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230Th-234U Age-Dating Uranium by Mass Spectrometry (open access)

230Th-234U Age-Dating Uranium by Mass Spectrometry

This is the standard operating procedure used by the Isotope Ratio Mass Spectrometry Group of the Chemical Sciences Division at LLNL for the preparation of a sample of uranium oxide or uranium metal for {sup 230}Th-{sup 234}U age-dating. The method described here includes the dissolution of a sample of uranium oxide or uranium metal, preparation of a secondary dilution, spiking of separate aliquots for uranium and thorium isotope dilution measurements, and purification of uranium and thorium aliquots for mass spectrometry. This SOP may be applied to uranium samples of unknown purity as in a nuclear forensic investigation, and also to well-characterized samples such as, for example, U{sub 3}O{sub 8} and U-metal certified reference materials. The sample of uranium is transferred to a quartz or PFA vial, concentrated nitric acid is added and the sample is heated on a hotplate at approximately 100 C for several hours until it dissolves. The sample solution is diluted with water to make the solution approximately 4 M HNO{sub 3} and hydrofluoric acid is added to make it 0.05 M HF. A secondary dilution of the primary uranium solution is prepared. Separate aliquots for uranium and thorium isotope dilution measurements are taken and spiked with …
Date: April 18, 2012
Creator: Williams, R. W. & Gaffney, A. M.
Object Type: Report
System: The UNT Digital Library
Accident at Three Mile Island and its aftermath (open access)

Accident at Three Mile Island and its aftermath

Viewgraphs are presented that describe the Three Mile Island-2 reactor; the severe accident in the reactor; activity levels following the accident; and estimated costs associated with the accident.
Date: April 18, 1983
Creator: Malinauskas, A.P.
Object Type: Report
System: The UNT Digital Library
Active Climate Stabilization: Practical Physics-Based Approaches to Prevention of Climate Change (open access)

Active Climate Stabilization: Practical Physics-Based Approaches to Prevention of Climate Change

We offer a case for active technical management of the radiative forcing of the temperatures of the Earth's fluid envelopes, rather than administrative management of atmospheric greenhouse gas inputs, in order to stabilize both the global- and time-averaged climate and its mesoscale features. We suggest that active management of radiative forcing entails negligible--indeed, likely strongly negative--economic costs and environmental impacts, and thus best complies with the pertinent mandate of the UN Framework Convention on Climate Change. We propose that such approaches be swiftly evaluated in sub-scale in the course of an intensive international program.
Date: April 18, 2002
Creator: Teller, E.; Hyde, T. & Wood, L.
Object Type: Article
System: The UNT Digital Library
Advanced gas cooled nuclear reactor materials evaluation and development program. Progress report, October 1, 1979-December 31, 1979 (open access)

Advanced gas cooled nuclear reactor materials evaluation and development program. Progress report, October 1, 1979-December 31, 1979

This report presents the results of work performed from October 1, 1979 through December 31, 1979. Work covered in this report includes the activities associated with the status of the simulated reactor helium supply system, testing equipment and gas chemistry analysis instrumentation and equipment. The progress in the screening test program is described. This includes: screening creep results, weight gain and post-exposure mechanical properties for materials thermally exposed at 750/sup 0/ and 850/sup 0/C (1382/sup 0/ and 1562/sup 0/F). In addition, the status of the data management system is described.
Date: April 18, 1980
Creator: unknown
Object Type: Report
System: The UNT Digital Library
Alternative Fuel News: Official Publication of the U.S. Department of Energy's Clean Cities Network and the Alternative Fuels Data Center; Vol. 5, No. 1 (open access)

Alternative Fuel News: Official Publication of the U.S. Department of Energy's Clean Cities Network and the Alternative Fuels Data Center; Vol. 5, No. 1

A quarterly magazine with articles on recent changes to the Clean Cities Program; the SuperTruck student engineering challenge; alternative fuel use in delivery fleets; and a propane vehicle rally and conference in February 2001, in Kansas City, Mo.
Date: April 18, 2001
Creator: LaRocque, T.
Object Type: Book
System: The UNT Digital Library
Applications of in situ gamma-ray spectrometry. [Monitoring radionuclides in soil] (open access)

Applications of in situ gamma-ray spectrometry. [Monitoring radionuclides in soil]

