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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 235 records · Page 13
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

The Impact of Increased Requirements for Verification Measurements of Category III and IV Receipts

As part of the regular nuclear material accounting and control process, sites that have accountable nuclear material regularly perform measurements of the material in their possession. The expectation for the type of measurements and their frequency is set out in Department of Energy (DOE) Order 474.2, and further detailed in each site’s respective material control and accountability (MC&A) plan and associated controlling documents. The measurements of interest in this report are those performed on external (between DOE sites) transfer receipts of Category III or IV accountable materials. In 2020, a revision of DOE Order 474.2 was proposed that would significantly increase the requirement that measurements be performed upon receipt of material, and further, that those measurements be quantitative verification (rather than qualitative confirmatory) measurements. A survey was performed of DOE sites to discuss the impact on their MC&A measurements program if more rigorous verification measurements requirements for Category III and IV receipts were implemented. An assessment of nondestructive assay (NDA) measurement instruments to meet those needs was also performed. Across the board, sites indicated that personnel and budget would cause the largest impact. Sites which are qualified as Category I/II indicated a reduced impact as these sites already have the measurement capabilities and some personnel but would require the acquisition of additional measurement systems. Category III/IV sites indicated a much larger impact as these sites generally have smaller MC&A programs. A few smaller sites stated a measurement program would need to be created to handle the demand. Calorimetry, quantitative gamma spectroscopy and neutron coincidence counting systems were identified as common systems that could meet the verification measurement requirements. The other, and perhaps larger issue is the need for calibration standards for the calorimetry and neutron coincidence counting systems. It is proposed that a comparative study be performed for ISOCS and ISOTOPICS, qualification of a COTS calorimetry system be performed, and development of an AWCC system that uses a neutron generator.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗
DOE OSTI2023

Outline for Feasibility Study on a Nuclear Material Accounting and Control System for Measurement of High-Activity Waste at Tokai Reprocessing Plant during Decommissioning

The objective of this collaboration between the DOE/NNSA International Nuclear Security Program (INS) and JAEA is to conduct a feasibility study on nuclear material accounting and control needs and requirements for NDA measurement of high-activity waste at TRP during the decommissioning process. Under this study, both sides will exchange information, perform an assessment of needs and requirements, and develop joint recommendations for development of the A-HMMS.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗
DOE OSTI2023

Automated Fissile Mass Estimation Python Script for the Advanced Experimental Fuel Counter (AEFC)

The Advanced Experimental Fuel Counter (AEFC) is a non-destructive assay (NDA) instrument developed to quantify the residual fissile mass in research reactor spent fuel assemblies. The system is installed in a spent fuel pool and measurements are acquired underwater. A calibration curve relates the totals and coincidence counting signal from active interrogation of the spent fuel assemblies to the fissile mass remaining in the fuel.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2024

Milestone 49 Report: Batched Sparse LA Phase 5 Implementation

Batched sparse linear algebra operations in general, and solvers in particular, have become the major algorithmic development activity and foremost performance engineering effort in the numerical software libraries work on modern hardware with accelerators such as GPUs. Many applications, ECP and non-ECP alike, require simultaneous solutions of many small linear systems of equations that are structurally sparse in one form or another. In order to move towards high hardware utilization levels, it is important to provide these applications with appropriate interface designs to be both functionally efficient and performance portable and give full access to the appropriate batched sparse solvers running on modern hardware accelerators prevalent across DOE supercomputing sites since the inception of ECP. To this end, we present here a summary of recent advances on the interface designs in use by HPC software libraries supporting batched sparse linear algebra and the development of sparse batched kernel codes for solvers and preconditioners. We also address the potential interoperability opportunities to keep the corresponding software portable between the major hardware accelerators from AMD, Intel, and NVIDIA, while maintaining the appropriate disclosure levels conforming to the active NDA agreements. The presented interface specifications include a mix of batched band, sparse iterative, and sparse direct solvers with their accompanying functionality that is already required by the application codes or we anticipated to be needed in the near future. This report summarizes progress in Kokkos Kernels and the xSDK libraries MAGMA, Ginkgo, hypre, PETSc, and SuperLU.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2024

IBR Black Model Lessons Learned (C45)

Blackbox modelling for SC analysis is a possible solution. Accuracy can be acceptable even without having vendor control diagrams. Blackbox modelling is not as user friendly as a generic model. Is an NDA required to share a vendor Blackbox model for SC analysis? Difference in VRT detection and injection logics. Angle rotation is not addressed. Current limitation logic during unbalanced faults is not clear.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2024

