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NASA NTRS2005

Control of Effluent Gases from Solid Waste Processing using Impregnated Carbon Nanotubes

One of the major problems associated with solid waste processing technologies is effluent contaminants that are released in gaseous forms from the processes. This is a concern in both biological as well as physicochemical solid waste processing. Carbon dioxide (CO2), the major gas released, does not present a serious problem and there are currently in place a number of flight-qualified technologies for CO2 removal. However, a number of other gases, in particular NOx, SO2, NH3, and various hydrocarbons (e.g. CH4) do present health hazards to the crew members in space habitats. In the present configuration of solid waste processing in the International Space Station (ISS), some of these gases are removed by the Trace Contaminant Control System (TCCS), demands a major resupply. Reduction of the resupply can be effective by using catalyst impregnated carbon nanotubes. For example, NO decomposition to N2 and O2 is thermodynamically favored. Data showing decomposition of NO on metal impregnated carbon nanotubes is presented. Comparisons are made of the existing TCCS systems with the carbon nanotube based technology for removing NOx based on mass/energy penalties.

Li, Jing↗

DOE OSTI2020

Metal oxide supported Ni-impregnated bifunctional catalysts for controlling char formation and maximizing energy recovery during catalytic hydrothermal liquefaction of food waste

Nickel (Ni)-impregnated metal oxide catalysts, Ni/CeZrO x , Ni/ZrO 2 , and Ni/CeO 2 , were investigated to maximize energy recovery and reduce char yield during catalytic hydrothermal liquefaction (CHTL) of food waste. Yields of char, biocrude, water soluble products, and gas were measured at 300 °C and 1 hour for both the parent oxides (CeZrO x , ZrO 2 , and CeO 2 ) and the Ni-impregnated versions. Using Ni-based catalysts reduced the carbon-weighted char yield from 16–24% to <10% and decreased the energy recovery of char from 39–47% to <21%, as compared with control tests. In particular, using Ni/ZrO 2 resulted in the greatest biocrude yield, greatest reduction of char yield, and greatest energy recovered as biocrude (39.2%). After factoring in all forms of usable energy produced from food waste, the total energy recovery obtained for the catalysts studied here was >60%. Ni/ZrO 2 and Ni/CeO 2 show the greatest potential for controlling char growth and maximizing energy recovered from food waste. The crystalline structures of all three oxides were hydrothermally stable. Catalyst reuse tests indicate that the biocrude and char yields remained the same for the first and second use (within uncertainty) and that the catalyst retains its initial crystallinity and 93% of its initial Ni content. Molecular composition of biocrudes analyzed by the state-of-the-art analytical platforms (including GC-MS, GC × GC, FT-ICR MS, and 1H NMR) revealed minor differences in the chemical constituents of biocrudes obtained using different catalysts and provided some insight regarding reaction mechanism.

09 BIOMASS FUELS↗

DOE OSTI2023

Modeling of Chemical Slurry Rheology in DWPF Sludge Batch (SB) 10 Simulants

The Defense Waste Processing Facility (DWPF) treats high-activity radionuclides from sludge through a process called vitrification. This process converts radioactive liquid waste currently stored in tank farms into a solid glass form that is suitable for long-term storage and disposal. Due to the complexities involved in vitrifying this waste within each operation of the Chemical Processing Cell (CPC), waste rheology is studied to characterize the fluid-mechanical properties as it passes through the CPC and into the Melter. To better understand the waste and validate flow behavior, slurry rheology of simulants that represents the waste was studied at various acid stoichiometry percentages and solids concentrations to determine the simulant’s yield stress and viscosity. This research work has been supported by the DOE-FIU Science & Technology Workforce Development Initiative, an innovative program developed by the U.S. Department of Energy’s Office of Environmental Management (DOE-EM) and Florida International University’s Applied Research Center (FIU-ARC). During the spring of 2022, a DOE Fellow intern, Brendon Cintas, spent 10 weeks doing a summer internship at Savannah River National Laboratory (SRS) under the supervision and guidance of Dan Lambert, Chemical Flowsheet Development. The intern’s project was initiated on June 6, 2022, and continued through August 11, 2022 with the objective of assisting scientists at SRNL’s Rheology and Grout Laboratory at Aiken Country Technology Lab (ACTL) better understand the sludge composition on the rheology of a simulant slurry using a HAAKE RheoStress 6000 rheometer and extrapolate the results to the real-waste data.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2012

