycol (EG) are capable of precipitating the most PS and ABS. These solvents were subsequently used to recover polymers and remove. flame retardants within the ESR feedstock. By optimizing the dissolution time and the solvents used, the highest polymer dissolution yield (99 wt.%%) was achieved using DCM for 48 hr. Both pre-screened anti-solvents (MeOH and EG) showed the highest polymer precipitation yield (71 wt.%). In terms of flame retardant removal rate, EG was found to have a high phosphorus-containing flame retardant removal rate (up to 98%). Characterization shows that the proposed solvent-based processing can preserve a high molecular weight fraction of the polymers and effectively remove flame retardants. Cost analysis indicates that the amount of the solvent/anti-solvent recovered after the reaction would play a critical role in reducing the operating costs. The energy analysis shows that the proposed solvent-based processes can save up to 60% of the embodied energy used to manufacture plastics used in electronics (PS and ABS were used for calculations). The results from this project prove the potential of solvent-based processing to produce secondary materials (plastics and metals) from e-waste for cross-industry reuse.

36 MATERIALS SCIENCE↗
DOE OSTI2015

Radiological characterization of high Cs-137 waste items at LANL combining Cs-137 NDA results and acceptable process knowledge - 15592

Radiological characterization is an important component to disposition and disposal of radioactive waste at the Los Alamos National Laboratory. Gamma and neutron based non-destructive assay systems are available at LANL's TA-54 Area G for radiological characterization and are generally very effective in quantifying the transuranic radionuclide concentration required for a TRU or low level waste disposition determination. This is routinely performed by scaling some nuclides to direct assay results using acceptable process knowledge scaling from a directly measured key TRU nuclide, e.g., for gamma systems using a standard isotopic distribution to determine the amount of Pu-240 associated with a measured value of Pu-239. However, for two groups of LANL waste items that have high levels of Cs-137, these non-destructive assay systems were unable to make a standard TRU/LLW determination. Therefore, it was necessary to apply an extension of the typical scaling technique that keyed in on the direct Cs-137 gamma assay result to effectively characterize these waste items for TRU processing or LLW disposition. Two basic types of waste packages contained the high Cs-137 waste requiring special scaling: drums and boxes. The drums included 55-gallon, 85-gallon and 110-gallon volume sizes and the boxes included a corrugated metal box, a Standard Waste Box, and several overpack boxes containing oversized waste. All of these items contained radioactive waste generated from operations at the Chemistry and Metallurgical Research facility at LANL that included hot cell, metallographic sectioning and maintenance activities. All of the drums as well as the CMB, SWB and one oversized item in a plywood box were located above-ground at LANL's TA-54 Area G, while five of the oversized items were hot cell liners in metal boxes stored below-ground in shafts. All of the items were measured in the 2013-2014 time period at TA-54 Area G with LANL NDA systems. Most of the items were counted with LLW certified far-field gamma spectroscopy systems employing portable far-field HPGe detectors and carts and some of the items were counted on WIPP certified gamma only or gamma with neutron NDA systems. In all cases Cs-137 was quantified directly with a gamma measurement but the key TRU nuclides were not detectable. Thus, for each waste item AK/PK was studied and scaling factors to Cs-137 were established and applied to provide a comprehensive radiological characterization. A total of 49 waste items were successfully characterized as LLW based on this technique. The above ground waste items were dispositioned and disposed of at an offsite LLW repository and the below ground boxes were left in place as LLW in the TA-54 Area G shafts. This NDA with scaling application has proved effective and defensible in these high Cs-137 cases at LANL and will continue to be used as applicable and appropriate for future waste characterization at LANL. (authors)