Gamma-ray spectrometric methods using high-resolution Ge(Li) and high purity Ge detectors have been used to quantify the concentrations and external exposure rates of radionuclides in the soil. These in situ methods have been used to study radionuclide deposition around nuclear power stations, the distribution of radionuclides at the Nevada Test Site, biogeochemical cycling of radionuclides, and the fate and impact of fallout radionuclides. Portable gamma-ray spectrometer systems used for various kinds of in situ field measurements include: large-volume coaxial Ge(Li) detectors for terrestrial gamma-ray surveys at several sites including preoperational nuclear power plants and for real-time measurements of nuclear reactor plume isotopic exposure rates; and planar, high purity Ge detectors for mapping /sup 241/Am and /sup 239/Pu soil concentrations, particularly at the Nevada Test Site. These applications are discussed along with a brief description of the methodology and techniques associated with in situ gamma-ray spectrometry.
Date: April 18, 1978
Creator: Ragaini, R. C. & Kirby, J. A.
Object Type: Article
System: The UNT Digital Library
ASC Predictive Science Academic Alliance Program Verification and Validation Whitepaper (open access)

ASC Predictive Science Academic Alliance Program Verification and Validation Whitepaper

None
Date: April 18, 2006
Creator: Klein, R.; Doebling, S.; Graziani, F.; Pilch, M. & Trucano, T.
Object Type: Report
System: The UNT Digital Library
Assessment of high temperature nuclear energy storage systems for the production of intermediate and peak-load electric power (open access)

Assessment of high temperature nuclear energy storage systems for the production of intermediate and peak-load electric power

Increased cost of energy, depletion of domestic supplies of oil and natural gas, and dependence on foreign suppliers, have led to an investigation of energy storage as a means to displace the use of oil and gas presently being used to generate intermediate and peak-load electricity. Dedicated nuclear thermal energy storage is investigated as a possible alternative. An evaluation of thermal storage systems is made for several reactor concepts and economic comparisons are presented with conventional storage and peak power producing systems. It is concluded that dedicated nuclear storage has a small but possible useful role in providing intermediate and peak-load electric power.
Date: April 18, 1977
Creator: Fox, E. C.; Fuller, L. C. & Silverman, M. D.
Object Type: Report
System: The UNT Digital Library
Atmospheric Radiation Measurement Program Facilities Newsletter, March 2002. (open access)

Atmospheric Radiation Measurement Program Facilities Newsletter, March 2002.

Monthly newsletter discussing news and activities related to the Atmospheric Radiation Measurement Program, articles about weather and atmospheric phenomena, and other related topics.
Date: April 18, 2002
Creator: Atmospheric Radiation Measurement Program (U.S.)
Object Type: Journal/Magazine/Newsletter
System: The UNT Digital Library
Beam-beam observations in RHIC (open access)

Beam-beam observations in RHIC

N/A
Date: April 18, 2013
Creator: Y., Luo & Fischer, W.
Object Type: Report
System: The UNT Digital Library

Biogeochemical Coupling of Fe and Tc Speciation in Subsurface Sediments: Implications to Long-Term Tc Immobilization

None
Date: April 18, 2005
Creator: Zachara, J. M.; Fredrickson, J. K.; Kukkadapu, R. K.; Jeon, B.-H.; Heald, S. M. & McKinley, J. P.
Object Type: Presentation
System: The UNT Digital Library
Biological monitoring program for East Fork Poplar Creek (open access)

Biological monitoring program for East Fork Poplar Creek

In May 1985, a National Pollutant Discharge Elimination System (NPDES) permit was issued for the Oak Ridge Y-12 Plant. As a condition of the permit, a Biological Monitoring and Abatement Program (BMAP) was developed to demonstrate that the effluent limitations established for the Y-12 Plant protect the classified uses of the receiving stream (East Fork Poplar Creek; EFPC), in particular, the growth and propagation of aquatic life (Lear et al. 1989). A second objective of the BMAP is to document the ecological effects resulting from the implementation of a water pollution control program designed to eliminate direct discharges of wastewaters to EFPC and to minimize the inadvertent release of pollutants to the environment. Because of the complex nature of the discharges to EFPC and the temporal and spatial variability in the composition of the discharges, a comprehensive, integrated approach to biological monitoring was developed. A new permit was issued to the Y-12 Plant on April 28, 1995 and became effective on July 1, 1995. Biological monitoring continues to be required under the new permit. The BMAP consists of four major tasks that reflect different but complementary approaches to evaluating the effects of the Y-12 Plant discharges on the aquatic integrity …
Date: April 18, 1997
Creator: Adams, S. M.; Ashwood, T. L.; Beaty, T. W.; Brandt, C. C.; Christensen, S. W.; Cicerone, D. S. et al.
Object Type: Report
System: The UNT Digital Library
Blending UNH streams of different uranium enrichments (open access)

Blending UNH streams of different uranium enrichments

The cost and feasibility of blending UNH streams of different uranium enrichments at HAPO was evaluated on a preliminary basis. Cases studied were blending 37.5% enriched UNH with depleted E metal UNH to yield a 0.947% enriched end product, and blending depleted E metal UNH with the depleted natural uranium to yield 0.7115% enriched end product. A reasonable degree of feasibility is indicated for such a blend program at HAPO.
Date: April 18, 1958
Creator: Campbell, B. F.
Object Type: Report
System: The UNT Digital Library
Budget Estimate for Fiscal Year 1964 (open access)

