955 Matching Results

Search Results

Advanced search parameters have been applied.

Radiation Stability Studies

Description: From abstract: "An investigation of the radiation stabilities of aqueous solutions of sodium ethylenediamine tetraacetate and sodium acetate was made using a 3000-curie Co⁶⁰ source...A study of the behavior of the standard-size Beckman type glass pH electrodes in a solution containing 0.36 curie of Ce¹⁴⁴-Pr¹⁴⁴ activity per milliliter showed the useful electrode life to be of the order of two to eight days."
Date: September 22, 1952
Creator: Blanco, R. E.; Kibbey, A. H. & Pannell, J. H.
Partner: UNT Libraries Government Documents Department

Solubilities of significant compounds in HLW tank supernate solutions - FY 1996 progress report

Description: The solubilities of two sodium salts of organic acids that are thought to exist in high-level waste at the Hanford Site were measured in tank supernate simulant solutions during FY1996 This solubility information will be used to determine if these organic salts could exist in solid phases (saltcake or sludges) in the waste where they might react violently with the nitrate or nitrite salts present in the tanks. Solubilities of sodium butyrate and trisodium N-(2-hydroxyethyl)ethylenediaminetriacetate were measured in simulated waste supernate solutions at 25 {degrees}C, 30 {degrees}C, 40 {degrees}C, and 50 {degrees}C. The organic compounds were selected because they are expected to exist in relatively high concentrations in the tanks. Two types of tank supernate simulants were used - a 4.O M sodium nitrate - 0.97 M sodium nitrite solution with sodium hydroxide concentrations ranging from O.00003 M to 2.O M and a 2.O M sodium nitrite solution saturated with crystalline sodium nitrate with sodium hydroxide concentrations ranging from 0.1 M to 2. 0 M. The solubilities of sodium butyrate and trisodium N-(2-hydroxyethyl)ethylene- diaminetriacetate in both types of HLW tank supernate solutions were high over the temperature and sodium hydroxide concentration ranges expected in the tanks. The solubilities of these compounds are similar (in terms of total organic carbon) to sodium glycolate, succinate, caproate, dibutylphosphate, citrate, formate, ethylenediaminetetraacetate, and nitrilotriacetate which were measured previously. High solubilities will prevent solid sodium salts of these organic acids from precipitating from tank supernate solutions. The total organic carbon concentrations (TOC) of actual tank supernates are generaly much lower than the TOC ranges for the simulated supernate solutions saturated (at the solubility limit) with the organic salts. This is true even if all the dissolved carbon in a given tank supernate is due to only one of these eight soluble compounds (an unlikely situation). ...
Date: September 30, 1996
Creator: Barney, G.S.
Partner: UNT Libraries Government Documents Department

Excess Sodium Tetraphenylborate and Intermediates Decomposition Studies

Description: The stability of excess amounts of sodium tetraphenylborate (NaTPB) in the In-Tank Precipitation (ITP) facility depends on a number of variables. Concentration of palladium, initial benzene, and sodium ion as well as temperature provide the best opportunities for controlling the decomposition rate. This study examined the influence of these four variable on the reactivity of palladium-catalyzed sodium tetraphenylborate decomposition. Also, single effects tests investigated the reactivity of simulants with continuous stirring and nitrogen ventilation, with very high benzene concentrations, under washed sodium concentrations, with very high palladium concentrations, and with minimal quantities of excess NaTPB.
Date: December 7, 1998
Creator: Barnes, M.J.
Partner: UNT Libraries Government Documents Department

Structure of charged polymer chains in confined geometry.

