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Reduction of pertechnetate by acetohydroxamic acid: Formation of [TcNO(AHA)2(H2O)]+ and implications for the UREX process.
Reductive nitrosylation and complexation of ammonium pertechnetate by acetohydroxamic acid has been achieved in aqueous nitric and perchloric acid solutions. The kinetics of the reaction depend on the relative concentrations of the reaction components and are accelerated at higher temperatures. The reaction does not occur unless conditions are acidic. Analysis of the x-ray absorption fine structure spectroscopic data is consistent with a pseudo-octahedral geometry with the linear Tc-N-O bond typical of technetium nitrosyl compounds, and electron spin resonance spectroscopy is consistent with a the d{sup 5} Tc(II) nitrosyl complex. The nitrosyl source is generally AHA, but may be augmented by products of reaction with nitric acid. The resulting low-valency trans-aquonitrosyl(diacetohydroxamic)-technetium(II) complex (1) is highly soluble in water, extremely hydrophilic, and is not extracted by tri-n-butylphosphate in a dodecane diluent. Its extraction properties are not pH-dependent; titration studies indicate a single species from pH 4.5 down to -0.6 (calculated). This molecule is resistant to oxidation by H{sub 2}O{sub 2}, even at high pH, and can undergo substitution to form other technetium nitrosyl complexes. The formation of 1 may strongly impact the fate of technetium in the nuclear fuel cycle.
Date:
February 26, 2008
Creator:
1Harry Reid Center for Environmental Studies, Nuclear Science and Technology Division, University of Nevada, Las Vegas, Las Vegas, NV, 89154-4006; Gong, Cynthia-May S; Poineau, Frederic; Lukens, Wayne W & Czerwinski, Kenneth R.
Object Type:
Article
System:
The UNT Digital Library
High-Level Waste Melter Review
The U.S. Department of Energy (DOE) is faced with a massive cleanup task in resolving the legacy of environmental problems from years of manufacturing nuclear weapons. One of the major activities within this task is the treatment and disposal of the extremely large amount of high-level radioactive (HLW) waste stored at the Hanford Site in Richland, Washington. The current planning for the method of choice for accomplishing this task is to vitrify (glassify) this waste for disposal in a geologic repository. This paper describes the results of the DOE-chartered independent review of alternatives for solidification of Hanford HLW that could achieve major cost reductions with reasonable long-term risks, including recommendations on a path forward for advanced melter and waste form material research and development. The potential for improved cost performance was considered to depend largely on increased waste loading (fewer high-level waste canisters for disposal), higher throughput, or decreased vitrification facility size.
Date:
February 26, 2002
Creator:
Ahearne, J.; Gentilucci, J.; Pye, L. D.; Weber, T.; Woolley, F.; Machara, N. P. et al.
Object Type:
Article
System:
The UNT Digital Library
[Bifurcations and Patterns in Nonlinear Dissifative Systems]
This report discusses the following topics: Rayleigh-Benard convection with an imposed horizontal flow; Rayleigh-Benard convection in a gas under non-boussinesq conditions; electro- convection in a nematic liquid crystal; and Rayleigh-Benard convection in a nematic liquid crystal. (LSP)
Date:
February 26, 1992
Creator:
Ahlers, G. & Cannell, D. S.
Object Type:
Report
System:
The UNT Digital Library
[Bifurcations and Patterns in Nonlinear Dissifative Systems]. Progress Report
This report discusses the following topics: Rayleigh-Benard convection with an imposed horizontal flow; Rayleigh-Benard convection in a gas under non-boussinesq conditions; electro- convection in a nematic liquid crystal; and Rayleigh-Benard convection in a nematic liquid crystal. (LSP)
Date:
February 26, 1992
Creator:
Ahlers, G. & Cannell, D. S.
Object Type:
Report
System:
The UNT Digital Library
Industrial Complex for Solid Radwaste Management at Chernobyle Nuclear Power Plant
In the framework of the preparation for the decommissioning of the Chernobyl Nuclear Power Plant (ChNPP) an Industrial Complex for Solid Radwaste Management (ICSRM) will be built under the EC TACIS Program in the vicinity of ChNPP. The paper will present the proposed concepts and their integration into existing buildings and installations. Further, the paper will consider the safety cases, as well as the integration of Western and Ukrainian Organizations into a cohesive project team and the requirement to guarantee the fulfillment of both Western standards and Ukrainian regulations and licensing requirements. The paper will provide information on the status of the interim design and the effects of value engineering on the output of basic design phase. The paper therefor summarizes the design results of the involved design engineers of the Design and Process Providers BNFL (LOT 1), RWE NUKEM GmbH (LOT 2 and General) and INITEC (LOT 3).
