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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 217 records · Page 12
All sourcesNASA NTRSDOE OSTI
DOE OSTI2018

Determining 235 U enrichment in bulk uranium items using dual-energy interrogation with delayed neutron measurement

Bulk uranium items are often measured using active neutron interrogation systems to take advantage of the relatively high penetrability of neutrons, providing the ability to measure uranium mass in large, dense configurations. Because the emitted neutrons from 235 U and 238 U in such configurations are, for all practical purposes, indistinguishable, established active measurement techniques require many representative calibration standards and/or well-known isotopic information to interpret the assay results (i.e., extract an isotopic mass from the effective mass). Here, the primary objective of this work is to investigate the ability of a dual-energy neutron interrogation technique to estimate uranium enrichment for bulk materials, which has the potential to eliminate the need for a (traditionally separate) gamma isotopic measurement. Dual neutron interrogation energies were achieved by adding a deuterium–tritium (D–T) neutron generator into the measurement chamber of the Oak Ridge National Laboratory 252 Cf Shuffler. This new technique exploits the change in fission rates as a function of interrogating neutron energy to independently determine the 235 U and 238 U content in the measurement item. Results from traditional 252 Cf measurements and the new D–T measurements were then used to develop a relationship between uranium enrichment and the ratio of the two delayed neutron count rates. Lastly, technical feasibility is successfully demonstrated using the modified 252 Cf Shuffler as a test bed, although several areas where refinements are both possible and needed before DEANI can be deployed as an analytical tool to meet specific measurement goals are identified.

252cf shuffler↗
DOE OSTI2021

The effects of low- Z shielding on uranium isotope discrimination using the time-emission profiles of long-lived delayed neutrons

Characteristic radiation signals can often be obscured or distorted by relatively small amounts of shielding, as is the case for highly-enriched uranium (HEU). Methods that can detect and identify special nuclear material (SNM) even in the presence of shielding are therefore of high value in many nuclear security and nonproliferation applications. It has been previously shown that the buildup and decay time profiles of long-lived delayed neutron emission from induced fission are unique and can be used to successfully discriminate between uranium isotopes and infer enrichment without the need for a calibration standard. Because the long-lived delayed neutron precursors exhibit decay times on the order of tens of seconds, their time profiles are not sensitive to the delays associated with scattering or diffusion in shielding materials, which occur on much shorter time scales. The use of capture-based neutron detectors can also mitigate the effects of shielding, because unlike recoil-based detectors, they do not have a low-energy detection threshold, so that neutrons that lose their energy in the shielding are still detectable. In this work, the effects of low-Z shielding on the discrimination of uranium isotopes using delayed neutron time profile measurements are investigated for the first time. Furthermore, the delayed neutron buildup and decay time profiles of polyethylene-shielded HEU and depleted uranium objects are measured using two different capture-gated detector designs. The recorded profiles show good agreement with the shapes predicted from six-group delayed neutron models even with the shielding in place, and the enrichment of the HEU and DU objects was estimated accurately to within 5%. While this method shows potential for discriminating and characterizing extreme cases of enrichment when a moderate amount of shielding is present, simulation results suggest that significant limitations exist for intermediate enrichment levels due to distortions to the delayed neutron time profile caused by neutron reflection in the shielding.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2021

