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DOE OSTI2020

High Throughput Argon-37 Field System

We report Pacific Northwest National Laboratory (PNNL) has developed a unique fieldable 37 Ar measurement system designed to measure 37 Ar activity concentrations from soil gas samples to detect above ground and underground nuclear explosions. The Argon-37 Field System is modular in design to accommodate both chemical processing and nuclear detection. The system can be packed into shipping crates and shipped to a location near where the sampling is taking place. The system can process six 2-m 3 whole-air samples in 24 hours and can measure the 37 Ar activity in each of the samples using six proportional counters. The proportional counters, designed and built at PNNL, are surrounded with both active and passive shielding to reduce background and can achieve a minimum detection concentration of 10 mBq/m 3 of 37 Ar in whole-air equivalent. The Argon-37 Field System has undergone extensive testing against rigorous requirements to assure the system meets the needs of the noble gas nuclear explosion monitoring community.

98 NUCLEAR DISARMAMENT, SAFEGUARDS, AND PHYSICAL P↗

DOE OSTI2020

Magnetic Tunability in RE-DOBDC MOFs via NO x Acid Gas Adsorption

The magnetic susceptibility of NO x -loaded RE-DOBDC (rare earth (RE): Y, Eu, Tb, Yb; DOBDC: 2,5-dihydroxyterephthalic acid) metal–organic frameworks (MOFs) is unique to the MOF metal center. RE-DOBDC samples were synthesized, activated, and subsequently exposed to humid NO x . Each NO x -loaded MOF was characterized by powder X-ray diffraction, and the magnetic characteristics were probed by using a VersaLab vibrating sample magnetometer (VSM). Lanthanide-containing RE-DOBDC (Eu, Tb, Yb) are paramagnetic with a reduction in paramagnetism upon adsorption of NO x . Y-DOBDC has a diamagnetic moment with a slight reduction upon adsorption of NO x . The magnetic susceptibility of the MOF is determined by the magnetism imparted by the framework metal center. The electronic population of orbitals contributes to determining the extent of magnetism and change with NO x (electron acceptor) adsorption. Eu-DOBDC results in the largest mass magnetization change upon adsorption of NO x due to more available unpaired f electrons. Experimental changes in magnetic moment were supported by density functional theory (DFT) simulations of NO x adsorbed in lanthanide Eu-DOBDC and transition metal Y-DOBDC MOFs.

36 MATERIALS SCIENCE↗

DOE OSTI2015

Sample registration software for process automation in the Neutron Activation Analysis (NAA) Facility in Malaysia nuclear agency

Neutron Activation Analysis (NAA) had been established in Nuclear Malaysia since 1980s. Most of the procedures established were done manually including sample registration. The samples were recorded manually in a logbook and given ID number. Then all samples, standards, SRM and blank were recorded on the irradiation vial and several forms prior to irradiation. These manual procedures carried out by the NAA laboratory personnel were time consuming and not efficient. Sample registration software is developed as part of IAEA/CRP project on ‘Development of Process Automation in the Neutron Activation Analysis (NAA) Facility in Malaysia Nuclear Agency (RC17399)’. The objective of the project is to create a pc-based data entry software during sample preparation stage. This is an effective method to replace redundant manual data entries that needs to be completed by laboratory personnel. The software developed will automatically generate sample code for each sample in one batch, create printable registration forms for administration purpose, and store selected parameters that will be passed to sample analysis program. The software is developed by using National Instruments Labview 8.6.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

NASA NTRS1994

ROSAT observations of X-ray-selected active galactic nuclei

We have observed sample of six optically faint, X-ray-selected active galactic nuclei with the Roentgen Satellite (ROSAT) Position Sensitive Proportional Counter (PSPC). These objects represents a sample of soft and hard spectrum sources; all were observed previously with the Einstein X-Ray Observatory. Included in this sample is EO132.8-4111, whose soft X-ray and ultraviolet flux distributions bear a striking resemblance to that of Mrk 841, but whose relative hard X-ray emission is much less than that of Mrk 841. The spectra are all fitted satisfactorily with single power-law models and their spectral indices (with one exception) agree with those estimated from the Einstein Image Propotional Counter (IPC) observations. Tests of short-term variability are carried out, with all sources showing constant count rates over the period of their ROSAT observations. Some sources do, however, show significant changes in count rate when compared to previous Einstein data taken a decade earlier.