Date:
February 26, 2002
Creator:
Ahner, S. & Fomin, V. V.
Object Type:
Article
System:
The UNT Digital Library
Driving Mechanism For Automobiles And The Like.
Patent for improvements in the automobile driving mechanism thorough changes in the transmission and transmission gearing.
Date:
February 26, 1918
Creator:
Allan, William N.
Object Type:
Patent
System:
The Portal to Texas History
Recommendation for Supplemental Technologies for Hanford River Protection Project Potential Mission Acceleration (RPP-11838)
In May of 2002, the River Protection Project at Hanford proposed as part of the accelerated cleanup for the entire Hanford Site to ''accelerate waste stabilization by developing and deploying alternative treatment and immobilization solutions that are aligned with the waste characteristics to add assurance that overall waste treatment/immobilization will be completed 20 or more years sooner.'' This paper addresses one of these elements: development of recommendations for the supplemental technologies that have the greatest potential to supplement the River Protection Project's new Waste Treatment Plant throughput and achieve completion of waste processing by 2028. Low-activity waste treatment in the Waste Treatment Plant needs either to be enhanced or supplemented to enable the full amount of low-activity feed in the single-shell and double-shell tanks to be processed by 2028. The supplemental technologies are considered for low-activity waste feed that represents the maximum effectiveness of treatment compared with Waste Treatment Plant processing. During the Spring of 2002, over two dozen candidate technologies were assessed by staff from the U.S Department of Energy (DOE) Headquarters, Hanford Office of River Protection, representatives from the Washington State Department of Ecology and Region 10 of the Environmental Protection Agency, staff from many national laboratories, as …
Date:
February 26, 2003
Creator:
Allen, D. I.; Raymond, R. E.; Group, CH2M Hill Hanford; Brouns, T. M.; Choho, A. F.; Corporation, Numatec Hanford et al.
Object Type:
Article
System:
The UNT Digital Library
Car-Door.
Patent for "an improved freight car door so supported that it will not be shaken or jarred off and can be easily opened and closed at all times no matter how heavily loaded the car may be." (Lines 16-20) Includes instructions and illustrations.
Date:
February 26, 1895
Creator:
Allen, Thomas C.
Object Type:
Patent
System:
The Portal to Texas History
Characterizing surplus US plutonium for disposition
The United States (US) has identified 61.5 metric tons (MT) of plutonium that is permanently excess to use in nuclear weapons programs, including 47.2 MT of weapons-grade plutonium. Surplus inventories will be stored safely by the Department of Energy (DOE) and then transferred to facilities that will prepare the plutonium for permanent disposition. The Savannah River National Laboratory (SRNL) operates a Feed Characterization program for the Office of Fissile Materials Disposition (OFMD) of the National Nuclear Security Administration (NNSA) and the DOE Office of Environmental Management (DOE-EM). SRNL manages a broad program of item tracking through process history, laboratory analysis, and non-destructive assay. A combination of analytical techniques allows SRNL to predict the isotopic and chemical properties that qualify materials for disposition through the Mixed Oxide (MOX) Fuel Fabrication Facility (MFFF). The research also defines properties that are important for other disposition paths, including disposal to the Waste Isolation Pilot Plant (WIPP) as transuranic waste (TRUW) or to high-level waste (HLW) systems.
Date:
February 26, 2013
Creator:
Allender, Jeffrey S. & Moore, Edwin N.
Object Type:
Article
System:
The UNT Digital Library
Technical Evaluations of Proposed Remote-Handled Transuranic Waste Characterization Requirements at WIPP
Characterization, packaging, transport, handling and disposal of remotely handled transuranic (RH TRU) waste at WIPP will be different than similar operations with contact handled transuranic (CH TRU) waste. This paper presents results of technical evaluations associated with the planned disposal of remotely handled transuranic waste at the Waste Isolation Pilot Plant (WIPP).