Practical considerations for amino acid isotope analysis

Over the last few decades, isotopic analysis of amino acids at the compound- and position-specific levels has been rapidly advancing across diverse fields. As these techniques progress, evaluation of isotopic fractionation associated with sample workup is essential. This critical review of analytical methods through the lens of isotope geochemistry provides a benchmark for researchers across disciplines seeking to make compound- and position-specific amino acid isotope measurements. We focus on preparation, acid hydrolysis, clean-up, derivatization, separation, and C, H, N, and S isotope measurement. Despite substantial customizability across these steps, the following general recommendations should maximize recovery while minimizing isotopic fractionation. Samples should be freeze-dried and stored anoxically at ≤ –20 °C prior to conventional acid hydrolysis (6N HCl, 110 °C, 20–24 h, anoxic), which suffices for many residues. Both gas and liquid chromatographic (GC and LC, respectively) techniques are well-established and separate about 15 amino acids; LC bypasses the need for derivatization, while GC provides higher sensitivity. Furthermore, when derivatization is needed, n-acetyl and alkoxycarbonyl esters provide the most reproducible C isotope ratios. For compound-specific analyses, online GC–IRMS and LC–IRMS systems offer the easiest workflow, but EA–IRMS enables potential multi-element isotope analysis. Emerging techniques like high-resolution mass spectrometry are also promising for multi-element analysis and recover position-specific isotopic information. Looking forward to the next decade of innovation, isotope geochemists and ecologists can improve amino acid isotope analysis by focusing on streamlining multi-element analysis and standardizing calibration practices across laboratories.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2015

Femtosecond filament-laser ablation molecular isotopic spectrometry

A new remote sensing technology for real-time isotopic analysis is introduced: Femtosecond Filament-Induced Laser Ablation Molecular Isotopic Spectrometry (F 2 -LAMIS). The technique combines femtosecond (fs) laser filamentation and ablation-based molecular isotopic spectroscopy, thereby enabling isotopic analysis of samples at a distance, in ambient air and at ambient pressure conditions. Isotopic analysis of zirconium (Zr) samples by F 2 -LAMIS is demonstrated, and the molecular and atomic emission intensity, and properties of the filament-induced plasma generated at different filament propagation distances were investigated. Spectral fitting of F 2 -LAMIS spectra enabled semi-quantitative isotopic analysis without the use of calibration standards, which was independent of the filament propagation distance for the studied range. As a result, this technology provides new capabilities for direct isotopic ratio measurements at remote distances.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2021

Remote isotope detection and quantification using femtosecond filament-laser ablation molecular isotopic spectrometry

We demonstrate the detection and quantification of isotopes from solid samples remotely at a distance of 36 m. This was accomplished through the combination of femtosecond filaments and laser ablation molecular isotopic spectrometry (F 2 -LAMIS). Isotopically enriched graphite samples with varying 13 C concentration were used and the F 2 -LAMIS emission was measured remotely using a portable spectrometer system. A standardless quantification approach was used to determine the corresponding isotopic ratios. The use of F 2 -LAMIS for the detection and quantification of isotopes at atmospheric pressure without the use of calibration standards opens the possibility to implement this technology for remote sensing of isotopes in field applications

07 ISOTOPE AND RADIATION SOURCES↗
DOE OSTI2023

Quantifying uncertainty in analysis of shockless dynamic compression experiments on platinum. I. Inverse Lagrangian analysis

Absolute measurements of solid-material compressibility by magnetically driven shockless dynamic compression experiments to multi-megabar pressures have the potential to greatly improve the accuracy and precision of pressure calibration standards for use in diamond anvil cell experiments. Here, to this end, we apply characteristics-based inverse Lagrangian analysis (ILA) to 11 sets of ramp-compression data on pure platinum (Pt) metal and then reduce the resulting weighted-mean stress–strain curve to the principal isentrope and room-temperature isotherm using simple models for yield stress and Grüneisen parameter. We introduce several improvements to methods for ILA and quasi-isentrope reduction, the latter including calculation of corrections in wave speed instead of stress and pressure to render results largely independent of initial yield stress while enforcing thermodynamic consistency near zero pressure. More importantly, we quantify in detail the propagation of experimental uncertainty through ILA and model uncertainty through quasi-isentrope reduction, considering all potential sources of error except the electrode and window material models used in ILA. Compared to previous approaches, we find larger uncertainty in longitudinal stress. Monte Carlo analysis demonstrates that uncertainty in the yield-stress model constitutes by far the largest contribution to uncertainty in quasi-isentrope reduction corrections. We present a new room-temperature isotherm for Pt up to 444 GPa, with 1-sigma uncertainty at that pressure of just under ±1.2%; the latter is about a factor of three smaller than uncertainty previously reported for multi-megabar ramp-compression experiments on Pt. The result is well represented by a Vinet-form compression curve with (isothermal) bulk modulus K 0 = 270.3 ± 3.8 GPa, pressure derivative K$^{'}_{0}$= 5.66 ± 0.10, and correlation coefficient $R_{K_{0},K^{'}_{0}}$= –0.843.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2021

