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All sourcesNASA NTRSDOE OSTI
DOE OSTI2017

Recovery of Rare Earth Elements from Coal and Coal Byproducts via a Closed Loop Leaching Process: Final Report

Objectives: Through this grant, Battelle proposes to address Area of Interest (AOI) 1 to develop a bench-scale technology to economically separate, extract, and concentrate mixed REEs from coal ash. U.S. coal and coal byproducts provide the opportunity for a domestic source of REEs. The DOE’s National Energy Technology Laboratory (NETL) has characterized various coal and coal byproducts samples and has found varying concentrations of REE ranging up to 1,000 parts per million by weight. The primary project objective is to validate the economic viability of recovering REEs from the coal byproduct coal ash using Battelle’s patented closed-loop Acid Digestion Process (ADP). This will be accomplished by selecting coal sources with the potential to provide REE concentrations above 300 parts per million by weight, collecting characterization data for coal ash samples generated via three different methods, and performing a Techno-Economic Analysis (TEA) for the proposed process. The regional availability of REE-laden coal ash, the regional market for rare earth concentrates, and the system capital and operating costs for rare earth recovery using the ADP technology will be accounted for in the TEA. Limited laboratory testing will be conducted to generate the parameters needed for the design of a bench scale system for REE recovery. The ultimate project outcome will be the design for an optimized, closed loop process to economically recovery REEs such that the process may be demonstrated at the bench scale in a Phase 2 project. Project Description: The project will encompass evaluation of the ADP technology for the economic recovery of REEs from coal and coal ash. The ADP was originally designed and demonstrated for the U.S. Army to facilitate demilitarization of cast-cured munitions via acid digestion in a closed-loop process. Proof of concept testing has been conducted on a sample of Ohio-based Middle Kittanning coal and has demonstrated the feasibility of recovering REEs using the ADP technology. In AOI 1, Ohio coal sources with the potential to provide a consistent source of rare earth element concentrations above 300 parts per million will be identified. Coal sample inventories from West Virginia and Pennsylvania will also be assessed for purposes of comparison. Three methods of preparing the coal ash will be evaluated for their potential to enhance the technical feasibility and economics of REE recovery. Three sources of coal ash are targeted for evaluation of the economics of REE recovery in this project: (1) coal ash from power generation stations, to include fly ash and/or bottom ash, (2) ash generated in a lower temperature ashing process, and (3) ash residual from Battelle’s coal liquefaction process. Making use of residual ash from coal liquefaction processes directly leverages work currently being conducted by Battelle for DOE NETL in response to DE-FOA-0000981 entitled “Greenhouse Gas Emissions Reductions Research and Development Leading to Cost-Competitive Coal-to-Liquids Based Jet Fuel Production.” Using the sample characterization results and regional information regarding REE concentration, availability and cost, a TEA will be developed. The previously generated laboratory testing results for leaching and REE recovery via the ADP will be used to perform the TEA, along with common engineering assumptions for scale up of equipment and labor costs. Finally, upon validation of the economic feasibility of the process by the TEA, limited laboratory testing will be performed to support the design of a bench scale system. In a future project phase, it is envisioned that the bench scale system will be constructed and operated to prove the process on a continuous basis.

20 FOSSIL-FUELED POWER PLANTS↗
DOE OSTI2026

Using Best Basis Inventory Data to Direct Strategies for Real Time Monitoring of Hanford High Level Waste – 26226

The potential to accelerate the processing of low- and high-level tank waste by applying real-time monitoring (RTM) of chemical and physical properties has prompted research into the suitability of multiple analytical methods for that purpose. The broad variety of waste stream properties and the large number of analytes of interest (as evidenced by Waste Acceptance Criteria (WAC) and Process Control Limit (PCL) lists) lead to an overwhelming set of possible analytical scenarios. This report describes the use of Best Basis Inventory (BBI) data to find the most relevant analytical targets for the specific case of monitoring the blending of High Level Waste from multiple tanks prior to introduction into a vitrification facility. Campaigns for blending this waste to minimize the risk of exceeding WACs and PCLs have been proposed. However, the predicted compositions of the blended materials do not incorporate any uncertainties that may be associated with the representativeness of the waste layer samples or the laboratory analyses that generated the BBI data. Also, they do not include any uncertainty associated with the precision of collecting highly specific fractions of the layers during a blending campaign or any inhomogeneities that may exist in those layers. Monte Carlo methods are used to apply uncertainties to the compositions of the individual layers specified in the campaign recipes. The resulting variations in the compositions of the blended materials allow estimation of the risks of exceeding WACs and PCLs for each campaign. A critical subset of WACs/PCLs – NOx, NaK, AlFeZr, and S – are especially at risk of being exceeded in multiple campaigns. These analytes should be the focus of instrument development. We also have extracted the expected solid/supernate distribution for these analytes, which establishes important performance criteria for individual analytical methods. The BBI data also permits an understanding of the different chemical forms in which the analytes appear. Thus, the need to establish instrumental sensitivity to these forms can be gainfully addressed. Although concentrating on one specific application – the blending of tank waste - this approach should be generalizable for the analysis of other possible RTM applications for waste processing.