Formic Acid Free Flowsheet Development To Eliminate Catalytic Hydrogen Generation In The Defense Waste Processing

The Defense Waste Processing Facility (DWPF) processes legacy nuclear waste generated at the Savannah River Site (SRS) during production of plutonium and tritium demanded by the Cold War. The nuclear waste is first treated via a complex sequence of controlled chemical reactions and then vitrified into a borosilicate glass form and poured into stainless steel canisters. Converting the nuclear waste into borosilicate glass canisters is a safe, effective way to reduce the volume of the waste and stabilize the radionuclides. Testing was initiated to determine whether the elimination of formic acid from the DWPF's chemical processing flowsheet would eliminate catalytic hydrogen generation. Historically, hydrogen is generated in chemical processing of alkaline High Level Waste sludge in DWPF. In current processing, sludge is combined with nitric and formic acid to neutralize the waste, reduce mercury and manganese, destroy nitrite, and modify (thin) the slurry rheology. The noble metal catalyzed formic acid decomposition produces hydrogen and carbon dioxide. Elimination of formic acid by replacement with glycolic acid has the potential to eliminate the production of catalytic hydrogen. Flowsheet testing was performed to develop the nitric-glycolic acid flowsheet as an alternative to the nitric-formic flowsheet currently being processed at the DWPF. This new flowsheet has shown that mercury can be reduced and removed by steam stripping in DWPF with no catalytic hydrogen generation. All processing objectives were also met, including greatly reducing the Slurry Mix Evaporator (SME) product yield stress as compared to the baseline nitric/formic flowsheet. Ten DWPF tests were performed with nonradioactive simulants designed to cover a broad compositional range. No hydrogen was generated in testing without formic acid.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2012

Mercury Reduction and Removal from High Level Waste at the Defense Waste Processing Facility - 12511

The Defense Waste Processing Facility processes legacy nuclear waste generated at the Savannah River Site during production of enriched uranium and plutonium required by the Cold War. The nuclear waste is first treated via a complex sequence of controlled chemical reactions and then vitrified into a borosilicate glass form and poured into stainless steel canisters. Converting the nuclear waste into borosilicate glass is a safe, effective way to reduce the volume of the waste and stabilize the radionuclides. One of the constituents in the nuclear waste is mercury, which is present because it served as a catalyst in the dissolution of uranium-aluminum alloy fuel rods. At high temperatures mercury is corrosive to off-gas equipment, this poses a major challenge to the overall vitrification process in separating mercury from the waste stream prior to feeding the high temperature melter. Mercury is currently removed during the chemical process via formic acid reduction followed by steam stripping, which allows elemental mercury to be evaporated with the water vapor generated during boiling. The vapors are then condensed and sent to a hold tank where mercury coalesces and is recovered in the tank's sump via gravity settling. Next, mercury is transferred from the tank sump to a purification cell where it is washed with water and nitric acid and removed from the facility. Throughout the chemical processing cell, compounds of mercury exist in the sludge, condensate, and off-gas; all of which present unique challenges. Mercury removal from sludge waste being fed to the DWPF melter is required to avoid exhausting it to the environment or any negative impacts to the Melter Off-Gas system. The mercury concentration must be reduced to a level of 0.8 wt% or less before being introduced to the melter. Even though this is being successfully accomplished, the material balances accounting for incoming and collected mercury are not equal. In addition, mercury has not been effectively purified and collected in the Mercury Purification Cell (MPC) since 2008. A significant cleaning campaign aims to bring the MPC back up to facility housekeeping standards. Two significant investigations are being undertaken to restore mercury collection. The SMECT mercury pump has been removed from the tank and will be functionally tested. Also, research is being conducted by the Savannah River National Laboratory to determine the effects of antifoam addition on the behavior of mercury. These path forward items will help us better understand what is occurring in the mercury collection system and ultimately lead to an improved DWPF production rate and mercury recovery rate. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2024

