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Evaluation of Isotopic Diagnostics for Subsurface Characterization and Monitoring: Field Experiments at the TAN And RWMC (SDA) Sites, INEEL

Description: The purpose of this project was to explore and refine applications of isotope ratio measurements for guiding environmental remediation strategies. The isotopic compositions of samples collected from field sites were analyzed to address both basic scientific issues and site-specific problems.
Date: June 1, 2000
Creator: DePaolo, Donald J.; Conrad, Mark E. & Miller, Eric E.
Partner: UNT Libraries Government Documents Department

Multi-collector Isotope Ratio Mass Spectrometer -- Operational Performance Report

Description: This report describes the operational testing of a new magnetic sector mass spectrometer that utilizes seven full-sized discrete dynode electron multipliers operating simultaneously. The instrument includes a newly developed ion dispersion lens that enables the mass dispersed individual isotope beams to be separated sufficiently to allow a full-sized discrete dynode pulse counting multiplier to be used to measure each isotope beam. The performance of the instrument was measured using SRM 996 (244Pu spike) at loadings of 2.4 and 12 fg on resin beads and with SRM 4350B Columbia River Sediment samples. The measured limit of detection (3s) for 240Pu was 3.4 attograms for SRM 996. The limit of quantitation (LOQ), defined as 10 s, was 11.2 attograms. The measured concentration of 239Pu in the CRS standard was 152 ± 6 fg/g.
Date: December 1, 2010
Creator: Appelhans, Anthony D; Olson, John E; Watrous, Matthew G; Ward, Michael B. & Dahl, David A.
Partner: UNT Libraries Government Documents Department

Sulfur isotope relative ratios determined by mass spectrometry

Description: BS>The ratio of the sulfur isotope ratio, /sup 34/S/(/sup 32/S + /sup 32/ S), in a sample of sulfur hexafluoride to that in an isotopically different sample (relative ratio) is determined to plus or minus 0.00003 (standard deviation) at relative ratios of 1.003-1.007 and near-natural isotopic abundances. (auth)
Date: December 1, 1973
Creator: Howard, O.H.
Partner: UNT Libraries Government Documents Department

Isotopic depletion with Monte Carlo

Description: This work considers a method to deplete isotopes during a time- dependent Monte Carlo simulation of an evolving system. The method is based on explicitly combining a conventional estimator for the scalar flux with the analytical solutions to the isotopic depletion equations. There are no auxiliary calculations; the method is an integral part of the Monte Carlo calculation. The method eliminates negative densities and reduces the variance in the estimates for the isotope densities, compared to existing methods. Moreover, existing methods are shown to be special cases of the general method described in this work, as they can be derived by combining a high variance estimator for the scalar flux with a low-order approximation to the analytical solution to the depletion equation.
Date: June 1, 1996
Creator: Martin, W.R. & Rathkopf, J.A.
Partner: UNT Libraries Government Documents Department

Recent improvements of a new thermal ionization cavity source for mass spectrometry

Description: Last year, we presented a prototype ion source design for mass spectrometry, which uses a tungsten crucible with a deep cavity for sample loading and enhanced surface ionization; the crucible is heated by high energy electron bombardment. This ion source was named as a thermal ionization cavity (TIC). In this present work, an TIC source has been designed with a vacuum interlock system and translational stage. It is now easier to operate and handle while maximizing sample throughput.
Date: June 1, 1996
Creator: Duan, Y.; Olivares, J.A.; Danen, R.E. & Cleland, T.J.
Partner: UNT Libraries Government Documents Department