Lascola, Robert [Savannah River National Laborator↗
DOE OSTI2021

Mapathons versus automated feature extraction: a comparative analysis for strengthening immunization microplanning

Background: Social instability and logistical factors like the displacement of vulnerable populations, the difficulty of accessing these populations, and the lack of geographic information for hard-to-reach areas continue to serve as barriers to global essential immunizations (EI). Microplanning, a population-based, healthcare intervention planning method has begun to leverage geographic information system (GIS) technology and geospatial methods to improve the remote identification and mapping of vulnerable populations to ensure inclusion in outreach and immunization services, when feasible. We compare two methods of accomplishing a remote inventory of building locations to assess their accuracy and similarity to currently employed microplan line-lists in the study area. Methods: The outputs of a crowd-sourced digitization effort, or mapathon, were compared to those of a machine-learning algorithm for digitization, referred to as automatic feature extraction (AFE). The following accuracy assessments were employed to determine the performance of each feature generation method: (1) an agreement analysis of the two methods assessed the occurrence of matches across the two outputs, where agreements were labeled as “befriended” and disagreements as “lonely”; (2) true and false positive percentages of each method were calculated in comparison to satellite imagery; (3) counts of features generated from both the mapathon and AFE were statistically compared to the number of features listed in the microplan line-list for the study area; and (4) population estimates for both feature generation method were determined for every structure identified assuming a total of three households per compound, with each household averaging two adults and 5 children. Results: The mapathon and AFE outputs detected 92,713 and 53,150 features, respectively. A higher proportion (30%) of AFE features were befriended compared with befriended mapathon points (28%). The AFE had a higher true positive rate (90.5%) of identifying structures than the mapathon (84.5%). The difference in the average number of features identified per area between the microplan and mapathon points was larger (t = 3.56) than the microplan and AFE (t = -2.09) (alpha = 0.05). Conclusions: Our findings indicate AFE outputs had higher agreement (i.e., befriended), slightly higher likelihood of correctly identifying a structure, and were more similar to the local microplan line-lists than the mapathon outputs. These findings suggest AFE may be more accurate for identifying structures in high-resolution satellite imagery than mapathons. However, they both had their advantages and the ideal method would utilize both methods in tandem.

59 BASIC BIOLOGICAL SCIENCES↗
NASA NTRSDate not supplied

A Chlorine Isotope Transect Across the Sudbury Impact Deposits Reveals Enigmatic Isotopic Fractionation

Volatile elements play an important role in a variety of cosmochemical and geochemical processes. As such, there has been significant interest in their abundance and isotopic composition. Chlorine is an important element for tracing these processes because it is incompatible in nearly all minerals, extremely volatile, and strongly hydrophilic [1]. The Cl isotope composition ( 37 Cl/ 35 Cl) of meteoritic components, therefore, can provide useful information regarding the isotopic reservoirs that were present in the early Solar System and any secondary processes that may have occurred on different parent bodies (e.g., [2-4]). There is a relatively narrow range in the Cl isotope compositions of terrestrial, Martian, and chondritic meteorites (δ 37 Cl ~ −6 to +4‰) (e.g., [2,3,5,6]), with exceptions to this being the Moon and Vesta (up to ~ +81‰ and ~ +40‰, respectively) [4, 5, 7-10]. One hypothesis for the extreme Cl isotope fractionation observed on the Moon is degassing following large-scale (possibly even crust-breaching) impact events [7-9]. The role of hypervelocity impacts and impact-generated magmatism in the isotopic evolution of planetary materials, however, has been until recently an area of limited published research with the majority of works focusing on the effects of impact shock (e.g., [10-13]). The ~ 1.85 Ga Sudbury impact crater [14] located in Ontario, Canada, is one of the three largest impact craters on Earth with good exposures of its impact melt sheet and overlying breccias [15,16]. The impact melt sheet, called the Sudbury Igneous Complex (SIC), is up to 5 km thick [17], with an estimated original volume of >10 4 km 3 [18], and differentiated. Recent work demonstrated evaporative loss and isotope fractionation of the moderately volatile element zinc and suggest melt sheets produced by impacts could have a significant effect on the Earth’s volatile inventory [19]. In this study we investigate the abundance and isotopic composition of Cl as well the water abundance of apatite from the SIC and the overlying crater-fill to test the hypothesis that large-scale impacts may have generated the extensive Cl isotopic fractionation observed on the Moon.

Sudbury↗
DOE OSTI2024

Site-specific Design Case Study for Wet Waste Hydrothermal Liquefaction and Biocrude Upgrading to Hydrocarbon Fuels