Thompson, R. J., Jr.↗

DOE OSTI2019

The spatial extension of extended narrow line regions in MaNGA AGN

ABSTRACT In this work, we revisit the size–luminosity relation of the extended narrow line regions (ENLRs) using a large sample of nearby active galactic nuclei (AGNs) from the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey. The ENLRs ionized by the AGN are identified through the spatially resolved BPT diagram, which results in a sample of 152 AGN. By combining our AGN with the literature high-luminosity quasars, we found a tight log-linear relation between the size of the ENLR and the AGN $\rm [O\, III]$λ5007 Å luminosity over four orders of magnitude of the $\rm [O\, III]$ luminosity. The slope of this relation is 0.42 ± 0.02 which can be explained in terms of a distribution of clouds photoionized by the AGN. This relation also indicates that the AGNs have the potential to ionize and heat the gas clouds at a large distance from the nuclei without the aids of outflows and jets for the low-luminosity Seyferts.†

Chen, Jianhang↗

DOE OSTI2012

Study of surface fluorination of photocatalytic TiO{sub 2} by thermal shock method

Surface fluorinated TiO{sub 2} powders were prepared by thermal shock method and an overall comparative study was achieved on the basis of XRD, SEM, UV-vis and XPS analyses. The main objective was to elucidate the influences of surface fluorination on the crystallite structures, morphologies, optical properties and surface chemistry with the temperature. According to the results, the surface fluorination under thermal shock method below 600 Degree-Sign C did not change the crystallite structure and the particles size, but successfully created chemisorbed fluoride ions, oxygen vacancies and increased the hydroxyl groups on the surface of TiO{sub 2}. The presence of oxygen vacancies was assigned to the red shift of TiO{sub 2} optical absorption edge, which was the origin of visible-light-induced photocatalytic activity of these samples. For the thermal shock temperatures over 600 Degree-Sign C, the K{sub 2}Ti{sub 6}O{sub 13}-like phase was formed, resulting from the decrease of surface hydroxyl groups and the blue shift in absorption edge which reduced the photocatalytic activity. - Graphical abstract: The influence of fluorination on the surface of TiO{sub 2} by thermal shock method at several temperatures has been investigated by following the evolution of the F1s spectra obtained by X-ray photoelectron spectroscopy. The blank peaks are assigned to the chemisorbed fluoride ions on the samples surface and the filled peaks to fluorine atoms in oxygenated environment of solid solution TiO{sub 2-x}F{sub x}, which is originated from the substitution of F ions for O ions in the TiO{sub 2} lattice. Highlights: Black-Right-Pointing-Pointer Surface fluorination of TiO{sub 2} P25 by thermal shock method. Black-Right-Pointing-Pointer Structure, morphology, surface and photocatalytic properties of fluorinated TiO{sub 2}. Black-Right-Pointing-Pointer Low thermal shock temperatures increase the photocatalytic activity. Black-Right-Pointing-Pointer Fluoride ions chemisorbed on the surface without structure and morphology change. Black-Right-Pointing-Pointer Formation of K{sub 2}Ti{sub 6}O{sub 13} phase at high thermal shock temperatures.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2017

Radiochemical Methodology Applied To Determination of gamma-Emitting Radionuclides In Waste Samples From IEA-R1 Reactor - 17265

