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Plutonium and environmental metals in man. Interlaboratory meeting, May 9, 1973

Description: From plutonium and environmental metals in man conference; Albuquerque, New Mexico, USA (9 May 1973). The various aspects of handling human autopsy tissues and methods used for the determination of Pu in tissues are discussed. Types of cases are classified as: the general population, with no known exposure to actinide elements; former AEC personnel which had an exposure potential; and Transuranium Registry cases representing known exposures to Pu and other actinides. It is pointed out that 5 millirem/yr has been proposed as the maximum permissible level of Pu for the general human population, which is equal to approximately thrvee 1 mu m particles of Pu deposited per person per year and the analytical chemist is confronted with what appears to be an almost insurmountable task to detect this level of Pu in man. The interlaboratory calibration of counting methods, using standards of /sup 239/Pu, /sup 238/Pu, and /sup 236/Pu plated on stainle ss steel or samples of ashed beef bone, liver, and lung spiked with /sup 239/Pu, is discussed. Methods used for the chemical preparation of the ashed tissue samples for radiometric analysis are reported. (CH)
Date: November 1, 1973
Creator: Campbell, E. & McInroy, J.F.
Partner: UNT Libraries Government Documents Department

Experience operating LANL`s passive/active neutron (PAN) assay system

Description: We present a summary of our operating experience with LANL`s mobile PAN assay system, which was acquired from the Carlsbad Area Office in 1994, refurbished, calibrated, and fielded for the first time on LANL`s TRU waste in the winter of 1996. It is functionally identical to other PAN systems throughout the DOE complex and its software is the same as at INEL. Since Jan. 1996, it has passed the first round of the Performance Demonstration Program and has been used to assay several hundred drums of LANL`s TRU waste. Difficulties in assaying homogeneous wastes with high ({alpha},n) neutron fluxes and experience in assaying debris waste in both active and passive PAN modes are reported on.
Date: January 1, 1997
Creator: Taggart, D.P.; Betts, S.E.; Martinez, E.F.; Mendez, J.L.; Rael, C.D. & Vigil, J.J.
Partner: UNT Libraries Government Documents Department

Comparison of attenuation correction methods for TGS and SGS: Do we really need selenium-75?

Description: We compared attenuation-coefficient mapping techniques for use in tomographic gamma scanner (TGS) image reconstructions to determine whether there is a significant improvement when using fully coupled methods. For the constrained least-squares image reconstruction method tested here, we found no significant improvement. We also compared the effectiveness of different transmission source combinations for 129- and 414-keV {sup 239}Pu TGS assays. We concluded that the best source combination for TGS assays of {sup 239}Pu and other isotopes is a mixture of {sup 133}Ba, {sup 54}Mn, and {sup 60}Co. Three other source combinations were found to be at least as effective as {sup 75}Se.
Date: September 1, 1996
Creator: Estep, R.J.; Prettyman, T.H. & Sheppard, G.A.
Partner: UNT Libraries Government Documents Department

Sampling and Analysis Plan for the Gunite and Associated Tanks Treatability Study, wall coring and scraping in Tanks W-3 and W-4 (North Tank Farm), Oak Ridge National Laboratory, Oak Ridge, Tennessee

Description: This plan documents the procedures for collecting and analyzing wall core and wall scraping samples from Tanks W-3 and W-4 in the North Tank Farm. This is in support of the Comprehensive Environmental Response, Compensation, and Liability Act Treatability Study of the Gunite and Associated Tanks at ORNL. The sampling and analysis will be in concert with sludge retrieval and sluicing of the tanks. Wall scraping and wall core samples will be collected from each quadrant in each tank by using a scraping sampler and a coring drill deployed by the Houdini robot vehicle. Each sample will be labeled, transported to the Radioactive Materials Analytical Laboratory and analyzed for physical/radiological characteristics, including total activity, gross alpha, gross beta, radioactive Sr + Cs, and other alpha and gamma emitting radionuclides. The Data Quality Objectives process, based on US EPA guidance (EPA QA/G-4, Sept. 1994), was applied to identify the objectives of this sampling and analysis. Results of the analysis will be used to validate predictions of a Sr concrete diffusion model, estimate the amount of radioactivity remaining in the tank shells, provide information to correlate with measurements taken by the Gunite Tank Isotope Mapping Probe and the Characterization End Effector, and estimate the performance of the wall cleaning system.
Date: August 1, 1997
Partner: UNT Libraries Government Documents Department

Passive active neutron radioassay measurement uncertainty for combustible and glass waste matrices