Hydrothermal liquefaction (HTL) is a thermal process that converts wet biomass to renewable hydrocarbon fuel blendstocks (i.e., renewable naphtha, renewable diesel, and sustainable aviation fuel (SAF)). It can utilize a wide range of pure and blended wet feedstocks, including sewage sludge from water resource recovery facilities (WRRF), food and agriculture wastes, algae, fats, oils and greases (FOG) and blends of dry and wet wastes/feedstocks. Historically, techno-economic analysis (TEA) and annual state of technology (SOT) assessments with standard economic assumptions used by the Bioenergy Technologies Office (BETO) were conducted for the wet waste HTL pathway leveraging experimental data collected from Pacific Northwest National Laboratory’s (PNNL) continuous flow reactor systems. The objective of the SOT assessment has been to guide and track progress of BETO’s HTL research and development (R&D) toward reduced cost and greenhouse gas (GHG) emissions for the pathway. However, gaps exist between BETO’s traditional SOT updates and the needs of key external stakeholders that – if addressed – will accelerate technology adoption. This Business Case Study aims to bridge this gap by providing an updated design, TEA, and LCA based on PNNL’s FY23 R&D with added analyses and information that provide enhanced relevance for stakeholders of the HTL technology. This includes specific siting, regional wet waste resource inventory and transportation cost analyses, fuel market information, sustainable fuel policy impacts, economic metrics of net present value (NPV) and internal rate of return (IRR), greenhouse gas (GHG) emissions analysis, and statistical analysis of cost and technical uncertainties of the HTL plant design. The study focuses on the “Detroit combined statistical area (CSA)” region for siting of a wet waste HTL plant adjacent to the Great Lakes Water Authority (GLWA) facility with guidance from industry participants. Regional resource and siting analyses were conducted to identify feedstock availability, scale, and cost, as well as a beneficial site location. TEA with detailed rigorous capital cost estimation for the specific site application was conducted to evaluate the key economic metrics of most value to industrial partners. These include total capital investment, operating costs, minimum fuel selling price (MFSP) of the biocrude and fuel blendstock, and NPV and internal rate of return IRR with sustainable fuel credits. Life cycle analysis was conducted to evaluate the supply chain greenhouse gas (GHG) emissions for the wet waste HTL process as compared with petroleum derived diesel. This study is also informed by years of R&D and process de-risking learnings and was conducted with a basic engineering HTL plant design and costing that akin to a “first-of-a-kind” plant economics. This differs from our conventional “nth plant ” SOT assessments. Specifically, the HTL process model has been updated with more operationally reliable methods for feed heating and phase separations. Further, we have implemented additional spare equipment for redundancy, a more rigorous installed equipment cost estimation approach, and additional costs associated with feed formatting and delivery, building, piping and site development. An Excel-based cost sheet based on the basic engineering design is also released alongside the report that allows users to conduct customized TEA with their own feed composition and financial assumptions.

09 BIOMASS FUELS↗
DOE OSTI2024

Supporting data for Site-specific Design Case Study for Wet Waste Hydrothermal Liquefaction and Biocrude Upgrading to Hydrocarbon Fuels

Hydrothermal liquefaction (HTL) is a thermal process that converts wet biomass to renewable hydrocarbon fuel blendstocks (i.e., renewable naphtha, renewable diesel, and sustainable aviation fuel (SAF)). It can utilize a wide range of pure and blended wet feedstocks, including sewage sludge from water resource recovery facilities (WRRF), food and agriculture wastes, algae, fats, oils and greases (FOG) and blends of dry and wet wastes/feedstocks. Historically, techno-economic analysis (TEA) and annual state of technology (SOT) assessments with standard economic assumptions used by the Bioenergy Technologies Office (BETO) were conducted for the wet waste HTL pathway leveraging experimental data collected from Pacific Northwest National Laboratory’s (PNNL) continuous flow reactor systems. The objective of the SOT assessment has been to guide and track progress of BETO’s HTL research and development (R&D) toward reduced cost and greenhouse gas (GHG) emissions for the pathway. However, gaps exist between BETO’s traditional SOT updates and the needs of key external stakeholders that – if addressed – will accelerate technology adoption. This Business Case Study aims to bridge this gap by providing an updated design, TEA, and LCA based on PNNL’s FY23 R&D with added analyses and information that provide enhanced relevance for stakeholders of the HTL technology. This includes specific siting, regional wet waste resource inventory and transportation cost analyses, fuel market information, sustainable fuel policy impacts, economic metrics of net present value (NPV) and internal rate of return (IRR), greenhouse gas (GHG) emissions analysis, and statistical analysis of cost and technical uncertainties of the HTL plant design. The study focuses on the “Detroit combined statistical area (CSA)” region for siting of a wet waste HTL plant adjacent to the Great Lakes Water Authority (GLWA) facility with guidance from industry participants. Regional resource and siting analyses were conducted to identify feedstock availability, scale, and cost, as well as a beneficial site location. TEA with detailed rigorous capital cost estimation for the specific site application was conducted to evaluate the key economic metrics of most value to industrial partners. These include total capital investment, operating costs, minimum fuel selling price (MFSP) of the biocrude and fuel blendstock, and NPV and internal rate of return IRR with sustainable fuel credits. Life cycle analysis was conducted to evaluate the supply chain greenhouse gas (GHG) emissions for the wet waste HTL process as compared with petroleum derived diesel. This study is also informed by years of R&D and process de-risking learnings and was conducted with a basic engineering HTL plant design and costing that akin to a “first-of-a-kind” plant economics. This differs from our conventional “nth plant ” SOT assessments. Specifically, the HTL process model has been updated with more operationally reliable methods for feed heating and phase separations. Further, we have implemented additional spare equipment for redundancy, a more rigorous installed equipment cost estimation approach, and additional costs associated with feed formatting and delivery, building, piping and site development. An Excel-based cost sheet based on the basic engineering design is also released alongside the report that allows users to conduct customized TEA with their own feed composition and financial assumptions.