Bioproduction of cerium-bearing magnetite and application to improve carbon-black supported platinum catalysts

Biogeochemical processing of metals including the fabrication of novel nanomaterials from metal contaminated waste streams by microbial cells is an area of intense interest in the environmental sciences. Here we focus on the fate of Ce during the microbial reduction of a suite of Ce-bearing ferrihydrites with between 0.2 and 4.2 mol% Ce. Cerium K-edge X-ray absorption near edge structure (XANES) analyses showed that trivalent and tetravalent cerium co-existed, with a higher proportion of tetravalent cerium observed with increasing Ce-bearing of the ferrihydrite. The subsurface metal-reducing bacterium Geobacter sulfurreducens was used to bioreduce Ce-bearing ferrihydrite, and with 0.2 mol% and 0.5 mol% Ce, an Fe(II)-bearing mineral, magnetite (Fe(II)(III) 2 O 4 ), formed alongside a small amount of goethite (FeOOH). At higher Ce-doping (1.4 mol% and 4.2 mol%) Fe(III) bioreduction was inhibited and goethite dominated the final products. During microbial Fe(III) reduction Ce was not released to solution, suggesting Ce remained associated with the Fe minerals during redox cycling, even at high Ce loadings. In addition, Fe L 2,3 X-ray magnetic circular dichroism (XMCD) analyses suggested that Ce partially incorporated into the Fe(III) crystallographic sites in the magnetite. The use of Ce-bearing biomagnetite prepared in this study was tested for hydrogen fuel cell catalyst applications. Platinum/carbon black electrodes were fabricated, containing 10% biomagnetite with 0.2 mol% Ce in the catalyst. The addition of bioreduced Ce-magnetite improved the electrode durability when compared to a normal Pt/CB catalyst. Different concentrations of Ce can inhibit the bioreduction of Fe(III) minerals, resulting in the formation of different bioreduction products. Bioprocessing of Fe-minerals to form Ce-containing magnetite (potentially from waste sources) offers a sustainable route to the production of fuel cell catalysts with improved performance.

59 BASIC BIOLOGICAL SCIENCES↗

DOE OSTI2023

The evaluation of aluminum and iron metal oxide settling behaviors for Hanford insoluble solids waste preprocessing

The Hanford site is currently one of the largest and most expensive cleanup sites for hazardous, radioactive waste. Over 20% of the waste found at the Hanford site is in the form of a high activity sludge. The insoluble solids in the sludge will need to be concentrated prior to vitrification in the high-level waste (HLW) melter. This will minimize the amount of liquid that will be evaporated during the melting process and expedite the melter processing rate. One proposed option for concentrating the insoluble solids is gravity settling in the storage tanks. Metal oxide compounds containing aluminum and iron make up the majority of the insoluble solids in the sludge, therefore understanding the behavior of these compounds in various tank waste matrices can facilitate sludge pretreatment options. A study of non-radioactive slurry solutions containing Al(OH) 3 (gibbsite), AlO(OH) (boehmite), and Fe 2 O 3 (iron (III) oxide) was conducted to determine the time dependent interface behavior and settling rates of these compounds. Variations in solids loading and sodium concentration were evaluated to represent waste processing conditions and the results of these settling studies were compared with prior tank waste settling tests. Information gathered from these studies can be used to inform future decisions on sludge treatment processes of the insoluble solids processed at the Hanford site.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2014