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

Stabilization process of metallic mercury by sulphur

The technical field of this subject can be described as the treatment of mercury based wastes in order to stock or eliminate them. Toxic mercury vapours prevent from directly stocking or incinerating the wastes. Therefore, some processes have already been implemented to reduce the mercury mobility. Those immobilization processes are created to avoid mercury release in the atmosphere by volatilization or in the soil by leaching. Among the 3 current processes: encapsulation, amalgamation and stabilization, we took an interest on the last one. Stabilization can be defined as an immobilization due to a combination between a molecule and motionless particles to reduce the release of dangerous elements in the atmosphere or the biosphere. The most common technique of metallic mercury stabilization found in readings is the sulphur amalgamation technique. It consists in the chemical reaction: Hg + S → HgS. A mercury sulphide is then produced and is very insoluble in the water. A 386 deg. C heating transforms it in red sulphide. The obtained mixture can be easily and safely stored in a waste storage. In this context, solid sulphur is added in wide excess compared to the liquid mercury to cause the reaction: Hg(l) + S(s) → HgS(s) with a molar ratio between 1/6.5 and 1/19. The main drawback of this technique is the generation of an important waste quantity: a mixture of HgS and sulphur. Moreover there's no guarantee about the absence of mercury vapours. Therefore there's a real need to improve the ratio and the safety of the reaction, which is the purpose of this study. The volume of the created product is greatly reduced in this case and authorizes significant savings on storage costs. The other experimental parameters discussed in this study are temperature, volume, flask type and mixing speed. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2020

Quantifying the impact of climate change on erosion - 20397

The New York State Energy Research and Development Authority (NYSERDA) is the owner of the Western New York Nuclear Service Center (WNYNSC), a 1,351-ha (3,338-ac) site located approximately 48 km (30 mi) south of Buffalo, New York. In 1962, Nuclear Fuel Services, Inc. (NFS) entered into Agreements with the Atomic Energy Commission and New York State to construct the first commercial reprocessing plant of nuclear fuel in the United States. NFS, a private company, built and operated the spent fuel reprocessing plant and waste disposal facilities, processing 640 Mg (metric tons, or 705 short tons) of spent nuclear fuel from 1966 to 1972 under an Atomic Energy Commission license. Nuclear fuel reprocessing operations ended in 1972 and never reopened, leaving behind radioactive and chemical wastes. Erosion can play an important role in the fate and transport of waste at sites where disposal of long-lived waste is anticipated. The statistical characterization of key processes related to erosion is essential to the understanding of site stability through time. One of the key processes governing erosion is extreme precipitation and it is critical that trends in the distribution of extreme precipitation events through time be represented. The evidence of climate change is increasingly well documented and projected impacts on extreme precipitation events should be incorporated in performance assessment studies when relevant. Not evaluating future climate states in a performance assessment is contradictory to good modeling practice. Specifically, excluding climate change limits development of modeling information that could aid in effective decision making. The current climate literature provides both observational evidence and climate model projections of climate trends and/or climate change in the late 20. and early 21. centuries for North America and the northeast United States. In this work, this information was used to assess the impacts of potential changes in climate on erosion processes. The goal was to understand how projections of future climate relate to the performance of the WNYNSC through time. In the first stage of this work multi-temporal historical aerial images were analyzed in conjunction with orthophotography and Lidar data to develop probability distributions for variables representing important erosion processes. The information from these analyses was then used in conjunction with simulated data from the West Valley Erosion Working Group (EWG). Analysis of EWG simulations provides estimates for the change in erosion rates through time that is driven by changes in climate. The time-varying rates of erosion change were applied to the historical aerial imagery data in order to inform time-varying rates of erosion that are driven by changes in climate. Ultimately, this process resulted in the identification of locations for features like gully heads using both the Lidar dataset and projection of the estimated location from the historical aerial photo under consideration back to the Lidar dataset. The distance between the estimate of the location from the historical image and that of the Lidar dataset was the estimated distance the feature has moved. This distance was then divided by the number of years between the Lidar dataset and the year of the historical aerial image of interest to get a rate of movement through time. This was done for several dozen points on each historical aerial image. The analyses from the EWG were used to characterize the relative impact of climate change on the erosion rates. This relative impact was quantified by comparing the LEM based estimates of erosion that were derived using historical climate data with LEM based estimates of erosion that were derived using projections of future climate. The relative increase in the erosion rates was then applied to the historical estimates of erosion derived from the analysis of the historical aerial imagery. This approach was used since the LEM-based estimated of the historical erosion rates from the past century have a bias towards underestimating erosion. This underestimation is hypothesized to be a consequence of an inability of the LEMs to account for the impacts of land-use change (i.e. deforestation) which had been shown to significantly increase erosion in similar Northern hardwood forest ecosystems. In summary, gully head retreat rate and gully widening rate were characterized using statistical probability distributions from the historical aerial image analysis. Simulated data from the EWG was used to estimate the climatically-driven changes in erosion rates through time. The changes through time from the EWG were applied to the gully head retreat rate and gully widening rate characterized using the historical aerial image analysis. This information can be used to inform PPA models to project future risks from a given site. (authors)

