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NASA NTRS2014

Self-Raman Nd:YVO4 Laser and Electro-Optic Technology for Space-Based Sodium Lidar Instrument

We are developing a laser and electro-optic technology to remotely measure Sodium (Na) by adapting existing lidar technology with space flight heritage. The developed instrumentation will serve as the core for the planning of an Heliophysics mission targeted to study the composition and dynamics of Earth's mesosphere based on a spaceborne lidar that will measure the mesospheric Na layer. We present performance results from our diode-pumped tunable Q-switched self-Raman c-cut Nd:YVO4 laser with intra-cavity frequency doubling that produces multi-watt 589 nm wavelength output. The c-cut Nd:YVO4 laser has a fundamental wavelength that is tunable from 1063-1067 nanometers. A CW (Continuous Wave) External Cavity diode laser is used as a injection seeder to provide single-frequency grating tunable output around 1066 nanometers. The injection-seeded self-Raman shifted Nd:VO4 laser is tuned across the sodium vapor D2 line at 589 nanometers. We will review technologies that provide strong leverage for the sodium lidar laser system with strong heritage from the Ice Cloud and Land Elevation Satellite-2 (ICESat-2) Advanced Topographic Laser Altimeter System (ATLAS). These include a space-qualified frequency-doubled 9 watts-at-532-nanometer wavelength Nd:YVO4 laser, a tandem interference filter temperature-stabilized fused-silica-etalon receiver and high-bandwidth photon-counting detectors.

Krainak, Michael A.↗

NASA NTRS2014

Self-Raman Nd:YVO4 Laser and Electro-Optic Technology for Space-Based Sodium Lidar Instrument

Krainak, Michael A.↗

DOE OSTI2023

Direct Alpha Spectrometry of Nuclear Fallout

Advanced instruments and methods are under development to allow direct alpha spectrometry of nuclear fallout debris near the point of collection, to support nuclear forensics (NF). New approaches are needed to support NF in order to accelerate the process for data generation and reduce the overall timeline for decision making. Fallout debris at short time periods following detonation can be difficult to work with for alpha spectrometry, due to the presence of intense beta radiation originating from significant quantities of high-activity fission products. Intense beta radiation can challenge traditional silicon-based high-resolution alpha spectrometers. Addressing this, single-crystal (sc) chemical vapor deposition (CVD) produced diamond semiconductors have been studied for use for alpha spectrometry for assaying nuclear fallout debris. Tests have been performed using scCVD sensors to assay a variety of actinide-bearing samples. Sample preparation, when done, has been limited to pulverization using a mechanical ball mill. To reduce measurement times, multi-chip arrays of scCVD diamond semiconductor have been developed in form factors suitable for field deployment in support of NF objectives. These arrays have been tested using high-beta-activity sol gel surrogate nuclear explosive debris (SNED) containing varying concentrations of uranium and plutonium. Results from the use of scCVD detectors with sol gel SNED will be presented.

46 - INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AN↗

DOE OSTI2016

Load-cell based characterization system for a “Violin-Mode” shadow-sensor in advanced LIGO suspensions

The background to this work was a prototype shadow sensor, which was designed for retro-fitting to an advanced LIGO (Laser Interferometer Gravitational wave Observatory) test-mass/mirror suspension, in which 40 kg test-mass/mirrors are each suspended by four approximately 600 mm long by 0.4 mm diameter fused-silica suspension fibres. The shadow sensor comprised a LED source of Near InfraRed (NIR) radiation and a rectangular silicon photodiode detector, which, together, were to bracket the fibre under test. The aim was to detect transverse Violin-Mode resonances in the suspension fibres. Part of the testing procedure involved tensioning a silica fibre sample and translating it transversely through the illuminating NIR beam, so as to measure the DC responsivity of the detection system to fibre displacement. However, an equally important part of the procedure, reported here, was to keep the fibre under test stationary within the beam, whilst trying to detect low-level AC Violin-Mode resonances excited on the fibre, in order to confirm the primary function of the sensor. Therefore, a tensioning system, incorporating a load-cell readout, was built into the test fibre’s holder. The fibre then was excited by a signal generator, audio power amplifier, and distant loudspeaker, and clear resonances were detected. A theory for the expected fundamental resonant frequency as a function of fibre tension was developed and is reported here, and this theory was found to match closely with the detected resonant frequencies as they varied with tension. Consequently, the resonances seen were identified as being proper Violin-Mode fundamental resonances of the fibre, and the operation of the Violin-Mode detection system was validated.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

DOE OSTI2016

Environmental Restoration of Diesel-Range Organics from Project Chariot, Cape Thompson, Alaska - 16147