Description: The intra- and interchain structure of sodium poly(styrenesulphonate) when free and when confined in contrast matched porous Vycor has been investigated by SANS. When confined, a peak is observed whose intensity increases with molecular weight and the 1/q scattering region is extended compared to the bulk. We infer that the chains are sufficiently extended, under the influence of confinement, to highlight the large scale disordered structure of Vycor. The asymptotic behavior of the observed interchain structure factor is = 1/q{sup 2} and = 1/q for free and confined chains respectively.
Date: December 15, 2000
Creator: Gilbert, E. P.; Auvray, L. & Lal, J.
Partner: UNT Libraries Government Documents Department

Corrosion mechanisms of spent fuel under oxidizing conditions

Description: The release of {sup 99}Tc can be used as a reliable marker for the extent of spent oxide fuel reaction under unsaturated high drip rate conditions at 90{degrees}C. Evidence from the leachate data and from scanning and transmission electron microscopy (SEM and TEM) examination of reacted fuel samples is presented for radionuclide release, potential reaction pathways, and the formation of alteration products. In the ATM-103 fuel, 0.03 of the total inventory of {sup 99}Tc is release in 3.7 years under unsaturated and oxidizing conditions. Two reaction pathways that have been identified from SEM are (1) through-grain dissolution with subsequent formation of uranyl alteration products, and (2) grain-boundary dissolution. The major alteration product identified by X-ray diffraction (XRD) and SEM, is Na-boltwoodite, Na[(UO{sub 2})(SiO{sub 3}OH)].H{sub 2}O, which is formed from sodium and silicon in the water leachant.
Date: September 1, 1997
Creator: Finn, P. A.; Finch, R. J.; Buch, E. C. & Bates, J. K.
Partner: UNT Libraries Government Documents Department

Densities of Sodium Tetrafluoroborate Aqueous Solutions at 20 Degrees C

Description: Analytical data and plant solution compositions are often reported in molarity units. Densities of salt solutions are needed to convert the concentrations to molal basis in order to utilize physical property data that have been established on a molal basis, for example, solution reaction equilibrium constants or activity coefficients. We report here the densities at 20.0 Degrees C of sodium tetrafluoroborate (NaBF4) solutions from 0.05 molal to 9.0 molal, near saturation of 9.2 molal.
Date: July 9, 2002
Creator: Crooks, W.J. III
Partner: UNT Libraries Government Documents Department

The Suitability of Sodium Peroxide Fusion for Production-Scale Plutonium Processing Operations

Description: Sodium peroxide (Na{sub 2}O{sub 2}) fusion is a method that offers significant benefits to the processing of high-fired plutonium oxide (PuO{sub 2}) materials. Those benefits include reduction in dissolution cycle time, decrease in residual solids, and reduction of the potential for generation of a flammable gas mixture during dissolution. Implementation of Na{sub 2}O{sub 2} fusion may also increase the PuO{sub 2} throughput in the HB-Line dissolving lines. To fuse a material, Na{sub 2}O{sub 2} is mixed with the feed material in a crucible and heated to 600-700 C. For low-fired and high-fired PuO{sub 2}, Na{sub 2}O{sub 2} reacts with PuO{sub 2} to form a compound that readily dissolves in ambient-temperature nitric acid without the use of potassium fluoride. The Savannah River National Laboratory (SRNL) demonstrated the feasibility of Na{sub 2}O{sub 2} fusion and subsequent dissolution for the processing of high-fired PuO{sub 2} materials in HB-Line. Testing evaluated critical dissolution characteristics and defined preliminary process parameters. Based on experimental measurements, a dissolution cycle can be complete in less than one hour, compared to the current processing time of 6-10 hours for solution heating and dissolution. Final Pu concentrations of 30-35 g/L were produced without the formation of precipitates in the final solution.
Date: October 26, 2010
Creator: Pierce, R. & Edwards, T.
Partner: UNT Libraries Government Documents Department

THE REACTION RATE OF SODIUM SULFITE WITH DISSOLVED OXYGEN. Technical Report No. 73