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

COMSOL Multiphysics Model for HLW Canister Filling

The U.S. Department of Energy (DOE) is building a Tank Waste Treatment and Immobilization Plant (WTP) at the Hanford Site in Washington to remediate 55 million gallons of radioactive waste that is being temporarily stored in 177 underground tanks. Efforts are being made to increase the loading of Hanford tank wastes in glass while meeting melter lifetime expectancies and process, regulatory, and product quality requirements. Wastes containing high concentrations of Al 2 O 3 and Na 2 O can contribute to nepheline (generally NaAlSiO 4 ) crystallization, which can sharply reduce the chemical durability of high level waste (HLW) glass. Nepheline crystallization can occur during slow cooling of the glass within the stainless steel canister. The purpose of this work was to develop a model that can be used to predict temperatures of the glass in a WTP HLW canister during filling and cooling. The intent of the model is to support scoping work in the laboratory. It is not intended to provide precise predictions of temperature profiles, but rather to provide a simplified representation of glass cooling profiles within a full scale, WTP HLW canister under various glass pouring rates. These data will be used to support laboratory studies for an improved understanding of the mechanisms of nepheline crystallization. The model was created using COMSOL Multiphysics, a commercially available software. The model results were compared to available experimental data, TRR-PLT-080, and were found to yield sufficient results for the scoping nature of the study. The simulated temperatures were within 60 ºC for the centerline, 0.0762m (3 inch) from centerline, and 0.2286m (9 inch) from centerline thermocouples once the thermocouples were covered with glass. The temperature difference between the experimental and simulated values reduced to 40 ºC, 4 hours after the thermocouple was covered, and down to 20 ºC, 6 hours after the thermocouple was covered. This level of precision is considered acceptable for the scoping nature of the model and the subsequent laboratory glass studies Using the model, two additional glass pouring cycles were conducted. Representative thermocouple data were plotted to show the variations between the two cycles. This provides preliminary data that will be used in laboratory experiments to determine the potential for controlling nepheline crystallization in glass by varying the glass pouring conditions.

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

A novel process for separation of polycarbonate, polyvinyl chloride and polymethyl methacrylate waste plastics by froth flotation

Highlights: • KMnO{sub 4} treatment changes selectively flotation behavior of PC, PVC and PMMA plastics. • Ternary waste plastics are separated efficiently by froth flotation. • Recycling of KMnO{sub 4} solutions is conducted to make the process green. • A novel process is proposed for separation of waste plastics by froth flotation. - Abstract: A novel process was proposed for separation of ternary waste plastics by froth flotation. Pretreatment of plastics with potassium permanganate (KMnO{sub 4}) solution was conducted to aid flotation separation of polycarbonate (PC), polyvinyl chloride (PVC) and polymethyl methacrylate (PMMA) plastics. The effect of pretreatment parameters including KMnO{sub 4} concentration, treatment time, temperature and stirring rate on flotation recovery were investigated by single factor experiments. Surface treatment with KMnO{sub 4} changes selectively the flotation behavior of PC, PVC and PMMA, enabling separation of the plastics by froth flotation. Mechanism of surface treatment was studied by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and X-ray photoelectron spectrum (XPS). Effect of frother concentration and flotation time on flotation behavior of plastic mixtures was further studied for flotation separation. The optimized conditions for separation of PC are KMnO{sub 4} concentration 2 mmol L{sup −1}, treatment time 10 min, temperature 60 °C, stirring rate 300 rpm, flotation time 1 min and frother concentration 17.5 mg L{sup −1}. Under optimum conditions, PVC and PMMA mixtures are also separated efficiently by froth flotation associated with KMnO{sub 4} treatment. The purity of PC, PVC and PMMA is up to 100%, 98.41% and 98.68%, while the recovery reaches 96.82%, 98.71% and 98.38%, respectively. Economic analysis manifests remarkable profits of the developed process. Reusing KMnO{sub 4} solution is feasible, enabling the process greener.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2019

