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Solvent extraction separation of trivalent lanthanide and actinide ions using an aqueous aminomethanediphosphonic acid.

Description: The possibility of separating the trivalent lanthanides, represented by EU{sup 3+}, and actinides, represented by Cf{sup 3+}, using HDEHP in toluene and an aqueous phase containing N-piperidinomethane-1,1-diphosphotic acid, PMDPA, has been investigated. This modified aqueous phase offers potential advantages over the diethylenetriaminepentaacetic acid based TALSPEAK process because of the improved complexation properties of PMDPA in acidic solutions, and the ability to decompose PMDPA before disposal. Extraction experiments were conducted at 25 C in 2 M NaClO{sub 4} between -log [H{sup +}] 1 and 2. The studies enabled us to derive the aqueous phase speciation, the stability constants of the aqueous complexes, and the Cf/Eu separation factors. Despite the presence of an amino group in PMDPA that should favor the retention of the actinides in the aqueous phase, the Cf/Eu separation factors are near unity under the conditions studied.
Date: October 14, 1998
Creator: Jensen, M. P.
Partner: UNT Libraries Government Documents Department

Chelant screening and refinement tests - Phase I, Task 2. Topical progress report, December 1993--June 1994

Description: The Department of Energy (DOE) is now faced with the task of meeting decontamination and decommissioning obligations at numerous facilities by the year 2019. Due to the tremendous volume of material involved, innovative decontamination technologies are being sought that can reduce the volumes of contaminated waste materials and secondary wastes requiring disposal. With sufficient decontamination, some of the material from DOE facilities could be released as scrap into the commercial sector for recycle, thereby reducing the volume of radioactive waste requiring disposal. Although recycling may initially prove to be more costly than current disposal practices, rapidly increasing disposal costs are expected to make recycling more and more cost effective. Additionally, recycling is now perceived as the ethical choice in a world where the consequences of replacing resources and throwing away reusable materials are impacting the well-being of the environment. This report describes efforts towards evaluating solvents for the decontamination of metals and removal of uranium.
Date: July 1, 1995
Partner: UNT Libraries Government Documents Department

Selective Separation of Trivalent Actinides from Lanthanides by Aqueous Processing with Introduction of Soft Donor Atoms

Description: Implementation of a closed loop nuclear fuel cycle requires the utilization of Pu-containing MOX fuels with the important side effect of increased production of the transplutonium actinides, most importantly isotopes of Am and Cm. Because the presence of these isotopes significantly impacts the long-term radiotoxicity of high level waste, it is important that effective methods for their isolation and/or transmutation be developed. Furthermore, since transmutation is most efficiently done in the absence of lanthanide fission products (high yield species with large thermal neutron absorption cross sections) it is important to have efficient procedures for the mutual separation of Am and Cm from the lanthanides. The chemistries of these elements are nearly identical, differing only in the slightly stronger strength of interaction of trivalent actinides with ligand donor atoms softer than O (N, Cl-, S). Research being conducted around the world has led to the development of new reagents and processes with considerable potential for this task. However, pilot scale testing of these reagents and processes has demonstrated the susceptibility of the new classes of reagents to radiolytic and hydrolytic degradation. In this project, separations of trivalent actinides from fission product lanthanides have been investigated in studies of 1) the extraction and chemical stability properties of a class of soft-donor extractants that are adapted from water-soluble analogs, 2) the application of water soluble soft-donor complexing agents in tandem with conventional extractant molecules emphasizing fundamental studies of the TALSPEAK Process. This research was conducted principally in radiochemistry laboratories at Washington State University. Collaborators at the Radiological Processing Laboratory (RPL) at the Pacific Northwest National Laboratory (PNNL) have contributed their unique facilities and capabilities, and have supported student internships at PNNL to broaden their academic experience. New information has been developed to qualify the extraction potential of a class of pyridine-functionalized tetraaza complexants ...
Date: September 22, 2009
Creator: Nash, Kenneth L.
Partner: UNT Libraries Government Documents Department