Description: The reaction rate of sodium sulfite was studied as a function of oxygen concentration, Na/sub 2/SO/sub 3//O/sub 2/ ratio, temperature, catalyst, pH and surface/volume ratio.The reaction rate of hydrazine with dissolved oxygen was also studied. Oxygen removal is incomplete when the sulfite to oxygen ratio is leas than the stoichiometric quantity. With the stoichiometric quantities of oxygen and sodium sulfite present, removal is incomplete at 100 deg F in 1 min, at 200 deg F, about 95% of the oxygen is removed in 10 sec and at 300 deg F oxygen removal is essentially complete in 10 sec. With an excess of sulfite present (10 Na/sub 2/SO/sub 3//1 O/sub 2/, molar), 95% of the oxygen is removed at 100 deg F in 10 sec. At 200 and 300 deg F, oxygen removal is essentially complete in 10 sec. The rate of oxygen removal is dependent to some extent on the container material. The sulfite oxygen reaction progresses at a higher rate in boiler water than in feedwater. The reaction rate of hydrazine with oxygen is low compared with the reaction rate of sulfite and dissolved oxygen. No reduction of oxygen was noted over a one-minute period with an excess of hydrazine. (auth)
Date: May 16, 1960
Creator: Rodgers, S.J.
Partner: UNT Libraries Government Documents Department

In situ XANES study of the passive film formed on iron in borate buffer and in sodium acetate

Description: The passive film formed on Fe in pH 8.4 borate buffer (0. 1 36 M) over a broad potential range was characterized by in situ XANES (x-ray absorption near edge structure). On stepping the potential to a value between -0.6 V and +0.4 V (MSE), a passive film forms without detectable dissolution. The edge position indicates that the valence state of Fe in the film is 10 {+-} 5% Fe{sup 2+} and 90 {+-} 5% Fe{sup 3+}. Formation of a passive film at potentials between -0.8 V and -0.65 V is associated with dissolution prior to passivation, and a lower average valence state of 17 {+-} 5% Fe{sup 2+} and 83 {+-} 5% Fe{sup 3+}. At -0.9 V, the Fe did not passivate. The passive film that forms in pH 8.2 sodium acetate (0.1 M) at +0.4 V gives an edge similar to the high potential passive film formed in borate buffer, but dissolution occurs prior to passivation.
Date: December 31, 1996
Creator: Oblonsky, L.J.; Ryan, M.P. & Isaacs, S.
Partner: UNT Libraries Government Documents Department

Description of the Material Balance Model and Spreadsheet for Salt Dissolution

Description: The model employed to estimate the amount of inhibitors necessary for bearing water and dissolution water during the salt dissolution process is described. This model was inputed on a spreadsheet which allowed many different case studies to be performed. This memo describes the assumptions and equations which are used in the model, and documents the input and output cells of the spreadsheet. Two case studies are shown as examples of how the model may be employed.
Date: October 12, 1994
Creator: Wiersma, B.J.
Partner: UNT Libraries Government Documents Department

Recommendations for the use of Inhibited Water During Phase I Salt Dissolutions In Tank 41

Description: A procedure was recommended for Phase 1 removal of saltcake from Tank 41 using inhibited water. The procedure is based on results from laboratory testing and a material balance model. A program is underway to examine the suitability of modifying the current technical standards for waste removal applications.
Date: January 1, 1996
Creator: Davis, P.L.
Partner: UNT Libraries Government Documents Department

Production test IP-728 half-plant sodium silicate test. Final report

Description: The sodium silicate addition to the coolant reduced the effluent concentrations of certain radionuclides. Nothing was observed during the course of the test to indicate that sodium silicate could not be used at all plants. However, the reductions obtained in effluent activity are not believed commensurate with the cost of silicate usage.
Date: July 28, 1966
Creator: Geier, R.G.
Partner: UNT Libraries Government Documents Department

Sodium and sulfur release and recapture during black liquor burning

Description: The objective of this study was to provide data on sulfur and sodium volatilization during black liquor burning, and on SO2 capture by solid sodium carbonate and sodium chloride. This data was interpreted and modeled into rate equations suitable for use in computational models for recovery boilers.
Date: August 1, 1995
Creator: Frederick, W.J.; Iisa, K.; Wag, K.; Reis, V.V.; Boonsongsup, L.; Forssen, M. et al.
Partner: UNT Libraries Government Documents Department