Cape Thompson, Alaska, is located approximately 120 miles north of Kotzebue, Alaska, within the Ogotoruk Creek valley. The remote Alaskan location is also home to the US Atomic Energy Commission (AEC) Project Chariot study area. Project Chariot was part of the Plowshare Program, created in 1957 by the AEC to study peaceful uses for atomic energy. Project Chariot began in 1958 when a scientific field team chose Cape Thompson as a potential site to excavate a harbor using a series of nuclear explosions. Between 1959 and 1962, AEC was responsible for over 40 pretest bio-environmental and geotechnical studies of the Cape Thompson area. Strong public opposition to the tests developed, which caused the project to be cancelled with no nuclear explosions ever conducted at the site. In the early 1960's, several deep boreholes were drilled to obtain subsurface, temperature, and high-explosive testing data. Refrigerated diesel was used as a drilling fluid to keep the boreholes open so that thermistors could measure subsurface temperatures. The test boreholes were named Able, Baker, Charlie, Dog, and X-1. In the summer of 2014, the US Department of Energy, Office of Legacy Management (LM) completed the remediation of remnant diesel at these sites. Prior to the 2014 remediation activities, LM conducted two separate characterization field studies to determine the nature and extent of the contamination from the 1960's drilling activities. In 2013, LM developed a remediation plan that was submitted and approved by the Alaska Department of Environmental Conservation (ADEC). The 2014 Project Chariot remediation had some unique logistical challenges and historic issues with stakeholders to overcome. Many of the historic issues centered on previous AEC scientific actions and a general mistrust of the government by the local stakeholders. Prior to and during the 2014 remediation work, an outreach campaign was implemented to discuss prior activities at the site and include stakeholders from Point Hope, Alaska, in the remediation-planning process. The remoteness of the region also provided unique logistical challenges. Because of the short field season, LM initiated several subcontracts over a year in advance. The field camp, heavy equipment, and soil storage containers were shipped by barge to the site. Personnel, food, and small materials were flown in by bush plane from Kotzebue, Alaska. Previous site characterization had identified diesel-range organics (DROs) as the primary contaminant. The cleanup levels for the site were provided by the Alaska Administrative Code (AAC) for the Arctic Zone region. The AAC cleanup level for DROs on gravel pads is 500 mg/kg and 12,500 mg/kg tundra in the arctic-zone region. To help determine the extent and direct soil excavation in the field, photoionization detectors (PIDs) were used for field screening. While the PID results provided rough limits for excavation, laboratory confirmation sampling was required to provide actual excavation guidance. All excavation locations remained open until laboratory results met AAC criteria and ADEC approved closure. The laboratory sample protocol required the bush plane to pick up samples almost daily and transfer them to Anchorage for analysis. In order to meet holding time requirements, all laboratory samples were analyzed on an expedited basis. Analytical results and ADEC approval notifications were e-mailed back to the site via satellite connection. A total of 202 laboratory analyses were needed to complete the remediation effort. At each location (Able, Baker, Charlie, Dog, and X-1), the boreholes were plugged and abandoned in accordance with ADEC regulations. Contaminated soil was excavated, and the material was placed in super-sacks and hauled to connex boxes located near the sea shore. Approximately 786 tons of material was removed and shipped by barge to the Columbia Ridge Landfill in Arlington, Oregon, for disposal. The well casings were cut and sealed below ground surface. Each location was graded to its original contours and reclaimed with native vegetation, and a geodetic survey was conducted. Tours with leaders of the Village of Point Hope and the land owner (Arctic Slope Regional Corporation) were conducted prior to the final demobilization. All remediation equipment and camp facilities were removed at the completion of the project. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

NASA NTRS1987

Tracking 3-D body motion for docking and robot control

An advanced method of tracking three-dimensional motion of bodies has been developed. This system has the potential to dynamically characterize machine and other structural motion, even in the presence of structural flexibility, thus facilitating closed loop structural motion control. The system's operation is based on the concept that the intersection of three planes defines a point. Three rotating planes of laser light, fixed and moving photovoltaic diode targets, and a pipe-lined architecture of analog and digital electronics are used to locate multiple targets whose number is only limited by available computer memory. Data collection rates are a function of the laser scan rotation speed and are currently selectable up to 480 Hz. The tested performance on a preliminary prototype designed for 0.1 in accuracy (for tracking human motion) at a 480 Hz data rate includes a worst case resolution of 0.8 mm (0.03 inches), a repeatability of plus or minus 0.635 mm (plus or minus 0.025 inches), and an absolute accuracy of plus or minus 2.0 mm (plus or minus 0.08 inches) within an eight cubic meter volume with all results applicable at the 95 percent level of confidence along each coordinate region. The full six degrees of freedom of a body can be computed by attaching three or more target detectors to the body of interest.