Panel Session 32: Panel: Bringing First-of-a-Kind Treatment Facilities On-Line: Idaho IWTU Commissioning Approach (2/5)

This panel discussed the activities of bringing a first-of-a-kind treatment facility online: The Integrated Waste Treatment Unit (IWTU). The design was designed to treat 900,000 gallons of sodium-bearing liquid waste. Construction of this first-of-a-kind treatment facility was completed in 2012. A new approach was adopted in 2016 after multiple challenges were encountered during facility commissioning. This session focused on the Integrated Waste Treatment Unit (IWTU), which was constructed to convert the remaining 900,000 gallons of liquid sodium-bearing waste at the Idaho National Laboratory Site, Idaho, USA, to a granular solid. The liquid waste was generated during historic spent nuclear fuel reprocessing campaigns at the Idaho Nuclear Technology and Engineering Center and was transferred to three underground storage tanks. The waste was not first-cycle waste but was rather the liquid rinse waste from flushing waste transfer lines between reprocessing runs. IWTU will employ a steam-reforming process to treat the liquid waste. The resulting granular solid will be transferred to stainless steel canisters and then to concrete vaults, which will be stored on site until an off-site national geologic repository is available to accept the waste. Presentation proposed: Bringing First-of-a-Kind Treatment Facilities On-Line: Idaho IWTU Commissioning Approach (Joel Case, US DOE (USA), Leo Thompson, Sterling Engineering and Consulting Group, LLC (USA), Joseph Giebel, Fluor Idaho, LLC (USA), Richard Boardman, Idaho National Laboratory (USA), Kevin O'Neill, US DOE (USA))

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
NASA NTRS2012

Using Pyrolysis and its Bioproducts to Help Close the Loop in Sustainable Life Support Systems

The next step in human exploration of space is beyond low Earth orbit and possibly to sites such as the Moon and Mars. Resupply of critical life support components for missions such as these are difficult or impossible. Life support processes for closing the loop of water, oxygen and carbon have to be identified .. Currently, there are many technologies proposed for terrestrial missions for waste, water, air processing and the creation of consumables. There are a variety of different approaches, but few address all of these issues simultaneously. One candidate is pyrolysis; a method where waste streams can be heated in the absence of oxygen to undergo a thermochemical conversion producing a series of bioproducts. Bioproducts like biochar made from non-edible biomass and human solid waste can possibly provide valuable benefits such as waste reduction, regolith fertilization for increased food production, and become a consumable for water processing and air revitalization systems. Syngas containing hydrogen, carbon monoxide and c~bon dioxide, can be converted to methane and dimethyl ether to create propellants. Bio-oils can be utilized as a heating fuel or fed to bioreactors that utilize oil-eating microbes. Issues such as carbon sequestration and subsequent carbon balance of the closed system and identifying ideal process methods to achieve the highest quality products, whilst being energy friendly, will also be addressed.

