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in subjects: "Transplutonium Elements"

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Transfer products from the reactions of heavy ions with heavy nuclei. [394 to 1156 MeV]

Production of nuclides heavier than the target from /sup 86/Kr- and /sup 136/Xe-induced reactions with /sup 181/Ta and /sup 238/U was investigated. Attempts were made to produce new neutron-excess Np and Pu isotopes by the deep inelastic mechanism. No evidence was found for /sup 242/Np or /sup 247/Pu. Estimates were made for the production of /sup 242/Np, /sup 247/Pu, and /sup 248/Am from heavy-ion reactions with uranium targets. Comparisons of reactions of /sup 86/Kr and /sup 136/Xe ions with … more

Date: November 1, 1979

Creator: Thomas, K.E. III

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Fission properties and production mechanisms for the heaviest known elements

Mass yields of the spontaneous fission of Fm isotopes, Cf isotopes, and /sup 259/Md are discussed. Actinide yields were measured for bombardments of /sup 248/Cm with /sup 16/O, /sup 18/O, /sup 20/Ne, and /sup 22/Ne. A superheavy product might be produced by bombarding /sup 248/Cm with /sup 48/Ca ions. 12 figures. (DLC)

Date: January 1, 1981

Creator: Hoffman, D.C.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Personnel neutron dosimetry studies at the Lawrence Livermore National Laboratory

A study was conducted to determine the effect of phantom size, shape and composition on the response of an albedo neutron dosimeter. The most important feature was the shape. The dose equivalent rate from a californium neutron source was determined. Ten different dose rates were determined which varied from 2.39 to 3.02 rem/h for the CF source used. (ACR)

Date: June 9, 1981

Creator: Hankins, D.E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Dynamical limitations to heavy-ion fusion

In spite of the many attempts to synthesize superheavy elements in recent years, these efforts have not yet been successful. Recent improved theoretical models of heavy-ion fusion reactions suggest that the formation of super-heavy elements is hindered by the dynamics of the process. Several recent experiments lend support to these theories. The necessity of an excess radial velocity (extra push) over the Coulomb barrier in order to induce fusion is observed experimentally as predicted by the t… more

Date: January 1, 1983

Creator: Back, B.B.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Calculated masses and decay properties for heavy and superheavy elements

Within the framework of the macroscopic-microscopic method, models have been developed that allow the calculation of nuclear masses and fission barriers to an accuracy of approximately 1 MeV, on the average. In one such calculation Moeller and Nix studied nuclei from /sup 16/O to the heaviest known elements. In that calculation the rms deviations between calculated and experimental masses and fission barriers were 0.835 MeV and 1.331 MeV, respectively. We have now used that model to extend the … more

Date: January 1, 1985

Creator: Leander, G. A.; Moeller, P. & Nix, J. R.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Quality engineering and control. Semiannual progress report, May-October 1978

The standard colorimetric procedure for thorium was improved by using lanthanum carrier precipitation of thorium fluoride, conversion to sulfate, and colorimetric measurement with thoron. Four types of anion-exchange resins were evaluated using breakthrough capacity, elution volume, and the neptunium-plutonium ratios in both wash solutions and ion-column eluates as criteria, and 100 to 200 mesh Dowex 1 x 4 resin had the most favorable separation characteristics. Use of commercially available aq… more

Date: August 20, 1979

Creator: Carpenter, R.L.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Technique for fission measurements of highly active and weak cross-section actinides

The Rensselaer Intense Neutron Spectrometer (RINS) system provides an intense neutron source that is well suited for measuring the fission cross sections of microgram quantities of highly-active actinides and gram quantities of nuclei with very weak cross sections. The system consists of a 75-ton lead assembly driven by the RPI electron linac, and the neutron fluxes are three-to-four orders of magnitude more intense than those available in conventional time-of-flight measurements. Examples of m… more

Date: January 1, 1989

Creator: Block, R.C.; Slovacek, R.E.; Hoff, R.W. & Nakagome, Yoshihiro

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Direct spectrophotometric assay of americium

Americium is determined by a simple, direct spectrophotometric assay. The sample is dissolved in acid, diluted to volume, and the Am(III) absorbance is measured at 503 nm. Absorbances with respect to concentration are linear to an absorbance of 0.7, corresponding to 0.5 mg/ml Am. The effects of HNO/sub 3/, HC1, H/sub 3/PO/sub 4/ and HF, and temperature on the absorbance are discussed.

