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Radiation Damage in Boron Carbide

Description: From introduction: "Report describing the study of radiation damage in boron carbide with an integrated thermal neutron flux of 3x10^20 neutrons/cm² in the Materials Testing Reactor (MTR)."
Date: August 18, 1953
Creator: Tucker, Charles W., Jr. & Senio, Peter
Partner: UNT Libraries Government Documents Department

The Boron-Carbon System: Final Technical Report, May 1, 1960 - April 30, 1961

Description: Abstract: The boron-carbon equilibrium diagram has been determined by X-ray, metallographic, and thermal analysis of sintered and arc-cast alloys. A single carbide having a range of solubility from approximately 9 to 20 a/o carbon and melting congruently exists in the system. The terminal solubility of carbon in boron is 0.1-0.2a/o. The freezing reaction at the composition and melting temperature of elemental boron; there is a eutectic reaction at 29a/o carbon and 2375 degrees Celcius. No allotropy of boron was observed.
Date: June 7, 1961
Creator: Elliott, Rodney P.
Partner: UNT Libraries Government Documents Department

The Boron-Carbon System: Quarterly Report No. 1, May 1, 1960 - June 31, 1960

Description: Abstract: A definitive investigation of the boron-carbon equilibrium system is being made by X-ray diffraction, metallographic, and thermal analytical techniques. Alloys are being produced by sintering pressed powder aggregates with subsequent arc melting. Alloys have been made at two atomic percent intervals up to thirty atomic per cent carbon. In the future, higher carbon compositions are to be investigated. Techniques have been worked out for the metallographic preparation of the extremely hard and friable alloys.
Date: August 5, 1960
Creator: Elliott, Rodney P. & Van Thyne, R. J.
Partner: UNT Libraries Government Documents Department

The Boron-Carbon System: Quarterly Report No. 2, August 1, 1960 - October 31, 1960

Description: Abstract: A definitive investigation of the boron-carbon equilibrium system is being made by X-ray diffraction, metallographic, and thermal analytical techniques. Additional baron-carbon alloys have been prepared by sintering and arc-melting compacts prepared from boron and high-purity graphite. Metallographic examinations of these alloys are in agreement with alloys previously preapred from lampblack. X-ray investigation of sintered compacts indicates that the solubility range of boron carbide extends almost to pure boron. Boron of various purities has been annealed for times up to four hours, but no structure other than beta-rhombohedral has been detected. Very high purity boron (10 ppm impurity) has been obtained for the study of allotropy and the equilibrium relationships at very dilute carbon contents.
Date: November 8, 1960
Creator: Elliott, Rodney P. & Van Thyne, R. J.
Partner: UNT Libraries Government Documents Department

The Boron-Carbon System: Quarterly Report No. 3, November 1, 1960 - January 31, 1961

Description: Abstract: A definitive investigation of the boron-carbon equilibrium system is being made by X-ray diffraction, metallographic, and thermal analytical techniques. On the basis of metallographic and X-ray diffraction studies it is concluded that boron carbide has a range of solubility from approximately 10 to 20 atomic per cent carbon at 1500 degrees to 2000 degrees Celsius. The melting point of the carbide-graphite eutectic has been established as 2325-2350 degrees Celsius. No reversible allotropy of the beta-rhombohedral structure has been observed. The solubility of carbon in boron is very small. The melting point of dilute carbon alloys is found to be essentially the same as that of pure boron (2040 degrees to 2050 degrees). No metallographic evidence of a three-phase reaction of dilute alloys is observed.
Date: February 6, 1961
Creator: Elliott, Rodney P.
Partner: UNT Libraries Government Documents Department

Calculated Heats of Formation and Combustion of Boron Compounds (Boron, Hydrogen, Carbon, Silicon)

Description: Memorandum presenting the calculation of the heats of formation and combustion for liquid and gaseous alkyl- and silyl-substituted boron compounds by a semitheoretical method. The results indicated that alkylation and more especially silylation reduce the heat of combustion. Results regarding alkyl- and silyldecaboranes, diborylmethane, diborylethane, and their alkyl derivatives, bipentaboranyl and bideocaboranyl, dipentaboranyl- and didecaboranylalkanes, and heats of combustion of isomers are provided.
Date: October 4, 1955
Creator: Altschuller, Aubrey P.
Partner: UNT Libraries Government Documents Department

Boral : A New Thermal Neutron Shield, Supplement I

Description: The following report provides information on the making of large sheets of boral, an engineering material for the absorption of thermal neutrons, as well as physical properties and recommendations on casting and rolling ingots into sheets.
Date: 1952
Creator: Kitzes, A. S. & Hullings, W. Q.
Partner: UNT Libraries Government Documents Department

Effect of Palladium Form on Tetraphenylborate Decomposition Rate

Description: Palladium catalyzes the decomposition of tetraphenylborate in alkaline solutions. Researchers postulate several decomposition mechanisms that differ in the form of the palladium catalyst. Potential forms include solid and soluble, different soluble species (such as aqueous or organic soluble), and different oxidation states (i.e., 0, II, and IV). Initial tests measured the reactivity and distribution of four Pd forms in tetraphenylborate slurries.
Date: April 28, 1998
Creator: Walker, D. D.
Partner: UNT Libraries Government Documents Department