The Brazilian reactor IEA-R1 has been in operation since 1957. It is an open pool-type nuclear research reactor, operating at 2 to 5 MW that uses water as coolant, moderator and biological shield. Polypropylene filter cartridges are part of the water treatment system of the reactor and become radioactive as they remove suspended solid material from the cooling water during the operation of the reactor. Annually, the replacement of the filters from the reactor's water treatment system generates about 36 units. The development of a method for the characterization of the radionuclides present in the filters is required for routine operation in the Radioactive Waste Management Facility (RWMF) in order to determine the radioisotopic inventory of the waste packages. Wastes from nuclear reactors contain transuranic elements, activation and fission products, only few of them emitting gamma radiation measurable by simple gamma scanning methods. The method of the Scaling Factors (SF) uses empirically determined proportions between the concentrations of Difficult to Measure (DTM) radionuclides and that of easily measurable gamma emitters called Key Nuclide (KN), to calculate DTM concentrations. The objective of this study is to describe a method of the dissolution of the filter cartridges for determination of gamma emitting radionuclides. To determine the activity of a sample by means of of gamma spectrometry, it is necessary previous knowledge of the efficiency curve for a given geometry, which can be obtained by calibrating the efficiency and energy of the detector. The need to dissolve the filter cartridges has arisen given the difficulty in obtaining a standard source with the same filter geometry. Therefore, for this work, the calibration curve was constructed using a mixed gamma-ray standard with known activities, same geometry, density, physical state and chemical composition of the source to be analyzed. A sample with background count (BG) was prepared and analyzed under the same conditions as the samples and the result was subtracted from the results obtained for each filter sample. After many tests, it was possible to establish a method for the dissolution of filter cartridges for the determination of gamma-emitting radionuclides. A mixed gamma-ray standard was produced in liquid form, containing the following radionuclides: {sup 241}Am, {sup 137}Cs and {sup 60}Co, which have photo-peaks at the following energies: 59.54, 661.66 and 1332.49 keV, respectively. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

NASA NTRS2016

Resource Prospector Instrumentation for Lunar Volatiles Prospecting, Sample Acquisition and Processing

Data gathered from lunar missions within the last two decades have significantly enhanced our understanding of the volatile resources available on the lunar surface, specifically focusing on the polar regions. Several orbiting missions such as Clementine and Lunar Prospector have suggested the presence of volatile ices and enhanced hydrogen concentrations in the permanently shadowed regions of the moon. The Lunar Crater Observation and Sensing Satellite (LCROSS) mission was the first to provide direct measurement of water ice in a permanently shadowed region. These missions with other orbiting assets have laid the groundwork for the next step in the exploration of the lunar surface; providing ground truth data of the volatiles by mapping the distribution and processing lunar regolith for resource extraction. This next step is the robotic mission Resource Prospector (RP). Resource Prospector is a lunar mission to investigate 'strategic knowledge gaps' (SKGs) for in-situ resource utilization (ISRU). The mission is proposed to land in the lunar south pole near a permanently shadowed crater. The landing site will be determined by the science team with input from broader international community as being near traversable landscape that has a high potential of containing elevated concentrations of volatiles such as water while maximizing mission duration. A rover will host the Regolith & Environment Science and Oxygen & Lunar Volatile Extraction (RESOLVE) payload for resource mapping and processing. The science instruments on the payload include a 1-meter drill, neutron spectrometer, a near infrared spectrometer, an operations camera, and a reactor with a gas chromatograph-mass spectrometer for volatile analysis. After the RP lander safely delivers the rover to the lunar surface, the science team will guide the rover team on the first traverse plan. The neutron spectrometer (NS) and near infrared (NIR) spectrometer instruments will be used as prospecting tools to guide the traverse path. The NS will map the water-equivalent hydrogen concentration as low as 0.5% by weight to an 80 centimeter depth as the rover traverses the lunar landscape. The NIR spectrometer will measure surficial H2O/OH as well as general mineralogy. When the prospecting instruments identify a potential volatile-rich area during the course of a traverse, the prospect is then mapped out and the most promising location identified. An augering drill capable of sampling to a depth of 100 centimeters will excavate regolith for analysis. A quick assay of the drill cuttings will be made using an operations camera and NIR spectrometer. With the water depth confirmed by this first auguring activity, a regolith sample may be extracted for processing. The drill will deliver the regolith sample to a crucible that will be sealed and heated. Evolved volatiles will be measured by a gas chromatograph-mass spectrometer and the water will be captured and photographed. RP is a solar powered mission, which given the polar location translates to a relatively short mission duration on the order of 4-15 days. This short mission duration drives the concept of operations, instrumentation, and data analysis towards critical real time analysis and decision support. Previous payload field tests have increased the fidelity of the hardware, software, and mission operations. Current activities include a mission level field test to optimize interfaces between the payload and rover as well as better understand the interaction of the science and rover teams during the mission timeline. This paper will include the current status of the science instruments on the payload as well as the integrated field test occurring in fall of 2015. The concept of operations will be discussed, including the real time science and engineering decision-making process based on the critical data from the instrumentation. The path to flight will be discussed with the approach to this ambitious low cost mission.