Determination of Seven Organic Impurities in FD&C Yellow No. 6 by Ultra-High-Performance Liquid Chromatography

The U.S. Food and Drug Administration (FDA) batch certifies FD&C Yellow No. 6 (Y6) to ensure that the color additive meets requirements published in the Code of Federal Regulations (CFR), including specifications for seven organic manufacturing impurities consisting of two intermediates, a reaction by-product, an impurity originating from an intermediate, and three subsidiary colors. An ultra-high-performance liquid chromatography (UHPLC) method was developed and validated for determining seven organic impurities in Y6. For comparison, the currently used high-performance liquid chromatography (HPLC) method was also validated. The new UHPLC method uses a 1.7 µm particle size biphenyl column with aqueous ammonium formate and methanol as eluants. Analytes are identified by comparing their retention times and UV-visible spectra to those of reference standards. Calibration is performed in the presence of the dye matrix and analyte levels are determined from their peak areas. UHPLC and HPLC validation studies obtained linear calibration curves and excellent values for limits of detection, limits of quantitation, recovery, repeatability, and intermediate precision for all analytes. Survey analyses of 30 samples using the UHPLC and HPLC methods yielded results that were consistent within experimental error; however, the UHPLC method provided more accurate results for two analytes that coelute using the HPLC method. The UHPLC method satisfies the accuracy and precision requisites for routine certification of Y6. The UHPLC method is faster and generates less waste than the HPLC method while delivering better sensitivity, separation, and accuracy.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2021

On asymmetric dark matter constraints from the asteroseismology of a subgiant star

ABSTRACT The asteroseismic modelling of solar-like stars has proved to be valuable in constraining dark matter. In this work, we study for the first time the influence of asymmetric dark matter (ADM) in the evolution of a subgiant star (KIC 8228742) by direct comparison with observational data. Both spectroscopic and seismic data are analysed with a new approach to the stellar calibration method, in which DM properties can also be considered as free inputs. In another phase of this study, a calibrated standard stellar model (without DM) is used as the benchmark for DM models. We find that the latter models consistently outperform the former for 10−40 ≤ σSD < 10−38 cm2, hinting that the presence of ADM in stars of this type does not go against observations. Moreover, we show that stellar seismology allows us to suggest exclusion limits that complement the constraints set by direct detection experiments. Different seismic observables are proposed to study DM properties and ΔΠℓ is found to be the most reliable, having the potential to build future DM exclusion diagrams. This new methodology can be a powerful tool in the analysis of the data coming from the next generation of asteroseismic missions.

Rato, João (ORCID:0000000320802361)↗
DOE OSTI2018

Discriminating Uranium Isotopes Using the Time-Emission Profiles of Long-Lived Delayed Neutrons

In nuclear nonproliferation and safeguards, detecting and accurately characterizing special nuclear material remains one of the greatest challenges. Uranium enrichment determination is typically achieved by measuring the ratio of characteristic γ -ray emissions from 235 U and 238 U. Fission also produces β -delayed neutrons, which have been used in the past to determine uranium enrichment from the time dependence of the long-lived delayed-neutron emission rate. Such measurements typically use moderated 3 He-tube detectors. We demonstrate an alternative measurement technique that employs a fast neutron active-interrogation probe and a scintillation detector to measure the enrichment of uranium using both the buildup and decay of β -delayed-neutron emission. Instead of 3 He tubes, a capture-based heterogeneous composite detector consisting of scintillating Li glass and polyvinyl toluene is constructed and used, offering a prospect to scale delayed-neutron measurements to larger detector sizes. Since the technique relies on the existing tabulated nuclear data, no calibration standards are required. It is shown that the buildup of delayed-neutron emission can be used to distinguish between uranium samples and infer the uranium enrichment level, with accuracy that rivals the method that employs the time-dependent decay of delayed-neutron emission.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2024