Characterisation of Ba(OH){sub 2}–Na{sub 2}SO{sub 4}–blast furnace slag cement-like composites for the immobilisation of sulfate bearing nuclear wastes

Soluble sulfate ions in nuclear waste can have detrimental effects on cementitious wasteforms and disposal facilities based on Portland cement. As an alternative, Ba(OH){sub 2}–Na{sub 2}SO{sub 4}–blast furnace slag composites are studied for immobilisation of sulfate-bearing nuclear wastes. Calcium aluminosilicate hydrate (C–A–S–H) with some barium substitution is the main binder phase, with barium also present in the low solubility salts BaSO{sub 4} and BaCO{sub 3}, along with Ba-substituted calcium sulfoaluminate hydrates, and a hydrotalcite-type layered double hydroxide. This reaction product assemblage indicates that Ba(OH){sub 2} and Na{sub 2}SO{sub 4} act as alkaline activators and control the reaction of the slag in addition to forming insoluble BaSO{sub 4}, and this restricts sulfate availability for further reaction as long as sufficient Ba(OH){sub 2} is added. An increased content of Ba(OH){sub 2} promotes a higher degree of reaction, and the formation of a highly cross-linked C–A–S–H gel. These Ba(OH){sub 2}–Na{sub 2}SO{sub 4}–blast furnace slag composite binders could be effective in the immobilisation of sulfate-bearing nuclear wastes.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2012

Advancing the Renewable Industry in Minnesota

This report deals with seven topics: 1. "Utilizing Ash Wastes as a Nutrient Source for Corn": As forms of gasification and combustion grow in the area of renewable energy in Minnesota the question arises regarding the utilization/application of the ash co product produced from these processes. Currently there are four facilities in Minnesota producing an ash co product (three ethanol facilities and one combusting biomass to produce energy). These ash wastes are generated from using ethanol by-products as a fuel or heating source for fermentation. Other ash wastes from agricultural sources include turkey litter ash. When applied to agricultural fields, ash wastes can be a source of nutrients for agricultural crops. Chemical analyses of ash wastes vary, but 200 to 300 lb of P 2 O 5 and K 2 O per ton of ash is typical. The value of ash wastes as a fertilizer has increased because commercial fertilizer prices have increased significantly over the last few years. Specifically: Compaction/Agglomeration research- Research included development of an appropriate product for use in current delivery systems by densifying the ash into the form of pellets or briquettes which may reduce fertilizer input cost to farmers. The initiative addresses the use of phosphorus and potassium from co-firing or gasification processes as a fertilizer source. 2. "Use of Glycerol as a Corn Replacement in Calf Starter Diets": Glycerol is a sugar alcohol by-product of bio-diesel production. About 1 gallon of glycerin is produced for every 10 gallons of bio-diesel of which the glycerol content may vary between 63 and almost 100%. There is some uncertainty of the exact energy value of glycerol as an ingredient for animal feed but it has been successfully used as a replacement for corn up to 10% of the diet dry matter for lactating dairy cows. There is a lack of information on incorporating glycerol into diets for pre- and post weaned dairy heifer calves which has the potential to expand the market for this by product. Preliminary work at SROC indicates that there are no palatability problems using glycerol up to 6% of the mix in post weaning pellets for group fed dairy heifers. 3. "Intervention Strategies for Reduction of Food-borne Pathogens in Cattle Fed Ethanol Byproducts": Ethanol plants and cattle producers create a symbiotic relationship: The use of wet and dry distiller’s grains in beef cattle rations provides significant improvement in overall feedlot performance for many producers in Minnesota and the Upper Midwest. Distiller’s grain is the coproduct that remains following the distillation of ethanol. It may be dehydrated to produce dried distiller’s grain (DDG) which is then commonly used as livestock feed. The use of distiller’s grains in livestock rations has been the subject of numerous research projects over the past ten years. Recently published research data conducted at Kansas State University (K-State) has created controversy over the feeding of distiller’s grains in beef cattle rations. The research indicates that cattle fed distiller’s grain may have an increased probability of Escherichia coli O157 in their hindgut. Specifically: This research assessment was a two part project consisting of feeding trials conducted at the University of Minnesota and an intervention study conducted at Kansas State University. This report is the Kansas State University portion. This report is a task-level final technical report. 4. "Impact of Distillers' Grains and Glycerin on Cattle Fecal Shedding of Escherichia coli O157:H7" 5. "Study Assessing the Opportunities and Potential of Soybean Based Products and Technologies": Based on demand/market potential, economic feasibility, stage of development and strength of institutional support, Informa Economics, Inc. ("Informa") narrowed down a list of more than 100 emerging soybean products and to 8 of the most promising for soybean, considered to have the greatest potential to add significant value to Minnesota's soybean commodity production. However, as with the potential of any biobased product or technology, the development of these emerging soybean products and technologies will be heavily reliant on future market price environments (especially for petroleum) and government policies. This report identifies what the contractor believes are the top 8 products and technologies for soybeans at the time of publishing. 6. "Study Assessing the Opportunities and Potential of Corn-Based Products and Technologies": Based on demand/market potential, economic feasibility, stage of development and strength of institutional support, Informa Economics, Inc. ("Informa") narrowed down a list of more than 100 emerging corn products and technologies to 8 of the most promising for corn, considered to have the greatest potential to add significant value to Minnesota's corn commodity production. However, as with the potential of any biobased product or technology, the development of these emerging corn products and technologies will be heavily reliant on future market price environments (especially for petroleum) and government policies. This report identifies what the contractor believes are the top 8 products and technologies for corn at the time of publishing. 7. "Distributed Power Generation Technology (Roseau Gasification)."

