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DESIGN AND OPERATION OF FORCED-CIRCULATION CORROSION TESTING LOOPS WITH MOLTEN SALT

Description: Standardized test facilities were developed and operate for investigating the compatibility of structural materials and flowing molten fluoride salts. The standard loop accommodates various combinations of materials, fluid, flow, rates, and temperature differentials and permits fabrication of components in sufficient quantity for cost reduction. The test loop consists of a pump, two heated sections, a cooled section, a drain tank, and a frozen-plug-type valve. Automatic controls and equipment were developed to prevent solidification of the salt mixtures (mp, 800 to 1100 un. Concent 85% F) in the event of a loss of power. Most test loops were fabricated of 0.5-in.-OD, 0.045-in.-wall tubing, and operate with a temperature differential of up to 200 un. Concent 85% F, a maximum wall temperature in the range 1200 to 1500 un. Concent 85% F, and a salt flow rate of up to 3 gpm. Twenty-five test loops were operated for an accumulated operating time of 290,00 hr. Individual loops were operated continuously for more than one year. (auth)
Date: May 1, 1963
Creator: Crowley, J.L.; McDonald, W.B. & Clark, D.L.
Partner: UNT Libraries Government Documents Department

Office of River Protection Integrated Safety Management System Phase 1 Verification Corrective Action Plan

Description: The purpose of this Corrective Action Plan is to demonstrate the OW planned and/or completed actions to implement ISMS as well as prepare for the RPP ISMS Phase II Verification scheduled for August, 1999. This Plan collates implied or explicit ORP actions identified in several key ISMS documents and aligns those actions and responsibilities perceived necessary to appropriately disposition all ISM Phase II preparation activities specific to the ORP. The objective will be to complete or disposition the corrective actions prior to the commencement of the ISMS Phase II Verification. Improvement products/tasks not slated for completion prior to the RPP Phase II verification will be incorporated as corrective actions into the Strategic System Execution Plan (SSEP) Gap Analysis. Many of the business and management systems that were reviewed in the ISMS Phase I verification are being modified to support the ORP transition and are being assessed through the SSEP. The actions and processes identified in the SSEP will support the development of the ORP and continued ISMS implementation as committed to be complete by end of FY-2000.
Date: August 9, 1999
Creator: CLARK, D.L.
Partner: UNT Libraries Government Documents Department

Office of River Protection Integrated Safety Management System Description

Description: Revision O was never issued. Finding safe and environmentally sound methods of storage and disposal of 54 million gallons of highly radioactive waste contained in 177 underground tanks is the largest challenge of Hanford cleanup. TWRS was established in 1991 and continues to integrate all aspects of the treatment and management of the high-level radioactive waste tanks. In fiscal Year 1997, program objectives were advanced in a number of areas. RL TWRS refocused the program toward retrieving, treating, and immobilizing the tank wastes, while maintaining safety as first priority. Moving from a mode of storing the wastes to getting the waste out of the tanks will provide the greatest cleanup return on the investment and eliminate costly mortgage continuance. There were a number of safety-related achievements in FY1997. The first high priority safety issue was resolved with the removal of 16 tanks from the ''Wyden Watch List''. The list, brought forward by Senator Ron Wyden of Oregon, identified various Hanford safety issues needing attention. One of these issues was ferrocyanide, a chemical present in 24 tanks. Although ferrocyanide can ignite at high temperature, analysis found that the chemical has decomposed into harmless compounds and is no longer a concern.
Date: August 9, 1999
Creator: CLARK, D.L.
Partner: UNT Libraries Government Documents Department

{sup 13}C and {sup 17}O NMR binding constant studies of uranyl carbonate complexes in near-neutral aqueous solution. Yucca Mountain Project Milestone Report 3351

