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The Production of U₂₃₄ by a Modified Calutron

Description: Abstract: Three and nine-tenths milligrams of U234 have been produced using a Calutron. A Beta-size Calutron was modified to produce complete resolution of the U234 beam from the U235 beam. With Beta charge the U234 current was 4 microamperes. The samples were collected upon flat pieces of graphite bent to fit the E curve.
Date: May 21, 1946
Creator: McKinney, C. R.
Partner: UNT Libraries Government Documents Department

Cleanup levels for Am-241, Pu-239, U-234, U-235 & U-238 in soils at the Rocky Flats Environmental Technology Site

Description: This presentation briefly outlines a cleanup program at a Rocky Flats site through viewgraphs and an executive summary. Exposure pathway analyses to be performed are identified, and decontamination levels are listed for open space and office worker exposure areas. The executive summary very briefly describes the technical approach, RESRAD computer code to be used for analyses, recommendations for exposure levels, and application of action levels to multiple radionuclide contamination. Determination of action levels for surface and subsurface soils, based on radiation doses, is discussed. 1 tab.
Date: July 3, 1997
Creator: Roberts, R.; Colby, B.; Brooks, L. & Slaten, S.
Partner: UNT Libraries Government Documents Department

Generation and mobility of radon in soils. Final report

Description: This report emphasizes research since 1993, but includes some description of previous work which has been discussed in prior reports and publications. The research has the objectives of answering the following questions: (1) How are Rn emanation coefficients related to the form of Ra and other U-series decay products? (2) How do Ra and Rn in soil depend on the form and behavior of their ancestors {sup 234}U and {sup 230}Th? (3) Under what conditions can thermally driven convection in soil have significant effects on radon transport in soil? (4) Under what conditions do soil moisture and soil air convection affect Rn in homes, and how are these variables relevant in mitigation?
Date: June 30, 1997
Creator: Rose, A. W.
Partner: UNT Libraries Government Documents Department

Isotopic signatures: An important tool in today`s world

Description: High-sensitivity/high-accuracy actinide measurement techniques developed to support weapons diagnostic capabilities at the Los Alamos National Laboratory are now being used for environmental monitoring. The measurement techniques used are Thermal Ionization Mass Spectrometry (TIMS), Alpha Spectrometry(AS), and High Resolution Gamma Spectrometry(HRGS). These techniques are used to address a wide variety of actinide inventory issues: Environmental surveillance, site characterizations, food chain member determination, sedimentary records of activities, and treaty compliance concerns. As little as 10 femtograms of plutonium can be detected in samples and isotopic signatures determined on samples containing sub-100 femtogram amounts. Uranium, present in all environmental samples, can generally yield isotopic signatures of anthropogenic origin when present at the 40 picogam/gram level. Solid samples (soils, sediments, fauna, and tissue) can range from a few particles to several kilograms in size. Water samples can range from a few milliliters to as much as 200 liters.
Date: December 1, 1995
Creator: Rokop, D.J.; Efurd, D.W.; Benjamin, T.M.; Cappis, J.H.; Chamberlin, J.W.; Poths, H. et al.
Partner: UNT Libraries Government Documents Department

Bird Surveys at DARHT Before and During Operations: Comparison of Species Abundance and Composition and Trace Element Uptake

Description: The Dual-Axis Radiographic Hydrodynamic Test (DARHT) Facility Mitigation Action Plan specifies the comparison of baseline conditions in biotic and abiotic media with those collected after operations have started. Operations at DARHT at Los Alamos National Laboratory started in 2000. In this study, the abundance and composition of birds collected near the DARHT facility from 2003 through 2006 were determined and compared to a preoperational period (1999). In addition, the levels of radionuclides and other inorganic chemicals in birds were compared to regional statistical reference levels (RSRLs). The number and diversity of bird species generally increased over preoperational levels with the greatest number of birds (412) and species (46) occurring in 2005. The most common bird species collected regardless of time periods were the chipping sparrow (Spizella passerina), the Virginia's warbler (Vermivora virginiae), the western bluebird (Sialia mexicana), the broad-tailed hummingbird (Selasphorus platycercus), the sage sparrow (Amphispiza belli), and the western tanager (Piranga ludoviciana). Most radionuclides, with the exception of uranium-234 and uranium-238, in (whole body) birds collected after operations began were either not detected or below RSRLs. Uranium-234 and uranium-238 concentrations in a few samples were far below screening levels and do not pose a potential unacceptable dose to the birds. In contrast, many inorganic chemicals, particularly arsenic and silver, in birds collected before and after operations began were in higher concentrations than RSRLs. Because birds (skin plus feathers) collected in the years before operations began contained higher levels of arsenic and silver than RSRLs and because there was no evidence of these metals in soil and sediment directly around the DARHT facility, the elevated levels of these metals in birds during early operations are probably not related to DARHT operations. Arsenic and silver in birds, however, have decreased over time to near background levels in 2007.
Date: November 30, 2007
Creator: P. R. Fresquez, D. C. Keller, C. D. Hathcock
Partner: UNT Libraries Government Documents Department