Description: Using a modified statistical sampling and verification approach, total uncertainty of INEL`s Passive Active Neutron (PAN) radioassay system was evaluated for combustible and glass content codes. Waste structure and content of 100 randomly selected drums in each the waste categories were computer modeled based on review of real-time radiography video tapes. Specific quantities of Pu were added to the drum models according to an experimental design. These drum models were then submitted to the Monte Carlo Neutron Photon code processing and subsequent calculations to produce simulated PAN system measurements. The reported Pu masses from the simulation runs were compared with the corresponding input masses. Analysis of the measurement errors produced uncertainty estimates. This paper presents results of the uncertainty calculations and compares them to previous reported results obtained for graphite waste.
Date: January 1, 1997
Creator: Blackwood, L.G.; Harker, Y.D.; Meachum, T.R. & Yoon, Woo Y.
Partner: UNT Libraries Government Documents Department

Wastes characterization using APSTNG technology

Description: The associated-particle sealed-tube neutron generator (APSTNG) interrogates the inspected object with 14-MeV neutrons from d-t reaction and detects the alpha-particle associated with each neutron inside a cone encompassing the region of interest. Gamma-ray spectra from resulting neutron reactions inside the inspected volume identify fissionable materials and many nuclides. Flight times from detection times of the gamma rays and alpha particles separate the prompt and delayed gamma-ray spectra and can yield coarse tomographic images from a single orientation. The high-energy neutrons and gamma rays penetrate large objects and dense materials. The gamma-ray detector and neutron generator can be on the same side of the interrogated objects, so walls and other confined areas can be inspected as well as sealed containers. No collimators or radiation shielding are needed. The neutron generator is simple and small. Commercial electronics are used. A complete system could be transported in a van. Laboratory and limited field tests indicate APSTNG could be useful in analyzing radioactive waste in drums, walls, soils, and processing systems, particularly for unknown or heterogeneous configurations that may attenuate radiation. Toxic chemicals could be identified in mixed waste, and the ability to detect pockets of water may address criticality concerns.
Date: March 1996
Creator: Rhodes, E. A. & Dickerman, C. E.
Partner: UNT Libraries Government Documents Department

Summary of the Research Work of the Trace Elements Section, Geochemistry and Petrology Branch for the Period October 1 - December 31, 1951

Description: Report summarizing the research done by the Geochemistry and Petrology branch of the Trace Elements Section during the period from October 1 - December 31, 1951. Research includes mineralogic, petrologic, and geochemical investigations of radioactive rocks, minerals, and ores, as well as investigations of chemical, spectrographic, and radiometric methods of analysis to be applied to radioactive materials such as uranium, thorium, and their compounds.
Date: February 1952
Creator: Rabbitt, John C.
Partner: UNT Libraries Government Documents Department

Summary of the Research Work of the Trace Elements Section Geochemistry and Petrology Branch for the Period July 1 - September 30, 1951

Description: Report summarizing the research done by the Geochemistry and Petrology branch of the Trace Elements Section during the period from July 1 - September 30, 1951. Research includes mineralogic and petrologic investigations of radioactive rocks, minerals, and ores, as well as investigations of chemical, spectrographic, and radiometric methods of analysis to be applied to radioactive materials such as uranium, thorium, and their compounds.
Date: February 1952
Creator: Rabbitt, John C.
Partner: UNT Libraries Government Documents Department

Summary of the Research Work of the Trace Elements Section, Geochemistry and Petrology Branch, for the Period January 1 - June 30, 1951

Description: Report discussing the research work done by the Geochemistry and Petrology Branch of the Trace Elements Section of the U.S. Geological Survey during the period from January 1 - June 30, 1951. The studies mentioned involve mineralogic and petralogic investigations of radioactive rocks, minerals, and ores, as well as investigations of chemical, spectrographic, and radiometric methods of analysis for radioactive materials.
Date: September 1951
Creator: Rabbitt, John C.
Partner: UNT Libraries Government Documents Department

Summary of the Research Work of the Trace Elements Section, Geochemistry and Petrology Branch, for the Period January 1 - March 31, 1951

Description: Report summarizing the research done by the Geochemistry and Petrology branch of the Trace Elements Section during the period from January 1 - March 31, 1951. Research includes mineralogic and petrologic investigations of radioactive rocks, minerals, and ores, as well as investigations of chemical, spectrographic, and radiometric methods of analysis to be applied to radioactive materials such as uranium, thorium, and their compounds.
Date: May 1951
Creator: Rabbitt, John C.
Partner: UNT Libraries Government Documents Department

Single scintillation crystal versus Phoswich detectors for in vivo low- energy photon detection