McCoy, LaShelle E.↗
NASA NTRS2013

A Review: Using Pyrolysis and its Bioproducts to Help Close the Loop in Sustainable Life Support Systems

The next step in human exploration of space is beyond low Earth orbit and possibly to sites such as the Moon and Mars. Resupply of critical life support components for missions such as these are difficult or impossible. Life support processes for closing the loop of water, oxygen and carbon have to be identified. Currently, there are many technologies proposed for terrestrial missions for waste, water, air processing. and the creation of consumables. There are a variety of different approaches, but few address all of these issues simultaneously. One candidate is pyrolysis; a method where waste streams can be heated in the absence of oxygen to undergo a thermochemical conversion producing a series of bioproducts. Bioproducts like biochar made from non-edible biomass and human solid waste can possibly provide valuable benefits such as waste reduction, regolith fertilization for increased food production, and become a consumable for water processing and air revitalization systems. Syngas containing hydrogen, carbon monoxide and carbon dioxide, can be converted to methane and dimethyl ether to create propellants. Bio-oils can be utilized as a heating fuel or fed to bioreactors that utilize oil-eating microbes.

McCoy, LaShelle E.↗
DOE OSTI2019

Use of In Situ Acoustic Backscatter Systems to Characterize Spent Nuclear Fuel and its Separation in a Thickener - 19288

To aid in the transportation, dewatering and storage of radioactive UK legacy waste sludges at Sellafield Ltd., the application of an Acoustic Backscatter System (ABS) was investigated in this study, as a method for monitoring suspended solids concentration and consolidation of cohesive and aggregated sludges (that form the basis of many wastes at Sellafield). An ABS represents a particularly promising technology, as they can be used with minimal intrusion, to measure both particle size and concentration depending on prior system knowledge, through inversion of the return echo voltage response of pulse-echo signals in the MHz range. To assess the application for continuous, high concentration (∼30 % v/v) thickened wastes, an ABS was utilised to characterise a pseudo-steady state laboratory thickener over hours, using flocculated calcite as a representative test material. Measurements were taken both horizontally through a consolidated bed using a 1 MHz transducer and vertically downwards with a 2 MHz transducer to measure sediment concentration above the settled bed and track bed height via the interface reflection. Characterisation of flocculated aggregate diameters was initially determined to be ∼510 μm, using an in-line Focussed Beam Reflectance Measurement (FBRM) device. The submerged 2 MHz probe indicated that there were only limited changes to the dispersion concentration or size over time. Changes in settled bed density, due to increasing bed height and changes in the underflow flow rate, were qualitatively measured via differences to the acoustic signal attenuation over time. An initial increase in attenuation with bed height was observed as the bed densified due to local compression. Once an equilibrium bed height was reached, the acoustic attenuation remained fairly constant with time, although the bulk underflow density was reduced with the increase in underflow rate. The solids residence time in the bed, determined from a transitive volume-balance model, was found to be ∼3200 s for pseudo-steady state operation at a maintained bed height of ∼0.175 m. Results of the study highlight the potential the ABS as a remote process monitoring tool for both relatively dilute suspensions and concentrated thickened mineral sludges, with potential applications across waste processing sites at Sellafield. (authors)