The Metabolism of Curium in the RAT

Description: The heaviest of the known elements is curium, which was recently discovered by Seaborg and his associates. This new element can be produced by the alpha particle transmutation of plutonium by the following reaction: {sub 94}Pu{sup 239} + {sub 2}He{sup 4} {yields} {sub 96}Cm{sup 242} + {sub 0}N{sup 1} This isotope of curium is radioactive and decays by the emission of an alpha particle to form plutonium 238 which, in turn, is also radioactive. Curium 242 has a half-life of 150 days, and its radioactive daughter, plutonium 238, has a half-life of 50 years. This isotope of plutonium decays by the emission of an alpha particle to form uranium 234 which has a half-life of 233,000 years. Shortly after the organization of the Atomic Energy Project, it became apparent that formidable problems would be presented as the result of the release of nuclear energy. One of the most urgent of these was the hazard presented by the production of large quantities of the radio-elements created by the fission of uranium and the coincidental formation of neptunium and plutonium. In an attempt to evaluate the potential danger presented by these radio-elements from the chain reacting pile, a large series of metabolic studies with experimental animals were undertaken in a number of laboratories working upon the Atomic Energy program. These studies, which have been briefly summarized elsewhere, included a series of investigations on the metabolism in the rat of the more important members of the fission products in the carrier-free state, as well as most of the heaviest elements at the end of the periodic table. These studies made it possible to predict on a semi-quantitative basis the potential hazards that this large number of radioactive elements might present should they gain entry into the body.
Date: January 15, 1948
Creator: Hamilton, J.; Scott, K. & Axelrod, D.
Partner: UNT Libraries Government Documents Department

The excretion of hexavalent uranium following intravenous administration. II, Studies on human subjects

Description: Tracer studies employing uranium enriched in the isotopes U{sup 234}, U{sup 235} have been carried out in six human subjects; four males and two females. The uranium, 6 micrograms to 70 micrograms per kilogram of body weight was given intravenously in the hexavalent state as uranyl nitrate. Each individual of the series received a single injection of the metal except for one who was given two widely spaced doses. The first of these was when his condition was normal and the second after an acidosis had been produced by ingestion of ammonium chloride. Renal function tests including urinary catalase, protein, amino N to Creatinine N ratio and clearances of mannitol and p-aminohippurate were done before and after administration of uranium. Only at the 70 microgram per kilogram level in Subject 6 was there a slight rise in urinary catalase and protein suggesting that tolerance had been reached. The excretion of uranium was mainly in the urine, where from 70 to 85% of the administered dose appeared in the first twenty-four hours. Urine of the second twenty-four hours contained about 4% and the third twenty-four hour urine, 1.5% of the administered dose. Detectable amounts were excreted for at least two weeks.
Date: June 25, 1948
Creator: Bassett, S.H.; Frankel, A.; Cedars, N.; VanAlstine, H.; Waterhouse, C. & Cusson, K.
Partner: UNT Libraries Government Documents Department

