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Description: The amount of Ac/sup 227/ per curie of Ra/sup 226/ was calculated for various values of neutron flux and various Irradiation times. The amount of Th/ sup 228/ produced per curie of Ra/sup 226/ and the percentage of Ac/sup 227/ converted to Th/sup 228/ relative to the total amount of Ac/sup 227/ produced were also calculated. (W.D.M.)
Date: August 28, 1952
Creator: Grove, G. R.; Russell, L. N. & Orr, S. R.
Partner: UNT Libraries Government Documents Department

Report for General Research September 18 to December 11, 1950 (Actinium Volume)

Description: The purpose of the research work presented in this volume is to develop a process for the separation and purification of actinium-227 produced by neutron bombardment of radium-226 and to develop methods by which uniform films of actinium metal may be deposited on metallic surfaces. The design work on the cave structure and mechanical equipment used in the actinium separation is proceeding on schedule. As the mechanical design phase is nearing completion the emphasis is being directed toward processing equipment. The process as well as the mechanical equipment has been adapted from the research work of F. T. Hagemann and the Remote Control Group at Argonne National Laboratory. Consequently, one of the first objectives is to become familiary with the chemistry of the process and the operation of the mechanical equipment. Cold runs have been made on the T.T.A. benzene extraction using lanthanum and barium in place of actinium and radium. No difficulty with the operation was observed. The formation of precipitates was one of the difficulties encountered with the process as the precipitates carry radium. It has been found that metals such as nickel cause these precipitates to form and should, therefore, be avoided in the construction of equipment. it was also found that a T.T.A. solution exposed to 0.5 curie of polonium over a period of days develops a precipitate. Some new mechanical features hav eshown promise. The use of copper-coated glassware which will hold together even though the glass is cracked has made it possible to replace custom-built heaters with standard heating mantles. A new graphite, silicone grease mixture appears to hold up in stopcocks handling benzene and, as a result, may eliminate the necessary of entering the cave for regreasing. Tests on the preparation of dense concrete have given results which meet the shielding requirements for ...
Date: January 15, 1951
Creator: Haring, M.M.
Partner: UNT Libraries Government Documents Department


Description: Information is presented in threc main sections: nuclear and radiochemistry. physical and organic chemistry, and process chemistry. Included is an investigation of naturally occurring Pu for isotopes other than Pu/sup 239/ , an examination of Mallinckrodt wastes for Ac/sup 227/ the half life of Pa/sup 240/ the cross section of Np /sup 237/ and a study of Np isomers, studies of various Tc and Re compounds, coincidence of interference in a pulse analyzer, absorption of neutrons in a sphere. separation of tritium and hydrogen, spectrophotometric studies of Pa, studies of salt-mixed solvent systems. spectra of ferric complexes, separation of Pu and Np. oxidation of Np(IV by Fe(III). magnetic susceptibilities of actinic compounds, Np(V) compounds. thermal decomposition of UO/sub 3/, physical properties of metal chloridephosphorus oxychloride systems, a continuous chromatographic adsorption method, fluoride volatility separations, fluorination of Th, Zr. Al. and Zr- U alloys, electrolysis of BrF/sub 3/ solutions, decontamination studies including U- Te separations, Pa volatility experiments, extraction of ionium from Mallinckrodt raffinate, and isolation of Pa from the ionium waste stream. (J.R.D.)
Date: June 1, 1950
Creator: Osborne, D.W. ed.
Partner: UNT Libraries Government Documents Department


Description: 8 7 6 2 ; 7 4 7 6 : 7 8 : : ; half life of 3.781 plus or minus 0.010 years based on calorimetric measuiements. The calorimetric assay of the sample will be continued ior several years to decrease the probable error. The decay scheme for /sup 209/Po--/sup 209/Po/ isitopic mixtures is being determined. The gamma spectrum is being studied using two sources of different isotopic composition. Definite peaks were established at 76, 260, 300, 575, and 9l0 kev. Various multiple coincidence experiments indicated that the 300- and 575-kev photons and the 76-kev x-ray are in triple coincidence. Relative intensities of the various gamma rays from the two different sources indicated that the 575-kev photon is associated with /sup 208/ Po decay, while the 260- and 910-kev states are attributed to /sup 209/Po. A theoretical estimate of the partial alpha half life for /sup 208/Po decay to the 2+ level in /sup 204/Pb (at 0.899 Mev) was made. This value (2.5 x 10/sup 6/ years) was determined graphically by extrapolation to an alpha particle energy of 4.2l1 Mev. /sup 209/Po--/sup 2o9/Po sources are being prepared for the investigation of the internal conversion electron spectra of these isotopes. Ion exchange techniques are being studied for the separation of /sup 227/Ac from / sup 227/Th, /sup 223/R a, and /sup 226/Ra. Naturally occurring lanthanum, thorium, and barium are being used as experimental substitutes. Composite elution curves indicated that lanthanum and /sup 232/Th can be successfully isolated with 2 M HCl, 3 M HNO/sub 3/, and ammonium acetate as elutrients. A purified form of the original Dowex 50W-X8 column packing matenial was used; the new material (AG-50W-X8) reduced tailing on the elution curves. /sup 228/Th was tentatively assigned a half life of 1.9132 years with an internal probable error of ...
Date: July 30, 1963
Creator: Eichelberger, J.F.; Grove, G.R. & Jones, L.V.
Partner: UNT Libraries Government Documents Department