Li, Shuyun↗
NASA NTRS2015

Data Recipes: Toward Creating How-To Knowledge Base for Earth Science Data

Both the diversity and volume of Earth science data from satellites and numerical models are growing dramatically, due to an increasing population of measured physical parameters, and also an increasing variety of spatial and temporal resolutions for many data products. To further complicate matters, Earth science data delivered to data archive centers are commonly found in different formats and structures. NASA data centers, managed by the Earth Observing System Data and Information System (EOSDIS), have developed a rich and diverse set of data services and tools with features intended to simplify finding, downloading, and working with these data. Although most data services and tools have user guides, many users still experience difficulties with accessing or reading data due to varying levels of familiarity with data services, tools, and or formats. The data recipe project at Goddard Earth Science Data and Information Services Center (GES DISC) was initiated in late 2012 for enhancing user support. A data recipe is a How-To online explanatory document, with step-by-step instructions and examples of accessing and working with real data (http:disc.sci.gsfc.nasa.govrecipes). The current suite of recipes has been found to be very helpful, especially to first-time-users of particular data services, tools, or data products. Online traffic to the data recipe pages is significant, even though the data recipe topics are still limited. An Earth Science Data System Working Group (ESDSWG) for data recipes was established in the spring of 2014, aimed to initiate an EOSDIS-wide campaign for leveraging the distributed knowledge within EOSDIS and its user communities regarding their respective services and tools. The ESDSWG data recipe group is working on an inventory and analysis of existing data recipes and tutorials, and will provide guidelines and recommendation for writing and grouping data recipes, and for cross linking recipes to data products. This presentation gives an overview of the data recipe activites at GES DISC and ESDSWG. We are seeking requirements and input from a broader data user community to establish a strong knowledge base for Earth science data research and application implementations.

data recipe↗
DOE OSTI2016

Life Sciences Laboratory 2 Fan Exhaust Mixing Study

An SF 6 tracer release was performed in the LSL-II ventilation stack over the weekend of March 5, 2016. The primary purpose of this study was to experimentally determine the gaseous concentration of material from a fume hood to the fan outlet, as well as at typical worker locations, to gain an understanding of potential worker exposures impacts. Five different fan operating configurations were utilized to ensure that the full spectrum of historical operating configurations was addressed. Some summary points from this study include: •Relatively high concentrations were observed within the stack area. –Between 50 and 100% of the exhaust concentration may be observed within the stack. •Background concentrations were observed outside the stack area. –Workers outside the stack itself, but on the roof, are unlikely to be impacted by the exhaust. •Elevated concentrations on the order of 25% of the exhaust concentrations were observed within the Penthouse. •Transport time from a laboratory fume hood to the exhaust fan is within one to two minutes. •Penthouse concentrations climb from background levels to steady state over 15+ minutes. •Wind speed and wind direction did not play a significant role in the test outcomes. –A slight bias in the concentration distribution may be discernable based on wind speed and direction. •When both fans are operating, material from fume hoods on the east side preferentially flow through the east fan, while material from fume hoods on the west side preferentially flow through the west fan. This effectively doubles the concentration at that fan. This mixing study will inform other study components to develop a more complete picture of the worker potential exposure from LSL-II Rooftop activities. Estimating the mean concentration in the stack from chemical inventories and fume hood emissions for both current and historical laboratory activities is a separate effort. These estimates of mean ventilation concentrations will utilize this mixing study to estimate the potential exposure to workers working in and around the LSL-II stack.

42 ENGINEERING↗
NASA NTRS2007

Generating a Long-Term Land Data Record from the AVHRR and MODIS Instruments

The goal of NASA's Land Long Term Iiata Record (LTDR) project is to produce a consistent long term data set from the AVHRR and MODIS instruments for land climate studies. The project will create daily surface reflectance and normalized difference vegetation index (NDVI) products at a resolution of 0.05 deg., which is identical to the Climate Modeling Grid (CMG) used for MODIS products from EOS Terra and Aqua. Higher order products such as burned area, land surface temperature, albedo, bidirectional reflectance distribution function (BRDF) correction, leaf area index (LAI), and fraction of photosyntheticalIy active radiation absorbed by vegetation (fPAR), will be created. The LTDR project will reprocess Global Area Coverage (GAC) data from AVHRR sensors onboard NOAA satellites by applying the preprocessing improvements identified in the AVHRR Pathfinder Il project and atmospheric and BRDF corrections used in MODIS processing. The preprocessing improvements include radiometric in-flight vicarious calibration for the visible and near infrared channels and inverse navigation to relate an Earth location to each sensor instantaneous field of view (IFOV). Atmospheric corrections for Rayleigh scattering, ozone, and water vapor are undertaken, with aerosol correction being implemented. The LTDR also produces a surface reflectance product for channel 3 (3.75 micrometers). Quality assessment (QA) is an integral part of the LTDR production system, which is monitoring temporal trands in the AVHRR products using time-series approaches developed for MODIS land product quality assessment. The land surface reflectance products have been evaluated at AERONET sites. The AVHRR data record from LTDR is also being compared to products from the PAL (Pathfinder AVHRR Land) and GIMMS (Global Inventory Modeling and Mapping Studies) systems to assess the relative merits of this reprocessing vis-a-vis these existing data products. The LTDR products and associated information can be found at http://ltdr.nascom.nasa.gov/ltdr/ltdr.html.