Tetraphenylborate Solids Stability Tests

Description: Tetraphenylborate solids provide a potentially large source of benzene in the slurries produced in the In-Tank Precipitation process. The stability of the solids is an important consideration in the safety analysis of the process and we desire an understanding of the factors that influence the rate of conversion of the solids to benzene.
Date: December 19, 1997
Creator: Walker, D.D. & Edwards, T.B.
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 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

ITP Solids Stability Operating Window Tests

Description: Tetraphenylborate solids provide a potentially large source of benzene in the slurries produced in the In-Tank Precipitation (ITP) process. The stability of the solids is an important consideration in the safety analysis of the process. Recent tests investigated the stability of the potassium tetraphenylborate (KTPB) solids under process conditions, during both precipitation and washing. In addition, the tests measured the relative stabilities of the sodium, potassium and cesium tetraphenylborate (NaTPB, KTPB, and CsTPB, respectively). Additional tests examined the similarity of the catalytic system in the reaction of soluble and insoluble tetraphenylborates.
Date: April 1998
Creator: Walker, D. D.
Partner: UNT Libraries Government Documents Department

The Solubility of Phenylborate Compounds in Benzene

Description: The original goal of this scoping study was to determine if the solubility of sodium and potassium tetraphenylborates in benzene was sufficiently large to justify designing and performing kinetic studies on a benzene-phase catalytic reaction.
Date: April 1998
Creator: Eibling, R. E.
Partner: UNT Libraries Government Documents Department

Development of a Boron-Copper Neutron Absorber Composite

Description: This report describes the fabrication of a new boron-copper neutron absorbing material that was developed to meet the upgrading needs of the Intense Pulsed Neutron Source (IPNS) at Argonne National Laboratory. To increase the intensity of the neutron beams from the IPNS, the target uranium was changed from depleted uranium to uranium enriched to 77.5% U-235. To keep the multiplication factor, k(sub eff) (number of fissions in one generation/number of fissions in preceding generation) at a safe level, a new neutron absorber material was needed. The previous materials, boral and cadmium, could not meet the new requirements and a search of the literature showed that no currently available material was acceptable.
Date: May 1991
Creator: Wiencek, T. C.; Thresh, H. R. & Summers, J. R.
Partner: UNT Libraries Government Documents Department

EBWR CORE 1A PHYSICS ANALYSIS

Description: The studies were primarily directed toward selection of the optimum loading for Core lA and a prediction of its properties. Included are analyses of some relevant experiments on Core 1, and prelimlnary modifications of Core 1 to Core lA. The factors which must be considered for the optimum loading determination are discussed. Four different loading pattenrs were investigated, which were considered to span the numerous possibilitles. Adequate cold shutdown was found to be almost unobtainable without the use of boric acid. For this reason, and because the heat transfer and stability limitations are severe, greater weight was given to heat transfer as opposed to control requirements. The use of boron-stainless steel poison strips fastened to the sides of the spike elements is considered insofar as in improving the loading from either the heat transfer or control standpoint. The relatlve advantages and disadvantages of the use of stainless steel fuel followers as opposed to Zircaloy followers are discussed. (B.O.G.)
Date: February 1, 1961
Creator: Avery, R.; Almenas, K.; Carson, C.; Iskenderian, H. & Kelber, C.
Partner: UNT Libraries Government Documents Department

Target studies for accelerator-based boron neutron capture therapy

Description: Two new concepts, NIFTI and DISCOS, are described. These concepts enable the efficient production of epithermal neutrons for BNCT (Boron Neutron Capture Therapy) medical treatment, utilizing a low current, low energy proton beam impacting on a lithium target. The NIFTI concept uses an iron layer that strongly impedes the transmission of neutrons with energies above 24 KeV. Lower energy neutrons readily pass through this iron ``filter``, which has a deep ``window`` in its scattering cross section at 24 KeV. The DISCOS concept uses a rapidly rotating, high g disc to create a series of thin ({approximately} 1 micron thickness) liquid lithium targets in the form of continuous films through which the proton beam passes. The average energy lost by a proton as it passes through a single target is small, approximately 10 KeV. Between the targets, the proton beam is reaccelerated by an applied DC electric field. The DISCOS approach enables the accelerator -- target facility to operate with a beam energy only slightly above the threshold value for neutron production -- resulting in an output beam of low-energy epithermal neutrons -- while achieving a high yield of neutrons per milliamp of proton beam current.
Date: March 1, 1996
Creator: Powell, J.R.; Ludewig, H.; Todosow, M. & Reich, M.
Partner: UNT Libraries Government Documents Department

ITP Filter Particulate Decontamination Measurement

Description: A new test method was developed which showed the installed In- Tank Precipitation Filter Unit {number_sign}3 provided at least 40, 000 x decontamination of the precipitated potassium tetraphenylborate (KTPB) during the cold chemical runs.This filter is expected to meet the needed 40,000 x hot cesium decontamination requirements, assuming that the cesium precipitate, CsTPB, behaves the same as KTPB. The new method permits cold chemicals field testing of installed filters to quantify particulate decontamination and verify filter integrity before going hot. The method involves a 1000 x concentration of fine particulate KTPB in the filtrate to allow direct analysis by counting for naturally radioactive isotope K-40 using the underground SRTC gamma spectroscopy facility. The particulate concentration was accomplished by ultra filtration at Rhone-Poulenc, NJ, using a small cross-flow bench facility, followed by collection of all suspended solids on a small filter disc for K analysis.
Date: May 21, 1993
Creator: Dworjanyn, L.O.
Partner: UNT Libraries Government Documents Department