09 BIOMASS FUELS↗

NASA NTRS1995

NASA LaRC Hazardous Material Pharmacy

In 1993-1994 the Office of Environmental Engineering contracted SAIC to develop NASA Langley's Pollution Prevention (P2) Program. One of the priority projects identified in this contract was the development of a hazardous waste minimization (HAZMIN)/hazardous materials reutilization (HAZMART) program in the form of a Hazardous Materials Pharmacy. A hazardous materials pharmacy is designed to reduce hazardous material procurement costs and hazardous waste disposal costs. This is accomplished through the collection and reissue of excess hazardous material. Currently, a rarely used hazardous material may be stored in a shop area, unused, until it passes its expiration date. The material is then usually disposed of as a hazardous waste, often at a greater expense than the original cost of the material. While this material was on the shelf expiring, other shop areas may have ordered new supplies of the same material. The hazardous material pharmacy would act as a clearinghouse for such materials. Material that is not going to be used would be turned in to the pharmacy. Other users could then be issued this material free of charge, thereby reducing procurement costs. The use of this material by another shop prevents it from expiring, thereby reducing hazardous waste disposal costs.

Esquenet, Remy↗

DOE OSTI2013

Reuse of low specific activity material as part of LLWR design optimisation

A final cap will be emplaced over the disposed waste as part of the closure engineering for the UK's Low Level Waste Repository (LLWR). Additional profiling material will be required above the waste to obtain the required land-form. Consideration has been given to the potential opportunity to reuse Low Specific Activity Material (LSAM, defined as up to 200 Bq g{sup -1}) imported from other sites as a component of the necessary profiling material for the final repository cap. Justification of such a strategy would ultimately require a demonstration that the solution is optimal with respect to other options for the long-term management of such materials. The proposal is currently at the initial evaluation stage and seeks to establish how LSAM reuse within the cap could be achieved within the framework of an optimised safety case for the LLWR, should such a management approach be pursued. The key considerations include the following: The LSAM must provide the same engineering function as the remainder of the profiling material. The cap design must ensure efficient leachate collection, drainage and control for Low Level Waste (LLW) (and, by extension, LSAM) during the Period of Authorisation. In the longer term the engineering design must passively direct any accumulating waters preferentially away from surface water systems. An initial design has been developed that would allow the placement of around 220,000 m{sup 3} of LSAM. The potential impact of the proposal has been assessed against the current Environmental Safety Case. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2012