Uranium and plutonium isotopic analysis using MGA++

Description: The Lawrence Livermore National Laboratory develops sophisticated gamma-ray analysis codes for the isotopic analysis of nuclear materials based on the principles used in the original MultiGroup Analysis (MGA) code. Over the years, the MGA methodology has been upgraded and expanded far beyond its original capabilities and is now comprised of a suite of codes known as MGA++. The early MGA code analyzed Pu gamma-ray data collected with high-purity germanium (HPGe) detectors to yield Pu isotopic ratios. While the original MGA code relied solely on the lower-energy gamma rays (around 100 keV), the most recent addition to the MGA++ code suite, MGAHI, analyzes Pu data using higher-energy gamma rays (200 keV and higher) and is particulatly useful for Pu samples - that are enclosed in thick-walled containers. The MGA++ suite also includes capabilities to perform U isotopic analysis on data collected with either HPGe or cadmium-zinc-tellutide (CZT) detectors. These codes are commercially available and are known as U235 and CZTU, respectively. A graphical user interface has also been developed for viewing the data and the fitting procedure. In addition, we are developing new codes that will integrate into the MGA++ suite. These will include Pu isotopic analysis capabilities for data collected with CZT detectors, U isotopic analysis with HPGe detectors which utilizes only higher energy gamma rays, and isotopic analyses on mixtures of Pu and U.
Date: July 1, 1998
Creator: Buckley, W; Clark, D; Friensehner, A; Parker, W; Raschke, K; Romine, W et al.
Partner: UNT Libraries Government Documents Department

Ambient Monitoring for Sinclair and Dyes Inlets, Puget Sound, Washington: Chemical Analyses for 2010 Regional Mussel Watch (AMB02)

Description: The Puget Sound Naval Shipyard & Intermediate Maintenance Facility (PSNS&IMF) and Naval Base Kitsap-Bremerton (Shipyard) located in Bremerton, WA are committed to a culture of continuous process improvement for all aspects of Shipyard operations, including reducing the releases of hazardous materials and waste in discharges from the Shipyard. Under the Project ENVVEST Final Project Agreement, a cooperative project among PSNS&IMF, the Environmental Protection Agency (EPA), and the Washington State Department of Ecology (Ecology), and local stakeholders (US Navy, EPA and Ecology 2002) has been helping to improve the environmental quality of the Sinclair and Dyes Inlet Watershed (ENVVEST 2006). An ambient monitoring program for sediment, water, and indigenous mussels began in 2009 to assess the status and trend of ecological resources, assess the effectiveness of cleanup and pollution control measures, and determine if discharges from all sources are protective of beneficial uses including aquatic life. This document presents the 2010 chemical residue data and stable isotopes of carbon (δ13C) and nitrogen (δ15N) for the regional mussel watch stations located in Sinclair Inlet, Dyes Inlet, Port Orchard Passage, Rich Passage, Agate Passage, Liberty Bay, and Keyport Lagoon. Indigenous bivalves were collected from a small boat and/or from along the shoreline, measured, composited, and analyzed for a suite of trace metals and organic contaminants. The trace metals included silver, arsenic, cadmium, chromium, copper, mercury, nickel, lead, and zinc. The organic contaminants included the list of NOAA Status and Trends 20 polychlorinated biphenyls (PCB) congeners and suite of parent and methylated polycyclic aromatic hydrocarbons (PAHs). These chemical residue data provide the first year of the biota ambient monitoring.
Date: October 20, 2010
Creator: Brandenberger, Jill M.; Kuo, Li-Jung; Suslick, Carolynn R. & Johnston, Robert K.
Partner: UNT Libraries Government Documents Department