Description: Using six hot-wire columns and three concentric tube thermal diffusion columns a cascade system was arranged to produce 0.04 g of 90% C/sup 13/ per day using methane as the feed gas-. The ten liter shipment of purchased methane enriched to 60% C/sup 13/ was received. This gas will be enriched to 90% C/slup 13/. Before removing the equilibrated gas from the concentric tube columns in preparation for using methane enriched in C/sup 13/ as feed material, a sample of methane taken from the bottom of the last column contained greater than 65% C/sup 13/. The hydrolysis of protactinium was found to be completely controllable and reversible and can serve as the basis for its separation from other elements, particularly its decay products. The tendency to hydrolyze is not a unlque characteristic of protactinium, but is exhibited, under appropriate conditions, by Th/sup 227/ and Ra/sup 223/ at trace levels. Traces of protactinium in 1N H/ sub 2/SO/sub 4/ can be removed from solution by a coarse glass wool filter through which the decay products pass readily. The reverse is true if the H/sub 2/SO/sub 4/ concentration is increased to 6N. The desorption of protactinium from platinum was a function of the reagent, the reagent concentration, and the amount of protactinium adsorbed. The relative solubility of protactinium in various reagents increased in the order: HNO/sub 3/ < HCl < H/sub 2/SO/sub 4/ < H/ sub 2/C/sub 2/O/sub 4/ < HF. Equations for computing the growth of the principal alpha-emitters in the Ac/sup 227/ decay chain were recalculated based on the recently redetermined half lives of Ac/sup 227/, Th/sup 227/, and Ra/sup 223/. Several laboratory experiments on waste disposal problems indicated that radioactivity levels in influent water can be significantly reduced by precipitating aluminum hydroxide as well as bismuth hydroxide in the ...
Date: March 30, 1963
Creator: Eichelberger, J.F.; Grove, G.R.; Jones, L.V. & Rembold, E.A.
Partner: UNT Libraries Government Documents Department

Mound Laboratory Progress Report for September 1963

Description: Three silicone-based conductive adhesives were formulated and evaluated. One of the formulations had a resistivity of 0.089 ohm-centimeter after aging one week. After the same period the other two formulations had resistivities of 0.871 and 38.0 ohm-centimeters, Erratic adsorptive behavior of / sup 140/Ba was traced to in impurity in the Ba--/sup 140/La stock solution. Repurification by cation exchange did not improve the reproducibility of the separations, possibly because impurities are reintroduced by the distilled water. Definite improvement was noted when the /sup 140/Ba was separated from /sup 140/ La and other hydrolyzable materials by residue adsorption methods. A calorimetric measurement of a salt sample over a period of 148 days gave a tritium half life of 12.361 plus or minus 0.028 years. This value confirmed the earlier value of l2.355 plus or minus 0.028 years. The /sup 208/Po--/sup 209/Po mixture returned from Argonne National Laboratory is being processed further. Two batches of polonium-contaminated organic material were wet-ashed in nitric and perchloric acids. Further purification will be by techniques similar to those presently used for separating /sup 210/Po from bismuth. An unidentified gamma activity was found in the polonium that was recovered from pieces of Monel fluorination apparatus. The optimum conditions for decontamination of polonium process waste are being determined. Ferric sulfate was dissolved in the solution, and the pH was adjusted to a value between 7.0 and 12.0 to precipitate ferric hydroxide. However, the alpha and beta activity was not decreased sufficiertly to allow dumping of the wastes without further processing. A method of separating /sup 227/Ac from a mixture of its daughter products and /sup 226/Ra is being developed using ion exchange and solvent extraction techniques. Substituted elements are being used to evaluate the separation procedures prior to the separation of the radioactive isotopes. More than 99% of ...
Date: September 30, 1963
Creator: Eichelberger, J. F.; Grove, G. R. & Jones, L. V.
Partner: UNT Libraries Government Documents Department