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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 1,297 records · Page 72
All sourcesNASA NTRSDOE OSTI
DOE OSTI2013

Development and Qualification of Advancements in Submersible Transfer Pump Performance and Life, and Implications for Advancing and Supporting Processing Options - 13343

From the 1950's through the 1990's, relatively inexpensive, 'off-the-shelf' type, vertical turbine pumps (VTP) were used to transfer Hanford waste. The technology of those pumps was rooted primarily in the mining and agricultural (irrigation) industries. HNF-3218, Double Shell Tank (DST) Transfer Pump History and Reliability Report, 1998, provides a summary of Hanford DST pump history to that date. Such pumps operated in the Hanford radioactive waste environment for an average of only 400 hours before failure. However, at that time, operating life was not a driving criteria within the Department of Energy (DOE) complex, as the failure of transfer pumps represented a relatively low replacement and disposal cost. The Environmental Protection Agency (EPA) issuance of the 'Debris Rule' in 1992, which mandated that mixed radioactive waste contaminated equipment be decontaminated to a 'low level waste' category prior to burial, elevated the significance of transfer pump reliability and decontamination capability as life-cycle cost criteria. Minimizing the frequency of transfer pump failures and design for decontamination became significantly important and served to drive the need toward specific, designed for application pumps to meet this challenge. To this end, Washington River Protection Solutions (WRPS) and the supplier, Curtiss-Wright EMD (EMD), have recently collaborated on an intense program to further transfer pump technology and performance. (authors)

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

A Degradation Model and Testing Protocol for Metallic Waste Forms

Metallic waste forms developed to immobilize high-level radioactive wastes generated in advanced (closed) fuel cycles are being evaluated as part of the US DOE Fuel Cycle Research and Development program. The electrometallurgical reprocessing of used metallic fuels to recover U and Pu generates two waste streams: salt waste comprised of electro-refiner salt contaminated with oxidized fission products and metallic waste comprised of activated cladding and metallic fission products that were not oxidized under the processing conditions. Metallic waste forms can be made by directly melting the cladding and fuel wastes with small amounts of trim metals to form a multiphase alloy material in which radionuclides and other waste constituents are immobilized within chemically durable intermetallic and iron-based solid solution phases. Some components of the waste streams serve as important constituents of phases comprising the waste form, such as Mo and Zr, which form Fe{sub 2}Mo and Fe{sub 2}Zr intermetallic phases. Other waste constituents are accommodated as substitutional contaminants, such as Tc within the Fe{sub 2}Mo intermetallic and U/TRU within the Fe{sub 2}Zr intermetallic. Sufficient amounts of these host phases must be available to accommodate all radionuclides in the waste stream. The compositional flexibility of the host phases to incorporate waste components is being utilized to formulate metal waste forms that will accommodate variations in waste streams compositions that will occur over long-term fuel reprocessing operations. Small amounts of trim metals can be added to tailor the phase assembly to match the waste stream composition and facilitate waste form processing. For example, additional Zr may be added during waste form production to ensure all U/TRU is sequestered in a durable Fe{sub 2}Zr host phase and trim Cr, Mo, and Ni can be added to supplement the amounts provided by the steel cladding to improve the durability of a metallic waste form. (authors)

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2013

THE IMPACT OF OZONE ON THE LOWER FLAMMABLE LIMIT OF HYDROGEN IN VESSELS CONTAINING SAVANNAH RIVER SITE HIGH LEVEL WASTE

The Savannah River Site, in conjunction with AREVA Federal services, has designed a process to treat dissolved radioactive waste solids with ozone. It is known that in this radioactive waste process, radionuclides radiolytically break down water into gaseous hydrogen and oxygen, which presents a well defined flammability hazard. Flammability limits have been established for both ozone and hydrogen separately; however, there is little information on mixtures of hydrogen and ozone. Therefore, testing was designed to provide critical flammability information necessary to support safety related considerations for the development of ozone treatment and potential scale-up to the commercial level. Since information was lacking on flammability issues at low levels of hydrogen and ozone, a testing program was developed to focus on filling this portion of the information gap. A 2-L vessel was used to conduct flammability tests at atmospheric pressure and temperature using a fuse wire ignition source at 1 percent ozone intervals spanning from no ozone to the Lower Flammable Limit (LFL) of ozone in the vessel, determined as 8.4%(v/v) ozone. An ozone generator and ozone detector were used to generate and measure the ozone concentration within the vessel in situ, since ozone decomposes rapidly on standing. The lower flammability limit of hydrogen in an ozone-oxygen mixture was found to decrease from the LFL of hydrogen in air, determined as 4.2 % (v/v) in this vessel. From the results of this testing, Savannah River was able to develop safety procedures and operating parameters to effectively minimize the formation of a flammable atmosphere.