Predicting 232U Content in Uranium

Description: The minor isotope 232U may ultimately be used for detection or confirmation of uranium in a variety of applications. The primary advantage of 232 U as an indicator of the presence of enriched uranium is the plentiful and penetrating nature of the radiation emitted by its daughter radionuclide 208Tl. A possible drawback to measuring uranium via 232U is the relatively high uncertainty in 232U abundance both within and between material populations. An important step in assessing this problem is to ascertain what determines the 232U concentration within any particular sample of uranium. To this end, we here analyze the production and eventual enrichment of 232 U during fuel-cycle operations. The goal of this analysis is to allow approximate prediction of 232 U quantities, or at least some interpretation of the results of 232U measurements. We have found that 232U is produced via a number of pathways during reactor irradiation of uranium and is subsequently concentrated during the later enrichment of the uranium' s 235U Content. While exact calculations are nearly impossible for both the reactor-production and cascade-enrichment parts of the prediction problem, estimates and physical bounds can be provided as listed below and detailed within the body of the report. Even if precise calculations for the irradiation and enrichment were possible, the ultimate 212U concentration would still depend upon the detailed fuel-cycle history. Assuming that a thennal-diffusion cascade is used to produce highly enriched uranium (HEU), dilution of reactor-processed fuel at the cascade input and the long-term holdup of 232U within the cascade both affect the 232U concentration in the product. Similar issues could be expected to apply for the other isotope-separation technologies that are used in other countries. Results of this analysis are listed below: 0 The 232U concentration depends strongly on the uranium enrichment, with depleted uranium (DU) ...
Date: January 7, 1999
Creator: Peurrung, AJ
Partner: UNT Libraries Government Documents Department

Chemical and isotopic variations of precipitation in the Los Alamos Region, New Mexico

Description: Precipitation collectors were installed at 14 locations on the Pajarito Plateau and surrounding areas to study variations in chemistry, stable isotopes and tritium for the years 1990 to 1993. The volume of precipitation was measured and samples were collected and analyzed every three to four months. All precipitation samples contain <2.50 mg/kg Cl and have pH values ranging from 5.4 to 6.7. The stable isotope ({delta}D/{delta}{sup 18}O) results record seasonal variations in precipitation as the weather patterns shift from sources in the Pacific Ocean to sources in the Gulf of Mexico. The stable isotope results also show isotopic variations due to elevation differences among the collection points. The tritium contents ({sup 3}H) in rain samples vary from 6.54 T.U. to 141 T.U. Contouring of high tritium values (e.g. >20 T.U.) from each collection period clearly shows that Laboratory activities release some tritium to the atmosphere. The effect of these releases are well below the limits set by the Environmental Protection Agency for drinking water (about 6200 T.U.). The magnitude of the releases is apparently greatest during the summer months. However, anomalous tritium values are detected as far north as Espahola, New Mexico for many collection periods. Tritium releases by the Laboratory are not constant; thus, the actual amount of tritium in each release has been diluted in the composite samples of our three to four month collection periods.
Date: February 1, 1995
Creator: Adams, A.I.; Goff, F. & Counce, D.
Partner: UNT Libraries Government Documents Department

Instrumentation for high-efficiency, high-sensitivity actinide analysis

Description: This is the final report of a 3-year project. We have developed a high-efficiency thermal ionization source that provides one to two orders of magnitude improvement in sample utilization efficiency in comparison with the traditional filament-type ion source currently used in thermal ionization mass spectrometry. This improved sample utilization efficiency results in a proportional increase in sample throughput and proportional decrease in analysis time. Coupling this source with a quadrupole mass spectrometer results in an instrument system for high-efficiency actinide analysis and other applications. In addition to its high efficiency, the sample used in this source can be much smaller than that in previous tube-type sources. The compact structure of the cavity makes it more applicable to any type of mass spectrometer and the whole instrument is small and transportable.
Date: April 1, 1996
Creator: Olivares, J.; Chamberlin, E.; Murrell, M.; Kahr, M. & Duan, Y.
Partner: UNT Libraries Government Documents Department