Donath, M.↗

NASA NTRSDate not supplied

In-Situ XRD/XRF to Support Life Detection on Mars

X-ray diffraction / X-ray fluorescence (XRD/XRF) analysis provides the most comprehensive mineralogical / compositional characterization of rocks and soils of any flight-capable technique. XRD data provide quantitative mineralogy (including abundance of X-ray amorphous materials) and crystal chemistry (structure, elemental composition and valence state), and XRF data provide complimentary major, minor, and some trace element abundances. Both types of data are important in evaluating habitability (environment of formation) and biosignature preservation/degradation (post-depositional diagenetic change). Whether or not a relict biosignature is detected, the mineral assemblage and its geochemistry can be used to determine the habitability of an ancient environment (e.g., salinity, pH, temperature), and to identify potential sources of energy for life (e.g., elements in different redox states). In this respect, a null result (a habitable environment lacking evidence of life) can play an important role in constraining the parameters of the search. Conversely, diagenetic alteration (taphonomic change) resulting from post-depositional variations in temperature, pressure or fluid chemistry can preserve evidence of biogenicity, erase such evidence completely or indeed can provide for post-depositional habitable conditions in the subsurface. XRD / XRF data are critical to these determinations. The CheMin instrument on the Mars Science Laboratory (MSL) Curiosity rover is the first XRD instrument flown in space. CheMin operates in transmission geometry with a Co X-ray source to minimize fluorescence from iron. Diffracted photons are collected with an energy-sensitive charge-coupled device (CCD). The position of the diffracted photons provides structural information for minerals, whereas the energy of sample-generated X-ray fluorescence photons provides elemental information, though these XRF data are qualitative. Mineralogical data from the CheMin XRD identified the three circumstances above: habitable depositional environments (e.g., Yellowknife Bay), habitable subsurface/diagenetic environments (e.g., throughout the Murray formation), and diagenetic conditions that may destroy evidence of habitability (e.g., oxidative and acidic environments at Vera Rubin ridge). Technological advances in X-ray technology and lessons learned from the operation of CheMin on Mars have resulted in a next-generation XRD/XRF, called CheMinX. Replacement of CheMin’s CCD with an array of hybrid pixel detectors and improvements in focusing optics dramatically decrease analysis time (15 minutes vs. 22 hours for MSL-CheMin) and result in a better angular resolution (0.18 vs. 0.30 °2θ for MSL-CheMin). This increased resolution improves mineral detection, including discrimination between types of pyroxenes, which is not possible with MSL-CheMin data. The hybrid pixel detectors do not require cooling like the MSL-CheMin CCD, therefore reducing the power needed to operate CheMinX. CheMinX has a silicon-drift detector (SDD) to measure fluoresced photons, enabling the quantification of major, minor, and some trace elements via XRF. XRD/XRF data are collected simultaneously in CheMinX, obviating the need for multiple compositional instruments. The CheMinX design also improves upon MSL-CheMin’s sample handling. Instead of sample cells on wheel, which are often not reusable and add complexity in commanding the instrument, CheMinX has single-use cells in a cartridge/dispenser configuration. Because of these improvements, CheMinX is an ideal instrument for Discovery-class life-detection missions, including Mars Life Explorer that was recommended for development in the Planetary Science and Astrobiology Decadal Survey 2023-2032.

E B Rampe↗

DOE OSTI2016

Status of Electronics Upgrades to the LANL Green is Clean Phoswich Detector Systems - 16419

Los Alamos National Laboratory radiological facilities produce low-density room trash that, in many cases, is not contaminated with radioactivity. It has been estimated that 50 to 90% of low-density room trash is free of radioactive contamination and eligible for inclusion in LANL's Green is Clean (GIC) program. The GIC program is a verification program for non-regulated waste from radiation controlled areas that has been actively segregated as nonradioactive through the use of the waste generator's acceptable knowledge. The GIC program has employed two large area Phoswich gamma ray detector systems (HERCULES and ZEUS) to assay and verify that GIC candidate waste meets free release disposal requirements. The large area (127 cm{sup 2}) Phoswich detectors consist of a thin NaI front crystal (3 mm thick) that is optically coupled to a thick CsI back crystal (50 mm thick). The crystals are set in an oxygen-free high-conductivity copper housing with a very thin (0.025 mm) aluminum entrance window. The scintillation properties of the two crystals are different enough to allow the system's electronic components to identify the origin of any pulse. The original systems utilize Nuclear Instrumentation Module (NIM) electronics to process the detector signals. These electronic modules provide the buffering, amplification, and pulse shape analyzer needed for the proper presentation of signals to the custom Phosmux router module. The router module separates the sodium iodide and cesium iodide signals by their rise times and transfers this information into the computer-mounted multichannel analyzer, a Canberra Model S-100 system. While these NIM Bin counting electronics configurations have been effective for approximately 20 years of operation, they are bulky requiring numerous modules per detector and the important Phosmux module is no longer manufactured by LANL. Modern advancement of commercial counting electronics now offer more compact options for equivalent detector signal processing. A pulse shape discriminator module, the DGF Pixie-4, made by XIA LLC, has been identified that can replace the majority of the original NIM bin electronics in a much more compact chassis - one Pixie-4 replaces four NIM amplifiers and four NIM PSAs and fits in a small National Instruments{sup TM} chassis. Thus, LANL has initiated a system upgrade project to replace the historic NIM electronics with the XIA Pixie4 and associated configuration software. The hardware for one Phoswich systems has been procured for the project and the configuration software, customized for the LANL Phoswich detector application, has been written by the manufacturer. Initial setup and optimization of the Pixie-4 configuration has been performed. Qualitative and quantitative baseline comparisons to the NIM electronics has been performed. Good agreement of key low energy gamma lines between the systems has allowed 'Proof of Concept' to be concluded. Further optimization and performance evaluations are in progress. Modifications to the LabVIEW{sup TM} based operating software (originally written by VI Control Systems Ltd.) are being performed by a LANL LabVIEW{sup TM} programmer to accommodate the electronics upgrade. A new LabVIEW{sup TM} interface to control the Pixie-4 has already been developed. Final optimization and testing, formal software QA, and revisions to operating procedures are in progress to achieve completion of the GIC system upgrade project. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2024