Letter report: Radiological analysis of Oak Ridge Y-12 plant groundwater data

Description: The Y-12 Plant groundwater radiological data bases have been analyzed to determine whether historical and current data is suitable for unqualified release to various user groups. User groups include those who routinely compare results to reference standards or regulatory levels, conduct hydrogeological transport studies, conduct statistical analyses and conduct risk assessment studies. The overall methodology used for the radiological analysis is to check whether results are consistent with chemical and physical expectations, plant operational history and, where applicable, with results from other sites. For example, the relationship among isotopes in a decay chain are predictable if no unusual sources for a particular isotope in the chain exists, the time history is known, and differential removal or concentration mechanisms for a particular isotope are understood or do not exist. Similarly, background concentrations for radioisotopes (e.g., {sup 238}U, {sup 234}U, {sup 235}U, {sup 230}Th, {sup 226}Ra, etc.) should be consistent with those obtained in other studies given similar mineralogical or hydrogeological conditions at the Y-12 Plant. If the analysis results in lack of agreement between results and expectations based on known relationships, plant operations and transport parameters, then results are investigated further.
Date: June 22, 1995
Creator: Walsh, P.
Partner: UNT Libraries Government Documents Department

Installation of reactive metals groundwater collection and treatment systems

Description: Three groundwater plumes contaminated with volatile organic compounds (VOCs) and radionuclides at the Rocky Flats Environmental Technology Site are scheduled for remediation by 1999 based on the Rocky Flats Cleanup Agreement (RFCA) (DOE, 1996). These three plumes are among the top 20 environmental cleanup sites at Rocky Flats. One of these plumes, the Mound Site Plume, is derived from a previous drum storage area, and daylights as seeps near the South Walnut Creek drainage. Final design for remediation of the Mound Site Plume has been completed based on use of reactive metals to treat the contaminated groundwater, and construction is scheduled for early 1998. The two other plumes, the 903 Pad/Ryan`s Pit and the East Trenches Plumes, are derived from VOCs either from drums that leaked or that were disposed of in trenches. These two plumes are undergoing characterization and conceptual design in 1998 and construction is scheduled in 1999. The contaminants of concern in these plumes are tetrachloroethene, trichloroethene, carbon tetrachloride and low levels of uranium and americium.
Date: July 1, 1998
Creator: Hopkins, J.K.; Primrose, A.L.; Vogan, J. & Uhland, J.
Partner: UNT Libraries Government Documents Department

Ambient air sampling for radioactive air contaminants at Los Alamos National Laboratory: A large research and development facility

Description: This paper describes the ambient air sampling program for collection, analysis, and reporting of radioactive air contaminants in and around Los Alamos National Laboratory (LANL). Particulate matter and water vapor are sampled continuously at more than 50 sites. These samples are collected every two weeks and then analyzed for tritium, and gross alpha, gross beta, and gamma ray radiation. The alpha, beta, and gamma measurements are used to detect unexpected radionuclide releases. Quarterly composites are analyzed for isotopes of uranium ({sup 234}U, {sup 235}U, {sup 238}U), plutonium ({sup 238}Pu, {sup 239/249}Pu), and americium ({sup 241}Am). All of the data is stored in a relational database with hard copies as the official records. Data used to determine environmental concentrations are validated and verified before being used in any calculations. This evaluation demonstrates that the sampling and analysis process can detect tritium, uranium, plutonium, and americium at levels much less than one percent of the public dose limit of 10 millirems. The isotopic results also indicate that, except for tritium, off-site concentrations of radionuclides potentially released from LANL are similar to typical background measurements.
Date: September 1, 1998
Creator: Eberhart, C.F.
Partner: UNT Libraries Government Documents Department

Direct-scanning alpha spectrometer for americium and plutonium contamination on highly-enriched uranium surfaces

Description: Trace Pu{sup 239} and Am{sup 241} contamination on a surface whose alpha count is dominated by U{sup 235} and U{sup 234} decay has been successfully quantified by counting swipes in external alpha spectroscopy chambers. The swipe process, however, is labor intensive and subject to uncertainties in the swiping process as well as degraded spectral resolution due to the presence of the swipe material. A multichannel instrument for automated in situ measurements of interior and exterior contamination has been developed which incorporates a rotary table, 13 fixed ion-implanted silicon detectors, and spectroscopy electronics. Custom software was written to allow alpha spectrometer to function as a virtual instrument in the LabView environment. This system gives improved speed and resolution as well as a complete log of the location of areas of high surface contamination, a feature not practical to obtain by other methods, and one which opens the possibility of long term studies such as Pu outgrowth evaluation employing the instrument. The authors present performance data as well as system integration, calibration, control, and dynamic geometric efficiency calculations related to the design of this and next generation systems.
Date: April 2, 1997
Creator: Ward, W.C.; Martinez, H.E.; Abeyta, C.L.; Morgan, A.N. & Nelson, T.O.
Partner: UNT Libraries Government Documents Department