MULTIDENTATE TEREPHTHALAMIDATE AND HYDROXYPYRIDONATE LIGANDS: TOWARDS NEW ORALLY ACTIVE CHELATORS

Description: The limitations of current therapies for the treatment of iron overload or radioisotope contamination have stimulated efforts to develop new orally bioavailable iron and actinide chelators. Siderophore-inspired tetradentate, hexadentate and octadentate terephthalamidate and hydroxypyridonate ligands were evaluated in vivo as selective and efficacious iron or actinide chelating agents, with several metal loading and ligand assessment procedures, using {sup 59}Fe, {sup 238}Pu, and {sup 241}Am as radioactive tracers. The compounds presented in this study were compared to commercially available therapeutic sequestering agents [deferoxamine (DFO) for iron and diethylenetriaminepentaacetic acid (DPTA) for actinides] and are unrivaled in terms of affinity, selectivity and decorporation efficacy, which attests to the fact that high metal affinity may overcome the low bioavailability properties commonly associated to multidenticity.
Date: July 13, 2011
Creator: Abergel, Rebecca J. & Raymond, Kenneth N.
Partner: UNT Libraries Government Documents Department

Radiation chemistry in solvent etxraction: FY2011 research

Description: This report summarizes work accomplished under the Fuel Cycle Research and Development (FCR&D) program in the area of radiation chemistry during FY 2011. The tasks assigned during FY 2011 included: (1) Continue measurements free radical reaction kinetics in the organic phase; (2) Continue development of an alpha-radiolysis program and compare alpha and gamma radiolysis for CMPO; (3) Initiate an effort to understand dose rate effects in radiation chemistry; and (4) Continued work to characterize TALSPEAK radiation chemistry, including the examination of metal complexed ligand kinetics. Progress made on each of these tasks is reported here. Briefly, the method developed to measure the kinetics of the reactions of the NO3 radical with solvent extraction ligands in organic solution during FY10 was extended here to a number of compounds to better understand the differences between radical reactions in the organic versus aqueous phases. The alpha-radiolysis program in FY11 included irradiations of CMPO solutions with 244Cm, 211At and the He ion beam, for comparison to gamma irradiations, and a comparison of the gamma irradiation results for CMPO at three different gamma dose rates. Finally, recent results for TALSPEAK radiolysis are reported, summarizing the latest in an effort to understand how metal complexation to ligands affects their reaction kinetics with free radicals.
Date: September 1, 2011
Creator: Mincher, Bruce J.; Mezyk, Stephen P. & Martin, Leigh R.
Partner: UNT Libraries Government Documents Department

Retention of plutonium in mouse tissues as affected by antiviral compounds and their analogs

Description: The chelating agent DTPA (diethylenetriaminepentaacetic acid) is an effective therapeutic substance for decorporation of extracellar monomeric plutonium in the mouse and dog, but is much less effective in removing intracellular polymeric plutonium (Pu-P). In the absence of effective therapy, this intracellular plutonium is long retained in the body, particularly in reticuloendothelial tissues like the liver. Our interest, therefore, turned to the development of adjunct substances capable of removing additional plutonium from the liver beyond that removable by DTPA alone. We showed that glucan, a yeast cell wall polysaccharide, is a useful adjunct to DTPA for removal of Pu-P from the mouse liver. Its toxicity, however, makes it a less than desirable drug for potential human use. Therefore, we initiated a search for more soluble (and presumably less hazardous) therapeutic agents similar to glucan, i.e., capable of adjunct action with DTPA. Of over 20 substances tested the most successful results were obtained with two antiviral, antitumor compounds, the pyran copolymers XA-124-177 and XA-146-85-2. These are condensation products of divinyl ether and maleic anhydride. Another analog, EMH-227, prepared by condensation of acrylic acid and itaconic acid, was similarly successful. Maximal removal of plutonium from mouse liver was obtained with a single intravenous (I.V.) injection of 10 to 90 mg/kg of pyran copolymer given 5 days after I.V. Pu-P administration. Although these doses increased splenic uptake of plutonium, a dose of 10 mg/kg produced a minimal increase in the splenic burden while producing maximal removal of hepatic plutonium. (auth)
Date: January 1, 1975
Creator: Lindenbaum, A.; Rosenthal, M.W. & Guilmette, R.A.
Partner: UNT Libraries Government Documents Department

Aspects of inhaled DTPA toxicity in the rat, hamster and beagle dog and treatment effectiveness for excorporation of Pu from the rat

