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At least 1,117 records · Page 62

Fourier Method for Calculating Fission Chain Neutron Multiplicity Distributions

Here, a new way of utilizing the fast Fourier transform is developed to compute the probability distribution for a fission chain to create n neutrons. We then extend this technique to compute the probability distributions for detecting n neutrons. Lastly, our technique can be used for fission chains initiated by either a single neutron inducing a fission or by the spontaneous fission of another isotope.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

Bayesian inference of Stochastic reaction networks using Multifidelity Sequential Tempered Markov Chain Monte Carlo

Stochastic reaction network models are often used to explain and predict the dynamics of gene regulation in single cells.These models usually involve several parameters, such as the kinetic rates of chemical reactions, that are not directly measurable and must be inferred from experimental data. Bayesian inference provides a rigorous probabilistic frame-work for identifying these parameters by finding a posterior parameter distribution that captures their uncertainty.Traditional computational methods for solving inference problems such as Markov Chain Monte Carlo methods based on classical Metropolis-Hastings algorithm involve numerous serial evaluations of the likelihood function, which in turn requires expensive forward solutions of the chemical master equation (CME). We propose an alternate approach based on a multifidelity extension of the Sequential Tempered Markov Chain Monte Carlo (ST-MCMC) sampler. This algorithm is built upon Sequential Monte Carlo and solves the Bayesian inference problem by decomposing it into a sequence of efficiently solved subproblems that gradually increase both model fidelity and the influence of the observed data. We reformulate the finite state projection (FSP) algorithm, a well-known method for solving the CME, to produce a hierarchy of surrogate master equations to be used in this multifidelity scheme. To determine the appropriate fidelity, we introduce a novel information-theoretic criteria that seeks to extract the most information about the ultimate Bayesian posterior from each model in the hierarchy without inducing significant bias. This novel sampling scheme is tested with high performance computing resources using biologically relevant problems.

97 MATHEMATICS AND COMPUTING↗

Estimating U.S. Methane Emissions from the Natural Gas Supply Chain. Approaches, Uncertainties, Current Estimates, and Future Studies

A growing number of studies have raised questions regarding uncertainties in our understanding of methane (CH 4 ) emissions from fugitives and venting along the natural gas (NG) supply chain. In particular, a number of measurement studies have suggested that actual levels of CH 4 emissions may be higher than estimated by EPA" tm s U.S. GHG Emission Inventory. We reviewed the literature to identify the growing number of studies that have raised questions regarding uncertainties in our understanding of methane (CH 4 ) emissions from fugitives and venting along the natural gas (NG) supply chain.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Automotive Lithium-ion Cell Manufacturing: Regional Cost Structures and Supply Chain Considerations

Manufacturing capacity for lithium-ion batteries (LIBs)--which power many consumer electronics and are increasingly used to power electric vehicles--is heavily concentrated in east Asia. Currently, China, Japan, and Korea collectively host 88% of all LIB cell and 79% of automotive LIB cell manufacturing capacity. Mature supply chains and strong cumulative production experience suggest that most LIB cell production will remain concentrated in Asia. However, other regions--including North America--could be competitive in the growing automotive LIB cell market under certain conditions. To illuminate the factors that drive regional competitiveness in automotive LIB cell production, this study models cell manufacturing cost and minimum sustainable price, and examines development of LIB supply chains and current LIB market conditions. Modeled costs are for large format, 20-Ah stacked pouch cells with lithium-nickel-manganese-cobalt-oxide (NMC) cathodes and graphite anodes suitable for automotive application. Production volume is assumed to be at commercial scale, 600 MWh per year.

25 ENERGY STORAGE↗

Global Carbon Fiber Composites. Supply Chain Competitiveness Analysis

The objective of this study is to identify key opportunities in the carbon fiber (CF) supply chain where resources and investments can help advance the clean energy economy. The report focuses on four application areas—wind energy, aerospace, automotive, and pressure vessels—that top the list of industries using CF and carbon fiber reinforced polymers (CFRP) and are particularly relevant to the mission of U.S. Department of Energy’s Office of Energy Efficiency and Renewable Energy (DOE EERE). For each of the four application areas, the report addresses the supply and demand trends within that sector, supply chain, and costs of carbon fiber and components.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Automotive Lithium-ion Cell Manufacturing: Regional Cost Structures and Supply Chain Considerations

Manufacturing capacity for lithium-ion batteries (LIBs) — which power many consumer electronics and are increasingly used to power electric vehicles — is heavily concentrated in East Asia. To illuminate the factors that drive regional competitiveness in automotive LIB cell production, this study models cell manufacturing cost and minimum sustainable price, and examines development of LIB supply chains and current LIB market conditions. The study shows that factors driving the cost competitiveness of LIB manufacturing locations are mostly built—supply chain developments and competition, access to materials, and production expertise. Some regional costs — including cost of capital, labor, and materials — are significant and should be considered.