ISRU↗

DOE OSTI2012

DEVELOPMENT OF A TAMPER RESISTANT/INDICATING AEROSOL COLLECTION SYSTEM FOR ENVIRONMENTAL SAMPLING AT BULK HANDLING FACILITIES

Environmental sampling has become a key component of International Atomic Energy Agency (IAEA) safeguards approaches since its approval for use in 1996. Environmental sampling supports the IAEA's mission of drawing conclusions concerning the absence of undeclared nuclear material or nuclear activities in a Nation State. Swipe sampling is the most commonly used method for the collection of environmental samples from bulk handling facilities. However, augmenting swipe samples with an air monitoring system, which could continuously draw samples from the environment of bulk handling facilities, could improve the possibility of the detection of undeclared activities. Continuous sampling offers the opportunity to collect airborne materials before they settle onto surfaces which can be decontaminated, taken into existing duct work, filtered by plant ventilation, or escape via alternate pathways (i.e. drains, doors). Researchers at the Savannah River National Laboratory and Oak Ridge National Laboratory have been working to further develop an aerosol collection technology that could be installed at IAEA safeguarded bulk handling facilities. The addition of this technology may reduce the number of IAEA inspector visits required to effectively collect samples. The principal sample collection device is a patented Aerosol Contaminant Extractor (ACE) which utilizes electrostatic precipitation principles to deposit particulates onto selected substrates. Recent work has focused on comparing traditional swipe sampling to samples collected via an ACE system, and incorporating tamper resistant and tamper indicating (TRI) technologies into the ACE system. Development of a TRI-ACE system would allow collection of samples at uranium/plutonium bulk handling facilities in a manner that ensures sample integrity and could be an important addition to the international nuclear safeguards inspector's toolkit. This work was supported by the Next Generation Safeguards Initiative (NGSI), Office of Nonproliferation and International Security (NIS), National Nuclear Security Administration (NNSA).

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

DOE OSTI2014

Physical properties of emission-line galaxies at z ∼ 2 from near-infrared spectroscopy with Magellan fire

We present results from near-infrared spectroscopy of 26 emission-line galaxies at z ∼ 2.2 and z ∼ 1.5 obtained with the Folded-port InfraRed Echellette (FIRE) spectrometer on the 6.5 m Magellan Baade telescope. The sample was selected from the WFC3 Infrared Spectroscopic Parallels survey, which uses the near-infrared grism of the Hubble Space Telescope Wide Field Camera 3 (WFC3) to detect emission-line galaxies over 0.3 ≲ z ≲ 2.3. Our FIRE follow-up spectroscopy (R ∼ 5000) over 1.0-2.5 μm permits detailed measurements of the physical properties of the z ∼ 2 emission-line galaxies. Dust-corrected star formation rates for the sample range from ∼5-100 M {sub ☉} yr{sup –1} with a mean of 29 M {sub ☉} yr{sup –1}. We derive a median metallicity for the sample of 12 + log(O/H) = 8.34 or ∼0.45 Z {sub ☉}. The estimated stellar masses range from ∼10{sup 8.5}-10{sup 9.5} M {sub ☉}, and a clear positive correlation between metallicity and stellar mass is observed. The average ionization parameter measured for the sample, log U ≈ –2.5, is significantly higher than what is found for most star-forming galaxies in the local universe, but similar to the values found for other star-forming galaxies at high redshift. We derive composite spectra from the FIRE sample, from which we measure typical nebular electron densities of ∼100-400 cm{sup –3}. Based on the location of the galaxies and composite spectra on diagnostic diagrams, we do not find evidence for significant active galactic nucleus activity in the sample. Most of the galaxies, as well as the composites, are offset diagram toward higher [O III]/Hβ at a given [N II]/Hα, in agreement with other observations of z ≳ 1 star-forming galaxies, but composite spectra derived from the sample do not show an appreciable offset from the local star-forming sequence on the [O III]/Hβ versus [S II]/Hα diagram. We infer a high nitrogen-to-oxygen abundance ratio from the composite spectrum, which may contribute to the offset of the high-redshift galaxies from the local star-forming sequence in the [O III]/Hβ versus [N II]/Hα diagram. We speculate that the elevated nitrogen abundance could result from substantial numbers of Wolf-Rayet stars in starbursting galaxies at z ∼ 2.