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

SRR's 'Next Step' in the Lean Journey -Taking Lean to the Workforce - 17247

The Savannah River Site, a U.S. Department of Energy (DOE) facility, contracted Savannah River Remediation (SRR) to manage its liquid waste project, which is a unique, high hazard nuclear waste treatment and disposal facility consisting of 51, one million-gallon underground waste tanks, a solvent extraction processing unit, a vitrification facility for the highest radioactive waste, and a grout solidification and disposal facility for a decontaminated salt solution. Our Project mission is to treat the nuclear waste and close the associated storage and treatment facilities, of which, 8 tanks have been closed to date. At SRR, the Lean business management system has been adopted to address site inefficiencies, aging infrastructure concerns and budget constraints. The Lean philosophy took root decades ago in the manufacturing sector and started with the work of W. Edwards Deming and his contemporaries. In more recent years the process has matured in the Toyota Production System and migrated into fields as diverse as services industries, health-care, and now the DOE complex. The first step of the SRR Lean Journey was to formally identify areas of improvement and initiate Value Stream Analysis (VSAs) and Rapid Improvement Events (RIEs). SRR has achieved improvements in procedure implementation, work planning and control, project schedule compression, and engineering requirements. SRR is now phasing in the next phase of Lean through Managing for Daily Improvement (MDI), Visual Management and 5S (sort, set in order, shine, standardize, and sustain). MDI is a fundamental Lean principle in that we use our most valuable asset, our employees, to drive continuous improvement versus a smaller population through formal events. Part of MDI includes visual management where the workforce can go to a 'dashboard' to see and understand the company mission and status. 5S is a process where a work group improves performance in an area by addressing physical organization, efficiency, uniformity, standardization, and mechanisms to sustain improvements. 5S stands for: Sort, Set in Order, Shine, Standardize, and Sustain. This paper will focus on the 'Next Step' in SRR's Lean journey by address how SRR is implementing MDI and 5S to improve CONOPs, Project efficiencies, and worker engagement in day to day operations. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2023

Small Angle X-Ray Scattering and Polymers

Polymers are some of the most versatile and useful materials on this planet. Properties of polymers are a result of their processing history, chemical makeup, and physical structure. Therefore, characterization is necessary to develop new polymer formulations and processes. Many established techniques for polymer characterization are destructive, and alternative methods that don’t destroy samples are in high demand. Thermal analysis techniques such as differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) yield important characteristic information for polymer samples while destroying the sample. Non-destructive strategies such as X ray diffraction (XRD) or small angle X-ray scattering (SAXS) can also find polymer characteristics while preserving a sample’s attributes. Sample preservation is desirable when investigating novel formulation and processing methods. SAXS analysis will be done on two different polymers: polyethylene, and a triblock copolymer. Using these two polymers allows for confidence between tests as polyethylene is very common, and well understood. Polyethylene analysis will be done first, and when methods have been refined so that the SAXS data matches accepted thermal analysis values for HDPE, there will be confidence to use the same analysis on block copolymers. Block copolymers remain relatively unexplored, so SAXS data will yield valuable information on their characteristics. Understanding the mechanical properties of these polymers is paramount to their application in upcycling, a process by which waste plastic can be converted into a higher value commodity. For this project, the upcycling process will be done via 3-dimensional (3d) printing.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Preliminary Characterization and Evaluation on FFF Manufactured 316H and ODS Steels

The Advanced Materials and Manufacturing Technology (AMMT) program develops cross-cutting technologies in support of a broad range of nuclear reactor technologies and maintains U.S. leadership in materials and manufacturing technologies for nuclear energy applications. The overarching vision of AMMT is to accelerate the development, qualification, demonstration, and deployment of advanced materials and manufacturing technologies to enable reliable and economical nuclear energy. Solid-state advanced manufacturing techniques can overcome some of the challenges in liquid-based additive manufacturing (AM) processes and should therefore be considered in material design and manufacturing as well. The work presented in this report forms part of a study on solid-state AM techniques of 316 stainless steels (SS) and oxide dispersion strengthened (ODS) steel components and supports the vision and goals of the AMMT program relevant to accelerate the development and deployment of advanced manufacturing processes. Achieving this can provide a safety improvement through larger safety margins, economic benefit for higher efficiency during operation, and a cost reduction through more effective manufacturing processes and less waste. This study provides preliminary information on development of the fused-filament fabrication (FFF) process using different powder types to demonstrate the sensitivity, and therefore the characterization of these sample components. The full solid-state manufacturing feasibility study will be completed and reported in a final feasibility evaluation during 2025. The study investigation used two 14YWT ODS powder batches, which provided information and the effect of different powder morphologies on manufacturability. The two 316SS powders demonstrated the effect of powder size on the manufacturability using FFF. Two product forms, namely a honeycomb structure and flat samples, were manufactured to demonstrate the flexibility of product form.