Probing the Isospin Composition of Short-Range Correlated Pairs at Jefferson Lab Hall B

Nucleons in short-range correlated (SRC) pairs, due to their close proximity and high relative momentum, can provide insight into the short-range part of the strong nuclear interaction. In particular, the prevalence of np pairs is due to the dominance of a tensor term for correlated nucleons with momenta of approximately 400?600 MeV/c. This dissertation comprises two studies advancing the community?s understanding of the isospin composition of SRC pairs. First, I performed a study of proton and neutron knockout from initially low-momentum and high-momentum states in 3He. Previous work has shown that protons are disproportionately represented in high-momentum states in neutron-rich nuclei. I demonstrate that spectral functions for the proton-rich nucleus 3He predict, in agreement with data, that neutrons are disproportionately represented in high-momentum states, but that 3He does not display the same strong prevalence of np pairs that is observed in larger nuclei. Second, Generalized Contact Formalism (GCF), a well-supported theory for predicting SRC behavior, predicts the transition from an isospin-dependent, tensor-dominant interaction at intermediate distances to a scalar-dominant, isospin-independent interaction at very short distances. This dissertation uses data from the CLAS12 Nuclear Targets Experiments in Hall B at Jefferson Lab to measure the relative abundances of pp and pn pairs for increasing relative momentum and decreasing separation. I provide an independent confirmation of the previously-observed increase in pp pairs at increasing momentum of the struck nucleon. I also contribute to the application of the new CLAS12 Central Neutron Detector by precisely measuring the neutron detection efficiency and developing a machine learning model for rejecting charged particle background.

Seroka, Erin↗

NASA NTRS2025

Limitations and Feasibility of Mini X-Ray Devices in Space Environments

LIMITATIONS AND FEASIBILITY OF MINI X-RAY DEVICES IN SPACE ENVIRONMENTS As space exploration advances toward long-duration missions, reliable medical diagnostic tools become increasingly critical. The miniature x-ray (XR) technology demonstrations by the Exploration Medical Capability (ExMC) and the Exploration Medical Integrated Product Team (XMIPT) aim to assess the feasibility and utility of miniature XR devices in spaceflight. This abstract explores the limitations of current miniature XR systems, the challenges of training crew members, the potential role of clinical decision support systems (CDSS), and the feasibility of ground-based image interpretation. We also propose the integration of miniature XR into other ExMC efforts aimed at identifying the capabilities and resources needed for future exploration class missions. One of the primary challenges with miniature XR devices is the ability to achieve specific anatomical views, particularly in the confined and weightless conditions of a spacecraft. Operators may struggle to acquire diagnostic-quality images when space is limited for proper patient positioning and the volume of the imaging device. Since space radiation and detector limitations may further impact image quality, the flexibility of the operating procedures of these devices will be critical for their success in space applications. CHALLENGES IN TRAINING CREW TO OPERATE IMAGING DEVICES Training in the skills necessary to acquire diagnostic-quality scans may be a barrier for non-clinician crewmembers. The curriculum developed for crew medical officers (CMOs) will require simplification and adaptation to fit into the highly truncated pre-flight training period. Therefore, hands-on familiarization and simulation, both pre-flight and just-in-time training during missions, will be crucial to ensuring the crew can operate the devices in real-life situations. The ability to adjust acquisition parameters must be simplified or made automatic through exam selections on equipment user interfaces, and subject and operator positioning should be assisted with laser guidance and pictorial guides. POTENTIAL FOR CDSS OR ARTIFICIAL INTELLIGENCE (AI)-ASSISTED CDSS CDSS and AI-assisted CDSS offer significant promise in assisting crew members with limited medical training. These systems could provide real-time feedback on image quality and interpretation, helping to mitigate the risks of human error during space missions. Integrating procedural guidance tools, such as virtual and augmented reality, will support crewmembers in accurately positioning patients and obtaining high-quality images. However, the success of such systems will depend on the development of robust training datasets, integration with spaceflight-rated hardware, and the medical decision-making capabilities of operators. FEASIBILITY OF GROUND INTERPRETATION AND DATA TRANSMISSION Reliance on ground-based interpretation may prove difficult for acute care during exploration class-missions due to delays in transmission with increasing distance from Earth or complete communication blackout periods. In such instances where immediate interpretation for clinical intervention is required, crew must be able to interpret the images independently or utilize AI-based assistance to do so. File sizes for XR exams can also be large if numerous images are acquired and bandwidth constraints may limit data transmissions for both radiography and ultrasound exams. FUTURE WORK AND INTEGRATION INTO THE EVIDENCE LIBRARY Future work proposes integrating miniature XR devices into NASA’s Evidence Library to address medical conditions identified as significant contributors to crew morbidity and mortality. The possibility of combining miniature XR with other imaging modalities, such as ultrasound devices, is also under investigation. In conclusion, while miniature XR technology holds potential for extraterrestrial medical systems, there are significant challenges to overcome. Training, integration of AI tools, dedicated exam protocols for microgravity, and improved data transmission systems will be key to realizing the full benefits of miniature XR technology in space.