Description: Valuable structural information, much of it unavailable by other methods, can be obtained about complexes in solution through NMR spectroscopy. From chemical shift and intensity measurements of complexed species, NMR can serve as a species-specific structural probe for molecules in solution and can be used to validate thermodynamic constants used in geochemical modeling. Fourier-transform nuclear magnetic resonance (FT-NMR) spectroscopy has been employed to study the speciation of uranium(VI) ions in aqueous carbonate solutions as a function of pH, ionic strength, carbonate concentration, uranium concentration, and temperature. Carbon-13 and oxygen-17 NMR spectroscopy were used to monitor the fractions, and hence thermodynamic binding constants of two different uranyl species U0{sub 2}(CO{sub 3}){sub 3}{sup 4{minus}} and (UO{sub 2}){sub 3}(CO{sub 3}){sub 6}{sup 6{minus}} in aqueous solution. Synthetic buffer solutions were prepared under the ionic strength conditions used in the NMR studies in order to obtain an accurate measure of the hydrogen ion concentration, and a discussion of pH = {minus}log(a{sub H}{sup +}) versus p[H] = {minus}log[H+] is provided. It is shown that for quantitative studies, the quantity p[H] needs to be used. Fourteen uranium(VI) binding constants recommended by the OECD NEA literature review were corrected to the ionic strengths employed in the NMR study using specific ion interaction theory (SIT), and the predicted species distributions were compared with the actual species observed by multinuclear NMR. Agreement between observed and predicted stability fields is excellent. This establishes the utility of multinuclear NMR as a species-specific tool for the study of the actinide carbonate complexation constants, and serves as a means for validating the recommendations provided by the OECD NEA.
Date: January 1, 1995
Creator: Clark, D.L.; Newton, T.W.; Palmer, P.D. & Zwick, B.D.
Partner: UNT Libraries Government Documents Department

Report on neptunium speciation by NMR and optical spectroscopies

Description: Hydrolysis and carbonate complexation reactions were examined for NpO{sub 2}{sup 2+} and NpO{sub 2}{sup +} ions by a variety of techniques including potentiometric titration, UV-Vis-NIR and NMR spectroscopy. The equilibrium constant for the reaction 3NpO{sub 2}(CO{sub 3}){sub 3}{sup 4{minus}} + 3H{sup +} {rightleftharpoons} (NpO{sub 2}){sub 3}(CO{sub 3}){sub 6}{sup 6{minus}} + 3HCO{sub 3}{sup {minus}} was determined to be logK = 19.7 ({plus_minus} 0.8) (I = 2.5 m). {sup 17}O NMR spectroscopy of NpO{sub 2}{sup n+} ions (n = 1,2) reveals a readily observable {sup 17}O resonance for n = 2, but not for n = 1. The first hydrolysis constant for NpO{sub 2}{sup +} was studied as a function of temperature, and the functional form for the temperature-dependent equilibrium constant for the reaction written as NpO{sub 2}{sup +} + H{sub 2}O {rightleftharpoons} NpO{sub 2}OH + H{sup +} was found to be logK = 2.28 {minus} 3780/T, where T is in {degree}K. Finally, the temperature dependence of neptunium(V) carbonate complexation constants was studied. For the first carbonate complexation constant, the appropriate functional form was found to be log{beta}{sub 01} = 1.47 + 786/T.
Date: November 1, 1995
Creator: Tait, C.D.; Palmer, P.D.; Ekberg, S.A. & Clark, D.L.
Partner: UNT Libraries Government Documents Department

Molecular models for actinide speciation

Description: Much effort has been devoted to the development of sensitive spectroscopic techniques for the study of actinide speciation based on the sensitivity of f-f electronic absorption bands to oxidation state and ligation of the actinide ions. These efforts assume that data obtained in such studies will be interpretable in terms of changes in complexation of the metal center. However, the current understanding of 5f electronic structure is based on data from solid state doped single crystals. In those studies, the local coordination geometry about the central actinide ion is maintained in an almost perfect high-symmetry environment and will have little relevance for species in solution where deviations from perfect high symmetry tend to be the rule rather than the exception. The authors have developed a vigorous research program in the systematic preparation and spectroscopic characterization of synthetic actinide complexes (Th, U, Np, and Pu) in which they can control nuclearity, oxidation state, and molecular structure. These complexes have been used to determine how observable electronic transitions are perturbed in response to structural changes in the complex in solution. From the spectra obtained for these model complexes, the authors have found that the f-f transitions naturally fall into obvious groupings by coordination number and symmetry by which they can now differentiate between monomeric, dimeric, and trimeric species in solution. The study of radionuclide speciation is fundamentally important to the determination of radionuclide solubility in the groundwater at Yucca Mountain.
Date: June 1, 1994
Creator: Clark, D.L.; Watkin, J.G.; Morris, D.E. & Berg, J.M.
Partner: UNT Libraries Government Documents Department

Development and maintenance of the Hanford Site Radiological Control Manual

Description: In June 1992 the US Department of Energy (DOE) issued DOE N5480.6, Radiological Control, which set forth DOE's Radiological Control Program and established the framework for its implementation at sites nationwide. Accompanying the Order was the DOE Radiological Control Manual (DOE RCM), which provided the detailed requirements for the program. The Order also mandated Field Office issuance of site-specific radiological control manuals by December 1, 1992. This paper presents the approach taken to develop, review, approve, implement, and subsequently maintain the site-specific manual for the DOE Richland Field Office (RL) at Hanford Site.
Date: April 1, 1993
Creator: Munson, L.H.; Selby, J.M; Vargo, G.J. & Clark, D.L.
Partner: UNT Libraries Government Documents Department