Derivation of guidelines for uranium residual radioactive material in soil at the B&T Metals Company site, Columbus, Ohio

Description: Guidelines for uranium residual radioactive material in soil were derived for the B&T Metals Company site in Columbus, Ohio. This site has been identified for remedial action under the US Department of Energy`s (DOE`s) Formerly Utilized Sites Remedial Action Program (FUSRAP). Single-nuclide and total-uranium guidelines were derived on the basis of the requirement that following remedial action, the 50-year committed effective dose equivalent to a hypothetical individual living or working in the immediate vicinity of the site should not exceed a dose constraint of 30 mrem/yr for the current use and likely future use scenarios or a dose limit of 100 n-mrem/yr for less likely future use scenarios. The DOE residual radioactive material guideline computer code, RESRAD, was used in this evaluation. RESRAD implements the methodology described in the DOE manual for establishing residual radioactive material guidelines. Three scenarios were considered; each assumed that for a period of 1,000 years following remedial action, the site would be used without radiological restrictions. The three scenarios varied with regard to the type of site use, time spent at the site by the exposed individual, and sources of food and water consumed. The evaluations indicate that the dose constraint of 30 mrem/yr would not be exceeded for uranium (including uranium-234, uranium-235, and uranium-238) within 1,000 years, provided that the soil concentration of total uranium (uranium-234, uranium-235, and uranium-238) at the B&T Metals site did not exceed 1, I 00 pCi/g for Scenario A (industrial worker, current use) or 300 pCi/g for Scenario B (resident with municipal water supply, a likely future use). The dose limit of 100 mrem/yr would not be exceeded at the site if the total uranium concentration of the soil did not exceed 880 pCi/g for Scenario C (resident with an on-site water well, a plausible but unlikely future use).
Date: January 1996
Creator: Kamboj, S.; Nimmagadda, Mm. & Yu, C.
Partner: UNT Libraries Government Documents Department

Particle count monitoring of reverse osmosis water treatment for removal of low-level radionuclides

Description: Laser diode particle counting technology and analytical measurements were used to evaluate a pilot-scale reverse osmosis (RO) water treatment system for removal of particulate matter and sub-picocurie low-level radionuclides. Stormwater mixed with Waste Water Treatment Plant (WWTP) effluent from the Rocky Flats Environmental Technology Site (RFETS), formerly a Department of Energy (DOE) nuclear weapons production facility, were treated. No chemical pretreatment of the water was utilized during this study. The treatment system was staged as follows: multimedia filtration, granular activated carbon adsorption, hollow tube ultrafiltration, and reverse osmosis membrane filtration. Various recovery rates and two RO membrane models were tested. Analytical measurements included total suspended solids (TSS), total dissolved solids (TDS), gross alpha ({alpha}) and gross beta ({beta}) activity, uranium isotopes {sup 233/234}U and {sup 238}U, plutonium {sup 239/240}Pu, and americium {sup 241}Am. Particle measurement between 1--150 microns ({mu}) included differential particle counts (DPC), and total particle counts (TPC) before and after treatment at various sampling points throughout the test. Performance testing showed this treatment system produced a high quality effluent in clarity and purity. Compared to raw water levels, TSS was reduced to below detection of 5 milligrams per liter (mg/L) and TDS reduced by 98%. Gross {alpha} was essentially removed 100%, and gross {beta} was reduced an average of 94%. Uranium activity was reduced by 99%. TPC between 1-150{mu} were reduced by an average 99.8% to less than 1,000 counts per milliliter (mL), similar in purity to a good drinking water treatment plant. Raw water levels of {sup 239/240}Pu and {sup 241}Am were below reliable quantitation limits and thus no removal efficiencies could be determined for these species.
Date: March 1, 1995
Creator: Moritz, E.J.; Hoffman, C.R. & Hergert, T.R.
Partner: UNT Libraries Government Documents Department

Closure Report for Corrective Action Unit 261: Area 25 Test Cell A Leachfield System, Nevada Test Site, Nevada