Date:
February 26, 2002
Creator:
Anastas, G. & Channell, J. K.
Object Type:
Article
System:
The UNT Digital Library
White paper report on using nuclear reactors to search for a value of theta13
There has been superb progress in understanding the neutrino sector of elementary particle physics in the past few years. It is now widely recognized that the possibility exists for a rich program of measuring CP violation and matter effects in future accelerator {nu} experiments, which has led to intense efforts to consider new programs at neutrino superbeams, off-axis detectors, neutrino factories and beta beams. However, the possibility of measuring CP violation can be fulfilled only if the value of the neutrino mixing parameter {theta}{sub 13} is such that sin{sup 2} (2{theta}{sub 13}) greater than or equal to on the order of 0.01. The authors of this white paper are an International Working Group of physicists who believe that a timely new experiment at a nuclear reactor sensitive to the neutrino mixing parameter {theta}{sub 13} in this range has a great opportunity for an exciting discovery, a non-zero value to {theta}{sub 13}. This would be a compelling next step of this program. We are studying possible new reactor experiments at a variety of sites around the world, and we have collaborated to prepare this document to advocate this idea and describe some of the issues that are involved.
Date:
February 26, 2004
Creator:
Anderson, K.; Anjos, J. C.; Ayres, D.; Beacom, J.; Bediaga, I.; de Bellefon, A. et al.
Object Type:
Report
System:
The UNT Digital Library
Technical Letter Report - Analysis of Ultrasonic Data on Piping Cracks at Ignalina Nuclear Power Plant Before and After Applying a Mechanical Stress Improvement Process, JCN-N6319, Task 2
Pacific Northwest National Laboratory (PNNL) is assisting the United States Nuclear Regulatory Commission (NRC) in developing a position on the management of primary water stress corrosion cracking (PWSCC) in piping systems previously analyzed for leak-before-break (LBB). Part of this work involves determining whether inspections alone are sufficient or if inspections plus mitigation techniques are needed. The work described in this report addresses the reliability of ultrasonic phased-array (PA) examinations for inspection of cracks that have been subjected to the mitigation method of mechanical stress improvement process (MSIP). It is believed that stresses imparted during MSIP may make ultrasonic crack responses in piping welds more difficult to detect and accurately characterize. To explore this issue, data were acquired, both before and after applying MSIP, and analyzed from cracked areas in piping at the Ignalina Nuclear Power Plant (INPP) in Lithuania. This work was performed under NRC Project JCN-N6319, PWSCC in Leak-Before-Break Systems.
Date:
February 26, 2008
Creator:
Anderson, Michael T.; Cumblidge, Stephen E. & Crawford, Susan L.
Object Type:
Report
System:
The UNT Digital Library
The Aerodynamic Characteristics of Airfoils at Negative Angles of Attack
From Introduction: "The present report gives all the results, including those published in reference 1 and the results of previously un-published tests tests of the airfoils at positive angles of attack."
Date:
February 26, 1932
Creator:
Anderson, Raymond F.
Object Type:
Report
System:
The UNT Digital Library
Waste Minimization Policy at the Romanian Nuclear Power Plant
The radioactive waste management system at Cernavoda Nuclear Power Plant (NPP) in Romania was designed to maintain acceptable levels of safety for workers and to protect human health and the environment from exposure to unacceptable levels of radiation. In accordance with terminology of the International Atomic Energy Agency (IAEA), this system consists of the ''pretreatment'' of solid and organic liquid radioactive waste, which may include part or all of the following activities: collection, handling, volume reduction (by an in-drum compactor, if appropriate), and storage. Gaseous and aqueous liquid wastes are managed according to the ''dilute and discharge'' strategy. Taking into account the fact that treatment/conditioning and disposal technologies are still not established, waste minimization at the source is a priority environmental management objective, while waste minimization at the disposal stage is presently just a theoretical requirement for future adopted technologies . The necessary operational and maintenance procedures are in place at Cernavoda to minimize the production and contamination of waste. Administrative and technical measures are established to minimize waste volumes. Thus, an annual environmental target of a maximum 30 m3 of radioactive waste volume arising from operation and maintenance has been established. Within the first five years of operations at …
Date:
February 26, 2002
Creator:
Andrei, V. & Daian, I.