79 ASTRONOMY AND ASTROPHYSICS↗

DOE OSTI2023

Stability of Cu(In x Ga 1− x )Se 2 Solar Cells Utilizing RbF Postdeposition Treatment under a Sulfur Atmosphere

Alkali halide postdeposition treatments (PDTs) have become a key tool to maximize efficiency in Cu(In x Ga 1− x )Se 2 (CIGS) photovoltaics. RbF PDTs have emerged as an alternative to the more common Na‐ and K‐based techniques. This study utilizes temperature‐dependent current–voltage ( JVT ) measurements to study a unique RbF PDT performed in a S atmosphere. The samples are measured before and after 6 months in a desiccator to study device stability. Both samples contain Na and K which diffuse from the soda–lime glass substrate. A reference sample and a RbF + S PDT sample both show the development of a rear contact barrier after aging. The contact barrier is higher for the RbF + S PDT sample, leading to decreased current in forward bias. Series resistance is also higher in the RbF + S PDT device which leads to lower fill factor. However, after aging the reference sample has a larger decrease in open‐circuit voltage ( V OC ). Ideality factor measurements suggest Shockley–Read–Hall recombination dominates both samples. V OC versus temperature and a temperature‐dependent activation energy model are used to calculate diode activation energies for each sample condition. Both techniques produce similar values that indicate recombination primarily occurs within the bulk absorber.

14 SOLAR ENERGY↗

DOE OSTI2020

Non-destructive spatial analysis of phosphatase activity and total protein distribution in the rhizosphere using a root blotting method

Phosphorus (P) is an essential macronutrient for plant growth, but bioavailable P in soils is often limited due to immobilization resulting from pH and geochemical interactions. Understanding the dynamics of P in soils and elucidating the mechanisms by which plants access P from their environment are critical to evaluating productivity, particularly in nutrient poor environments. Phosphorus from organic matter can act as a major source of P for organisms in soil systems. Phosphatases, enzymes that liberate inorganic P from organic sources, are produced by both plants and microbes and are considered one of the most active classes of enzymes in soil. In this work we developed a root blotting method to spatially image phosphatase activity in the rhizosphere. Proteins from the rhizosphere are transferred to a nitrocellulose membrane while retaining their enzymatic activity and two-dimensional spatial distribution. Subsequent application of a fluorogenic phosphatase indicator, DDAO phosphate, enables visualization of the distribution of phosphatase activity in the sample. The proteins can then be fixed to the membrane and treated with a SYPRO® Ruby gel stain, a fluorescent total protein stain, allowing for visualization of total protein distribution. Taken together, the images of phosphatase activity and total protein localization can be mapped back to the root architecture and provide insight into factors affecting the spatial distribution of enzymatic activity and protein accumulation in the rhizosphere. Notably, this method can be applied to plants growing in rhizoboxes containing soil or soilless growth mixtures (e.g., sand or various potting mixes) and, because of the non-destructive nature of this approach, be performed over time to track changes. We anticipate that this fluorescent indicator imaging technique on root blots can be used in diverse plant-microbe-soil systems to better understand the role of phosphatases in P acquisition and soil P cycling.