Transition width of the of the $J$ $π$ = $1$ – two-phonon state of $88$ $Sr$

The ground-state decay width of the two-phonon $J$ $π$ = $1$ – , 4742 keV state of 88 Sr has been determined with the relative self-absorption method combined with a monoenergetic photon beam. This width is important to determine the decay transition strengths into the ground state and the one-phonon $2$$^{+}_{1}$ and $3$$^{–}_{1}$ levels which are required to verify the two-phonon character of the $J$ $π$ = $1$ – state. Here, the experiment was performed at the High Intensity γ-ray Source (HI⁢ γ⁢S) using a novel experimental approach to adapt the relative self-absorption method to monoenergetic photon beams. The result for the ground-state decay width is, thus, independent of any calibration standard and confirms the two-phonon character of the 88 Sr, $J$ $π$ = $1$ – , 4742 keV state within an improved uncertainty.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2015

Carbon and sulfur isotopic signatures of ancient life and environment at the microbial scale: Neoarchean shales and carbonates

An approach to coordinated, spatially resolved, in situ carbon isotope analysis of organic matter and carbonate minerals, and sulfur three- and four-isotope analysis of pyrite with an unprecedented combination of spatial resolution, precision, and accuracy is described. Organic matter and pyrite from eleven rock samples of Neoarchean drill core express nearly the entire range of δ 13 C, δ 34 S, Δ 33 S, and Δ 36 S known from the geologic record, commonly in correlation with morphology, mineralogy, and elemental composition. A new analytical approach (including a set of organic calibration standards) to account for a strong correlation between H/C and instrumental bias in SIMS δ 13 C measurement of organic matter is identified. Small (2–3 μm) organic domains in carbonate matrices are analyzed with sub-permil accuracy and precision. Separate 20- to 50-μm domains of kerogen in a single ~0.5 cm3 sample of the ~2.7 Ga Tumbiana Formation have δ 13 C = -52.3 ± 0.1‰ and -34.4 ± 0.1‰, likely preserving distinct signatures of methanotrophy and photoautotrophy. Pyrobitumen in the ~2.6 Ga Jeerinah Formation and the ~2.5 Ga Mount McRae Shale is systematically 13 C-enriched relative to co-occurring kerogen, and associations with uraniferous mineral grains suggest radiolytic alteration. A large range in sulfur isotopic compositions (including higher Δ 33 S and more extreme spatial gradients in Δ 33 S and Δ 36 S than any previously reported) are observed in correlation with morphology and associated mineralogy. Changing systematics of δ 34 S, Δ 33 S, and Δ 36 S, previously investigated at the millimeter to centimeter scale using bulk analysis, are shown to occur at the micrometer scale of individual pyrite grains. These results support the emerging view that the dampened signature of mass-independent sulfur isotope fractionation (S-MIF) associated with the Mesoarchean continued into the early Neoarchean, and that the connections between methane and sulfur metabolism affected the production and preservation of S-MIF during the first half of the planet's history.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2014