Description: After inhaling 1 to 4 HD (human dose equivalents, i.e., 1 g calcium trisodium N,N-bis (2-bis(carboxymethyl)amino) ethyl) glycinate/70 kg body weight) of Ca-DTPA rats and hamsters developed a transitory vesicular emphysema. This was not found in animals sacrificed later than 3 weeks after the last exposure. Dogs were anesthetised and administered Ca-DTPA aerosols via an intratracheal catheter for 30 min/day for 5 days. The average dose/exposure was 4 HD. One week following the last exposure, 3/4 treated dogs and 0/2 dogs exposed to saline aerosols showed enlargement and submucosal lymphoid follicles in the pyloric region of the stomach; this was not present in dogs sacrificed at 4, 8 or 18 weeks postexposure. Epithelial atypia in the alveolar lining was noted in 5/16 dogs inhaling Ca-DTPA and in 1/8 dogs exposed to saline aerosols, and may or may not be treatment-related. Rats receiving 1.2 $mu$Ci $sup 238$Pu(NO$sub 3$)$sub 4$ intramuscularly were treated promptly with 1.2 HD inhaled or intraperitoneally injected Ca-DTPA. The two methods of Ca-DTPA administration gave statistically identical Pu excorporation. Similar treatments initiated 8 months following the Pu injection also showed no effect of administration route. These experiments and implications for the safety and efficacy of inhaled Ca-DTPA as treatment for transuranic incorporations in man are discussed. (auth)
Date: January 1, 1975
Creator: Smith, V.H.; Ballou, J.E.; Lund, J.E.; Dagle, G.E.; Ragan, H.A.; Busch, R.H. et al.
Partner: UNT Libraries Government Documents Department

Separation of strontium from fecal matter

Description: The present invention relates to a method of separating strontium, and, more particularly, to a method of separating strontium from a sample of biomass potentially contaminated with various radionuclides. Radioactive strontium is a radionuclide which represents a hazard to man because of its long half-life and, if ingested, its tendency to be retained in the human body. In the event that radionuclides such as strontium or various actinides are ingested, it is desirable to monitor the discharge or release of these radionuclides from the human body through analysis of fecal matter. In laboratories and other facilities where potential for radionuclide contamination exists, fecal analysis for strontium is routinely conducted for individuals who are terminating from their position or are suspected of having been contaminated with radionuclides. Methods for separating and analyzing radioactive actinides from a biomass sample are well known and have been extensively developed for the US Department of Energy. These methods, described in the Department`s internal procedure, USDOE, RESL/ID, A-16, 1981, as well as in US Patent 5,190,881, involve the use of an iron phosphate precipitation step to separate actinides from a solution, or supernate. However, there are no established procedures for the separation of strontium from a biomass sample wherein an iron phosphate precipitation step is involved.
Date: December 31, 1994
Creator: Kester, D.K.
Partner: UNT Libraries Government Documents Department

Gadolinium as an element for neutron capture therapy

Description: At BNL, preparations are being made to test in vitro compounds containing Gd and compare their response to the response of GD-DTPA to determine if one or several compounds can be located that enter the cells and enhance the Auger effect. Two similar rotators with positions for cell vials that have been constructed for these tests. The first rotator is made of only paraffin which simulates healthy tissue and provides control curves. The second rotator has 135 ppM of Gd-157 in the paraffin to simulate a Gd loaded tumor. Cells are irradiated in vials in the paraffin rotator and in the Gd-paraffin rotator at the epithermal beam of the Brookhaven Medical Research Reactor (BMRR). This produces an irradiation similar to what a patient would receive In an actual treatment. A combination of irradiations are made with both rotators; with no Gd compound or IdUrd In the cell media, with only Gd compound in the cell media and with both Gd compound and IdUrd in the cell media. The first set shows the effects of gamma rays from the H(n,gamma) reaction and the prompt gamma rays from capture of neutrons by Gd. The second set shows if there is any effect of Gd being in the cell media or inside the cells, i.e., an Auger effect. The third set shows the effect of enhancement by the IdUrd produced by the gamma rays from neutrons captured by either H or Gd. The fourth set combines all of the reactions and enhancements. Preliminary calculations and physical measurements of the doses that the cells will receive In these rotators have been made.
Date: December 31, 1992
Creator: Brugger, R. M.; Liu, H. B.; Laster, B. H.; Gordon, C. R.; Greenberg, D. D. & Warkentien, L. S.
Partner: UNT Libraries Government Documents Department