Formed Core Sampler Hydraulic Conductivity Testing

A full-scale formed core sampler was designed and functionally tested for use in the Saltstone Disposal Facility (SDF). Savannah River National Laboratory (SRNL) was requested to compare properties of the formed core samples and core drilled samples taken from adjacent areas in the full-scale sampler. While several physical properties were evaluated, the primary property of interest was hydraulic conductivity. Differences in hydraulic conductivity between the samples from the formed core sampler and those representing the bulk material were noted with respect to the initial handling and storage of the samples. Due to testing conditions, the site port samples were exposed to uncontrolled temperature and humidity conditions prior to testing whereas the formed core samples were kept in sealed containers with minimal exposure to an uncontrolled environment prior to testing. Based on the results of the testing, no significant differences in porosity or density were found between the formed core samples and those representing the bulk material in the test stand.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2013

Gunnar uranium mine environmental remediation - Northern Saskatchewan

The Gunnar Mine and mill site was the largest of some 38 now-abandoned uranium mines that were developed and operated in Northern Saskatchewan, Canada, during the Cold War years. During their operating lifetimes these mines produced large quantities of ore and tailings. The Gunnar mine (open pit and underground) produced over 5 million tonnes of uranium ore and nearly 4.4 million tonnes of mine tailings during its operations from 1955 through 1963. An estimated 2.2 to 2.7 million m{sup 3} of waste rock that was generated during the processing of the ore abuts the shores of Lake Athabasca, the 22. largest lake in the world. After closure in the 1960's, the Gunnar site was abandoned with little to no decommissioning being done. The Saskatchewan Research Council has been contracted to manage the clean-up of these abandoned northern uranium mine and mill sites. The Gunnar Mine, because of the magnitude of tailings and waste rock, is subject to an environmental site assessment process regulated by both provincial and federal governments. This process requires a detailed study of the environmental impacts that have resulted from the mining activities and an analysis of projected impacts from remediation efforts. The environmental assessment process, specific site studies, and public involvement initiatives are all now well underway. Due to the many uncertainties associated with an abandoned site, an adaptive remediation approach, utilizing a decision tree, presented within the environmental assessment documents will be used as part of the site regulatory licensing. A critical early task was dealing with major public safety hazards on the site. The site originally included many buildings that were remnants of a community of approximately 800 people who once occupied the site. These buildings, many of which contained high levels of asbestos, had to be appropriately abated and demolished. Similarly, the original mine head frame and mill site buildings, many of which still contained the original machinery and equipment, also had to be dismantled. Remediation options for the accumulated demolition debris have been assessed, as have remediation options for the waste rock and tailings, all of which form part of the environmental assessment. The regulatory requirements include the environmental assessment processes, a complex public involvement strategy, and licensing from the Canadian Nuclear Safety Commission (CNSC) with the long-term goal of releasing the property in a remediated and stable state to the Province of Saskatchewan. Prescribed environmental and land use endpoints will be determined based on the environmental assessment studies and remediation options analyzed and implemented. Ultimately, the site will be released into an institutional controls program that will allow long-term government management and monitoring. (authors)

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

DOE OSTI2020

Occupational and dietary differences in hydroxylated and methoxylated PBDEs and metals in plasma from Puget Sound, Washington, USA region volunteers