25 ENERGY STORAGE↗

Global Carbon Fiber Composites Supply Chain Competitiveness Analysis

This analysis identifies key opportunities in the carbon fiber supply chain where resources and investments can help advance the clean energy economy. The report focuses on four application areas — wind energy, aerospace, automotive, and pressure vessels — that top the list of industries using carbon fiber and carbon fiber reinforced polymers. For each of the four application areas, the report addresses the supply and demand trends within that sector, supply chain, and costs of carbon fiber and components.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗

Non-RF Chain of Custody Item Monitor (CoCIM) User Manual.

This User Manual contains a description of the wired and infrared (IR) variants of the Chain of Custody Item Monitor (CoCIM), the Coordinator for reading stored messages, and the inspector Message Viewer user interface (UI) software, as well as instructions for use. This manual does not include descriptions or use instructions for the radio frequency (RF) variant of the CoCIM. The intended audience is planners and participants in treaty verification exercises where chain of custody (CoC) elements are required.

97 MATHEMATICS AND COMPUTING↗

Industry Partnerships and Their Role in Reducing Natural Gas Supply Chain Greenhouse Gas Emissions

This analysis is the product of collaboration between Our Nation’s Energy Future (ONE Future) and the United States (U.S.) Department of Energy’s (DOE) National Energy Technology Laboratory (NETL). This analysis has three objectives: 1. Calculate a greenhouse gas (GHG) emission profile representative of ONE Future’s supply chain, including methane (CH4) emission rates. 2. Compare ONE Future’s emission profile to the emission profile for the average U.S. natural gas supply chain. 3. Evaluate specific emission reduction opportunities.

03 NATURAL GAS↗

Understanding the Life Cycle Environmental Footprint of the Natural Gas Value Chain [Slides]

This is a presentation given to the North Association of Regulatory Utility Commissioners (NARUC), Gas Subcommittee meeting on February 9, 2014. The agenda includes the importance of understanding methane emissions from the natural gas sector, the Department of Energy Office's role in reducing methane emissions from the natural gas value chain, and a primer on life cycle analysis and understanding the life cycle environmental footprint of the natural gas value chain.

03 NATURAL GAS↗

Supply Chain Sustainability Analysis of Renewable Hydrocarbon Fuels via Indirect Liquefaction, Fast Pyrolysis, and Hydrothermal Liquefaction: Update of the 2016 State-of-Technology Cases and Design Cases

This technical memorandum describes the supply chain sustainability analyses (SCSA) for the production of three renewable hydrocarbon transportation fuels: (1) renewable high octane gasoline (HOG) via indirect liquefaction (IDL) of woody lignocellulosic biomass; (2) renewable gasoline (RG) via fast pyrolysis of woody lignocellulosic biomass; and (3) renewable diesel via hydrothermal liquefaction of algae. This technical memorandum focuses on the 2016 State of Technology (SOT) technical, economic, and environmental performance of these three fuel production pathways, as well as the 2016 SOT woody feedstock blend production and the 2016 SOT for algae feedstock production. The results of these renewable hydrocarbon fuel pathways in these SCSA analyses update those for the respective 2015 SOT cases (Cai et al., 2016; Adom et al., 2016; Frank et al., 2016), and provide an opportunity to examine the impact of technology improvements of both biomass feedstock production and biofuel production that have been achieved since the 2015 SOTs on the sustainability performance of these renewable transportation fuels. Furthermore, they reflect updates to Argonne National Laboratory's Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET[R]) model, which was released in October 2016 (ANL, 2016). The 2015 SOT case was re-evaluated using this newly-released version, which includes updates to the production of natural gas, electricity, and liquid fuels that can influence biofuels' supply chain greenhouse gas (GHG) (CO 2 , CH 4 , and N 2 O) emissions. These emissions and water consumption are the two sustainability metrics assessed in this analysis. The design cases (future target projections) for these three fuel production pathways were also re-evaluated using GREET 2016. In particular, the 2016 woody blend feedstock SOT was used in lieu of the previous design case woody blend feedstock, which utilized construction and demolition waste (INL, 2014). In the 2016 woody blend feedstock SOT, the construction and demolition waste was eliminated due to a lack of Renewable Identification Number (RINs) generation, and replaced with short rotation hybrid poplar in order to align with the woody feedstock blend that was chosen by the BETO Feedstock-Conversion Interface Consortium (FCIC) for the 2017 fast pyrolysis verification.