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DOE OSTI2013

The analysis of metal melting application in the management of metallic radioactive materials arising from decommissioning of nuclear installations

Basic characterization of the waste management process during decommissioning of nuclear installations is described in the presented paper. A brief description is given of conditional and unconditional release of materials into the environment. The paper deals also with metal melting as prospective decontamination technique which can significantly reduce metallic radioactive waste. The material and radioactivity flow in the decommissioning process should be followed using the integrated material flow tool that is implemented into the standardized analytical decommissioning parameters calculation code OMEGA. Applying the integrated material flow tool, it is possible to monitor radiological and physical properties of individual material items listed in the nuclear installation input database, from dismantling up to their release into the environment or disposal in repository. Using the OMEGA code and two model databases, several scenarios related to metal melting are evaluated. The impact of applying different input decommissioning parameters on the metal distribution is the main result discussed in the paper. (authors)

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DOE OSTI2018

Precipitation Risk when Diluting DFLAW Feed Saturated in Aluminum Hydroxide

The technical bases to support the One System River Protection Project Integrated Flowsheet assumption for diluting staged Direct Feed Low-Activity Waste (DFLAW) from the Hanford waste tanks with raw river water must be assessed in light of the risk of aluminum hydroxide (gibbsite) precipitation prior to the subsequent transfer of tank contents into the Low-Activity Waste Pretreatment System (LAWPS) from days to months after dilution. The operational and mission impacts of using other dilution fluids such as inhibited water, demineralized water, or a 2 M sodium hydroxide solution also must be assessed. As a first step to help inform this investigation, a survey was conducted of Hanford waste-related tests documenting the processing of tank waste materials (solutions, salt cakes, sludges) or their simulants for instances of gibbsite dissolution and precipitation. Experience from the aluminum industry, particularly the Bayer process, also was surveyed to gain insight into the precipitation and dissolution of gibbsite in sodium hydroxide solutions. The dependence of aluminum concentration on hydroxide concentration in analyses of actual tank waste solutions also was surveyed for tanks that have a long-term static inventory and tanks suspected of containing or known to contain substantial gibbsite solid phase in their sludge solids. Finally, an experimental program is outlined to aid prediction of the outcomes of DFLAW staged feed dilution with respect to significant variables that influence gibbsite dissolution and precipitation. The results of these investigations are summarized in this report.

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NASA NTRS1978

Waste heat utilization in industrial processes

A survey is given of new developments in heat exchangers and heat pumps. With respect to practical applications, internal criteria for plant operation are discussed. Possibilities of government support are pointed out. Waste heat steam generators and waste heat aggregates for hot water generation or in some cases for steam superheating are used. The possibilities of utilization can be classified according to the economic improvements and according to their process applications, for example, gascooling. Examples are presented for a large variety of applications.

Weichsel, M.↗
DOE OSTI2016

The Path to Nitrate Salt Disposition

The topic is presented in a series of slides arranged according to the following outline: LANL nitrate salt incident as thermal runaway (thermally sensitive surrogates, full-scale tests), temperature control for processing, treatment options and down selection, assessment of engineering options, anticipated control set for treatment, and summary of the overall steps for RNS.

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DOE OSTI2012

Life Cycle Assessment of the MBT plant in Ano Liossia, Athens, Greece

Highlights: Black-Right-Pointing-Pointer We model the operation of an MBT plant in Greece based on LCA. Black-Right-Pointing-Pointer We compare four different MBT operating scenarios (among them and with landfilling). Black-Right-Pointing-Pointer Even the current operation of the MBT plant is preferable to landfilling. Black-Right-Pointing-Pointer Utilization of the MBT compost and metals generates the most environmental gains. Black-Right-Pointing-Pointer Thermal exploitation of RDF improves further the environmental performance of the plant. - Abstract: The aim of this paper is the application of Life Cycle Assessment to the operation of the MBT facility of Ano Liossia in the region of Attica in Greece. The region of Attica is home to almost half the population of Greece and the management of its waste is a major issue. In order to explicitly analyze the operation of the MBT plant, five scenarios were generated. Actual operation data of the MBT plant for the year 2008 were provided by the region of Attica and the LCA modeling was performed via the SimaPro 5.1 software while impact assessment was performed utilizing the Eco-indicator'99 method. The results of our analysis indicate that even the current operation of the MBT plant is preferable to landfilling. Among the scenarios of MBT operation, the one with complete utilization of the MBT outputs, i.e. compost, RDF, ferrous and non-ferrous metals, is the one that generates the most environmental gains. Our analysis indicates that the exploitation of RDF via incineration is the key factor towards improving the environmental performance of the MBT plant. Our findings provide a quantitative understanding of the MBT plant. Interpretation of results showed that proper operation of the modern waste management systems can lead to substantial reduction of environmental impacts and savings of resources.