Date: January 1, 1981

Creator: Harmon, A. W.; Dahlby, J. W.; Marshall, T. K.; Baughman, W. J. & Bonner, A. S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Mass transfer in a geologic environment

A new analytical solution is presented that predicts the rate of dissolution of species from a waste package surrounded by a wet porous medium. By equating the rate of diffusive mass transfer into the porous rock to the rate of liquid-surface chemical reaction, an analytical solution for the time-dependent dissolution rate and the time-dependent concentration of dissolved species at the waste surface is obtained. From these results it is shown that for most of the important species in a package… more

Date: November 1, 1984

Creator: Zavoshy, S. J.; Chambre, P. L. & Pigford, T. H.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Separation of Am-Cm from NaNO/sub 3/ waste solutions by in-canyon-tank precipitation as oxalates

A process for the purification of Am-Cm residues was developed specifically for application in Savannah River Plant (SRP) canyon tanks. These Am-Cm residues were collected from several campaigns to produce plutonium containing high isotopic concentrations of /sup 240/Pu. An initial purification from Al/sup 3 +/ had already been accomplished by a solvent extraction process. The product of this process was contaminated with NaNO/sub 3/ as a result of entrainment of the solvent extraction NaNO/sub… more

Date: September 1, 1981

Creator: Gray, L. W.; Burney, G. A.; Wilson, T. W. & McKibben, J. M.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Pilot-scale production of dicesium hexachloroplutonate (Cs/sub 2/PuCl/sub 6/) and filtrate recovery

The Rocky Flats Plant is introducing the use of dicesium hexachloroplutonate (DCHP) into the Molten Salt Extraction Process (MSE). DCHP (Cs/sub 2/PuCl/sub 6/) extracts americium from molten plutonium metal into a molten calcium chloride matrix. The DCHP is produced by precipitating plutonium (IV) from hydrochloric acid with cesium chloride. Before production of the DCHP began, we performed a pilot-scale test to determine yields, track impurities, and test filtrate recovery for the proposed proc… more

Date: March 15, 1989

Creator: Muscatello, A. C.; Stevens, J. R.; Killion, M. E.; Valdez, J. D. & Ames, R. L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Explosion of cation exchange column in americium recovery service Hanford Plant, August 30, 1976

A cation exchange column in americium recovery service exploded on August 30, 1976 at the Hanford plutonium-finishing plant operated by Atlantic Richfield Hanford Company for the Energy Research and Development Administration at Richland, Washington. The column burst, shattering the glovebox windows. Detectable but small amounts of americium were released from the building in which the explosion occurred. Decontamination efforts and physical repairs to equipment and facilities are estimated to … more

Date: October 8, 1976

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Removal of americium and curium from high-level wastes. [DHDECMP; OPIX; Talspeak]

The DHDECMP process was demonstrated to give a 99.5% removal of actinides from actual HLLW in small-scale, batch extraction tests. Results from cold tests indicate that it may be possible to carry out the oxalate precipitation step of the OPIX process continuously. About 90% recovery of the trivalent actinides and lanthanides can be achieved in the continuous precipitation. the presence of zirconium impurity in feed solutions to Talspeak process at concentrations of 10/sup -4/ M (0.5% of the Zr… more

Date: January 1, 1979

Creator: Bond, W D & Leuze, R E

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Measurement of plutonium and americium in molten salt residues

The measurement of plutonium and americium in molten salt residues using a segmented gamma-ray scanning device is described. This system was calibrated using artificially fabricated as well as process generated samples. All samples were calorimetered and the americium to plutonium content of the samples determined by gamma-ray spectroscopy. For the nine samples calorimetered thus far, no significant biases are present in the comparison of the segmented gamma-ray assay and the calorimetric assay… more

Date: January 1, 1979

Creator: Haas, F. X.; Lawless, J. L.; Herren, W. E. & Hughes, M. E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Chemistry research and development progress report, May-October, 1978

Work in progress includes: calorimetry and thermodynamics of nuclear materials; americium recovery and purification; optimization of the cation exchange process for recovering americium and plutonium from molten salt extraction residues, photochemical separations of actinides; advanced ion exchange materials and techniques; secondary actinide recovery; removal of plutonium from lathe coolant oil; evaluation of tributyl phosphate-impregnated sorbent for plutonium-uranium separations; plutonium r… more

Date: August 30, 1979

Creator: Miner, F. J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Isolating /sup 241/Am from waste solutions containing Al, Ca, Fe, and Cr

About 2.4 kg of /sup 241/Am contaminated with calcium and aluminum had been recovered from low-activity waste during recycle of 11% /sup 240/Pu. A process was developed and demonstrated to purify the americium before shipment as /sup 241/AmO/sub 2/. The americium and some of the calcium were batch extracted into 50% TBP-n-paraffin from 2.2M Al(NO/sub 3/)/sub 3/ - 0.3M HNO/sub 3/ solution in a canyon tank. Pregnant solvent was scrubbed first with 2.1M Al/sup 3 +/-0.3M Li/sup +/-6.7M NO/sub 3/- a… more