Pedelty, Jeffrey↗
DOE OSTI2014

Preliminary Evaluation of Removing Used Nuclear Fuel from Shutdown Sites

In this paper, a preliminary evaluation of removing used nuclear fuel (UNF) from 12 shutdown sites was conducted. Shutdown sites are defined as those commercial nuclear power reactor sites where the nuclear power reactors have been shut down and the site has been decommissioned or is undergoing decommissioning. The shutdown sites were Maine Yankee, Yankee Rowe, Connecticut Yankee, Humboldt Bay, Big Rock Point, Rancho Seco, Trojan, La Crosse, Zion, Crystal River, Kewaunee, and San Onofre. The evaluation was divided into four components: • characterization of the UNF and greater-than-Class C low-level radioactive waste (GTCC waste) inventory • a description of the on-site infrastructure and conditions relevant to transportation activities • an evaluation of the near-site transportation infrastructure and experience relevant to shipping transportation casks containing UNF from the shutdown sites, including gaps in information • an evaluation of the actions necessary to prepare for and remove UNF and GTCC waste from the shutdown sites. The primary sources for the inventory of UNF and GTCC waste are the DOE RW-859 used nuclear fuel inventory database, industry sources such as StoreFUEL and SpentFUEL, and government sources such as the NRC. The primary sources for the information on the site conditions and near-site transportation infrastructure and experience include site visits to the Maine Yankee, Yankee Rowe, Connecticut Yankee, Humboldt Bay, Big Rock Point, Rancho Seco, Trojan, La Crosse, and Zion sites; information provided by managers at the shutdown sites; Facility Interface Data Sheets compiled for DOE in 2005; Services Planning Documents prepared for DOE in 1993 and 1994; industry publications such as Radwaste Solutions; and Google Earth. State and Regional Group representatives, a Tribal representative, and a Federal Railroad Administration representative participated in six of the shutdown site visits. All sites were found to have at least one off-site transportation mode option for removing their UNF and GTCC waste, and some sites have two options. Large component removals during reactor decommissioning provided an important source of information in determining transportation mode options. Especially important in conducting the evaluation were site visits, through which information was obtained that would not have been available otherwise. Extensive photographs taken during the site visits proved to be particularly useful in documenting the current conditions at or near the sites. Additional conclusions from this evaluation include: • Although there are common aspects, each site has some unique features and/or conditions. • The 12 sites use designs from 4 different suppliers, including 9 different (horizontal and vertical) storage systems that would require 8 different transportation cask designs. • Although some regulatory actions will be required, all UNF at the initial 9 shutdown sites (Maine Yankee, Yankee Rowe, Connecticut Yankee, Humboldt Bay, Big Rock Point, Rancho Seco, Trojan, La Crosse, and Zion) is in licensed systems that can be transported, including a small amount of high-burnup fuel. • Each site indicated that 2-3 years of advanced time is required for preparations prior to pick-up. • Most sites have multiple transportation options, e.g., rail, barge, or heavy haul truck, as well as constraints and preferences. It is expected that additional site visits will be conducted to update the information used in the evaluation. Additional sites may be added to the evaluation if further site closures are announced.

shutdown sites, used nuclear fuel, NFST, Nuclear F↗
DOE OSTI2018

Measurements toward refined methane emission factors from industrial and commercial natural gas meters

The methane emission factors used in the U.S. EPA Greenhouse Gas Inventory (GHGI) for several categories of equipment in the natural gas supply chain currently have large uncertainties. The purpose of this project was to focus on one of those categories, industrial/commercial customer meters. The potential effect of the uncertainty for this category could be large due to the 5.6 million meters nationwide. We divided the country into six regions and worked extensively with local natural gas distribution companies to gain access to the meters. Ten weeks of measurements were conducted with an additional three weeks spent later revisiting the first sites. Sites were selected pseudo-randomly, by first randomly selecting a location then driving to as many meters as possible during that day, then randomly selecting another starting meter for the next day. At each site, every component was scanned with a combustible gas indicator (CGI), all components were counted, and all leaks with indications above 100ppm were logged. For 3 of the 10 weeks of measurements all leaks above 100ppm were quantified and for the remaining seven only leaks with an indication concentration above 22,500 ppm (45% of lower explosive limit) were quantified. Leaks were quantified using an enclosure, a vacuum pump, and methane sensor (either a CGI or Los Gatos Research Greenhouse Gas Analyzer). Through the initial visits 18,934 components were scanned, resulting in 1,170 leak indications above 100ppm, 351 leaks quantified at 174 different meter sets. The data was collected in a way so that it could be stratified by region, meter type, and component type. The largest number of components scanned were valves (4908) and flanges (4571). Very preliminary analysis of the data indicates that the mean leak size (not by meter) by region was Southeast (0.78 ± 2.2 lpm) Southwest (0.63 ± 1.5 lpm), Rocky Mountain (0.54 ± 1.3 lpm) Northeast (0.14 ± 0.56 lpm), Midwest (0.14 ± 0.56 lpm), and Pacific (0.07 ± 0.56 lpm). We also have determined that of the component types logged, roughly 2 – 5% of all components leaked. Our results are only preliminary, but initial indications are that based on data from this study, the current emission factors could increase by a factor of 5 to 10. Data analysis is ongoing to verify.