Model of Inverter-Based Resources

Blackbox modelling for SC analysis is a possible solution. Accuracy can be acceptable even without having vendor control diagrams. Is an NDA required to share a vendor Blackbox model for SC analysis? Differences in VRT detection and injection logics. Angle rotation is not addressed in control logics of most vendors. Current limitation logic during unbalanced faults is not clear. Model IBR as a current source with shunt to improve convergence

IBRs, Model of IBRs, Short Circuit Analysis, Class↗
DOE OSTI2016

A DECAMETER STATIONARY TYPE IV BURST IN IMAGING OBSERVATIONS ON 2014 SEPTEMBER 6

First-of-its-kind radio imaging of a decameter solar stationary type IV radio burst has been presented in this paper. On 2014 September 6 the observations of type IV burst radio emission were carried out with the two-dimensional heliograph based on the Ukrainian T-shaped radio telescope (UTR-2), together with other telescope arrays. Starting at ∼09:55 UT and for ∼3 hr, the radio emission was kept within the observational session of UTR-2. The interesting observation covered the full evolution of this burst, “from birth to death.” During the event lifetime, two C-class solar X-ray flares with peak times 11:29 UT and 12:24 UT took place. The time profile of this burst in radio has a double-humped shape that can be explained by injection of energetic electrons, accelerated by the two flares, into the burst source. According to the heliographic observations, we suggest that the burst source was confined within a high coronal loop, which was part of a relatively slow coronal mass ejection. The latter has been developed for several hours before the onset of the event. Through analysis of about 1.5 × 10{sup 6} heliograms (3700 temporal frames with 4096 images in each frame that correspond to the number of frequency channels), the radio burst source imaging shows a fascinating dynamical evolution. Both space-based ( GOES , SDO , SOHO , STEREO ) data and various ground-based instrumentation (ORFEES, NDA, RSTO, NRH) records have been used for this study.

79 ASTRONOMY AND ASTROPHYSICS↗
NASA NTRS1993

Asynchronous timing and Doppler recovery in DSP based DPSK modems for fixed and mobile satellite applications

While conventional analog modems employ some kind of clock wave regenerator circuit for synchronous timing recovery, in sampled modem receivers the timing is recovered asynchronously to the incoming data stream, with no adjustment being made to the input sampling rate. All timing corrections are accomplished by digital operations on the sampled data stream, and timing recovery is asynchronous with the uncontrolled, input A/D system. A good timing error measurement algorithm is a zero crossing tracker proposed by Gardner. Digital, speech rate (2400 - 4800 bps) M-PSK modem receivers employing Gardner's zero crossing tracker were implemented and tested and found to achieve BER performance very close to theoretical values on the AWGN channel. Nyguist pulse shaped modem systems with excess bandwidth factors ranging from 100 to 60 percent were considered. We can show that for any symmetric M-PSK signal set Gardner's NDA algorithm is free of pattern jitter for any carrier phase offset for rectangular pulses and for Nyquist pulses having 100 percent excess bandwidth. Also, the Nyquist pulse shaped system is studied on the mobile satellite channel, where Doppler shifts and multipath fading degrade the pi/4-DQPSK signal. Two simple modifications to Gardner's zero crossing tracker enable it to remain useful in the presence of multipath fading.

Koblents, B.↗
NASA NTRS1994

The Effects of Compressive Preloads on the Compression-After-Impact Strength of Carbon/Epoxy

A fixture to apply compressive loads to composite specimens during an impact event was used to assess the effect of prestresses on the compression-after-impact (CAI) strength of 16 ply quasi-isotropic carbon/epoxy test coupons. Advanced design of experiments techniques were used to evaluate a range of prestresses and impact energies on two material systems, T300/934 and IM7/8551-7. An instrumented drop tower supplied impact energies between 1 and 9 Joules for the T300/934 material and between 4 and 16 Joules for the IM7/8551-7 material. The prestress values varied between a low of 5.7 Wa and a high of 287 NDa. Results showed some change in CAI strength that could be attributed to the prestresses on the specimens.