A M Nelson↗

DOE OSTI2019

Experimental Evaluation of the Fast-Neutron Passive Collar (FNPC) Performance (Interim Report)

This report represents a deliverable in the Safeguards Technology WBS # Project Title, 24.1.3.1, Task 3 (Report on laboratory-based performance testing of the FNPC). A new, simplified method for the verification of the 235 U mass in fresh LEU fuel assemblies that is relatively independent of burnable poison content is being developed. LWR fresh fuel is currently verified using the uranium neutron coincidence collar (UNCL), which relies on an AmLi source to induce fission in the 235 U. AmLi neutrons are slowed down in polyethylene, so the induced fission is primarily due to thermal neutrons. Burnable poisons, which are added to nuclear fuel assemblies to extend the lifetime of the fuel, absorb neutrons that would otherwise have induced fission in the fuel, thereby reducing the neutron count rate and thus the measured 235 U mass. To remove this bias factor a correction is applied based on the operator’s declared burnable poison content. The new technique uses 238 U spontaneous fission in LWR fresh fuel rods to self-interrogate the 235 U mass. The 238 U spontaneous fission neutrons have a hard neutron energy spectrum, which means that the technique is less sensitive to burnable poisons than the AmLi based systems. This project has continued the work done over the past two years to study this new technique using the optimized 3 He based fastneutron passive collar (FNPC). Fabrication of the FNPC has been completed and measurements are in progress using the LANL mockup PWR fuel assembly. Also, preliminary evaluations of advanced analysis techniques and unattended mode operation have been performed. In FY18, the 3 He tube based detector was compared with a 10 B sealed cell based detector for the same set of PWR fuel assemblies in the Rodeo-II program. The results were that the optimized 3 He detector had higher efficiency and less weight than the 10 B based system where both systems had about the same cost. Thus, the FY19 work continued exclusively with the 3 He based detector; although, either system had the potential for future applications. However, the high efficiency of the FPNC (~24%) is critical for precise measurements of the triples rate necessary in the multiplicity advanced analysis technique which can solve for the burnable poison content.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