03 NATURAL GAS↗
NASA NTRSDate not supplied

Formation of Complex Organic Molecules (COMs) from Polycyclic Aromatic Hydrocarbons (PAHs): Top-Down Synthesis of organics in planetary systems

Complex, organic molecules have been found in many solar system objects (i.e., dust, comets, meteorites, moons, etc.); however, their origins and formation remain a mystery. Two chemical evolutionary pathways have been proposed to explain the organic inventory of our solar system. The first pathway, the top-down approach, suggests an interstellar (ISM) heritage whereby the organic material found in the solar system formed from the erosion and functionalization of large pre-solar carbon-bearing species (mainly large Polycyclic Aromatic Hydrocarbons or PAHs). The second pathway suggests that the origin of the Solar System prebiotic matter is the result of bottom-up synthesis from small reactive molecules (e.g., formaldehyde – H2CO, acetylene – H2C2, and similar species). In this second scenario, it is supposed that very few, if any, pre-solar large molecules could have survived due to the proto - solar nebula radiation environment. Polycyclic Aromatic Hydrocarbons or PAHs comprise ~20-30% of all available carbon in the Universe. The PAHs found within our Solar System tend to be smaller than those suspected to be in the ISM, comprised of only 14 to 18 carbon atoms in size whereas ISM PAHs are typically 50 to 100 carbon atoms. The disparity in PAH sizes between the ISM and Solar System environments is not understood, but may point to conversion of large ISM PAHs to Solar System Organics. This presentation details recent experiments regarding the stability of large PAHs to the various types of radiation found within a proto - solar disk and the production of smaller, complex, molecules from the degradation of the larger PAHs. The presentation will highlight differences and similarities in degradation products based on experimental conditions (e.g., radiation type) and discuss future work with a new experimental setup known as ICEE (Institute for Carbon Evolution Experiments).

molecukes↗
DOE OSTI2015

Sensitivities and correlations of critical experiments due to uncertainties of system parameters and nuclear data - 14416

With increasing demand on accuracy of criticality calculations, correlations between benchmark experiments due to system parameter uncertainties become of interest in bias determination. The impact of different interpretations of system parameter uncertainties on the calculation of covariances and correlations of k{sub eff} is discussed in this article. Following the suggestion of the OECD/NEA EGUACSA Benchmark phase IV [1], 21 experiments from the ICSBEP international Handbook of Evaluated Criticality Safety Benchmarks [2] are used for this analysis (LEU-COMP-THERM series 07, exp. 01-04 and 39, exp. 01-17). The experiments share certain assembly and fuel features and were carried out in the same lab. Therefore, correlations in the calculation of k{sub eff} appear. Correlation coefficients between experiments due to nuclear data uncertainties are calculated with TSUNAMI [3] and show high values for most experiments. For the correlation analysis due to system parameter uncertainties mainly two scenarios are considered: In scenario A all uncertain parameters are varied mutually for all fuel rods, representing a systematic deviation of the actual experimental setup from the design value. This analysis is performed for all experiments listed above. In scenario E certain parameters like the outer cladding diameter are varied for each fuel rod individually, representing a random scattering of the varied parameter. Scenarios B, C and D represent intermediate scenarios between A and E, which are discussed shortly. Uncertainty and sensitivity calculations of k{sub eff} on the uncertain experimental parameters based on Monte Carlo sampling are presented and discussed. The calculations were performed with SUnCISTT (Sensitivities and Uncertainties in Criticality Inventory and Source Term Tool [4]) and SCALE 6.1.2 [3]. For the 21 EGUACSA proposed experiments the outer cladding diameter is the leading effect for the uncertainty of k{sub eff} for scenario A. In contrast, for scenario E the impact of the cladding diameter on k{sub eff} cancels out due to rod wise variations leaving the fuel diameter as the leading effect. The correlation analysis based on system parameter uncertainties indicates a significant dependence of the correlation coefficients on the interpretation of the uncertainties. It shows high values for scenario A, if the neutronic features are similar (EALF, H/U). For scenario E the overall correlations are significantly smaller and variations between experiments decrease. The impact of the determined correlations on bias calculations of application cases will be discussed by the authors in the accompanying paper 'Impact of correlated data in validation procedures'. (authors)

42 ENGINEERING↗
DOE OSTI2017

Controls on rare earth element distributions in ancient organic-rich sedimentary sequences: Role of post-depositional diagenesis of phosphorus phases

Here, the processes that dictate the formation and preservation of rare earth element (REE) signatures in ancient marine black shales are incompletely understood, thus potentially limiting the utility of the REEs as geochemical tracers. Here, we report on whole-rock REE analyses of six black shale formations from different ages and depositional settings, which fall within three general groupings: Group 1 is characterized by low whole-rock REE content (ΣREE) (< 250 μg/g) and middle- and heavy-REE-enriched patterns (Gd N /La N < 2, Yb N /La N < 2.5); Group 2 is characterized by low ΣREE (< 250 μg/g) but greater middle-REE-enriched patterns (Gd N /La N > 2, Yb N /La N < 3); and Group 3 is characterized by high ΣREE (> 250 μg/g) and moderately middle-REE-enriched patterns (Gd N /La N ~ 1.5–2.5, Yb N /La N ~ 1). Representative samples from these groups were selected from the Marcellus and Hushpuckney shales and subjected to a multi-step leaching procedure, to isolate four extractable P-phases (reducible, authigenic carbonate-associated, detrital apatite, organic). In Group 1 samples with low carbonate content (< 4% CaCO 3 ), REEs were hosted mainly in the organic (50% of ΣREE) and siliciclastic fractions (37%); whereas in samples with greater carbonate content (> 25% CaCO 3 ), REEs were hosted mainly in carbonate-associated phases (53%). In Group 2, REEs were hosted mainly in the carbonate-associated (64%) and organic fractions (30%), and in Group 3, REEs were hosted mainly in the carbonate-associated (60%), detrital apatite (23%), and siliciclastic fractions (16%). Authigenic phases include minerals such as carbonate fluorapatite and authigenic calcite that, if present, tend to dominate the whole-rock REE inventory. In the absence of carbonate, whole-rock REE content depends on the relative REE contributions of the organic and siliciclastic fractions.