Object Type:
Article
System:
The UNT Digital Library
Calculational Models for Beta Dose From Spherical Particles
This report addresses the calculational models for beta dose from spherical particles.
Date:
February 26, 1965
Creator:
Anno, G.H.
Object Type:
Report
System:
The UNT Digital Library
REPORT ON THE PROCESSING OF PITCHBLENDE
A detailed description of the processing of pitchblende ores used at the Port Hope, Canada, refinery is given including both the recovery and purification of U and Fu. The health hazards present in the processing are discussed, and recommendations are made which will insure adequate health protection. (L.T.W.)
Date:
February 26, 1945
Creator:
Anonsen, S.H.
Object Type:
Report
System:
The UNT Digital Library
Saltcake Dissolution Studies in Single-Shell Tank Retrieval
Results of column dissolution experiments designed to evaluate the physical and chemical processes inherent to saltcake dissolution are presented along with model chemical equilibrium calculations. Two different compositions representing saltcakes in Hanford tanks were characterized, and porosities and permeabilities for a third composition based upon the saltcake waste in Tank 41H at the Savannah River Site (SRS) were also evaluated. Whereas the surrogates are all chemically similar, the presence of high phosphate loadings for the Hanford (HNF) simulants was noted as significantly affecting draining. The permeability was higher for the SRS saltcake, and the sodium nitrate loading in this saltcake was roughly 80% by weight compared to less than 60% by weight for the HNF compositions. Average values of the permeability and porosity were reduced for the surrogates based on Hanford Tanks S-112 and S-101. Here a secondary layer formed above the saltcake bed and was found to contain a large amount of gibbsite, Al(OH)3. Experiments with 3 molal (m) NaOH as a diluent, compared to water, did not result in additional layer formation that has been attributed to a change in local pH thereby altering the solid liquid equilibrium. Chemical analysis of the two HNF saltcakes indicated solids re-precipitation …
Date:
February 26, 2003
Creator:
Antonyraj, A.; Durve, T.; Toghiani, R. K.; Lindner, J. S. & Hunt, R.
Object Type:
Article
System:
The UNT Digital Library
Reactive Membrane Barriers for Containment of Subsurface Contamination
The overall goal of this project was to develop reactive membrane barriers--a new and flexible technique to contain and stabilize subsurface contaminants. Polymer membranes will leak once a contaminant is able to diffuse through the membrane. By incorporating a reactive material in the polymer, however, the contaminant is degraded or immobilized within the membrane. These processes increase the time for contaminants to breakthrough the barrier (i.e. the lag time) and can dramatically extend barrier lifetimes. In this work, reactive barrier membranes containing zero-valent iron (Fe{sup 0}) or crystalline silicotitanate (CST) were developed to prevent the migration of chlorinated solvents and cesium-137, respectively. These studies were complemented by the development of models quantifying the leakage/kill time of reactive membranes and describing the behavior of products produced via the reactions within the membranes. First, poly(vinyl alcohol) (PVA) membranes containing Fe{sup 0} and CST were prepared and tested. Although PVA is not useful in practical applications, it allows experiments to be performed rapidly and the results to be compared to theory. For copper ions (Cu{sup 2+}) and carbon tetrachloride, the barrier was effective, increasing the time to breakthrough over 300 times. Even better performance was expected, and the percentage of the iron used …
Date:
February 26, 2007
Creator:
Arnold, William A. & Cussler, Edward L.
Object Type:
Report
System:
The UNT Digital Library
Preparation of Radium and Other Spent Sealed Sources Containing Long-Lived Radonuclides to Long-Term Storage
At present time management of radioactive waste containing long-lived a radionuclides, is one of the most serious problems. The complexity of the management this kind of waste is due to extended half-life of these radionuclides. Hence it is difficult to predict not only long-term behavior of packages with waste, but also conditions of containing geological medium. The spent sources containing long-lived radionuclides are not suitable for disposal in shallow ground repositories. They must be temporary stored in special engineered structures. Long terms storage of these sources require application of additional measures for diminishing of risk of incidents with them.
Date:
February 26, 2003
Creator:
Arustamov, A. E.; Ojovan, M. I.; Semenov, K. N. & Sobolev, I. A.