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DOE OSTI2014

An investigation on the fuel savings potential of hybrid hydraulic refuse collection vehicles

Highlights: • Driving cycle acquisition in a refuse collection vehicle. • Vehicle modeling and validation for numerical simulations based on the measured driving cycle. • Fuel consumption analysis for a conventional diesel vehicle and a hybrid hydraulic vehicle. - Abstract: Refuse trucks play an important role in the waste collection process. Due to their typical driving cycle, these vehicles are characterized by large fuel consumption, which strongly affects the overall waste disposal costs. Hybrid hydraulic refuse vehicles offer an interesting alternative to conventional diesel trucks, because they are able to recuperate, store and reuse braking energy. However, the expected fuel savings can vary strongly depending on the driving cycle and the operational mode. Therefore, in order to assess the possible fuel savings, a typical driving cycle was measured in a conventional vehicle run by the waste authority of the City of Stuttgart, and a dynamical model of the considered vehicle was built up. Based on the measured driving cycle and the vehicle model including the hybrid powertrain components, simulations for both the conventional and the hybrid vehicle were performed. Fuel consumption results that indicate savings of about 20% are presented and analyzed in order to evaluate the benefit of hybrid hydraulic vehicles used for refuse collection.

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DOE OSTI2020

Field-Scale Lysimeter Studies of Glass and Cementitious Waste Forms at the Hanford Site - 20392

The Hanford site Integrated Disposal Facility (IDF) will receive waste forms from vitrification activities at the Hanford Waste Treatment and Immobilization Plant (WTP). The waste form inventory to be disposed of at the IDF will consist of vitrified low-activity waste (LAW) in glass forms and solidified (or encapsulated) secondary wastes in cementitious forms. The IDF is a near-surface burial facility located near Hanford's Waste Treatment and Immobilization Plant in the 200 East Area of the site's Central Plateau. An extensive set of laboratory experimental data has been collected to support IDF performance assessment calculations of the eventual degradation of waste forms and mobility of contaminants. This paper describes the start of a field experiment to generate waste-form performance data on a larger scale (tens of centimeters), over a longer duration (five years or more), and under field conditions representative of the IDF. Results from this study are expected to improve model descriptions of contaminant mobility, reduce uncertainties about the representativeness of laboratory results in the IDF performance assessment, improve stakeholder confidence in the safe disposal of treated waste at the IDF, and facilitate the adoption of informed facility designs with the potential to reduce operational costs. A lysimeter test facility near Hanford's 200 West Area has been repurposed to carry out long-term assessments of waste forms buried in sediments excavated from the IDF. The waste forms are buried in large drainage lysimeters, open caissons that are two meters in diameter and three meters deep. Waste forms are buried in up to six locations in each lysimeter. Samplers collect pore water and drainage water beneath the waste forms and air from the pore space adjacent to waste forms. Sensors measure temperature, soil water content, soil water tension, and drainage flux. One lysimeter containing cementitious waste forms and one containing glass waste forms have been completed, along with a control lysimeter (without waste forms). The cementitious waste forms are Cast Stone grout formulations using a liquid secondary waste simulant and a generic Hanford high-salt simulant, as well as a hydrated lime-based grout formulation using a liquid secondary waste simulant. Technetium-99 and iodine-127 were added as tracers to monitor contaminant mobility. Glass waste forms were fabricated in two formulations (LAWA44 and ORLEC28), with rhenium and molybdenum tracers to monitor waste form degradation. The predicted performance of the waste forms in the lysimeters was modeled prior to installation to determine waste form size, tracer concentration/activity, and locations of sensors and samplers. (authors)

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DOE OSTI2020

Environmentally improved CdTe photovoltaic recycling through novel technologies and facility location strategies