BACKGROUND: Electronic waste (E-waste) recycling is a rapidly growing occupation in the USA with the potential for elevated exposure to flame retardants and metals associated with electronic devices. We previously measured polybrominated diphenyl ethers (PBDEs) in plasma from E-waste workers and found them similar to non-E-waste workers. OBJECTIVES: This study focused on structurally related PBDE derivatives, the hydroxylated (OH-PBDEs) and methoxylated (MeO-PBDEs) forms along with metals known to occur in E-waste. Humans can metabolize PBDEs and some MeO-PBDEs into OH-PBDEs, which is a concern due to greater health risks associated with OH-PBDEs METHODS: We measured 32 different OH-PBDEs and MeO-PBDEs in plasma samples provided by 113 volunteers living in the greater Puget Sound region of Washington State, USA. We measured 14 metals in a subset of 10 E-waste and 10 non-E-waste volunteers. Volunteers were classified based on occupational and dietary habits: work outdoors and weekly consume = 5 seafood servings (outdoor), electronic waste recycling (E-waste) or non-specific indoor occupations (indoor). A two-week food consumption diary was obtained from each volunteer prior to blood sampling. RESULTS: OH-PBDEs were detected in all volunteers varying between 0.27 – 102 ng/g/g-lipid. The MeO-PBDEs were detected in most, but not all volunteers varying between 0 – 60.4 ng/g/g-lipid. E-waste recyclers had OH-PBDE and MeO-PBDE plasma levels that were similar to the indoor group. The outdoor group had significantly higher levels of MeO-PBDEs, but not OH-PBDEs. Comparison of plasma concentrations of BDE-47 with its known hydroxylated metabolites suggested OH-PBDE levels were likely determined by biotransformation and at least two subpopulations identified differing in their apparent rates of OH-PBDE formation. The metals analysis indicated no significant differences between E-waste workers and non-E-waste workers. CONCLUSIONS: Our results indicate E-waste workers do not have elevated plasma levels of these contaminants relative to non-E-waste workers with similar dietary habits.

Schultz, Irvin↗

DOE OSTI2015

Milestones for Selection, Characterization, and Analysis of the Performance of a Repository for Spent Nuclear Fuel and High-Level Radioactive Waste at Yucca Mountain.

This report presents a concise history in tabular form of events leading up to site identification in 1978, site selection in 1987, subsequent characterization, and ongoing analysis through 2009 of the performance of a repository for spent nuclear fuel and high - level radioactive waste at Yucca Mountain in southern Nevada. The tabulated events generally occurred in five periods: (1) commitment to mined geologic disposal and identification of sites; (2) site selection and analysis, based on regional geologic characterization through literature and analogous data; (3) feasibility analysis demonstrating calculation procedures and importance of system components, based on rough measures of performance using surface exploration, waste process knowledge, and general laboratory experiments; (4) suitability analysis demonstrating viability of disposal system, based on environment - specific laboratory experiments, in - situ experiments, and underground disposal system characterization; and (5) compliance analysis, based on completed site - specific characterization . The current sixth period beyond 2010 represents a new effort to set waste management policy in the United States. Because the relationship is important to understanding the evolution of the Yucca Mountain Project , the tabulation also shows the interaction between the policy realm and technical realm using four broad categories of events : (a) Regulatory requirements and related federal policy in laws and court decisions, (c) Presidential and agency directives, (c) technical milestones of implementing institutions, and (d) critiques of the Yucca Mountain Project and pertinent national and world events related to nuclear energy and radioactive waste. Preface The historical progression of technical milestones for the Yucca Mountain Project was originally developed for 10 journal articles in a special issue of Reliability Engineering System Safety on the performance assessment for the Yucca Mountain license application [1-10]. The listing of mile stones, a distinct feature of those articles, has been collected and tabulated here. A lthough a brief description is presented here (based on the summaries in the 10 journal articles), the emphasis remains on the tabulation because of its usefulness in providing a comprehensive but concise history of the Yucca Mountain Project. The tabulation presented here is more elaborate than originally presented in that many of the interactions that occurred between the technical realm and policy realm can be depicted in separate columns. The usefulness of the milestones table is due in part to L.A. Connolly, for editorial and reference support, and S.K. Best, Raytheon, and L. Mays, Sandia National Laboratories (SNL), for illustration support. Reviewers P.N. Swift, SNL, and K. Gupta, University of Oklahoma, helped improve the discussion. The historical perspective presented is that of the author and is not necessarily held by reviewers, Sandia National Laboratories , and the US Department of Energy. As a historic perspective, the author is reporting on the work of others; however, any interpretative error s of the documentation are those of the author alone. The characterization and modeling of the Yucca Mountain disposal system required numerous participants with expertise in many areas of science and technology, as evident from the extensive reference list. Their diligent efforts are generally acknowledged here and through the many references to their impressive work, but the 10 journal articles acknowledge by name many of the numerous participants that contributed to the Yucca Mountain Project .