Actinide(IV) and actinide(VI) carbonate speciation studies by PAS and NMR spectroscopies; Yucca Mountain Project: Milestone report 3031-WBS 1.2.3.4.1.3.1

Description: Pulsed-laser photoacoustic spectroscopy (PAS) and Fourier-transform nuclear magnetic resonance (NMR) spectroscopy were used to study speciation of actinide(IV) and actinide(VI) ions (Np, Pu, Am) in aqueous carbonate solutions vs pH, carbonate content, actinide content, temperature. PAS focused on Pu(IV) speciation. Stability fields on a pH (8.4 to 12.0) versus total carbonate content (0.003 to 1.0 M) plot for dilute Pu(IV) carbonate species ([Pu]{sub tot} = 1 mM) were mapped. Four plutonium species, with absorption peaks at 486, 492, 500, and 512 nm were found. Loss of a single carbonate ligand does not account for the difference in speciation for the 486 and 492 nm absorption peaks, nor can any of the observed species be identified as colloidal Pu(IV). NMR data have been obtained for UO{sub 2}{sup 2+}, PuO{sub 2}{sup 2+} and AmO{sub 2}{sup 2+}. This report focuses on results for PuO{sub 2}{sup 2+}. The ligand exchange reaction between free and coordinated carbonate on the PuO{sub 2}(CO{sub 3}){sub 3}{sup 4{minus}} systems has been examined by variable temperature {sup 13}C NMR spectroscopy. In each of the six different PuO{sub 2}(CO{sub 3}){sub 3}{sup 4{minus}} samples, two NMR signals are present, one for the free carbonate ligand and one for the carbonate ligand coordinated to a paramagnetic plutonium metal center. The single{sup 13}C resonance line for coordinated carbonate is consistent with expectations of a monomeric PuO{sub 2}(CO{sub 3}){sub 3}{sup 4{minus}} species in solution. A modified Carr-Purcell-Meiboom-Gill NMR pulse sequence was used for determining ligand exchange parameters for paramagnetic actinide complexes. Eyring analysis at standard conditions provided activation parameters of {Delta}H = 38 KJ/M and {Delta}S = {minus}60 J/K for the plutonyl triscarbonate system, suggesting an associative transition state for the plutonyl(VI) carbonate complex self-exchange reaction.
Date: September 1, 1994
Creator: Clark, D.L.; Ekberg, S.A.; Morris, D.E.; Palmer, P.D. & Tait, C.D.
Partner: UNT Libraries Government Documents Department

A portable medium-resolution gamma-ray spectrometer and analysis software

Description: There is a strong need for portable radiometric instrumentation that can both accurately confirm the presence of nuclear materials and allow isotopic analysis of radionuclides in the field. To fulfill this need the Safeguards Technology Program at LLNL has developed a hand-held, non-cryogenic, low-power gamma-ray and x-ray measurements and analysis instrument that can both search for and then accurately verify the presence of nuclear materials. We will report on the use of cadmium zinc telluride (CZT) detectors, detector electronics, and the new field-portable instrument being developed. We will also describe the isotopic analysis that allows enrichment measurements to be made accurately in the field. These systems provide capability for safeguards inspection and verification applications and could find application in counter-smuggling operations.
Date: July 1, 1996
Creator: Lavietes, A.D.; McQuaid, J.H.; Ruhter, W.D.; Buckley, W.M.; Clark, D-L. & Paulus, T.J.
Partner: UNT Libraries Government Documents Department

Oxalate complexation with aluminum(III) and iron(III) at moderately elevated temperatures

Description: To add to our understanding of the weathering of rocks in organic rich environments such as sedimentary brines and oil field waters, we have examined the temperature dependent complexation of aluminum with oxalate. Raman vibrational studies show that even the association constant for the highly charged Al(ox){sub 3}{sup 3{minus}} unexpectedly increases with moderate temperature increases to 80{degrees}C. To evaluate the potential importance of these Al-oxalate species in complex natural systems, temperature dependent competition experiments Fe(III) and Al(III) for oxalate have been initiated. Similar to aluminum, ferric oxalates show increases in association constants at higher temperatures. In competition experiments, the first association constant for Fe(ox){sup +} increases faster than that for Al(ox){sup +} to 90{degrees}C.
Date: January 1, 1992
Creator: Tait, C.D.; Janecky, D.R.; Clark, D.L. (Los Alamos National Lab., NM (United States)) & Bennett, P.C. (Texas Univ., Austin, TX (United States). Dept. of Geological Sciences)
Partner: UNT Libraries Government Documents Department