Abstract Photovoltaic waste is projected to reach up to 78 million tons across globally dispersed locations through 2050. Current recycling infrastructure is inadequate to process these waste volumes responsibly. This necessitates commercializing novel, environmentally advantageous photovoltaic recycling technologies that improve upon incumbent industrial operations. CdTe photovoltaic recycling is a promising candidate for improvements as 25,000 tons of spent modules are recycled worldwide annually. This paper evaluates the operational performance and compares six novel technologies, the incumbent technology used in industry and one technology which extends the incumbent process across ten environmental impact categories. The tradeoff between incurring a transportation burden (ship or road) to recycle in a large‐scale centralized facility with a higher operational efficiency and avoiding transportation by recycling in a small‐scale decentralized facility with a lower operational efficiency is evaluated. Thermal delamination to eliminate the ethylene vinyl acetate and separate the photovoltaic glass panels is preferable to the incumbent mechanical process across nine environmental impact categories and decreases the climate‐change impact of CdTe photovoltaic recycling by 23%. Bath and probe sonication are ineffective for delamination, and the use of organic solvents is more environmentally burdensome than the incumbent mechanical process. Centralized recycling with shipping is environmentally preferable than with road‐based transportation. For every 100‐km increase in road transportation from the decentralized to the centralized facility, the inventory requirement in the centralized facility should be 6% lower than the decentralized facility for centralized recycling to have a lower climate‐change impact than decentralized recycling. The corresponding value for shipping is 0.4%.

Ravikumar, Dwarakanath↗
DOE OSTI2014

Continuing the Validation of CCIM Processability for Glass Ceramic HLLW Forms: Plan for Test AFY14CCIM-GC1

This test plan covers test AFY14CCIM-GC1which is the first of two scheduled FY-2014 test runs involving glass ceramic waste forms in the Idaho National Laboratory’s Cold Crucible Induction Melter Pilot Plant. The test plan is based on the successes and challenges of previous tests performed in FY-2012 and FY-2013. The purpose of this test is to continue to collect data for validating the glass ceramic High Level Liquid Waste form processability advantages using Cold Crucible Induction Melter technology. The major objective of AFYCCIM-GC1 is to complete additional proposed crucible pouring and post tapping controlled cooling experiments not completed during previous tests due to crucible drain failure. This is necessary to qualify that no heat treatments in standard waste disposal canisters are necessary for the operational scale production of glass ceramic waste forms. Other objectives include the production and post-test analysis of surrogate waste forms made from separate pours into the same graphite mold canister, testing the robustness of an upgraded crucible bottom drain and drain heater assembly, testing the effectiveness of inductive melt initiation using a resistive starter ring with a square wave configuration, and observing the tapped molten flow behavior in pans with areas identical to standard High Level Waste disposal canisters. Testing conditions, the surrogate waste composition, key testing steps, testing parameters, and sampling and analysis requirements are defined.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2020

Characterization and CST Batch Contact Equilibrium Testing of Modified Tank 9H Process Supernate Samples in Support of TCCR