Description: The purpose of this Closure Report (CR) is to provide documentation of the completed corrective action at the Test Cell A Leachfield System and to provide data confirming the corrective action. The Test Cell A Leachfield System is identified in the Federal Facility Agreement and Consent Order (FFACO) of 1996 as Corrective Action Unit (CAU) 261. Remediation of CAU 261 is required under the FFACO (1996). CAU 261 is located in Area 25 of the Nevada Test Site (NTS) which is approximately 140 kilometers (87 miles) northwest of Las Vegas, Nevada (Figure 1). CAU 261 consists of two Corrective Action Sites (CASS): CAS 25-05-01, Leachfield; and CAS 25-05-07, Acid Waste Leach Pit (AWLP) (Figures 2 and 3). Test Cell A was operated during the 1960s and 1970s to support the Nuclear Rocket Development Station. Various operations within Building 3124 at Test Cell A resulted in liquid waste releases to the Leachfield and the AWLP. The following existing site conditions were reported in the Corrective Action Decision Document (CADD) (U.S. Department of Energy, Nevada Operations Office [DOE/NV], 1999): Soil in the leachfield was found to exceed the Nevada Division of Environmental Protection (NDEP) Action Level for petroleum hydrocarbons, the U.S. Environmental Protection Agency (EPA) preliminary remediation goals for semi volatile organic compounds, and background concentrations for strontium-90; Soil below the sewer pipe and approximately 4.5 meters (m) (15 feet [ft]) downstream of the initial outfall was found to exceed background concentrations for cesium-137 and strontium-90; Sludge in the leachfield septic tank was found to exceed the NDEP Action Level for petroleum hydrocarbons and to contain americium-241, cesium-137, uranium-234, uranium-238, potassium-40, and strontium-90; No constituents of concern (COC) were identified at the AWLP. The NDEP-approved CADD (DOWNV, 1999) recommended Corrective Action Alternative 2, ''Closure of the Septic Tank and Distribution Box, Partial ...
Date: April 1, 2001
Creator: Fitzmaurice, T. M.
Partner: UNT Libraries Government Documents Department

U-234/U-238 ratio: Qualitative estimate of groundwater flow in Rocky Flats monitoring wells

Description: Groundwater movement through various pathways is the primary mechanism for the transport of radionuclides and trace elements in a water/rock interaction. About three dozen wells, installed in the Rocky Flats Plant (RFP) Solar Evaporation Ponds (SEP) area, are monitored quarterly to evaluate the extent of any lateral and downgradient migration of contaminants from the Solar Evaporation Ponds: 207-A; 207-B North, 207-B Center, and 207-B South; and 207-C. The Solar Ponds are the main source for the various contaminants: radionuclides (U-238, U-234, Pu-239, 240 and Am-241); anions; and trace metals to groundwaters. The U-238 concentrations in Rocky Flats groundwaters vary from <0.2 to 69 pCi/I (IpCi = 3 ug). However, the activity U-234/U-238 ratios are low and range mostly 1.2 to 2.7. The low activity ratios can be interpreted to suggest that the groundwaters are moving slow (<l meter/year); this is supported with an estimate of about a few ft/year based on hydrologic parameters [1]. Uranium is probably present in the +6 state, predominantly as a uranyl carbonate complexes UO{sub 2}(CO{sub 3}){sub 2}{sup 2{minus}}, because of the predominant bicarbonate medium.
Date: February 1, 1994
Creator: Laul, J. C.
Partner: UNT Libraries Government Documents Department

Mound Laboratory Progress Report for December, 1964

Description: This monthly report has the following sections: (1) Radioelements - Uranium-234, Hydrolytic Separations of Protactinium, Polonium-208 and Polonium-209; (2) Isotope Separation and Purification - Carbon-13, Helium, Neon, Argon, Krypton, Xenon, Thermal Diffusion Research, and Helium Research; (3) Analytical and Instrumentation - Neptunium Analysis, Cobalt Analysis, Analysis of Enriched Uranium-234 for Comparison Purposes, Analysis of Stearic Acid in Silver Powder, Nuclear Magnetic Resonance Studies, Semiconductor Radiation Detectors, and Calorimetry.
Date: December 21, 1964
Creator: EIchelberger, J.F.; Grove, G.R. & Jones, L.V.
Partner: UNT Libraries Government Documents Department