DOE OSTI2023

Data Summary Report for Soil and Slab Sampling at Former Building 175

Lawrence Livermore National Security (LLNS) and the U.S. Department of Energy (DOE) are in the process of returning the area where Building 175 existed to beneficial use for future site development. The completed assessment will help LLNS and DOE to outline project scope and costs associated with the removal, characterization, and disposal of materials generated when the concrete slab for the former building and any associated remaining subsurface structures are demolished. Slab removal under the Transition & Disposition process requires full screening for potential site contamination to determine appropriate future land use. Borehole locations and depths were designed to correctly assess DOE’s future liability for characterizing residual vadose zone contamination. If a residual source area is identified at depth, DOE will need to evaluate the additional cost of future subsurface cleanup (with limited access) due to planned development. This is necessary to leave the location in a “ready-to-build” status. As a result, Phase II sampling requirements may in some cases extend beyond the construction zone required for slab removal to ensure the necessary due diligence. To avoid the potential spread of contamination and/or the creation of an environmental release by impacting the integrity of known contamination areas (e.g., pit within room 102 and the east to west boundary seam), these locations were not sampled for this project. During demolition of the slab, these locations and their underlying soils should be further evaluated. The assessment was conducted in accord with the May 2022 Lawrence Livermore National Laboratory Former Building 175 Assessment Soil Sampling and Analysis Plan / Quality Assurance Plan. Thirty-six, direct-push borings were advanced, along with collecting concrete (where present) and soil samples for laboratory analyses. Thirty-two of the borings were advanced to a depth of 25 feet below ground (bgs), and four borings were advanced to a depth of 55 feet bgs. The concrete slab for former Building 175 ranged from approximately 8 inches to over two feet in thickness. Soils encountered during the investigation consisted primarily of clayey silt, with interbeds of sandy gravel and silty sand to the total depth explored of 55 feet bgs. Field photoionization detector readings – checking for volatile organic compound (VOC) vapors in soils, ranged from zero (0) to a peak of 33 parts per million at 25 feet bgs in boring PC-B175- 028. The cause for the peak reading is unknown, however, no visually discolored or odorous soils were encountered during the assessment and all VOC results were below Lawrence Livermore National Laboratory’s (LLNL’s) Soil Screening and Management Plan (SSMP) soil screening levels (SSL). Groundwater was not encountered during the assessment and is expected to occur at roughly 65 feet bgs in the project area. No metals were detected at concentrations of concern in the concrete core samples collected and analyzed. Low gross alpha and beta activity concentrations were detected in the concrete core samples collected and analyzed. The detected activity concentrations would appear to be from naturally occurring radioactive isotopes, i.e., potassium 40, present in the raw materials used to make concrete and not artificially added. Tritium was not detected above the testing laboratory's Method Detection Limit (MDL) in any of the concrete core samples collected and analyzed. The radioactive isotopes - actinium 228, bismuth 214, lead 212, lead 214, potassium 40, radium 226, radium 228, and thallium 208, were detected at low activity concentrations in the concrete core samples analyzed. Based on the detected activity concentrations, the isotopes would appear to be naturally occurring in the raw materials used to make concrete and not artificially added. Acetone – a common laboratory contaminant, was detected in nine of the soil samples collected and analyzed. Concentrations of two other volatile organic compounds (benzene and tetrachloroethene) were detected in five of the soil samples analyzed. All concentrations were below SSLs. Total petroleum hydrocarbons as diesel range organics were detected at 43.9 milligrams per kilogram (mg/kg) in the 20-foot bgs duplicate sample from boring PC-B175-007. Total petroleum hydrocarbons as motor oil were detected at 7.20 mg/kg in the 15-foot bgs routine sample from boring PC-B175-001, and at 20.7 mg/kg in the 20-foot bgs duplicate sample from boring PC-B175-007. The SSL for diesel-range TPHs is 260 mg/kg. LLNL does not have an SSL for motor oil range TPHs. No indications of a release, e.g., visibly stained, or odorous soil, were present at the boring locations. No samples collected contained polychlorinated biphenyls (PCBs) in concentrations above the laboratory reporting limit. Arsenic was detected above its SSL of 8.51 mg/kg in the 25-foot bgs routine sample collected from boring PC-B175-023. Nickel was detected above its SSL of 86.0 mg/kg in the 10-foot bgs routine sample from boing PC-B175-005, the 20-foot bgs routine sample from boring PC-B175-025, and the 25-foot bgs routine sample from boring PC-B175-034. The detected concentrations, however, were well below ten times (10x) their respective STLCs. Gross alpha and/or gross beta were detected above their respective SSL activity concentrations in three routine soil samples. Retesting (two per sample) of the samples showed that the initial reported activity concentrations were anomalous. Tritium was not detected in any of the routine or duplicate soil samples collected and analyzed during the investigation. The radioactive isotopes - actinium 228, bismuth 212 and 214, lead 212 and 214, potassium 40, radium 224, 226 and 228, thallium 208, thorium 234 and uranium, were detected at low activity concentrations in the soil samples analyzed for radioactive constituents. The detected isotopes and their associated activity concentrations are typical of those naturally occurring in the marine-type sedimentary deposits underlying the Livermore Valley. No radiological controls are necessary for the soil evaluated.

54 ENVIRONMENTAL SCIENCES↗

NASA NTRS1975

Interim Report of the Astronomy Spacelab Payloads Study: Ultraviolet and Optical Astronomy - Volume 2

The Space Shuttle will comprise NASA's primary transportation system into near-earth orbit during the 1980s. The Shuttle will provide the astronomical community with a major new capability to send a wide variety of instrumentation into orbit, to utilize it there under manned or automatic control for periods from seven to thirty days, and to return it to the ground. To this end the European Space Research Organization (ESRO) is developing Spacelab, an array of interchangeable components -pressurized manned modules, unpressurized pallets and related support systems - to be mounted in the Shuttle payload bay. Spacelab will offer important opportunities to carry out astronomical research with instruments optimized for specific objectives. With a high flight frequency and with the ability to modify or interchange telescopes and instruments between flights, one will not need to make rigid long-term commitments to specific and compromised telescope/instrument/ detector combinations as is the case for automated satellites. Observational techniques demanding the physical return of data and equipment - in particular the use of photographic film, instruments requiring tight calibration controls, cryogens, high-risk detectors and degradeable optical coatings -will open research areas not readily addressed by automated satellites. Although Shuttle flight duration will be limited to periods from seven to thirty days, substantial data can be obtained with a single instrument on short missions, if targets are carefully selected and prioritized, and a large number of instruments can be accommodated on a single flight. Important astronomical data are regularly obtained on sounding rocket flights of five minutes duration. Spacelab will provide far longer observing periods for large and small telescopes, with resources greatly exceeding those of sounding rockets, while retaining much of the sounding rocket philosophy in terms of instrument flexibility, simplicity, reliability assurance and development costs. The Ultraviolet and Optical Astronomy Program on Spacelab is being planned to provide optical astronomers with relatively simple and regular access to the extended wavelength coverage, the superior image quality and the darkness of the night sky available above the earth's atmosphere. In a rapidly evolving science one cannot predict what problems will be timely in the 1980s. Extrapolating from the current epoch, however, one can envision a continuing interest in such areas as the structure, composition and phenomenology of planetary surfaces and atmospheres; the composition and physical nature of the interstellar medium; the composition, structure and life history of stars, especially those in advanced stages of evolution; the stellar population of other galaxies; such enigmatic phenomena as X-ray binary black holes, pulsars, active galactic nuclei and quasars; large scale interactions between galaxies and the nature of the intergalactic medium; precise calibration of the Hubble law for the expansion of the universe; the average density of the universe; and the existence of extraterrestrial life.