PC/FRAM, Version 3.2 User Manual

Description: This manual describes the use of version 3.2 of the PC/FRAM plutonium isotopic analysis software developed in the Safeguards Science and Technology Group, NE-5, Nonproliferation and International Security Division Los Alamos National Laboratory. The software analyzes the gamma ray spectrum from plutonium-bearing items and determines the isotopic distribution of the plutonium 241Am content and concentration of other isotopes in the item. The software can also determine the isotopic distribution of uranium isotopes in items containing only uranium. The body of this manual descnies the generic version of the code. Special facility-specific enhancements, if they apply, will be described in the appendices. The information in this manual applies equally well to version 3.3, which has been licensed to ORTEC. The software can analyze data that is stored in a file on disk. It understands several storage formats including Canberra's S1OO format, ORTEC'S `chn' and `SPC' formats, and several ASCII text formats. The software can also control data acquisition using an MCA and then store the results in a file on disk for later analysis or analyze the spectrum directly after the acquisition. The software currently only supports the control of ORTEC MCB'S. Support for Canbema's Genie-2000 Spectroscopy Systems will be added in the future. Support for reading and writing CAM files will also be forthcoming. A versatile parameter fde database structure governs all facets of the data analysis. User editing of the parameter sets allows great flexibility in handling data with different isotopic distributions, interfering isotopes, and different acquisition parameters such as energy calibration, and detector type. This manual is intended for the system supervisor or the local user who is to be the resident expert. Excerpts from this manual may also be appropriate for the system operator who will routinely use the instrument.
Date: February 23, 1999
Creator: Kelley, T.A. & Sampson, T.E.
Partner: UNT Libraries Government Documents Department

Determination of plutonium metal origins

Description: Forensic signatures are present in any Pu sample that can determine the sample`s origin: isotopic ratio of Pu, progeny species that grow into the sample, and contaminant species left over from incomplete purification of the Pu in fuel reprocessing. In the context of intelligence information, this can result in attribution of responsibility for the product of clandestine proliferant operations or material smuggled from existing stockpiles. A list of signature elements and what can be determined from them have been developed. Work needs to be done in converting concentrations of signature species into a quantitative forensic analysis, particularly in regard to reactor performance, but this should require only a small effort. A radiochemical analysis scheme has been developed for measuring these nuclides; more work is needed, particularly for determining fission product concentrations. A sample of Pu metal has been analyzed and several parameters determined that are strong indicators of its point of origin.
Date: February 1995
Creator: Moody, K. J.
Partner: UNT Libraries Government Documents Department

Groundwater ''fast paths'' in the Snake River plain aquifer: Radiogenic isotope ratios as natural groundwater tracers

Description: Preferential flow paths are expected in many groundwater systems and must be located because they can greatly affect contaminant transport. The fundamental characteristics of radiogenic isotope ratios in chemically evolving waters make them highly effective as preferential flow path indicators. These ratios tend to be more easily interpreted than solute-concentration data because their response to water-rock interaction is less complex. We demonstrate this approach with groundwater {sup 87}Sr/{sup 86}Sr ratios in the Snake River Plain aquifer within and near the Idaho National Engineering and Environmental Laboratory. These data reveal slow-flow zones as lower {sup 87}Sr/{sup 86}Sr areas created by prolonged interaction with the host basalts and a relatively fast flowing zone as a high {sup 87}Sr/{sup 86}Sr area.
Date: September 1, 2000
Creator: Johnson, Thomas M.; Roback, Robert C.; McLing, Travis L.; Bullen, Thomas D.; DePaolo, Donald J.; Doughty, Christine et al.
Partner: UNT Libraries Government Documents Department

Initial report on characterization of excess highly enriched uranium

Description: DOE`s Office of Fissile Materials Disposition assigned to this Y-12 division the task of preparing a report on the 174.4 metric tons of excess highly enriched U. Characterization included identification by category, gathering existing data (assay), defining the likely needed processing steps for prepping for transfer to a blending site, and developing a range of preliminary cost estimates for those steps. Focus is on making commercial reactor fuel as a final disposition path.
Date: July 1, 1996
Partner: UNT Libraries Government Documents Department

Renewal: Continential lithosphere evolution as a function of tectonic environment