Budget Estimate for Fiscal Year 1964

The stated objective of the SNAP-50 reactor and primary system development program is the design, fabrication, development and test operation of a series of reactors and associated equipment leading to a fully qualified and accepted SNAP-50 flight reactor and primary system.
Date: April 18, 1962
Creator: unknown
Object Type: Report
System: The UNT Digital Library
C reactor overbore fuel examination (open access)

C reactor overbore fuel examination

On April 16, 1962, the fuel charge in overbore tube 3062-C sustained a failure, and upon examination after discharge was found to contain three split failures and three ``worm tracked`` elements (depression in the aluminum cladding apparently the result of uranium cleavage and subsequent yielding of the cladding). These failures occurred approximately ten days following a period of reactor neutron flux cycling, and during a second cycle at C Reactor. In addition to the failures, a total of 17 elements, from nine separate fuel charges, contained worm tracks. Four of these elements were sent to Radiometallurgy Laboratory for destructive examination, to determine the mechanism of the suspected uranium cleavage.
Date: April 18, 1963
Creator: Hladek, K. L.; Teats, R. & Weakley, E. A.
Object Type: Report
System: The UNT Digital Library
Calculation of Departure From Nucleate Boiling Conditions for the Spert Iii Reactor in the High Pressure Region (open access)

Calculation of Departure From Nucleate Boiling Conditions for the Spert Iii Reactor in the High Pressure Region

Calculations are made to determine the safe steadystate power operating limits of the Spert III reactor from the viewpoint of fuel plate burnout. A computer program is developed for the IBM 704 to aid in these calculations. The Bettis design departure from nucleate boiling (DNB) equation is used in conjunction with the LeTourneau and Grimble method of hot channel'' analysis in the development of the calculations. For cases where DNB occurs in the bulk boiling region, a modified Martinelli-Nelson twophase flow correlation and some experimental singlephase pressure drop data are employed. DNB for a typical operating condition of 550 deg F inlet temperature and 2500 psig is computed to check the code. The results of the sample calculation show that at a steady- state power level of 60 Mw (maximum design power) the minimum flow rate required to prevent DNB is approximately 8000 gpm. (auth)
Date: April 18, 1962
Creator: Dugone, J.
Object Type: Report
System: The UNT Digital Library
Can Handheld Plastic Detectors Do Both Gamma and Neutron Isotopic Identification with Directional Source Location? (open access)

Can Handheld Plastic Detectors Do Both Gamma and Neutron Isotopic Identification with Directional Source Location?

This paper demonstrates, through MCNPX simulations, that a compact hexagonal array of detectors can be utilized to do both gamma isotopic identification (ID) along with neutron identification while simultaneously finding the direction of the source relative to the detector array. The detector array itself is composed of seven borated polyvinyl toluene (PVT) hexagonal light pipes approximately 4 inches long and with a 1.25 inch face-to-face thickness assembled in a tight configuration. The gamma ID capability is realized through judicious windowing algorithms as is the neutron spectral unfolding. By having multiple detectors in different relative positions, directional determination of the source can be realized. By further adding multiplicity counters to the neutron counts, fission events can be measured.
Date: April 18, 2008
Creator: Hayes, Robert
Object Type: Article
System: The UNT Digital Library
Carbon Sequestered, Carbon Displaced and the Kyoto Context (open access)

Carbon Sequestered, Carbon Displaced and the Kyoto Context

The integrated system that embraces forest management, forest products, and land-use change impacts the global carbon cycle - and hence the net emission of the greenhouse gas carbon dioxide - in four fundamental ways. Carbon is stored in living and dead biomass, carbon is stored in wood products and landfills, forest products substitute in the market place for products made from other materials, and forest harvests can be used wholly or partially to displace fossil fuels in the energy sector. Implementation of the Kyoto Protocol to the United Nations Framework Convention on Climate Change would result in the creation of international markets for carbon dioxide emissions credits, but the current Kyoto text does not treat all carbon identically. We have developed a carbon accounting model, GORCAM, to examine a variety of scenarios for land management and the production of forest products. In this paper we explore, for two simple scenarios of forest management, the carbon flows that occur and how these might be accounted for under the Kyoto text. The Kyoto protocol raises questions about what activities can result in emissions credits, which carbon reservoirs will be counted, who will receive the credits, and how much credit will be available? …
Date: April 18, 1999
Creator: Marland, G. & Schlamadinger, B.
Object Type: Article
System: The UNT Digital Library
Center for Multiscale Plasma Dynamics: Report on Activities (UCLA/MIT), 2009-2010 (open access)