Source record↗

DOE OSTI2020

Modeling and Control Using Stochastic Distribution Control Theory for Intersection Traffic Flow

In this work, we investigated stochastic distribution control theory-based traffic signal optimization to achieve a smooth and uniform flow of vehicles through signalized intersections. In this context, the static and linear dynamic stochastic distribution models were developed to express the relationship between the signal timing and the traffic queue length together with its probability density function. Two stochastic distribution control algorithms were designed to control the signal timing at intersections such that the probability density function of the traffic queue of each intersection road segment is made as narrow and as small as possible. Also, a recursive input-output traffic queue estimation model was proposed, which is data-driven and dynamic in nature, to calculate real-time traffic queue length using traffic signal timings and loop-detector data. The control algorithms were evaluated for a one-signal corridor, two-signal corridor, and 2 x 2 network of signalized intersections. MATLAB simulation examples are provided to demonstrate the use of the proposed algorithms and comparison to the existing widely-used semi-actuated control has been made. Desired results were obtained.

97 MATHEMATICS AND COMPUTING↗

DOE OSTI2013

Summary of the Preliminary Optical ICHMI Design Study: A Preliminary Engineering Design Study for a Standpipe Viewport

This summary report examines an in-vessel optical access concept intended to support standoff optical instrumentation, control and human-machine interface (ICHMI) systems for future advanced small modular reactor (AdvSMR) applications. Optical-based measurement and sensing systems for AdvSMR applications have several key benefits over traditional instrumentation and control systems used to monitor reactor process parameters, such as temperature, flow rate, pressure, and coolant chemistry (Anheier et al. 2013). Direct and continuous visualization of the in-vessel components can be maintained using external cameras. Many optical sensing techniques can be performed remotely using open optical beam path configurations. Not only are in-vessel cables eliminated by these configurations, but also sensitive optical monitoring components (e.g., electronics, lasers, detectors, and cameras) can be placed outside the reactor vessel in the instrument vault, containment building, or other locations where temperatures and radiation levels are much lower. However, the extreme AdvSMR environment present challenges for optical access designs and optical materials. Optical access is not provided in any commercial nuclear power plant or featured in any reactor design, although successful implementation of optical access has been demonstrated in test reactors (Arkani and Gharib 2009). This report outlines the key engineering considerations for an AdvSMR optical access concept. Strict American Society of Mechanical Engineers (ASME) construction codes must be followed for any U.S. nuclear facility component (ASME 2013); however, the scope of this study is to evaluate the preliminary engineering issues for this concept, rather than developing a nuclear-qualified design. In addition, this study does not consider accident design requirements. In-vessel optical access using a standpipe viewport concept serves as a test case to explore the engineering challenges and performance requirements for sodium fast reactor (SFR) and high-temperature gas reactor (HTGR) AdvSMR applications. The expected environmental conditions for deployment are reviewed for both AdvSMR designs. Optical and mechanical materials that maximize component lifetime are evaluated for the standpipe viewport design under these conditions. Optical components and opto-mechanical designs that provide robust optical-to-metal seals and stress-free optical component mounting are identified, and then key performance specifications are developed for a sapphire optical viewport concept. Design strategies are examined that protect the internal optical surfaces from liquid-coolant condensation and impurity deposits. Finally, a conceptual standpipe viewport design that is suggestive of how this concept could be assembled using standard nuclear-qualified pipe components, is presented.

42 ENGINEERING↗

DOE OSTI2020

Modeling and Detection of Future Cyber-Enabled DSM Data Attacks

Demand-Side Management (DSM) is an essential tool to ensure power system reliability and stability. In future smart grids, certain portions of a customer’s load usage could be under the automatic control of a cyber-enabled DSM program, which selectively schedules loads as a function of electricity prices to improve power balance and grid stability. In this scenario, the security of DSM cyberinfrastructure will be critical as advanced metering infrastructure and communication systems are susceptible to cyber-attacks. Such attacks, in the form of false data injections, can manipulate customer load profiles and cause metering chaos and energy losses in the grid. The feedback mechanism between load management on the consumer side and dynamic price schemes employed by independent system operators can further exacerbate attacks. To study how this feedback mechanism may worsen attacks in future cyber-enabled DSM programs, we propose a novel mathematical framework for (i) modeling the nonlinear relationship between load management and real-time pricing, (ii) simulating residential load data and prices, (iii) creating cyber-attacks, and (iv) detecting said attacks. In this framework, we first develop time-series forecasts to model load demand and use them as inputs to an elasticity model for the price-demand relationship in the DSM loop. This work then investigates the behavior of such a feedback loop under intentional cyber-attacks. We simulate and examine load-price data under different DSM-participation levels with three types of random additive attacks: ramp, sudden, and point attacks. We conduct two investigations for the detection of DSM attacks. The first studies a supervised learning approach, with various classification models, and the second studies the performance of parametric and nonparametric change point detectors. Results conclude that higher amounts of DSM participation can exacerbate ramp and sudden attacks leading to better detection of such attacks, especially with supervised learning classifiers. We also find that nonparametric detection outperforms parametric for smaller user pools, and random point attacks are the hardest to detect with any method.