Nettles, Alan T.↗
NASA NTRS2000

General Aviation in Nebraska: Nebraska SATS Project Background Paper No. 1

The Nebraska SATS project is a state-level component of NASA's Small Aircraft Transportation System (SATS). During the next several years the project will examine several different factors affecting SATS implementation in Nebraska. These include economic and taxation issues, public policy issues, airport planning processes, information dissemination strategies, and systemic change factors. This background paper profiles the general aviation system in Nebraska. It is written to provide information about the "context" within which SATS will be pursued. The primary focus is thus on describing and providing background information about the current situation. A secondary focus is on drawing general conclusions about the ability of the current system to incorporate the types of changes implied by SATS. First, some brief information on the U.S. aviation system is provided. The next two sections profile the current general aviation aircraft and pilot base. Nebraska's system of general aviation airports is then described. Within this section of the paper, information is provided on the different types of general aviation airports in Nebraska, airport activity levels and current infrastructure. The fourth major section of the background paper looks at Nebraska's local airport authorities. These special purpose local governments oversee the majority of the general aviation airports in the state. Among the items examined are total expenditures, capital expenditures and planning activities. Next, the paper provides background information on the Nebraska Department of Aeronautics (NDA) and recent Federal funding for general aviation in Nebraska. The final section presents summary conclusions.

Smith, Russell↗
NASA NTRS2015

Reliability on ISS Talk Outline

1. Overview of ISS 2. Space Environment and it effects a. Radiation b. Microgravity 3. How we ensure reliability a. Requirements b. Component Selection i. Note: I plan to stay away from talk about Rad Hardened components and talk about why we use older processors because they are less susceptible to SEUs. c. Testing d. Redundancy / Failure Tolerance e. Sparing strategies 4. Operational Examples a. Multiple MDM Failures on 6A due to hard drive failure In general, my plan is to only talk about data that is currently available via normal internet sources to ensure that I stay away from any topics that would be Export Controlled, ITAR, or NDA‐controlled. The operational example has been well‐reported on in the media and those are the details that I plan to cover. Additionally I am not planning on using any slides or showing any photos during the talk.

Misiora, Mike↗
DOE OSTI2014

Adsorptive Films in Support of In-field UF6 Destructive Assay Sample Collection and Analysis

International Atom Energy Agency (IAEA) safeguard verification measures in gaseous centrifuge enrichment plants (GCEPs) rely on environmental sampling, non-destructive assay (NDA), and destructive assay (DA) sampling and analysis to determine uranium enrichment. UF6 bias defect measurements are made by DA sampling and analysis to assure that enrichment is consistent with declarations. DA samples are collected from a limited number of cylinders for high precision, offsite mass spectrometer analysis. Samples are typically drawn from a sampling tap into a UF6 sample bottle, then packaged, sealed, and shipped under IAEA chain of custody to an offsite analytical laboratory. Future DA safeguard measures may require improvements in efficiency and effectiveness as GCEP capacities increase and UF6 shipping regulations become increasingly more restrictive. The Pacific Northwest National Laboratory (PNNL) DA sampler concept and Laser Ablation Absorption Ratio Spectrometry (LAARS) assay method are under development to potentially provide DA safeguard tools that increase inspection effectiveness and reduce sample shipping constraints. The PNNL DA sampler concept uses a handheld sampler to collect DA samples for either onsite LAARS assay or offsite laboratory analysis. The DA sampler design will use a small sampling planchet that is coated with an adsorptive film to collect controlled quantities of UF6 gas directly from a cylinder or process sampling tap. Development efforts are currently underway at PNNL to enhance LAARS assay performance to allow high-precision onsite bias defect measurements. In this paper, we report on the experimental investigation to develop adsorptive films for the PNNL DA sampler concept. These films are intended to efficiently capture UF6 and then stabilize the collected DA sample prior to onsite LAARS or offsite laboratory analysis. Several porous material composite films were investigated, including a film designed to maximize the chemical adsorption and binding of gaseous UF6 onto the sampling planchet.

destructive assay↗
DOE OSTI2014

An Unattended Verification Station for UF6 Cylinders: Implementation Concepts and Development Status

In recent years, the International Atomic Energy Agency (IAEA) has pursued innovative techniques and an integrated suite of safeguards measures to address the verification challenges posed by advanced centrifuge technologies and the growth in separative work unit capacity at modern centrifuge enrichment plants. These measures would include permanently installed, unattended instruments capable of performing the routine and repetitive measurements previously performed by inspectors. Among the unattended instruments currently being explored by the IAEA is an Unattended Cylinder Verification Stations (UCVS) that could provide independent verification of the declared relative enrichment, 235U mass and total uranium mass of 100% of the declared cylinders moving through the plant, as well as the application and verification of an ‘Non-destructive Assay Fingerprint’ to preserve verification knowledge on the contents of each cylinder throughout its life in the facility. As the IAEA’s vision for a UCVS has evolved, Pacific Northwest National Laboratory (PNNL) and Los Alamos National Laboratory (LANL) have been developing and testing candidate nondestructive assay (NDA) methods for inclusion in a UCVS. Modeling and multiple field campaigns have indicated that these methods are capable of assaying relative cylinder enrichment with a precision comparable to or perhaps better than today’s high-resolution handheld devices, without the need for manual wall-thickness corrections. In addition, the methods interrogate the full volume of the cylinder, thereby offering the IAEA a new capability to assay the absolute 235U mass in the cylinder and much-improved sensitivity to substituted or removed material. Building on this prior work a UCVS field prototype is being developed and tested. This paper describes potential implementation concepts, a preliminary UCVS prototype design and functional description, and preparations for upcoming field trials.