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

DOE OSTI2014

Milestones for Selection, Characterization, and Analysis of the Performance of a Repository for Spent Nuclear Fuel and High-Level Radioactive Waste at Yucca Mountain

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2015

Vermicomposting as manure management strategy for urban small-holder animal farms – Kampala case study

Highlights: • Poor manure management can increase burden of disease and environmental impact. • A low-maintenance vermicompost reactor was set-up in Kampala, Uganda. • High material reduction (45.9%) and waste-to-biomass conversion (3.6% on a TS basis). • Five year return on investment of 275% of system in Uganda. • Technically and economically viable system for improved urban manure management. - Abstract: Inadequate organic waste management can contribute to the spread of diseases and have negative impacts on the environment. Vermicomposting organic waste could have dual beneficial effects by generating an economically viable animal feed protein in the form of worm biomass, while alleviating the negative effects of poor organic waste management. In this study, a low-maintenance vermicomposting system was evaluated as manure and food waste management system for small-holder farmers. A vermicomposting system using the earthworm species Eudrilus eugeniae and treating cow manure and food waste was set up in Kampala, Uganda, and monitored for 172 days. The material degradation and protein production rates were evaluated after 63 days and at the end of the experiment. The material reduction was 45.9% and the waste-to-biomass conversion rate was 3.5% in the vermicomposting process on a total solids basis. A possible increase in the conversion rate could be achieved by increasing the frequency of worm harvesting. Vermicomposting was found to be a viable manure management method in small-scale urban animal agriculture; the return of investment was calculated to be 280% for treating the manure of a 450 kg cow. The vermicompost was not sanitised, although hygiene quality could be improved by introducing a post-stabilisation step in which no fresh material is added. The value of the animal feed protein generated in the process can act as an incentive to improve current manure management strategies.

09 BIOMASS FUELS↗

DOE OSTI2018

Differential effects of divalent cations on elk prion protein fibril formation and stability

Misfolding of the normally folded prion protein of mammals (PrP C ) into infectious fibrils causes a variety of diseases, from scrapie in sheep to chronic wasting disease (CWD) in cervids. The misfolded form of PrP C , termed PrP Sc , or in this case PrP CWD , interacts with PrP C to create more PrP CWD . This process is not clearly defined but is affected by the presence and interactions of biotic and abiotic cofactors. These include nucleic acids, lipids, glycosylation, pH, and ionic character. PrP C has been shown to act as a copper-binding protein in vivo, though it also binds to other divalents as well. The significance of this action has not been conclusively elucidated. Previous reports have shown that metal binding sites occur throughout the N-terminal region of PrP C . Other cations like manganese have also been shown to affect PrP C abundance in a transcript-independent fashion. Here, we examined the ability of different divalent cations to influence the stability and in vitro conversion of two variants of PrP from elk (L/M132, 26–234). We find that copper and zinc destabilize PrP. We also find that PrP M132 exhibits a greater degree of divalent cation induced destabilization than L132. This supports findings that leucine at position 132 confers resistance to CWD, while M132 is susceptible. However, in vitro conversion of PrP is equally suppressed by either copper or zinc, in both L132 and M132 backgrounds. This report demonstrates the complex importance of ionic character on the PrP C folding pathway selection on the route to PrP Sc formation.

59 BASIC BIOLOGICAL SCIENCES↗