59 BASIC BIOLOGICAL SCIENCES↗

DOE OSTI2010

Completion Report for Well ER-EC-11 Corrective Action Units 101 and 102: Central and Western Pahute Mesa

Well ER-EC-11 was drilled for the U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office, in support of the Nevada Environmental Restoration Project at the Nevada National Security Site (formerly Nevada Test Site), Nye County, Nevada. The well was drilled in September and October 2009 as part of the Pahute Mesa Phase II drilling program. A main objective was to investigate radionuclide migration down-gradient from Well Cluster ER-20-5 and Well ER-20-7 and across the northern Timber Mountain moat structural zone into the area referred to as the Bench, between Pahute Mesa and the Timber Mountain caldera complex. A secondary purpose of the well was to provide detailed hydrogeologic information for the shallow- to intermediate-depth Tertiary volcanic section in the Bench area. This well also provided detailed hydrogeologic information in the Tertiary volcanic section to reduce uncertainties within the Pahute Mesa-Oasis Valley hydrostratigraphic framework model (Bechtel Nevada, 2002). The main 52.1-centimeter hole was drilled to a depth of 507.5 meters and then opened to a diameter of 66.0 centimeters. It was cased with 50.8-centimeter casing to 504.9 meters. The hole diameter was then decreased to 47.0 centimeters, and drilling continued to a total depth of 979.3 meters. It was then cased with 34.0-centimeter casing set at 965.5 meters. The hole diameter was then decreased to 31.1 centimeters and the borehole was drilled to a total depth of 1,264.3 meters. The completion casing string, set to the depth of 1,262.5 meters, consists of 19.4-centimeter stainless-steel casing hanging from 19.4-centimeter carbon-steel casing. The stainless-steel casing has two slotted intervals open to the Tiva Canyon and Topopah Spring aquifers. Four piezometer strings were installed in Well ER-EC-11. A string of carbon-steel 6.0-centimeter tubing with one slotted interval was inserted outside the 50.8-centimeter casing, within the 66.0-centimeter borehole for access to the Timber Mountain aquifer, and landed at 475.3 meters. A second string of 6.0-centimeter tubing with one slotted interval was inserted outside the 34.0-centimeter casing, within the 47.0-centimeter borehole for access to the Benham aquifer, and landed at 911.7 meters. A third piezometer string consists of 7.3-centimeter stainless-steel tubing that hangs from 6.0-centimeter carbon-steel tubing via a crossover sub. This string was landed at 1,029.5 meters to monitor the Tiva Canyon aquifer. The deepest string of 7.3-centimeter tubing was landed at 1,247.8 meters to monitor the Topopah Spring aquifer. Data collected during and shortly after hole construction include composite drill cuttings samples collected every 3.0 meters, 67 percussion gun and rotary sidewall core samples, various geophysical logs, fluid samples (for groundwater chemistry analysis and tritium measurements), and water-level measurements. The well penetrated 1,264.3 meters of Tertiary volcanic rock, including three saturated welded-tuff aquifers and one saturated lava-flow aquifer. A water level was measured in the Timber Mountain aquifer at 449.6 meters, during open-hole geophysical logging on September 20, 2009. The fluid level measured after the total depth was reached and the upper aquifer was cased off was 450.0 meters when measured in the open borehole on October 17, 2009. Measurements on samples taken from the undeveloped well indicated that tritium levels averaging approximately 12,430 picocuries per liter (less than Safe Drinking Water Act levels) were encountered within the Benham aquifer. Tritium was below the minimum detectable activity concentration for samples collected from the Tiva Canyon aquifer and the Topopah Spring aquifer.