Smith, Leon E.↗
DOE OSTI2016

A Multi-Energy Approach for Neutron Interrogation of Uranium Items

Bulk uranium items are often measured using active neutron interrogation systems to take advantage of the high penetrability of neutrons, providing the ability to quickly and accurately measure effective uranium masses in large, dense configurations. These active techniques employ an external neutron source to induce fission in the uranium and subsequently measure emitted prompt fission or delayed neutrons. Unfortunately, the emitted neutrons from 235U and 238U are, for all practical purposes, indistinguishable; therefore, common systems such as the Active Well Coincidence Counter and other systems based on measurement of prompt or delayed fission neutrons require many representative calibration standards or known isotopic information to interpret the results, thus limiting the application of these techniques for safeguards purposes. This paper presents the motivation for a multi-energy neutron interrogation technique which aims to improve the accuracy of these NDA techniques through the use of multiple neutron interrogation sources. Potentially, the dual measurement approach will allow the mass values of the isotopes in the item to be independently determined while minimizing the number of representative standards needed and/or eliminating the need for prior knowledge of the isotopic information. This work examines the change in fission rates with differing interrogating neutron energy and, therefore, the potential of this new technique to independently measure the masses of 235U and 238U in the measurement item. Initial simulation and measurement results will be presented.

Hayward, Jason P.↗
DOE OSTI2020

EBR-II Driver Fuel Cladding Hull Analytical Data

Sharing EBR-II driver fuel cladding hull data with General Atomics under NDA No. 20NDA155. Data share is needed to advance discussions regarding process technologies to decontaminate separated cladding hulls

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2020

Smart-DS: Synthetic Models for Advanced, Realistic Testing: Distribution Systems and Scenarios

The explosion of new ideas for distributed energy resources and advanced distribution grid algorithms faces a critical challenge: how can one effectively develop and evaluate these breakthrough technologies without an adequate set of power systems network, load, and resource data to test against? Today's open test systems, particularly for distribution systems, are tiny and incomplete; and though with enough effort, obtaining utility data under NDA can overcome scale challenges, the results can't be openly shared, preventing fair comparison. The Smart-DS project-led by NREL in partnership with MIT, Universidad Pontificia Comillas, CYME, and EDD-is working to overcome this gap by generating multiple large-scale, open, synthetic, distribution systems that are realistic but not real. These datasets go beyond a single medium voltage feeder (~1000 customers) to cover entire metropolitan areas and their surrounds with up to hundreds of feeders and millions of customers, complete with low voltage customer connections and high voltage sub-transmission. This scale allows adequate testing and analysis of not just local controls and advanced DERs, but also multiple substation interactions, optimized switching, full-scale distribution-OPF, and more. To accompany these datasets, the project is also building a rich set of scenario generation tools that can be used for distribution and transmission systems alike. This includes automated, spatially aware access to world-class, high-resolution solar, wind, and weather data: forward looking generation mixes: and highly configurable DER, load, climate, outage, control-scheme, and other scenarios. We will also highlight DiTTo, an exciting open-source, multi-way distribution dataset transformation tool for many-to-many format translation with scenario, merge/split, and many other manipulation capabilities.

DERs↗
DOE OSTI2021

University Research to Support the MPACT 2020 Milestone

University research is a strong focus of the Office of Nuclear Energy within the Department of Energy. This research complements existing work in the various program areas and provides support and training for students entering the field. Four university projects have provided support to the Material Protection Accounting and Controls Technologies (MPACT) 2020 milestone focused on safeguards for electrochemical processing facilities. The University of Tennessee Knoxville has examined data fusion of NDA measurements such as Hybrid K-Edge Densitometry and Cyclic Voltammetry. Oregon State University and Virginia Polytechnic Institute have examined the integration of accountancy data with process monitoring data for safeguards. The Ohio State University and the University of Utah have developed a Ni-Pt SiC Schottky diode capable of high temperature alpha spectroscopy for actinide detection of molten salts. Finally, the University of Colorado has developed a key enabling technology for the use of Microcalorimetry.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