Object Type:
Article
System:
The UNT Digital Library
LANDFILL OPERATION FOR CARBON SEQUESTRATION AND MAXIMUM METHANE EMISSION CONTROL
Controlled landfilling is an approach to manage solid waste landfills, so as to rapidly complete methane generation, while maximizing gas capture and minimizing the usual emissions of methane to the atmosphere. With controlled landfilling, methane generation is accelerated to more rapid and earlier completion to full potential by improving conditions (principally moisture, but also temperature) to optimize biological processes occurring within the landfill. Gas is contained through use of surface membrane cover. Gas is captured via porous layers, under the cover, operated at slight vacuum. A field demonstration project has been ongoing under NETL sponsorship for the past several years near Davis, CA. Results have been extremely encouraging. Two major benefits of the technology are reduction of landfill methane emissions to minuscule levels, and the recovery of greater amounts of landfill methane energy in much shorter times, more predictably, than with conventional landfill practice. With the large amount of US landfill methane generated, and greenhouse potency of methane, better landfill methane control can play a substantial role both in reduction of US greenhouse gas emissions and in US renewable energy. The work described in this report, to demonstrate and advance this technology, has used two demonstration-scale cells of size (8000 …
Date:
February 26, 2000
Creator:
Augenstein, Don; Yazdani, Ramin; Moore, Rick; Byars, Michelle; Kieffer, Jeff; Barlaz, Professor Morton et al.
Object Type:
Report
System:
The UNT Digital Library
Implementation of DOE/NFDI D&D Cost Estimating Tool (POWERtool) for Initiative Facilities at the Savannah River Site
The Savannah River Site (SRS) has embarked on an aggressive D&D program to reduce the footprint of excess facilities. Key to the success of this effort is the preparation of accurate cost estimates for decommissioning. SRS traditionally uses ''top-down'' rough order-of-magnitude (ROM) estimating for decommissioning cost estimates. A second cost estimating method (POWERtool) using a ''bottoms-up'' approach has been applied to many of the SRS excess facilities in the T and D-area. This paper describes the use of both estimating methods and compares the estimated costs to actual costs of 5 facilities that were decommissioned in 2002.
Date:
February 26, 2003
Creator:
Austin, W. E.; WSRC; Baker, S. B. III, Cutshall, C. M. & Crouse, J. L.
Object Type:
Article
System:
The UNT Digital Library
Development of Monte Carlo Methods for Investigating Migration of Radionuclides in Contaminated Environments
This paper presents the results of an ongoing research and development project conducted by Russian institutions in Moscow and Snezhinsk, supported by the International Science and Technology Center (ISTC), in collaboration with the University of Oklahoma. The joint study focuses on developing and applying analytical tools to effectively characterize contaminant transport and assess risks associated with migration of radionuclides and heavy metals in the water column and sediments of large reservoirs or lakes. The analysis focuses on the development and evaluation of theoretical-computational models that describe the distribution of radioactive wastewater within a reservoir and characterize the associated radiation field as well as estimate doses received from radiation exposure. The analysis focuses on the development and evaluation of Monte Carlo-based, theoretical-computational methods that are applied to increase the precision of results and to reduce computing time for estimating the characteristics the radiation field emitted from the contaminated wastewater layer. The calculated migration of radionuclides is used to estimate distributions of radiation doses that could be received by an exposed population based on exposure to radionuclides from specified volumes of discrete aqueous sources. The calculated dose distributions can be used to support near-term and long-term decisions about priorities for environmental remediation …
Date:
February 26, 2002
Creator:
Avrorin, E. N.; Tsvetokhin, A. G.; Xenofontov, A. I.; Kourbatova, E. I. & Regens, J. L.
Object Type:
Article
System:
The UNT Digital Library
Key Facts About Private Health Insurance
This report is on Key Facts About Private Health Insurance.
Date:
February 26, 1976
Creator:
Bailey, Susan
Object Type:
Report
System:
The UNT Digital Library
Preparing Algebraic Multigrid for Exascale
None
Date:
February 26, 2012
Creator:
Baker, A H; Falgout, R D; Gahvari, H; Gamblin, T; Gropp, W; Kolev, T V et al.
Object Type:
Report
System:
The UNT Digital Library