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Hydrogen Release from Simulated Sludge and Saltcake

Description: This report describes the results of the Savannah River Technology Center (SRTC) program to address bubble gas release potential as requested by Concentration, Storage and Transfer Engineering. Researchers from the Waste Processing Technology Section (WPTS) and Immobilization Technology Section (ITS) contributed to the results presented.
Date: January 5, 1999
Creator: Peterson, R.A.
Partner: UNT Libraries Government Documents Department

Idealized mixing impacts

Description: The dispersion of tetraphenylborate in continuous stirred tank reactors plays a significant role in the utility achieved from the tetraphenylborate. Investigating idealized mixing of the materials can illuminate how this dispersion occurs.
Date: December 8, 1999
Creator: Peterson, R.A.
Partner: UNT Libraries Government Documents Department

Solvent Extraction External Radiation Stability Testing

Description: Personnel irradiated a number of samples of calixarene-based solvent. Analysis of these samples indicated that measurable loss of the calixarene occurred at very high doses (-16 Mrad). No measurable loss of the Cs-7SB modifier occurred at equivalent doses. The primary degradation product, 4-sec-butylphenol, observed during analysis of the samples came from degradation of the modifier. Also, TOA proved more susceptible to damage than the other components of the solvent. The total degradation of the solvent proved relatively minor. The consistent solvent performance, as indicated by the measured D Cs values, after exposure at high total doses serves as evidence of the relatively low degree of degradation of the solvent components. Additional tests employing internal irradiation of solvents with both simulants and SRS tank waste will be completed by the end of March 2001 to provide confirmation of the results presented herein.
Date: January 5, 2001
Creator: Peterson, R.A.
Partner: UNT Libraries Government Documents Department

Decomposition Studies of Triphenylboron, Diphenylborinic Acid and Phenylboric Acid in Aqueous Alkaline Solutions Containing Copper

Description: This report documents the copper-catalyzed chemical kinetics of triphenylboron, diphenylborinic acid and phenylboric acid (3PB, 2PB and PBA) in aqueous alkaline solution contained in carbon-steel vessels between 40 and 70 degrees C.
Date: February 11, 1997
Creator: Crawford, C.L. & Peterson, R. A.
Partner: UNT Libraries Government Documents Department

Sodium tetraphenylborate solubility and dissolution rates

Description: The rate of solid sodium tetraphenylborate (NaTPB) dissolution in In-Tank Precipitation salt solutions has been experimentally determined. The data indicates that the dissolution rate of solid NaTPB is a minor contributor the lag time experienced in the 1983 Salt Decontamination Demonstration Test and should not be considered as the rate determining step. Current analytical models for predicting the time to reach the composite lower flammability limit assume that the lag time is not more than 6 hours, and the data supports this assumption (i.e., dissolution by itself requires much less than 6 hours). The data suggests that another step--such as mass transport, the reaction of a benzene precursor or the mixing behavior--is the rate determining factor for benzene release to the vapor space in Tank 48H. In addition, preliminary results from this program show that the degree of agitation employed is not a significant parameter in determining the rate of NaTPB dissolution. As a result of this study, an improved equation for predicting equilibrium tetraphenylborate solubility with respect to temperature and sodium ion concentration has been determined.
Date: December 31, 1995
Creator: Barnes, M.J.; Peterson, R.A.; Swingle, R.F. & Reeves, C.T.
Partner: UNT Libraries Government Documents Department

Apparent Benzene Solubility in Tetraphenylborate Slurries

Description: Personnel conducted testing to determine the apparent solubility of benzene in potassium tetraphenylborate (KTPB) slurries. The lack of benzene vapor pressure suppression in these tests indicate that for a 6.5 wt percent solids KTPB slurry in 4.65 M Na+ salt solution at approximately 25 degrees Celsius, no significant difference exists between the solubility of benzene in the slurry and the solubility of benzene in salt solution without KTPB solids. The work showed similar results in slurry with 6,000 mg/L sludge and 2,000 mg/L monosodium titanate added. Slurries containing tetraphenylborate decomposition intermediates (i.e., 4,200 mg/L triphenylboron (3PB), 510 mg/L diphenylborinic acid (2PB) and 1,500 mg/L phenylboric acid (1PB) or 100 mg/L tri-n-butylphosphate (TBP)) also showed no significant difference in benzene solubility form filtrate containing no KTPB solids. Slurry containing 2,000 mg/L Surfynol 420 did exhibit significant additional benzene solubility, as did irradiated slurries. The vapor pressure depression in the irradiated slurries presumably results from dissolution of biphenyl and other tetraphenylborate irradiation products in the benzene.
Date: November 1, 1997
Creator: Swingle, R.F.; Peterson, R.A. & Crawford, C.L.
Partner: UNT Libraries Government Documents Department