Description: The development of in vivo body-count measurement systems for the detection of low-energy photons from americium and plutonium has stressed the importance of low background counting rates for better sensitivity. The measurement systems are develeped for use in the body-counting facility, which has been in operation at the Rocky Flats Plant, to detect exposures in humans from radioactive materials. The facility is in a separate building and houses the body courter which consists of thick steel walls. The detectors within the body counter section are arranged over a table or couch and can be positioned over various parts of the body of an individual being checked for the presence of radioactive materials. The systems in current use provide an improvement in background counting rates for sodium-iodide thallium detectors with the two- crystal sandwich or Phoswich scintillator. The two types of electronic configurations used with the Phoswich detectors demonstrate improvements in background counting rates over results from a single crystal detector. Tabulated data comparing the operating parameters of a single crystal and a dual-crystal configuration are included. (auth)
Date: January 1, 1974
Creator: Tyree, W. H.
Partner: UNT Libraries Government Documents Department

Sampling and verification methods for the uncertainty analysis of NDA and NDE waste characterization systems

Description: Use of nondestructive assay (NDA) and evaluation (NDE) systems in critical waste characterization requires a realistic assessment of the uncertainty in the measurements. The stated uncertainty must include potential effects of a variety of complicating external factors on the expected bias and precision. These factors include material heterogeneity (matrix effects), fluctuating background levels, and other variable operating conditions. Uncertainty figures from application of error propagation methods to data from controlled laboratory experiments using standard test materials can grossly underestimate the expected error. This paper reviews the standard error propagation method of uncertainty analysis, discusses some of its limitations, and presents an alternative approach based on sampling and verification. Examples of application of sampling and verification methods to measurement systems at INEL are described.
Date: January 1, 1997
Creator: Blackwood, L.G.
Partner: UNT Libraries Government Documents Department

Time and frequency domain measurements for plutonium metal rings

Description: The {sup 252}Cf-source-driven noise analysis method was used to measure the neutron multiplication factor for subcritical systems and to identify fissionable materials and configurations. These measurements with the moderator-ring configuration have shown that the {sup 252}Cf-source-driven noise methods, both in the time and frequency domain, can be used to identify and distinguish the {sup 242}Pu from the {sup 239}Pu ring. Signatures for each ring can be used to track and confirm the presence of these two types of Pu rings. Because of the sensitivity of these signatures to mass, these measurements can also confirm the Pu mass. These preliminary measurements have not yet explored the full range of capability of this method for this application.
Date: September 1996
Creator: Mihalczo, J. T.; Pare, V. K.; Blakeman, E. D.; Valentine, T. E.; Vessard, S. & Pruvost, N. L.
Partner: UNT Libraries Government Documents Department

Physics design of fissile mass-flow monitoring system

Description: The system measures the flow rate and uranium-235 content in liquid or gas streams; it does not penetrate the process piping. A moderated fission neutron source is used to periodicially introduce a burst of thermal neutrons into the fluid stream to induce fission; delayed gamma emissions from the resulting fission fragments are detected by high-efficiency scintillators downstream of the neutron source. The fluid flow rate is measure from the time between initiation of the thermal neutron burst and detection of the fission product gamma emissions, and the U-235 content is inferred from the intensity of the gamma burst detected. Design of the fissile mass flow monitor requires satisfaction of several competing constraints. Efficient operation of the monitor requires that source-induced fission rate and detection efficiency be maximized while the source-induced background rate is simultaneoulsy minimized. Near optical nuclear design of the system was achieved using numerous Monte Carlo calculations and measurements. This paper addresses calculational aspects of the physics design for the system applied to UF{sub 6} gas.
Date: September 1, 1997
Creator: Mattingly, J.K.; March-Leuba, J.; Valentine, T.E.; Mihalczo, J.T. & Uckan, T.
Partner: UNT Libraries Government Documents Department

Volatile organic compound monitoring by photo acoustic radiometry

Description: Two methods for sampling and analyzing volatile organics in subsurface pore gas were developed for use at the Hazardous Waste Disposal Site at Los Alamos National Laboratory. One is Thermal Desorption Gas Chromatography Mass Spectrometry (TDGCMS), the other is Photoacoustic Radiometry (PAR). Presented here are two years worth of experience and lessons learned as both techniques matured. The sampling technique is equally as important as the analysis method. PAR is a nondispersive infrared technique utilizing band pass filters in the region from 1 to 15 {mu}m. A commercial instrument, the Model 1302 Multigas Analyzer, made by Bruel and Kjaer, was adapted for field use. To use the PAR there must be some a priori knowledge of the constellation of analytes to be measured. The TDGCMS method is sensitive to 50 analytes. Hence TDGCMS is used in an initial survey of the site to determine what compounds are present and at what concentration. Once the major constituents of the soil-gas vapor plume are known the PAR can be configured to monitor for the five analytes of most interest. The PAR can analyse a sample in minutes, while in the field. The PAR is also quite precise in controlled situations.
Date: December 1, 1995
Creator: Sollid, J.E.; Trujillo, V.L.; Limback, S.P. & Woloshun, K.A.
Partner: UNT Libraries Government Documents Department