58 GEOSCIENCES↗
DOE OSTI2016

Evaluation of Pre- and Post- Redevelopment Groundwater Chemical Analyses from LM Monitoring Wells

This report documents the efforts and analyses conducted for the Applied Studies and Technology (AS&T) Ancillary Work Plan (AWP) project titled Evaluation of Pre- and Post- Redevelopment Groundwater Sample Laboratory Analyses from Selected LM Groundwater Monitoring Wells. This effort entailed compiling an inventory of nearly 500 previous well redevelopment events at 16 U.S. Department of Energy Office of Legacy Management (LM) sites, searching the literature for impacts of well redevelopment on groundwater sample quality, and—the focus of this report—evaluating the impacts of well redevelopment on field measurements and sample analytical results. Study Catalyst Monitoring well redevelopment, the surging or high-volume pumping of a well to loosen and remove accumulated sediment and biological build-up from a well, is considered an element of monitoring well maintenance that is implemented periodically during the lifetime of the well to mitigate its gradual deterioration. Well redevelopment has been conducted fairly routinely at a few LM sites in the western United States (e.g., the Grand Junction office site and the Gunnison processing site in Colorado), but at most other sites in this region it is not a routine practice. Also, until recently (2014–2015), there had been no specific criteria for implementing well redevelopment, and documentation of redevelopment events has been inconsistent. A catalyst for this evaluation was the self-identification of these inconsistencies by the Legacy Management Support contractor. As a result, in early 2015 Environmental Monitoring Operations (EMO) staff began collecting and documenting additional field measurements during well redevelopment events. In late 2015, AS&T staff undertook an independent internal evaluation of EMO's well redevelopment records and corresponding pre- and post-well-redevelopment groundwater analytical results. Study Findings Although literature discussions parallel the prevailing industry-wide assumption that well redevelopment is necessary to increase production or to extend the life of a well, no data in the literature indicate that redevelopment affects chemical signatures in monitoring wells. The comprehensive evaluation undertaken for this study also yielded no evidence that redevelopment has any quantifiable or predictable effect on groundwater sample quality. Both short-term and long-term changes in groundwater chemistry were assessed relative to preceding and subsequent well redevelopment events. Although short-term changes in specific conductance or contaminant concentrations likely attributable to well redevelopment were found at some sites, these cases were limited to a small subset of wells in which chemical stratification had been observed. Redevelopment causes mixing of the well water, resulting in short-term impacts, but not in a consistent direction. Long-term groundwater concentration trends of uranium, the primary contaminant of concern at most LM Uranium Mill Tailings Radiation Control Act (UMTRCA) sites, were evaluated for all 16 sites addressed in this study. Based on the data evaluated, there are no apparent impacts of well redevelopment on uranium trends. In most cases where deviations in trends were found, these could be attributed to water level fluctuations or other factors. A few exceptions were found where spikes or marked decreases in uranium concentrations could potentially be related to the preceding well redevelopment, but apparent impacts were neither predictable nor quantifiable. Summary and Recommendations A catalyst for this project was a concern that there was a need for strict criteria for a program-wide approach to well redevelopment at LM sites. There was also an implicit question as to whether well redevelopment was a necessary practice that was being overlooked at some sites. The primary objective of this study was to determine if there are significant differences in laboratory analytical results between pre- and post-redevelopment groundwater samples. Results of this evaluation indicate that this is not the case—groundwater concentrations of uranium, the primary contaminant of concern at most LM UMTRCA sites, generally remained unchanged pre- and post-well-redevelopment. The literature supports redevelopment of monitoring and municipal wells if signs of reduced productivity, biofouling, sediment buildup, or other conditions potentially affecting long-term well integrity are observed. In these cases, use of a downhole camera to examine the condition of the well screen and casing may be useful. However, based on the data sets examined for this study, there is no evidence that well redevelopment is needed in order to obtain samples that have the same chemical concentrations as those in the groundwater. To conclusively demonstrate that point—that is, to define chemical effects—the underlying mechanisms have to be understood. For example, if biofouling is observed in a well and is considered a potential cause of spurious or invalid chemical data, appropriate hypothesis-testing ethodology should be used to test the validity of this claim. Until late 2014, the onset of this project, there was no standard procedure for documenting well redevelopment events; some (perhaps many) had not been captured in the historical record. EMO has made notable progress in this regard since 2015, having established a format for documenting well redevelopment events and associated field measurements, as well as a data repository for capturing those records. This policy should be continued to ensure that all well redevelopment events and associated field observations are recorded and easily tracked.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2026

Life Cycle Analysis of Growing Canola for Biofuel Production in the United States