Decomposition of triphenylborane with enhanced comprehensive catalyst under aerated and inert conditions

Description: This work investigated the decomposition of triphenylborane in a statistically-designed set of tests to determine the effects of four process variables: temperature, hydroxide concentration, catalyst concentration, and atmosphere. Analysis of these tests provide the following conclusions:(1) The presence of tetraphenylborate solids facilitate a 10X increase in the rate of decomposition of triphenylborane, (2) The presence of oxygen slows the decomposition of triphenylborane, (3) The activation energy of the decomposition reaction in the presence of oxygen (59.88 + 27.73 kJ/mol) is statistically lower than inerted systems (99.11 + 10.14 kJ/mol), (4) Rate constants derived from the nitrogen inerted tests encompass the rate constants from previous tests with slurries. These rate constants agree reasonably with similar values obtained from Tank 48H operations at ambient temperatures, and (5) For test conducted in air, the decomposition reaction rate constant correlated with the catalyst concentration. In tests inerted by nitrogen, the same correlation did not hold.
Date: September 30, 1997
Creator: Wilmarth, W.R.; Crawford, C.L.; Peterson, R.A. & White, T.L.
Partner: UNT Libraries Government Documents Department

Decomposition studies of filtered slurries using the enhanced comprehensive catalyst

Description: This study examined decomposition of the soluble phenylborates at elevated temperatures (45 degrees Celsius) to determine the effects of filtering the solid tetraphenylborate, solid sludge and monosodium titanate and spiking additional levels of transition metal catalyst.
Date: November 13, 1997
Creator: Wilmarth, W.R.; Crawford, C.L. & Peterson, R.A.
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 variables 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. These tests showed the following.The testing demonstrates that current facility configuration does not provide assured safety of operations relative to the hazards of benzene (in particular to maintain the tank headspace below 60 percent of the lower flammability limit (lfl) for benzene generation rates of greater than 7 mg/(L.h)) from possible accelerated reaction of excess NaTPB. Current maximal operating temperatures of 40 degrees C and the lack of protection against palladium entering Tank 48H provide insufficient protection against the onset of the reaction. Similarly, control of the amount of excess NaTPB, purification of the organic, or limiting the benzene content of the slurry (via stirring) and ionic strength of the waste mixture prove inadequate to assure safe operation.
Date: April 1998
Creator: Barnes, M. J. & Peterson , R. A.
Partner: UNT Libraries Government Documents Department

Selection of Pretreatment Processes for Removal of Radionuclides from Hanford Tank Waste

Description: The U.S. Department of Energy's (DOE's), Office of River Protection (ORP) located at Hanford Washington has established a contract (1) to design, construct, and commission a new Waste Treatment and Immobilization Plant (WTP) that will treat and immobilize the Hanford tank wastes for ultimate disposal. The WTP is comprised of four major elements, pretreatment, LAW immobilization, HLW immobilization, and balance of plant facilities. This paper describes the technologies selected for pretreatment of the LAW and HLW tank wastes, how these technologies were selected, and identifies the major technology testing activities being conducted to finalize the design of the WTP.
Date: February 26, 2002
Creator: Carreon, R.; Mauss, B. M.; Johnson, M. E.; Holton, L. K.; Wright, G. T.; Peterson, R. A. et al.
Partner: UNT Libraries Government Documents Department

Decomposition of Tetraphenylborate In Tank 48H

Description: This report provides a qualitative and semiquantitative description of the chemical reaction that decomposed the excess sodium tetraphenylborate in Tank 48H during November and December 1995.
Date: May 10, 1996
Creator: Barnes, M.J.; Walker, D.D.; Crawford, C.L.; Swingle, R.S.; Peterson, R.A.; Hay, M.S. et al.
Partner: UNT Libraries Government Documents Department