36 MATERIALS SCIENCE↗
NASA NTRS1989

Ozone/Ultraviolet-Photo-Oxidation Reactor

Experimental chemical-processing system destroys waste hydrazine in water by use of ozone in ultraviolet-photo-oxidation reactor. New process reduces concentrations of hydrazines and intermediate decomposition products in effluent liquid and gas to below limit of detectability. Liquid sprayed in reaction chamber past ultraviolet lamps, against flow of oxygen and ozone. Hydrazines and intermediate decomposition products oxidized to harmless substances. Effectiveness and speed of process depends on maintenance of circulating liquid at correct pH, determines lower limit of oxidation by ozone.

Swartz, Ari Ben↗
NASA NTRS1993

Strategy for the reduction of total integrated fluid logistics to the Space Station Freedom

The use of an integrated environmental control and life support system (ECLSS) and secondary propulsion system (SRS) on the Space Station Freedom (SSF) has many potential advantages. Through the metabolism of food, the crew on-board the station will produce carbon dioxide as a waste gas and an excess of water in the form of urine and condensate. The processing of these waste fluids by the ECLSS could produce quantities of oxygen that would eliminate the need for cryogenic oxygen resupply and hydrogen, carbon dioxide, and/or methane that could be used with the addition of a resistojet system to provide a constant low thrust for station. This additional thrust would represent significant savings in required hydrazine resupply.

Gould, Marston J.↗
DOE OSTI2017

Melter Downtime Impacts on DFLAW Glass Production and Process Efficiency - 17117

The Hanford Tank Waste Treatment and Immobilization Plant (WTP) pilot studies found that semi-volatile elements started to leave the molten glass pool and enter the offgas stream when the melter became idle. The rate at which the semi-volatile elements leave the molten glass pool follows a typical half-life decay curve. The WTP Direct Feed Low-Activity Waste (DFLAW) program is using existing LAW offgas treatment systems to capture semi-volatile elements leaving the melters. A new building, Effluent Management Facility (EMF), will be built to process effluents generated by the offgas treatment equipment. The effluents are concentrated by evaporation and are recycled to the melter feed streams. Computer modeling studies show that increased amounts of semi-volatile elements in the recycles due to melter downtime adversely impact the DFLAW operations. The extent to which glass productions and process efficiencies are hampered depends upon the frequency, duration, and pattern of the downtime events. Various scenarios were investigated using randomly generated and operator-anticipated downtime schedules. This paper discusses 1) derivation of the volatility half-life curves, 2) downtime schedules, 3) increased amount of semi-volatile elements in recycled material as a result of melter shut down, 4) impacts to glass production and process efficiency, and 5) comparison of scenario results. This study concludes that plant operators can mitigate much of the negative effects of semi-volatile element recycles by managing melter downtime and idle time when possible. (authors)

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

Safety Basis Development for the Tank Closure Cesium Removal (TCCR) Demonstration - 19596

The Tank Closure Cesium Removal (TCCR) system has been installed at Savannah River Site (SRS) to supplement the existing salt waste treatment facilities. The TCCR system is intended to demonstrate the capability of ion exchange (IX) technology to remove Cs-137 from high level liquid waste. Separation is performed by Crystalline Silicotitanate (CST) IX media. The media is stored in shielded columns within a small enclosure. Following processing in the TCCR system, decontaminated waste can receive further treatment and be dispositioned at other SRS facilities. The Cesium-laden columns will instead be removed from the enclosure and transported to another location on site for interim storage. Developing the safety basis for the TCCR system and integrating it into the documented safety analysis for existing facilities presented a unique challenge. Most notably, utilizing new methodologies to analyze new hazards resulted in unexpectedly high consequences. The TCCR system therefore required more rigorous controls than had initially been anticipated. However, the integrated control set developed for the TCCR system should have little impact on its operating capabilities and will allow it to begin operating in 2019. This may lay the foundations for future utilization of similar systems at SRS and across the Department of Energy complex. (author)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