Center for Multiscale Plasma Dynamics: Report on Activities (UCLA/MIT), 2009-2010

The final 'phaseout' year of the CMPD ended July 2010; a no cost extension was requested until May 2011 in order to enable the MIT subcontract funds to be fully utilized. Research progress over this time included verification and validation activities for the BOUT and BOUT++ code, studies of spontaneous reconnection in the VTF facility at MIT, and studies of the interaction between Alfven waves and drift waves in LAPD. The CMPD also hosted the 6th plasma physics winter school in 2010 (jointly with the NSF frontier center the Center for Magnetic Self-Organization, significant funding came from NSF for this most recent iteration of the Winter School).
Date: April 18, 2011
Creator: Carter, Troy
Object Type: Report
System: The UNT Digital Library
CENTER FOR PULSED POWER DRIVEN HIGH ENERGY DENSITY PLASMA STUDIES (open access)

CENTER FOR PULSED POWER DRIVEN HIGH ENERGY DENSITY PLASMA STUDIES

This annual report summarizes the activities of the Cornell Center for Pulsed-Power-Driven High-Energy-Density Plasma Studies, for the 12-month period October 1, 2005-September 30, 2006. This period corresponds to the first year of the two-year extension (awarded in October, 2005) to the original 3-year NNSA/DOE Cooperative Agreement with Cornell, DE-FC03-02NA00057. As such, the period covered in this report also corresponds to the fourth year of the (now) 5-year term of the Cooperative Agreement. The participants, in addition to Cornell University, include Imperial College, London (IC), the University of Nevada, Reno (UNR), the University of Rochester (UR), the Weizmann Institute of Science (WSI), and the P.N. Lebedev Physical Institute (LPI), Moscow. A listing of all faculty, technical staff and students, both graduate and undergraduate, who participated in Center research activities during the year in question is given in Appendix A.
Date: April 18, 2007
Creator: Kusse, Professor Bruce R. & Hammer, Professor David A.
Object Type: Report
System: The UNT Digital Library
CENTERLINE FOIL MEASUREMENTS OF THERMAL NEUTRON INTENSITIES FOR EXPERIMENT 1 (open access)

CENTERLINE FOIL MEASUREMENTS OF THERMAL NEUTRON INTENSITIES FOR EXPERIMENT 1

None
Date: April 18, 1951
Creator: Johnson, E. B.; McCammon, G. & Haydon, M. P.
Object Type: Report
System: The UNT Digital Library
Chemical Characterization of Selected Core Samples From the Vicinity of Tatum Salt Dome, Lamar County, Mississippi. Technical Letter: Dribble-35 (open access)

Chemical Characterization of Selected Core Samples From the Vicinity of Tatum Salt Dome, Lamar County, Mississippi. Technical Letter: Dribble-35

This report addresses the chemical characterization of selected core samples from the vicinity of Tatum Salt Dome, Lamar County, Mississippi.
Date: April 18, 1963
Creator: Jenne, E. A.
Object Type: Report
System: The UNT Digital Library
Committee report: LLL re-evaluation of the simple mirror for a fusion reactor (open access)

Committee report: LLL re-evaluation of the simple mirror for a fusion reactor

None
Date: April 18, 1975
Creator: Moir, R. W.; Baldwin, D. E.; Carlson, G. A.; Fowler, T. K.; Logan, B. G.; Lieberman, M. A. et al.
Object Type: Report
System: The UNT Digital Library
Comparison of Fabrication Approaches for Selectively Oxidized VCSEL Arrays (open access)

Comparison of Fabrication Approaches for Selectively Oxidized VCSEL Arrays

The impressive performance improvements of laterally oxidized VCSELs come at the expense of increased fabrication complexity for 2-dimensional arrays. Since the epitaxial layers to be wet-thermally oxidized must be exposed, non-planarity can be an issue. This is particularly important in that electrical contact to both the anode and cathode of the diode must be brought out to a package. They have investigated four fabrication sequences suitable for the fabrication of 2-dimensional VCSEL arrays. These techniques include: mesa etched polymer planarized, mesa etched bridge contacted, mesa etched oxide isolated (where the electrical trace is isolated from the substrate during the oxidation) and oxide/implant isolation (oxidation through small via holes) all of which result in VCSELs with outstanding performance. The suitability of these processes for manufacturing are assessed relative to oxidation uniformity, device capacitance, and structural ruggedness for packaging.
Date: April 18, 2000
Creator: Geib, Kent M.; Choquette, Kent D.; Allerman, Andrew A.; Briggs, Ronald D. & Hindi, Jana Jo
Object Type: Article
System: The UNT Digital Library