Description: The Cenozoic tectonic environment and stress regime of the southwestern United States have changed dramatically from compression during shallow-angle subduction during the Laramide orogeny in the early Cenozoic to the current mode of Basin and Range extension. Questions remain unresolved concerning the causes of this transition, including the timing of the initiation of extension (estimates range from 36 to 25 Ma), and is the Basin and Range simply an mega-example of back-arc extension, or is extension related to the subduction of an oceanic spreading center about 30 Ma? We have examined the patterns of magmagenesis and geochemical composition through Cenozoic time in southern New Mexico. We have defined four magma sources that have contributed to Cenozoic magmas. Immediately following the Laramide, magmas contain substantial contributions from the lower crust. Mid-Tertiary extension is related to the eruption of rhyolitic ash-flow tuffs and basalts. The basalts were generated by melting of the lithospheric mantle; intercalated rhyolites have a strong upper crustal signature. Eruption of basalts and andesites with sources in the lithospheric mantle and lower crust continued for several million years after rhyolitic volcanism ceased. The region was nearly void of volcanic activity for 16 million years despite continued extension, but at 10 Ma, basalts derived from the asthenosphere began to erupt.
Date: June 1, 1995
Creator: McMillan, N.J. & Baldridge, W.S.
Partner: UNT Libraries Government Documents Department

ISO/GUM UNCERTAINTIES AND CIAAW (UNCERTAINTY TREATMENT FOR RECOMMENDED ATOMIC WEIGHTS AND ISOTOPIC ABUNDANCES)

Description: The International Organization for Standardization (ISO) has published a Guide to the expression of Uncertainty in Measurement (GUM). The IUPAC Commission on Isotopic Abundance and Atomic Weight (CIAAW) began attaching uncertainty limits to their recommended values about forty years ago. CIAAW's method for determining and assigning uncertainties has evolved over time. We trace this evolution to their present method and their effort to incorporate the basic ISO/GUM procedures into evaluations of these uncertainties. We discuss some dilemma the CIAAW faces in their present method and whether it is consistent with the application of the ISO/GUM rules. We discuss the attempt to incorporate variations in measured isotope ratios, due to natural fractionation, into the ISO/GUM system. We make some observations about the inconsistent treatment in the incorporation of natural variations into recommended data and uncertainties. A recommendation for expressing atomic weight values using a tabulated range of values for various chemical elements is discussed.
Date: July 23, 2007
Creator: Holden, N. E.
Partner: UNT Libraries Government Documents Department

Measurement of isotope separation factors in the palladium-hydrogen system using a thermistor technique

Description: The range of available data on separation factors in the palladium-hydrogen/deuterium system has been extended. A matched pair of glass-coated bead thermistors was used to measure gas phase compositions. The compositions of the input gas--assumed also to be the solid phase composition--were measured independently be mass spectrometry as being within 0.5 mole% of the values used to calibrate the thermistors. This assumption is based on the fact that > 99% of the input gas is absorbed into the solid. Separation factors were measured for 175 K {le} T {le} 389 K and for 0.195 {le} x{sub H} {le} 0.785.
Date: May 1998
Creator: Ortiz, T. M.
Partner: UNT Libraries Government Documents Department

Chinguetti - terrestrial age and pre-atmospheric size

Description: Chinguetti is a 4.5 kg mesosiderite find recovered from the Adra region of Mauretania. In this paper the authors analyse a portion of the recovered sample for cosmogenic radionuclides to determine its terrestrial age, and to determine its pre-atmospheric radius. They determined the terrestrial age of Chinguetti to be &lt; 30 ky. They constrain the pre-atmospheric radius to 50--80 cm and the shielding depths of 15--25 cm. These data indicate that Chinguetti is a comparatively recent fall.
Date: January 14, 2000
Creator: Welten, K C; Masarik, J; Bland, P A; Caffee, M W; Russell, S S; Grady, M M et al.
Partner: UNT Libraries Government Documents Department