Jointly Sponsored Research Program on Energy Related Research

Cooperative Agreements, DE-FC26-08NT43293, DOE-WRI Cooperative Research and Development Program for Fossil Energy-Related Resources began in June 2009. The goal of the Program was to develop, commercialize, and deploy technologies of value to the nation’s fossil and renewable energy industries. To ensure relevancy and early commercialization, the involvement of an industrial partner was encouraged. In that regard, the Program stipulated that a minimum of 20% cost share be achieved in a fiscal year. This allowed WRI to carry a diverse portfolio of technologies and projects at various development technology readiness levels. Depending upon the maturity of the research concept and technology, cost share for a given task ranged from none to as high as 67% (two-thirds). Over the course of the Program, a total of twenty six tasks were proposed for DOE approval. Over the period of performance of the Cooperative agreement, WRI has put in place projects utilizing a total of $\$$7,089,581 in USDOE funds. Against this funding, cosponsors have committed $\$$7,398,476 in private funds to produce a program valued at $\$$14,488,057. Tables 1 and 2 presented at the end of this section is a compilation of the funding for all the tasks conducted under the program. The goal of the Cooperative Research and Development Program for Fossil Energy-Related Resources was to through collaborative research with the industry, develop or assist in the development of innovative technology solutions that will: • Increase the production of United States energy resources – coal, natural gas, oil, and renewable energy resources; • Enhance the competitiveness of United States energy technologies in international markets and assist in technology transfer; • Reduce the nation's dependence on foreign energy supplies and strengthen both the United States and regional economies; and • Minimize environmental impacts of energy production and utilization. Success of the Program can be measured by several criteria. Using the deployment of the federal funding with industrial participation as a performance criterion, over the course of the program, the cosponsors contributed more dollars than the federal funds. As stated earlier, a little more than half of the funding for the Program was derived from industrial partners. The industrial partners also enthusiastically supported the research and development activities with cash contribution of $\$$4,710,372.67, nearly 65% of the required cost share. Work on all of the tasks proposed under the Cooperative Agreement has been completed. This report summarizes and highlights the results from the Program. Under the Cooperative Agreement Program, energy-related tasks emphasized petroleum processing, upgrading and characterization, coal and biomass beneficiation and upgrading, coal combustion systems development including oxy-combustion, emissions monitoring and abatement, coal gasification technologies including gas clean-up and conditioning, hydrogen and liquid fuels production, and the development of technologies for the utilization of renewable energy resources. Environmental-related activities emphasized cleaning contaminated soils using microbial fuel cells, development of processes and sorbents for emissions reduction and recovery of water from power plant flue gas, and biological carbon capture and reuse. Technology enhancement activities included resource characterization studies, development of improved methods, monitors and sensors. In general the goals of the tasks proposed were to enhance competitiveness of U.S. technology, increase production of domestic resources, and reduce environmental impacts associated with energy production and utilization. Technologies being brought to commercialization as a result of the funds provided by the Cooperative Agreement contribute to the overall goals of the USDOE and the nation. Each has broad applicability both within the United States and abroad, thereby helping to enhance the competitiveness of U.S. energy technologies in international markets and assisting in technology transfer. Under the Cooperative Agreement Program, WRI has furthered the development of two different coal upgrading technologies. River Basin Energy technology was scaled-up and demonstrated at a nominal 40 tpd size. Similarly, WRI’s patented mercury removal technology further developed into WRITE Coal technology which was then integrated into oxy-combustion and gasification systems for IGCC and fuels production. Integrated systems with WRITE Coal technology applied at the front end represent substantial environmental and efficiency gains. A variation of the RBE coal upgrading technology is being commercialized as a torrefaction technology for woody biomass. WRI worked with EPRI and NIST to develop and improve mercury calibration standards for emissions monitoring. Working with Chart Energy and Chemicals, WRI scaled-up compact reactor technology for the synthesis of fuels and chemicals from syngas. Compact reactor technology represents a five-fold increase in productivity over conventional reactors making smaller-scale distributed synthesis plants an economical viability. Similarly, WRI's patented mixed alcohol synthesis catalyst production is being scaled-up in collaboration with a commercial catalyst manufacturer.