Date: January 1, 1982

Creator: Gray, L. W.; Burney, G. A. & King, C. M.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Frontiers of chemistry for americium and curium

The discoveries of americium and curium were made only after Seaborg had formulated his actinide concept in order to design the chemistry needed to separate them from irradiated /sup 239/Pu targets. Their discoveries thus furnished the first clear-cut evidence that the series exists and justified Seaborg's bold assumption that even though Th and Pa appeared to presage a following 6d series, the pattern established by the periodic table after Cs and Ba would be repeated exactly after Fr and Ra. … more

Date: January 1, 1984

Creator: Keller, O.L. Jr.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Application of alpha spectrometry to the discovery of new elements by heavy-ion-beam bombardment

Starting with polonium in 1898, ..cap alpha..-spectrometry has played a decisive role in the discovery of new, heavy elements. For even-even nuclei, ..cap alpha..-spectra have proved simple to interpret and exhibit systematic trends that allow extrapolation to unknown isotopes. The early discovery of the natural ..cap alpha..-decay series led to the very powerful method of genetically linking the decay of new elements to the well-established ..cap alpha..-emission of daughter and granddaughter … more

Date: May 1, 1983

Creator: Nitschke, J.M.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Chemistry research and development. Progress report, November 1978-April 1979

The status of the following studies is given: calorimetry and thermodynamics of nuclear materials; americium recovery and purification; optimization of the cation exchange process for recovering americium and plutonium from molten net extraction residues; evaluation and comparison of bidentate extractants and methods for actinide recovery; a combined anion exchange-bidontate organophosphorus extraction process for molten salt extraction residues; a combined anion exchange-extraction chromatogra… more

Date: October 5, 1979

Creator: Miner, F. J.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Quasi-fission

Recent experimental and theoretical investigations have led to the characterization of a new reaction mechanism called quasi-fission. This process is characterized by the emergence of fission-like fragments, which do not originate from the fission decay of a compound nucleus formed by heavy-ion fusion, but rather from the break up of a short-lived intermediate complex. The occurrence of quasi-fission processes appear to be limited to heavy reaction systems and/or large angular momenta, although… more

Date: January 1, 1983

Creator: Back, B.B.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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TUCS: A new class of aqueous complexing agents for use in solvent extraction processes

The 1-hydroxyethyl-1,1-diphosphonic (HEDPA) and vinylidene-1,1-disphosphonic (VDPA) acids have been studied as stripping agents for Am, Pu, and U from TRUEX process solvent (0.2 M CMPO-1.2 M TBP-dodecane). Both disphosphonic acids have been shown to be highly effective stripping agents using pristine process solvent as well as radiolytically degraded solvent. The actinide-HEDPA and -VDPA complexes are more soluble than the corresponding oxalate complexes and are readily destroyed by metal-catal… more

Date: January 1, 1990

Creator: Horwitz, E.P.; Diamond, H.; Gatrone, R.C.; Nash, K.L. & Rickert, P.G.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Americium assay instrument

A simple in-line americium assay instrument (AAI) was installed at an americium recovery process area at LASL for use in process development and for providing process control information. The AAI counts 59.5-keV /sup 241/Am gamma rays, using a NaI(T1) detector and Eberline SAM II electronics. It has a useful range of 3 x 10/sup -5/ to 10 g Am/l and does not suffer from plutonium interference. Comparative analyses of samples assayed in the AAI and samples assayed by the LASL Analytical Laborator… more

Date: January 1, 1979

Creator: Marshall, R.S.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Actinide removal from nitric acid waste streams

Actinide separations research at the Rocky Flats Plant (RFP) has found ways to significantly improve plutonium secondary recovery and americium removal from nitric acid waste streams generated by plutonium purification operations. Capacity and breakthrough studies show anion exchange with Dowex 1x4 (50 to 100 mesh) to be superior for secondary recovery of plutonium. Extraction chromatography with TOPO(tri-n-octyl-phosphine oxide) on XAD-4 removes the final traces of plutonium, including hydroly… more

Date: January 1, 1986

Creator: Muscatello, A.C. & Navratil, J.D.

Item Type: Article

Partner: UNT Libraries Government Documents Department

open access

Evaluation of a photo-electron rejecting alpha liquid scintillation (PERALS) spectrometer for the measurement of alpha-emitting radionuclides

Results from the evaluation of a PERALS spectrometer for alpha particle measurements by liquid scintillation counting in samples from the nuclear fuel cycle are presented. Examples of PERALS spectra of process, waste, and environmental samples containing Th, U, Pu and Am from the Savannah River Site are shown. The advantages, disadvantages, and limitations of the PERALS technique are discussed. 15 refs., 11 figs.

Date: January 1, 1990

Creator: Cadieux, J.R.

Item Type: Article

Partner: UNT Libraries Government Documents Department