97 MATHEMATICS AND COMPUTING↗

DOE OSTI2012

MPACT Fast Neutron Multiplicity System Design Concepts

This report documents work performed by Idaho National Laboratory and the University of Michigan in fiscal year (FY) 2012 to examine design parameters related to the use of fast-neutron multiplicity counting for assaying plutonium for materials protection, accountancy, and control purposes. This project seeks to develop a new type of neutron-measurement-based plutonium assay instrument suited for assaying advanced fuel cycle materials. Some current-concept advanced fuels contain high concentrations of plutonium; some of these concept fuels also contain other fissionable actinides besides plutonium. Because of these attributes the neutron emission rates of these new fuels may be much higher, and more difficult to interpret, than measurements made of plutonium-only materials. Fast neutron multiplicity analysis is one approach for assaying these advanced nuclear fuels. Studies have been performed to assess the conceptual performance capabilities of a fast-neutron multiplicity counter for assaying plutonium. Comparisons have been made to evaluate the potential improvements and benefits of fast-neutron multiplicity analyses versus traditional thermal-neutron counting systems. Fast-neutron instrumentation, using for example an array of liquid scintillators such as EJ-309, have the potential to either a) significantly reduce assay measurement times versus traditional approaches, for comparable measurement precision values, b) significantly improve assay precision values, for measurement durations comparable to current-generation technology, or c) moderating improve both measurement precision and measurement durations versus current-generation technology. Using the MCNPX-PoliMi Monte Carlo simulation code, studies have been performed to assess the doubles-detection efficiency for a variety of counter layouts of cylindrical liquid scintillator detector cells over one, two, and three rows. Ignoring other considerations, the best detector design is the one with the most detecting volume. However, operational limitations guide a) the maximum acceptable size of each detector cell (due to PSD performance and maximum-acceptable per-channel data throughput rates, limited by pulse pile-up and the processing rate of the electronics components of the system) and b) the affordability of a system due to the number of total channels of data to be collected and processed. As a first estimate, it appears that a system comprised of two rows of detectors 5" Ø $\times$ 3" would yield a working prototype system with excellent performance capabilities for assaying Pu-containing items and capable of handling high signal rates likely when measuring items with Pu and other actinides. However, it is still likely that gamma-ray shielding will be needed to reduce the total signal rate in the detectors. As a first step prior to working with these larger-sized detectors, it may be practical to perform scoping studies using small detectors, such as already-on-hand 3" Ø $\times$ 3" detectors.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

DOE OSTI2023

Integration of Nuclear Material Accounting Data and Process Monitoring Data for Improvement on Detection Probability in Safeguarding Electrochemical Processing Facilities (Final Technical Report)

The KAERI advanced spent fuel conditioning process (ACP) process is a critical component of the US- South Korean nuclear cooperation and the following “123 Agreement.” Its development has received considerable attention in both countries. The ACP is an electrochemical processing (pyroprocessing) that recycles over 96% of the used nuclear fuel (UNF). It is also intrinsically proliferation-resistant in theory. In normal operation, the U/TRU product is very hot radiologically. In addition, the Cm provides a high level of spontaneous neutrons, making the product unsuitable for weapon use. However, as pointed in some study, “the need for safeguards to protect against the diversion and misuse of separated plutonium applies essentially equally to all grades of plutonium.” As pointed by many studies, the well-established traditional Nuclear Material Accounting (NMA) approach cannot be directly applied to electrochemical processing because of the lack of an input accountability tank, the non-continuous material flow, and the unsatisfactory level of confidence in sampling methods. Therefore, nuclear safeguards remain a grand challenge in the developing of commercial electrochemical separations facilities, especially around the heart of such facilities, the electrorefiner (ER) systems. In contrast to NMA data, process monitoring (PM) data is normally an indirect measurement of the SNM and is acquired much more frequently. In a broad sense, PM includes monitoring by various types of equipment, e.g. radiation detectors, cameras, voltage, current sensors. Because it is already being collected by the operator, the additional cost to safeguards is low. It has long been believed that PM data can supplement NMA data and help improve safeguards, although the benefits are hard to quantify. The U.S. DOE’s Material Protection, Accounting, and Control Technology (MPACT) campaign has made substantial investments into innovative PM sensor technology and predictive model development for real- or near real-time measurement and prediction of molten salt density and level, salt composition and actinide concentration especially Pu, the cell voltage, and the cell current to supplement traditional NMA. For aqueous-based reprocessing facilities, it is reported that PM, integrated with traditional NMA, have a high detection probability for specific diversions. For electrochemical reprocessing, preliminary studies have shown that PM data can support traditional NMA in various ways by providing a basis to estimate some of the in-processing nuclear material inventories. Despite early success, further studies on fusion of PM data and NMA data are still needed, which is the goal of this proposed work.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