The Tank Closure Cesium Removal (TCCR) system uses ion exchange columns filled with crystalline silicotitanate (CST) media to process radioactive waste solutions for the removal of ¹³⁷Cs. TCCR currently focuses on dissolving Savannah River Site (SRS) radioactive tank waste (primarily sodium saltcake solids) within Tank 10H followed by at-tank ion exchange column treatment. Two supernate batches from Tank 10H have been processed through the TCCR unit and processing of a third batch is expected soon. After processing of this supernate batch, plans are to replace the CST columns and process dissolved salt solution from Tank 9H through Tank 10H and then through the new CST columns installed in the TCCR unit. The new columns are expected to contain either a media similar to an archived CST batch (IE-911) or the R9120-B CST media used in the current TCCR columns (the two materials are fundamentally the same; just different specifications, product names, and preconditioning steps). Samples of Tank 9H dissolved saltcake were received at the Savannah River National Laboratory (SRNL) and characterized. The Tank 9H supernate contained a high sodium concentration (~9.6 M Na⁺) and will require dilution to near 6 M [Na⁺] prior to processing through the TCCR unit. The cesium concentration in Tank 9H is currently significantly higher than was observed with Tank 10H. Three dilutions of the Tank 9H supernate were conducted to mimic possible dilutions that could be conducted in the tank farm prior to TCCR processing using inhibited water, sodium hydroxide, and sodium nitrate solutions. Dilution #1 was prepared by diluting the Tank 9H supernate by a factor of 1.6 with inhibited water, Dilution #2 was prepared by diluting the Tank 9H supernate by a factor of 3.7 with a mixed sodium hydroxide/sodium nitrate diluent, and Dilution #3 was prepared by also diluting by a factor of 3.7 but with sodium hydroxide only. All three dilutions have similar Na⁺ concentrations (~6 M), but Dilutions #2 and #3 contain significantly less cesium. Major and key minor components of the diluted Tank 9H supernate samples are provided in Table ES-1. Batch contact equilibrium tests were conducted with the Tank 9H dilutions and the two different CST media batches being considered for use in the new TCCR columns. Results are summarized in Table ES-2 and compared to ZAM model predictions. The highest cesium distribution coefficient and percent removal were observed with Dilution #3. IE-911 CST (an archived CST media batch) was more effective at removing cesium than the more recently prepared R9120-B CST media, though both media samples removed >88% of the cesium and the differences may not be statistically different considering the overall uncertainty. Based on the results, maximum cesium loadings were calculated for each CST media type and Tank 9H dilution. In general, maximum cesium loadings from dilutions of this supernate batch are quite high (approaching 0.1 mmol total Cs⁺/g CST for Dilution #1). The highest calculated maximum ¹³⁷Cs loading for the Tank 9H dilutions using the ZAM model with input of the tank compositions and batch contact results was 207 Ci/kg CST (Dilution #1 with IE-911 CST). In all cases, higher maximum cesium loading values were predicted for IE-911 CST versus R9120-B, although the differences varied considerably between the dilutions. The maximum loading value for IE-911 CST with Tank 9H Dilution #1 was only 7% higher than the maximum loading for R9120-B. The maximum loading value for IE-911 CST with Dilution #3 was 24% higher than the maximum loading for R9120-B. Dilution #2 was intermediate between these values. Note that these maximum loading values are the theoretical calculated values, and actual operating conditions will cause differences. A CST binder dilution (correction) factor near 0.7 (relative to pure powder CST) was required for each batch contact test with IE-911 engineered CST using the three Tank 9H dilutions. Correction factors calculated for R9120-B CST ranged from 0.56 to 0.66 for the three dilutions. Following the batch contact tests, the CST samples were isolated from the Tank 9H solution, washed, dried, and digested in acid following established procedures. The analysis results are provided in Table ES-3. Total cesium loading values determined by CST digestion were similar to the calculated loading values based on solution analysis (Table ES-2) for all samples. In addition, the CST was observed to load calcium (R9120-B sample only), iron, strontium, lead, uranium, and plutonium after contact with the waste supernate, as has been observed previously.

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DOE OSTI2013

Wastes associated with recycling spent MOX fuel into fast reactor oxide fuel

A study sponsored by the DOE has been performed by AREVA to estimate the process and secondary wastes produced from an 800 MTIHM/yr (initial metric tons heavy metal a year) recycling plant proposed to be built in the U.S. utilizing the COEX process and utilized some DOE defined assumptions and constraints. In this paper, this plant has been analyzed for a recycling campaign that included 89% UO{sub x} and 11% MOX UNF to estimate process and secondary waste quantities produced while manufacturing 28 MTIHM/yr of SFR fuel. AREVA utilized operational data from its backend facilities in France (La Hague and MELOX), and from recent advances in waste treatment technology to estimate the waste quantities. A table lists the volumes and types of the different final wastes for a recycling plant. For instance concerning general fission products the form of the final wastes is vitrified glass and its volume generation rate is 135 l/MTHM, concerning Iodine 129 waste its final form is synthetic rock and its volume generation rate is 0.625 l/MTIHM.