Carbon-13 NMR characterization of actinyl(VI) carbonate complexes in aqueous solution

Description: The uranyl(VI) carbonate system has been re-examined using {sup 13}C NMR of 99.9% {sup 13}C-enriched U{sup VI}O{sub 2} ({sup 13}CO{sub 3}){sub 3}{sup 4{minus}} in millimolar concentrations. By careful control of carbonate ion concentration, we have confirmed the existence of the trimer, and observed dynamic equilibrium between the monomer and the timer. In addition, the ligand exchange reaction between free and coordinated carbonate on Pu{sup VI}O{sub 2}({sup 13}CO{sub 3}){sub 3}{sup 4{minus}} and Am{sup VI}O{sub 2}({sup 13}CO{sub 3}){sub 3}{sup 4{minus}} systems has been examined by variable temperature {sup 13}C NMR line-broadening techniques {sup 13}C NMR line-broadening techniques. A modified Carr-Purcell-Meiboom-Gill NMR pulse sequence was written to allow for experimental determination of ligand exchange parameters for paramagnetic actinide complexes. Preliminary Eyring analysis has provided activation parameters of {Delta}G{sup {double dagger}}{sub 295} = 56 kJ/M, {Delta}H{sup {double dagger}} = 38 kJ/M, and {Delta}S{sup {double dagger}} = {minus}60 J/M-K for the plutonyl triscarbonate system, suggesting an associative transition state for the plutonyl (VI) carbonate complex self-exchange reaction. Experiments for determination of the activation parameters for the americium (VI) carbonate system are in progress.
Date: January 1, 1992
Creator: Clark, D.L.; Hobart, D.E.; Palmer, P.D. (Los Alamos National Lab., NM (United States)); Sullivan, J.C. (Argonne National Lab., IL (United States)) & Stout, B.E. (Cincinnati Univ., OH (United States). Dept. of Chemistry)
Partner: UNT Libraries Government Documents Department

Pulsed photothermal spectroscopy applied to lanthanide and actinide speciation

Description: Several key elements important for the application of laser-based photothermal spectroscopies to the study of the complexation chemistry of lanthanides and actinides in solution have been demonstrated. The sensitivity of f-f electronic transition energies and band intensities to subtle changes in complexation was illustrated through comparison of visible and near infra-red absorption spectra of well-characterized U(IV) dimers with alkoxide ligands. Significant improvements in spectroscopic band resolution and energy measurement precision for solution species were shown to be achievable through work in frozen glasses at 77 K using a very simple cryogenic apparatus. A pulsed-laser photothermal spectroscopy apparatus was constructed and shown to be sensitive to optical density changes of 10{sup {minus}5} in an aqueous Nd{sup 3+} solution. In addition, the capability of obtaining photothermal lensing spectra of dilute actinide solutions in frozen glasses at 77 K was demonstrated. 6 refs., 5 figs.
Date: January 1, 1991
Creator: Berg, J.M.; Morris, D.E.; Clark, D.L.; Tait, C.D.; Woodruff, W.H. (Los Alamos National Lab., NM (USA)) & Ven Der Sluys, W.G. (Montana Univ., Missoula, MT (USA). Dept. of Chemistry)
Partner: UNT Libraries Government Documents Department

Direct speciation of metal and metalloid ions by optical spectroscopies

Description: Molecular level spectroscopic investigations of organic/inorganic interactions provide important new information on sedimentary geochemistry through the identification of interactions over moderate temperature and pH ranges. Although the official title of this project indicates the use of only optical spectroscopies, a combination of Uv/Vis/IR absorption, Raman scattering, and {sup 29}Si and {sup 13}C nuclear magnetic resonance (NMR) experiments are actually employed. A major advantage of integrating spectroscopic results with diagenesis studies is the ability to directly examine the mechanisms of interactions, even in complex matrices and with competing processes. Furthermore, we are extending these techniques to probe fluid inclusions with micro Raman and luminescence techniques to directly compare laboratory results with natural reservoir systems. 25 refs., 4 figs.
Date: January 1, 1991
Creator: Tait, C.D.; Janecky, D.R.; Clark, D.L.; Ekberg, S.A.; Dixon, P.R.; Musgrave, J.A. (Los Alamos National Lab., NM (United States)) et al.
Partner: UNT Libraries Government Documents Department