09 BIOMASS FUELS↗

The Application of Current Mineral Processing and Extractive Metallurgy Technologies to Potential Rare Earth Ores in the U.S. Coal Measures: Near-Term Opportunities to Fill Out the U.S. Value Chain

This report will consider the potential for currently available mineral processing and extractive metallurgy technologies to produce separated rare earth compounds from U.S. coal and coal byproducts. Implementation of production as such would require restoration of elements of the rare earth value chain that have recently been absent in the U.S., notably for chemical extraction of rare earth compounds from the mineral form (i.e. hydrometallurgical extraction). A variety of existing technologies are available for use in both mineral processing and extractive metallurgy applied to RE production in the U.S. As will be discussed, once a mineral concentrate is produced, the contained rare earth value can be large compared with transportation costs, and the sections of the value chain dealing with chemical extraction (the largest cost) and separation into individual rare earth compounds can be remotely located. Also, as will be discussed, this has been the rule rather than exception in the history of the rare earth industry in the U.S. A strategy, possibly to include repurposing of existing metallurgical processing facilities, will be presented for near-term production, using a decentralized set of facilities. Also presented will be research results from the Office of Fossil Energy (FE) and the National Energy Technology Laboratory (NETL), within the U.S. Department of Energy, relevant to economic feasibility of rare earth production, notably from the standpoint of establishing which materials are capable of providing economic production. Simple methodologies are presented for both establishment of cutoff grades and economic evaluation of a process. The goal of this report is to present an overview of methods and pathways that will result in “the achievement of near-term rare earth production, using currently available technologies to produce a mixed, chemical extracted rare earth concentrate, and existing and new facilities to produce separated rare earths that can “plug in” to the metals and magnet production facilities.” A set of recommendations appears at the end of this work, involving both research and project development activities which will enable the achievement of this noble goal. A set of recommendations appears at the end of this work, involving both research and project development activities.

58 GEOSCIENCES↗

Radioactive Decay Chain Truncation Rules for Emergency Response Radiological Assessments

A set of radionuclide - decay chain truncation rules have been developed for use in the Turbo FRMAC and Specialized Hazard Assessment Response Capability (SHARC) software programs used to support radiological emergency response activities . Following the proposed rules, the software will truncate a decay chain after it encounters a progeny radionuclide with a half - life greater than 5,000 years. An analysis of the projected dose from many parent and progeny radionuclides over a 50 - year time period yielded that a radionuclide half - life cutoff of 5,000 years will exclude a negligible dose. Implementing the truncation rules will reduce the time required for assessments and minimize computer hardware requ irements without having a significant detrimental effect on dose projections and emergency response decisions. It is noted that the truncation rules may not be suited for long - term ( greater than 50 year) environmental assessments.

07 ISOTOPE AND RADIATION SOURCES↗

Transitional Markov Chain Monte Carlo Sampler in UQTk

Transitional Markov Chain Monte Carlo (TMCMC) is a variant of a class of Markov Chain Monte Carlo algorithms known as tempering-based methods. In this report, the implementation of TMCMC in the Uncertainty Quantification Toolkit is investigated through the sampling of high-dimensional distributions, multi-modal distributions, and nonlinear manifolds. Furthermore, the Bayesian model evidence estimates obtained from TMCMC are tested on problems with known analytical solutions and shown to provide consistent results.

97 MATHEMATICS AND COMPUTING↗

Supply Chain Sustainability Analysis of Renewable Hydrocarbon Fuels via Indirect Liquefaction, Ex Situ Catalytic Fast Pyrolysis, Hydrothermal Liquefaction, Combined Algal Processing, and Biochemical Conversion: Update of the 2019 State-of-Technology Cases

This technical report describes the supply chain sustainability analysis (SCSAs) for the production of renewable hydrocarbon transportation fuels via a range of conversion technologies: (1) renewable high octane gasoline (HOG) via indirect liquefaction (IDL) of woody lignocellulosic biomass (note that the IDL pathway in this SCSA represents the syngas conversion design in the 2019 SOT); (2) renewable gasoline (RG) and diesel (RD) blendstocks via ex situ catalytic fast pyrolysis of woody lignocellulosic biomass; (3) RD via hydrothermal liquefaction (HTL) of wet sludge from a wastewater treatment plant; (4) renewable hydrocarbon fuels via biochemical conversion of herbaceous lignocellulosic biomass; (5) renewable diesel via HTL of a blend of algae and woody biomass; and (6) renewable diesel via combined algae processing (CAP). This technical report focuses on the environmental performance of these six biofuel production pathways in their 2019 SOT cases. The results of these renewable hydrocarbon fuel pathways in these SCSA analyses update those for the respective 2018 SOT cases. They also provide an opportunity to examine the impact of technology improvements in both biomass feedstock production and biofuel production that have been achieved in 2019 SOTs on the sustainability performance of these renewable transportation fuels, and they reflect updates to Argonne National Laboratory’s Greenhouse gases, Regulated Emissions, and Energy use in Transportation (GREET®) model, which was released in October 2019. These GREET updates include the production of natural gas, electricity, and petroleum-based fuels that can influence biofuels’ supply chain greenhouse gas (GHG) (CO₂, CH₄, and N₂O) emissions, water consumption, and air pollutant emissions. GHG emissions, water consumption, and nitrogen oxides (NO x ) emissions are the main sustainability metrics assessed in this analysis. In this analysis, we define water consumption as the amount of water withdrawn from a freshwater source that is not returned (or returnable) to a freshwater source at the same level of quality. Life-cycle fossil energy consumption and net energy balance, which is the life-cycle fossil energy consumption deducted from the renewable biofuel energy produced, are also assessed.