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DOE OSTI2016

Implementation Guide for the Revised Branch Technical Position on Concentration Averaging and Encapsulation - 16021

As a result of the research begun in 2007 to better understand the bases of the Branch Technical Position (BTP) on 'Concentration Averaging and Encapsulation' and 10 CFR 61 'Licensing Requirements for Land Disposal of Radioactive Waste', EPRI identified three regulatory initiatives that could be pursued to enhance disposal options for the industry. These initiatives directly follow the NRC strategic assessment. The first was to revise the BTP to allow broader blending of compatible waste types. The second was to examine how 10 CFR 61.58 'Alternative requirements for waste classification and characteristics' could be used to allow for an alternative disposal criterion based on site-specific hydro-geological characteristics and end land use scenarios. And, the third is to develop a technical basis for risk informed disposal regulations in anticipation of a 10CFR 61 rulemaking. By the summer of 2015 these initiatives had been broadly addressed and resulted in the NRC issuing Revision 1 to the BTP in February of 2015. Revision 1 of the BTP (BTP 2015) is a significant re-write of the draft issued in May 2012 and a significant improvement over the 1995 BTP (BTP 1995). The NRC has altered many of the positions in the interest of clarification. The development of an Implementation Guide for applying BTP 2015 to industry-specific waste streams that is vetted and supported by a EPRI sponsored working group consisting of industry participants (including utilities, disposal sites, NRC and Agreement State representatives and industry experts) will ensure compliant and consistent application during waste generation, packaging, processing and disposal activities. The Implementation Guide will provide for a comparison to previous BTP guidance and provide clarification and common understanding of the key concepts contained within the revised BTP. These include averaging constraints, hot spots, waste streams, waste types, discrete items, blending, solidification, encapsulation and alternative approaches. EPRI plans to publish the BTP Implementation Guide in the second quarter of 2016 and it will be available to the public. (authors)

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NASA NTRS1978

Simultaneous treatment of SO2 containing stack gases and waste water

A process for simultaneously removing sulfur dioxide from stack gases and the like and purifying waste water such as derived from domestic sewage is described. A portion of the gas stream and a portion of the waste water, the latter containing dissolved iron and having an acidic pH, are contacted in a closed loop gas-liquid scrubbing zone to effect absorption of the sulfur dioxide into the waste water. A second portion of the gas stream and a second portion of the waste water are controlled in an open loop gas-liquid scrubbing zone. The second portion of the waste water contains a lesser amount of iron than the first portion of the waste water. Contacting in the openloop scrubbing zone is sufficient to acidify the waste water which is then treated to remove solids originally present.

Poradek, J. C.↗
DOE OSTI2023

Heat Exchanger Design for Waste Heat Recovery using Additive Manufacturing

With anticipated increases in global energy use and their associated emissions, there are many efforts to improve the emissions and efficiency of many industrial processes through waste heat recovery (WHR). To maximize improvements, the heat exchangers in WHR power cycles must be designed and optimized for a given heat source. Meanwhile, additive manufacturing (AM) is a single part manufacturing technique that provides the opportunity to develop unique and complex heat exchanger designs. Consequently, this work centers on the modeling, design, optimization, and testing of AM shell and tube heat exchangers for WHR. Specifically, a modified one-dimensional (1+1-D) and three-dimensional (3-D) heat exchanger models were developed and validated, with the 1+1-D model serving as the basis for design optimization. After modifications to the design to allow for AM, heat exchanger geometry optimizations were completed, targeting increased effectiveness across a range of physical parameters. Of the designs considered, nine were additively manufactured using Ti5553, and then tested using an external heat source and working fluid. Experimentally, the nineteen-tube, zero-baffle heat exchanger displayed the best overall performance, with the effects of dimensional accuracy, surface roughness, and baffles in the other designs also indicated. Next, the experimental results were used as inputs for the 1+1-D model. Although the original model was able to predict fluid outlet temperatures within 5% differences, larger variations in the heat exchanger performance parameters, temperature differences, and pressure drop necessitated optimizing the pressure drop and heat transfer calculations within the model. Thus, the resulting improved model was able to predict the heat transfer rates, heat source temperature difference, and effectiveness within 15% differences, while showing improvements in the pressure drops and working fluid temperature differences. The improved model serves as the foundation for future work to improve the design and performance of AM heat exchangers.

Spickler, Bailey Ann↗
DOE OSTI2025

Electrochemical Denitration and Caustic Generation (EDCGe) System: Year One Project Report

An advanced electrochemical denitration and caustic generation (EDCGe) system is being developed to process legacy waste through the direct feed high-level waste (DFHLW) flowsheet at Hanford. This system aims to destroy nitrates and organics in DFHLW and potentially DFHLAW feeds, significantly reducing off-gas concerns from both process safety and process flowsheet perspectives. Supported by a multidisciplinary team, this effort includes creating a tandem denitration electrolyzer/off-gas system as part of a broader mission to accelerate waste treatment through fundamental and applied research and development initiatives. The progress for the first year of the three-year program to develop technology for the EDCGe system is described within this document.

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