Transuranic isotopic analysis using gamma rays

Description: Transuranic waste typically emits gamma rays that are characteristic of the isotopic composition of the materials. If the area of the gamma ray photopeaks in a High Purity Ge (HPGe) spectrum can be accurately determined and if the gamma ray/x-ray branching ratios and half-lives for the radionuclides in the sample are known the relative concentration of each isotope in the waste can be determined using tomographic techniques. Methods used to accurately determine these photopeaks usually requires a computer code that does multi-peak analysis and unfolding of a given part of the gamma-ray spectrum. Computer techniques allow an accurate determination of the photopeaks and hence the isotopic composition of the waste material. These computer techniques can be automated for different spectra within a wide range of possible isotopic compositions. To improve photopeak statistics all of the spectra taken in a tomographic survey of the sample are summed and are used in the isotopic analysis. The method, accuracy, and limitations of this type of isotopic analysis system will be discussed. The gamma ray acquisition system is currently being upgraded with multiple HPGe detectors to improve the counting statistics obtainable in a given amount of time. The results of the DOE performance evaluations and the progress of the multiple detector upgrade will be discussed.
Date: October 15, 1998
Creator: Clark, D & Decman, D
Partner: UNT Libraries Government Documents Department

Inductively coupled plasma mass spectrometry with a twin quadrupole instrument using laser ablation sample introduction and monodisperse dried microparticulate injection

Description: The focus of this dissertation is the use of a twin quadrupole inductively coupled plasma mass spectrometer (ICP-MS) for the simultaneous detection of two m/z values. The twin quadrupole ICP-MS is used with laser ablation sample introduction in both the steady state (10 Hz) and single pulse modes. Steady state signals are highly correlated and the majority of flicker noise cancels when the ratio is calculated. Using a copper sample, the isotope ratio {sup 63}Cu{sup +}/{sup 65}Cu{sup +} is measured with a relative standard deviation (RSD) of 0.26%. Transient signals for single laser pulses are also obtained. Copper isotope ratio measurements for several laser pulses are measured with an RSD of 0.85%. Laser ablation (LA) is used with steel samples to assess the ability of the twin quadrupole ICP-MS to eliminate flicker noise of minor components of steel samples. Isotopic and internal standard ratios are measured in the first part of this work. The isotope ratio {sup 52}Cr{sup +}/{sup 53}Cr{sup +} (Cr present at 1.31 %) can be measured with an RSD of 0.06 % to 0.1 %. For internal standard elements, RSDs improve from 1.9 % in the Cr{sup +} signal to 0.12% for the ratio of {sup 51}V{sup +} to {sup 52}Cr{sup +}. In the second part of this work, one mass spectrometer is scanned while the second channel measures an individual m/z value. When the ratio of these two signals is calculated, the peak shapes in the mass spectrum are improved significantly. Pulses of analyte and matrix ions from individual drops are measured simultaneously using the twin quadrupole ICP-MS with monodisperse dried microparticulate injection (MDMI). At modest Pb concentrations (500 ppm), a shoulder on the leading edge of the Li{sup +} signal becomes apparent. Space charge effects are consistent with the disturbances seen.
Date: February 1, 1997
Creator: Allen, L.A.
Partner: UNT Libraries Government Documents Department

Compulsory Deep Mixing of 3He and CNO Isotopes in the Envelopes of low-mass Red Giants

Description: Three-dimensional stellar modeling has enabled us to identify a deep-mixing mechanism that must operate in all low mass giants. This mixing process is not optional, and is driven by a molecular weight inversion created by the {sup 3}He({sup 3}He,2p){sup 4}He reaction. In this paper we characterize the behavior of this mixing, and study its impact on the envelope abundances. It not only eliminates the problem of {sup 3}He overproduction, reconciling stellar and big bang nucleosynthesis with observations, but solves the discrepancy between observed and calculated CNO isotope ratios in low mass giants, a problem of more than 3 decades standing. This mixing mechanism operates rapidly once the hydrogen burning shell approaches the material homogenized by the surface convection zone. In agreement with observations, Pop I stars between 0.8 and 2.0 M{sub {circle_dot}} develop {sup 12}C/{sup 13}C ratios of 14.5 {+-} 1.5, while Pop II stars process the carbon to ratios of 4.0 {+-} 0.5. In stars less than 1.25 M{sub {circle_dot}}, this mechanism also destroys 90% to 95% of the {sup 3}He produced on the main sequence.
Date: March 20, 2007
Creator: Eggleton, P P; Dearborn, D P & Lattanzio, J C
Partner: UNT Libraries Government Documents Department