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2018

Reduced Sample Masses for Characterization of Simulated Hanford Low-Activity Waste Glasses

In this report, a method for preparing a smaller mass of simulated low-activity waste glass for anion measurements is demonstrated. The required mass of sample was reduced from 1.0 g to 0.2 g. This method will be used in future studies to reduce the amount of time and effort needed to produce sulfur saturated glasses for characterization.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

DOE OSTI2015

Characterization of plutonium activities in soil - 15429

Plutonium (Pu) contamination in soils at the Nevada National Security Site (NNSS) is characterized using Am-241 activity results from gamma spectroscopy (gamma Am-241) analysis. This is done by inferring the Pu activities using Pu to Am-241 ratios developed from Pu and Am-241 results from alpha spectroscopy isotopic analyses (isotopic Pu and isotopic Am-241). Although the isotopic Pu and Am-241 methods can accurately measure isotopic activities within the sampled material, the amount of soil analyzed is small (typically 1 gram [g] of soil). If there is heterogeneity of particle distribution within the contaminated release site soil, isotopic methods may provide results that are not representative of the contaminated site. The degree of potential heterogeneity needs to be considered before using isotopic analyses to characterize a Pu-contaminated site. Results from various Pu-contaminated sites at the NNSS are presented that demonstrate significant heterogeneity. A larger sample size (∼1,600 g) within a Marinelli container is used for the gamma spectroscopy analysis. This greatly reduces the impact of heterogeneously distributed discrete particles and provides results that are more representative of true contaminant activities at the release site. However, this method cannot provide Pu activities and has the potential to provide less accurate results due to the haphazard location of contaminant particles within the Marinelli container at the time of measurement. The distance of particles from the detector would result in some differential self-absorption of the emissions from radioactive particles. As the magnitude of this problem was not previously understood, a study was conducted to evaluate the variability in Am-241 results due to self-absorption from particle position. Results from this study are shown that demonstrate that this effect provides minimal variability in replicate Am-241 measurements. The method used at the NNSS to characterize Pu activities in soil takes advantage of the accuracy of the alpha spectroscopy isotopic analyses to establish Pu to Am-241 ratios and the more representative gamma spectroscopy results for Am-241 to provide a reliable characterization of Pu activities at contaminant release sites. (authors)

54 ENVIRONMENTAL SCIENCES↗

DOE OSTI2012

Closure Report for Corrective Action Unit 547: Miscellaneous Contaminated Waste Sites, Nevada National Security Site, Nevada

This Closure Report (CR) presents information supporting closure of Corrective Action Unit (CAU) 547, Miscellaneous Contaminated Waste Sites, and provides documentation supporting the completed corrective actions and confirmation that closure objectives for CAU 547 were met. This CR complies with the requirements of the Federal Facility Agreement and Consent Order (FFACO) that was agreed to by the State of Nevada; the U.S. Department of Energy (DOE), Environmental Management; the U.S. Department of Defense; and DOE, Legacy Management (FFACO, 1996 as amended). CAU 547 consists of the following three Corrective Action Sites (CASs), located in Areas 2, 3, and 9 of the Nevada National Security Site: (1) CAS 02-37-02, Gas Sampling Assembly; (2) CAS 03-99-19, Gas Sampling Assembly; AND (3) CAS 09-99-06, Gas Sampling Assembly Closure activities began in August 2011 and were completed in June 2012. Activities were conducted according to the Corrective Action Decision Document/Corrective Action Plan (CADD/CAP) for CAU 547 (U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office [NNSA/NSO], 2011). The recommended corrective action for the three CASs in CAU 547 was closure in place with administrative controls. The following closure activities were performed: (1) Open holes were filled with concrete; (2) Steel casings were placed over vertical expansion joints and filled with cement; (3) Engineered soil covers were constructed over piping and exposed sections of the gas sampling system components; (4) Fencing, monuments, Jersey barriers, radiological postings, and use restriction (UR) warning signs were installed around the perimeters of the sites; (5) Housekeeping debris was picked up from around the sites and disposed; and (6) Radiological surveys were performed to confirm final radiological postings. UR documentation is included in Appendix D. The post-closure plan was presented in detail in the CADD/CAP for CAU 547 and is included as Appendix F of this report. The requirements are summarized in Section 5.2 of this report. The proposed post-closure requirements consist of visual inspections to determine the condition of postings and radiological surveys to verify contamination has not migrated. NNSA/NSO requests the following: (1) A Notice of Completion from the Nevada Division of Environmental Protection to NNSA/NSO for closure of CAU 547; and (2) The transfer of CAU 547 from Appendix III to Appendix IV, Closed Corrective Action Units, of the FFACO.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