This study quantifies and compares the life cycle greenhouse gas (GHG) emissions of renewable diesel (RD), sustainable aviation fuel (SAF), and biodiesel (BD) produced from two U.S. canola production systems: 1) emerging intermediate winter canola, typically grown in double- or relay-cropping systems between the growing seasons of main crops, and 2) main canola, mostly spring canola but also including winter canola, which are grown as primary crops occupying the field for a full growing season. Using the Research and Development version of the Greenhouse gases, Regulated Emissions, and Energy use in Technologies (R&D GREET) model and the most up-to-date life cycle inventory data─field trial data for intermediate winter canola (>37,000 acres) and recent national survey data for spring canola─this life cycle analysis (LCA) estimates the direct emissions from canola cultivation and harvest, the conversion of canola into fuels, fuel transportation, and combustion. In addition, we account for market-mediated emissions associated with a scenario of 0.5 billion gallons per year of spring canola-based biofuels, including induced land use change (ILUC), induced other crop (nonfeedstock) production changes, and induced livestock production changes. For intermediate winter canola, these market-mediated effects were not modeled, as ILUC is expected to be negligible due to its integration into existing rotations, and data are currently insufficient to reliably quantify other market-mediated changes. The estimated life cycle direct emissions of RD/SAF derived from intermediate winter canola and main spring canola are about 32 and 33 g of CO2-equivalent per megajoule of fuel (g CO 2 e/MJ), respectively. Corresponding emissions for BD from intermediate winter canola and main spring canola are about 30 and 31 g of CO 2 e/MJ, respectively. Farming is the dominant emissions source for both canola systems, with intermediate winter canola and main spring canola emitting about 19 and 20 g of CO 2 e/MJ, respectively. ILUC and other induced changes increase emissions of main spring canola-derived RD/SAF and BD by about 18 and 17 g of CO 2 e/MJ, respectively. These results indicate that the GHG emissions of biofuels produced from the two canola systems may differ substantially due to the different land use dynamics of the systems.

biodiesel↗
DOE OSTI2017

Estimating Aboveground Biomass in Tropical Forests: Field Methods and Error Analysis for the Calibration of Remote Sensing Observations

Mapping and monitoring of forest carbon stocks across large areas in the tropics will necessarily rely on remote sensing approaches, which in turn depend on field estimates of biomass for calibration and validation purposes. Here, we used field plot data collected in a tropical moist forest in the central Amazon to gain a better understanding of the uncertainty associated with plot-level biomass estimates obtained specifically for the calibration of remote sensing measurements. In addition to accounting for sources of error that would be normally expected in conventional biomass estimates (e.g., measurement and allometric errors), we examined two sources of uncertainty that are specific to the calibration process and should be taken into account in most remote sensing studies: the error resulting from spatial disagreement between field and remote sensing measurements (i.e., co-location error), and the error introduced when accounting for temporal differences in data acquisition. We found that the overall uncertainty in the field biomass was typically 25% for both secondary and primary forests, but ranged from 16 to 53%. Co-location and temporal errors accounted for a large fraction of the total variance (>65%) and were identified as important targets for reducing uncertainty in studies relating tropical forest biomass to remotely sensed data. Although measurement and allometric errors were relatively unimportant when considered alone, combined they accounted for roughly 30% of the total variance on average and should not be ignored. Lastly, our results suggest that a thorough understanding of the sources of error associated with field-measured plot-level biomass estimates in tropical forests is critical to determine confidence in remote sensing estimates of carbon stocks and fluxes, and to develop strategies for reducing the overall uncertainty of remote sensing approaches.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2022

Representativeness assessment of the pan-Arctic eddy covariance site network and optimized future enhancements

Abstract. Large changes in the Arctic carbon balance are expected as warming linked to climate change threatens to destabilize ancient permafrost carbon stocks. The eddy covariance (EC) method is an established technique to quantify net losses and gains of carbon between the biosphere and atmosphere at high spatiotemporal resolution. Over the past decades, a growing network of terrestrial EC tower sites has been established across the Arctic, but a comprehensive assessment of the network's representativeness within the heterogeneous Arctic region is still lacking. This creates additional uncertainties when integrating flux data across sites, for example when upscaling fluxes to constrain pan-Arctic carbon budgets and changes therein. This study provides an inventory of Arctic (here > = 60∘ N) EC sites, which has also been made available online (https://cosima.nceas.ucsb.edu/carbon-flux-sites/, last access: 25 January 2022). Our database currently comprises 120 EC sites, but only 83 are listed as active, and just 25 of these active sites remain operational throughout the winter. To map the representativeness of this EC network, we evaluated the similarity between environmental conditions observed at the tower locations and those within the larger Arctic study domain based on 18 bioclimatic and edaphic variables. This allows us to assess a general level of similarity between ecosystem conditions within the domain, while not necessarily reflecting changes in greenhouse gas flux rates directly. We define two metrics based on this representativeness score: one that measures whether a location is represented by an EC tower with similar characteristics (ER1) and a second for which we assess if a minimum level of representation for statistically rigorous extrapolation is met (ER4). We find that while half of the domain is represented by at least one tower, only a third has enough towers in similar locations to allow reliable extrapolation. When we consider methane measurements or year-round (including wintertime) measurements, the values drop to about 1/5 and 1/10 of the domain, respectively. With the majority of sites located in Fennoscandia and Alaska, these regions were assigned the highest level of network representativeness, while large parts of Siberia and patches of Canada were classified as underrepresented. Across the Arctic, mountainous regions were particularly poorly represented by the current EC observation network. We tested three different strategies to identify new site locations or upgrades of existing sites that optimally enhance the representativeness of the current EC network. While 15 new sites can improve the representativeness of the pan-Arctic network by 20 %, upgrading as few as 10 existing sites to capture methane fluxes or remain active during wintertime can improve their respective ER1 network coverage by 28 % to 33 %. This targeted network improvement could be shown to be clearly superior to an unguided selection of new sites, therefore leading to substantial improvements in network coverage based on relatively small investments.

54 ENVIRONMENTAL SCIENCES↗