99 GENERAL AND MISCELLANEOUS↗
DOE OSTI2016

Spectrophotometers for plutonium monitoring in HB-line

This report describes the equipment, control software, calibrations for total plutonium and plutonium oxidation state, and qualification studies for the instrument. It also provides a detailed description of the uncertainty analysis, which includes source terms associated with plutonium calibration standards, instrument drift, and inter-instrument variability. Also included are work instructions for instrument, flow cell, and optical fiber setup, work instructions for routine maintenance, and drawings and schematic diagrams.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2019

SESAME 2985: A new molybdenum equation of state table

Molybdenum is a body centered-cubic metal with a variety of high technology applications due to it’s thermal, mechanical, and chemical stability. In high pressure research, it is used as a calibration standard in diamond anvil cell (DAC) measurements. Many theoretical and experimental studies have been performed to study the Mo equation of state (EOS) to high pressure.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Workshop on Improving Holdup Monitoring in the US

The characterization and quantification of nuclear deposits, or residual nuclear material retained in process equipment, generally referred to as holdup, continues to challenge nuclear processing facilities in DOE program areas such as nuclear criticality safety, material control and accountability, environmental management. The efficiency and effectiveness of nuclear operations in these facilities depends heavily on the results from nondestructive techniques designed to measure nuclear materials in situ. The traditional methods used to measure holdup were established more than 30 years ago and assume unrealistic conditions for most measurement cases. These blind, in situ measurements present unique challenges due to the following attributes: unique, non-ideal geometries; unknown deposit thicknesses; lack of representative calibration standards; large number of holdup deposit locations; and poor accessibility for many measurement locations. These difficulties and the poor assumptions made to handle them have resulted in measurement uncertainties that are often too large for many programs to effectively utilize. In an effort to address and identify solutions to the current holdup challenges facing the US nuclear industry, Oak Ridge National Laboratory hosted the Technical Workshop on Improving Holdup Monitoring in the US. The two-day workshop held August 21–22, 2019, was attended by 35 holdup measurement practitioners, program managers, stakeholders from US Department of Energy sites, the Nuclear Regulatory Commission, and representatives from commercial industry. The primary objectives were to identify critical elements of a successful and defensible holdup measurement program; identify technical challenges, needs, and potential improvements associated with measurement of holdup; and share best practices and lessons learned from recent accumulation events. Fourteen presentations were delivered on holdup topics including necessary elements for effective program management, measurement needs, emerging technologies and other measurement solutions, and lessons learned from recent events. These presentations highlighted best practices related to accumulation monitoring, considerations and proactive steps to facilitate holdup in new facility designs, imaging solutions to improve holdup assumptions, and new software developed in support of holdup measurements. Breakout sessions were also employed to determine additional needs and identify potential solutions to common holdup challenges. The primary discussions focused on causes and prevention of material accumulations, needs for uranium and plutonium measurements, and reduction of measurement uncertainty, all of which were explicitly identified as critical needs during the 2018 Workshop on Technical and Programmatic Needs for a Sustainable NDA Program for the US DOE.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2021

Cold Testing for Characterization of Oxide Feed Impurities in Support of the ARIES Program

The Advanced Recovery and Integrated Extraction System (ARIES) Program converts surplus plutonium metal components into an oxide powder form and packages the material for final disposition. In support of the ARIES program, over a metric ton (MT) of plutonium has been removed from surplus nuclear weapons since 1998 and packaged for long-term storage in 3013 cans. The oxide production rate is anticipated to increase substantially over the next decade in support of dilute and dispose goals. Analytical chemistry data from destructive analysis of the resulting 70+ blend lots to date has been reported for contaminants in the product oxide. Changes in the Pu product specification for Pu oxide product, induced by a different pit mix, the LANL swap program and processing Alternate (non-Pit Pu) Feed Stock (AFS) metals, will affect the level and the mix of these contaminants in the upcoming years. With these changes in feed material, it will be important to provide fast and efficient measurement of elemental impurities in the oxide to be certain that the process is under control and to monitor the anticipated changes from the historical blend lot data. Non-destructive methods need to be evaluated for the characterization of the plutonium oxide product and the quantification of the impurities at the current and anticipated levels. A feasibility study has begun to investigate the applicability of new spectroscopic methods for oxide impurity characterization. To this end, here we describe the preparation of surrogate materials to support these investigations, and the results of a feasibility study investigating the use of LIBS (Laser Induced Breakdown Spectroscopy) to characterize the surrogate materials as calibration standards.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