NASA NTRS2003

Simulation of Wind Profile Perturbations for Launch Vehicle Ascent Flight Systems Design Assessments

Ideally, a statistically representative sample of measured high-resolution wind profiles with wavelengths as small as tens of meters is required for assessment of launch vehicle ascent flight systems component capability and vehicle operability for a selected launch site. At most potential launch sites a sample of high-resolution measured wind profiles may not exist. Representative samples of Rawinsonde wind profiles are more likely to be available because of the extensive network of measurement sites established for routine measurements at 12-hr intervals in support of national and international weather observing and forecasting activity. Such a sample, although large enough to statistically represent relatively large wavelength perturbations, would be inadequate for launch system design assessment applications because the Rawinsonde system can accurately measure wind perturbations with wavelengths no smaller than 2000m (1000m altitude increment). Wavelengths less than 2000m in the raw Rawinsonde data, which tend to be dominated by un-damped spurious balloon motion and radar tracking system noise, are filtered within the data processing scheme. The Kennedy Space Center (KSC) Jimsphere wind profiles (150/month and seasonal pairs) are the only adequate high resolution (approximately 150 to 300m effective resolution, but over-sampled at 25m intervals) data that have been used extensively in launch vehicle design, operability assessments and operational protection of vehicle systems for wind perturbation uncertainty. Jimsphere wind profiles have been measured at a few other potential launch sites but the number of profiles is relatively small and the samples are not statistically representative of the site dependent wind profile variability. A simulation process has been developed for enhancement of measured low-resolution Rawinsonde profiles that are more likely to be available in the vicinity of potential launch sites and are a statistically representative sample of wind profile perturbation wavelengths greater than 2000m. The enhancement produces perturbed wind profiles with wavelengths as small as desired for application in launch vehicle ascent flight simulations and design assessments.

Adelfang, S. I.↗

DOE OSTI2015

A new sample of obscured AGNs selected from the XMM-Newton and AKARI surveys

We report a new sample of obscured active galactic nuclei (AGNs) selected from the XMM-Newton serendipitous source and AKARI point-source catalogs. We match X-ray sources with infrared (18 and 90 μm) sources located at |b|>10{sup ∘} to create a sample consisting of 173 objects. Their optical classifications and absorption column densities measured by X-ray spectra are compiled and study efficient selection criteria to find obscured AGNs. We apply the criteria (1) X-ray hardness ratio defined by using the 2–4.5 keV and 4.5–12 keV bands > −0.1 and (2) EPIC-PN count rate (CR) in the 0.2–12 keV to infrared flux ratio CR/F{sub 90}<0.1 or CR/F{sub 18}<1, where F{sub 18} and F{sub 90} are infrared fluxes at 18 and 90 μm in Jy, respectively, to search for obscured AGNs. X-ray spectra of 48 candidates, for which no X-ray results have been published, are analyzed and X-ray evidence for the presence of obscured AGNs such as a convex shape X-ray spectrum indicative of absorption of N{sub H} ∼ 10{sup 22–24} cm{sup −2}, a very flat continuum, or a strong Fe–K emission line with an equivalent width of >700 eV is found in 26 objects. Six of them are classified as Compton-thick AGNs, and four are represented by either Compton-thin or Compton-thick spectral models. The success rate of finding obscured AGNs combining our analysis and the literature is 92% if the 18 μm condition is used. Of the 26 objects, 4 are optically classified as an H ii nucleus and are new “elusive AGNs” in which star formation activity likely overwhelms AGN emission in the optical and infrared bands.

79 ASTRONOMY AND ASTROPHYSICS↗