09 BIOMASS FUELS↗

Supply Chain Sustainability Analysis of Renewable Hydrocarbon Fuels via Indirect Liquefaction, Ex Situ Catalytic Fast Pyrolysis, Hydrothermal Liquefaction, Combined Algal Processing, and Biochemical Conversion: Update of the 2020 State-of-Technology Cases

The Department of Energy’s (DOE) Bioenergy Technologies Office (BETO) aims to develop and deploy technologies to transform renewable biomass resources into commercially viable, high-performance biofuels, bioproducts, and biopower through public and private partnerships (U.S. Department of Energy, 2016). BETO and its national laboratory teams conduct in-depth techno-economic assessments (TEA) of biomass feedstock supply and logistics and conversion technologies to produce biofuels. There are two general types of TEAs: A design case outlines a target case (future projection) for a particular biofuel pathway. It enables identification of data gaps and research and development needs and provides goals and benchmarks against which technology progress is assessed. A state of technology (SOT) analysis assesses progress within and across relevant technology areas based on actual results at current experimental scales relative to technical targets and cost goals from design cases, and includes technical, economic, and environmental criteria as available. In addition to developing a TEA for a pathway of interest, BETO also performs a supply chain sustainability analysis (SCSA). The SCSA takes the life-cycle analysis approach that BETO has been supporting for about 20 years. It enables BETO to identify energy consumption, environmental, and sustainability issues that may be associated with biofuel production. Approaches to mitigate these issues can then be developed. Additionally, the SCSA allows for comparison of energy and environmental impacts across biofuel pathways in BETO’s research and development portfolio. This technical report describes the SCSAs for the production of renewable hydrocarbon transportation fuels via a range of conversion technologies in the 2020 SOTs: (1) renewable high octane gasoline (HOG) via indirect liquefaction (IDL) of woody lignocellulosic biomass (note that the IDL pathway in this SCSA represents the syngas conversion design [Harris et al. 2021]); (2) renewable gasoline (RG) and diesel (RD) blendstocks via ex situ catalytic fast pyrolysis of woody lignocellulosic biomass [Abhijit et al. 2021]; (3) RD via hydrothermal liquefaction (HTL) of wet sludge from a wastewater treatment plant; (4) renewable hydrocarbon fuels via biochemical conversion of herbaceous lignocellulosic biomass (Davis et al. 2021; Lin et al. 2021); (5) renewable diesel via HTL of a blend of algae (Davis and Klein, 2021) and woody biomass (Hartley et al. 2020); and (6) renewable diesel via combined algae processing (CAP) (Wiatrowski and Davis, 2021). This technical report focuses on the environmental performance of these six biofuel production pathways in their 2020 SOT cases. The results of these renewable hydrocarbon fuel pathways in these SCSA analyses update those for the respective 2019 SOT cases (Cai et al. 2020). They also provide an opportunity to examine the impact of technology improvements in both biomass feedstock production and biofuel production that have been achieved in 2020 SOTs on the sustainability performance of these renewable transportation fuels. The SCSA results also reflect updates to Argonne National Laboratory’s Greenhouse gases, Regulated Emissions, and Energy use in Technologies (GREET®) model, which was released in October 2020 (Wang et al. 2020). These GREET updates include the production of natural gas, electricity, and petroleum-based fuels that can influence biofuels’ supply chain greenhouse gas (GHG) (CO 2 , CH 4 , and N 2 O) emissions, water consumption, and air pollutant emissions. GHG emissions, water consumption, and nitrogen oxides (NO x ) emissions are the main sustainability metrics assessed in this analysis. In this analysis, we define water consumption as the amount of water withdrawn from a freshwater source that is not returned (or returnable) to a freshwater source at the same level of quality. Life-cycle fossil energy consumption and net energy balance, which is the life-cycle fossil energy consumption deducted from the renewable biofuel energy produced, are also assessed.

09 BIOMASS FUELS↗

Hydropower: Supply Chain Deep Dive Assessment

This report examines the hydropower supply chain to identify potential bottlenecks, challenges, and opportunities, particularly if the U.S. demand for hydropower components grows significantly to meet decarbonization targets. It is part of a series of DOE reports directed by Executive Order 14017 "America's Supply Chains"

13 HYDRO ENERGY↗