Electron beam techniques were used to characterize
uranium-contaminated soils at the Fernald site in
Ohio. Uranium particulates had been deposited on the
soil through chemical spills and from the operation
of an incinerator plant on the site. The major
uranium phases were identified using analytical
electron microscopy (AEM) combined with electron
diffraction as uranyl phosphate (meta-autunite),
uranium oxide (uraninite), and uranium metaphosphate
[U(PO3)4]. The
U(PO3)4 was found predominantly at
an incinerator site at Fernald. Carbonate leaching in
an
oxygen environment has removed some of the U(IV)
phases; however, U(PO3)4 has not been removed
by
any of the chemical remediation technologies tried
to date. These observations suggest that an
additional
physical extraction procedure is needed to remove
this phase. Some evidence suggests that the
uranium has undergone weathering, resulting in its
redistribution within the soil.
Laricobius erichsonii Rosen. is one of several species that have been introduced into the Atlantic Provinces since 1933 for the biological control of the balsam woolly aphid, Adelges piceae (Ratz.). This small beetle occurs commonly on A. piceae infestations in Europe where it is one of the more numerous predators of the adelgid (Mesnil, 1950:). Franz (1953) described its range in Europe as from the Italian Alps to near southern Denmark and from Normandy almost to the Carpathian Mountains, srating that its distribution is bound to that of the Coniferae on which its prey live. Franz also described the morphology of all stages in detail and discussed the bionomics and ecology in Europe. Prior to these studies the biology of thc insect was unknown.
Polymeric-coated ferromagnetic particles with an absorbed layer of octyl(pheny1)-N,N-diisobutylcarbamoylmethylphosphine oxide (CMPO) diluted by tributyl phosphate (TBP) are being evaluated for application in the separation and the recovery of low concentrations of americium and plutonium from nuclear waste solutions. Due t o their chemical nature, these extractants selectively complex americium and plutonium contaminants onto the particles, which can be recovered from the waste solution using a magnet.The effectiveness of the extractant-absorbed particles at removing transuranics (TRU) from simulated solutions and various nitric acid solutions was measured by gamma and liquid scintillation counting of plutonium and americium. The HNOQ concentration range was 0.01M to 6U. The partition coefficients (Kd) for various actinides at 2M HNO3 were determined t o be between 3000 and 30,000. These values are larger than those projected for TRU recovery by traditional liquid/liquid extraction. Results from transmission electron microscopy indicated a large dependence of Kd on relative magnetite location within the polymer and the polymer surface area.Energy disperse spectroscopy demonstrated homogeneous metal complexation on the polymer surface with no metal clustering. The radiolytic stability of the particles was determined by using 6oCo gamma irradiation under various conditions. The results showed that I Q more strongly depends on the nitric acid dissolution rate of the magnetite than the gamma irradiation dose. Results of actinide separation from simulated high-level waste representative of that at various DOE sites are also discussed.
Characterization of the actinide content of a sample of contaminated coral soil from Johnston Atoll, the site of three non-nuclear destructs of nuclear warhead-carrying THOR missiles in 1962, revealed that >99% of the total actinide content is associated with discrete bomb fragments. After removal of these fragments, there was an inverse correlation between actinide content and soil particle size in particles from 43 to 0.4 µm diameter. Detailed analyses of this remaining soil revealed no discrete actinide phase in these soil particles, despite measurable actinide content. Observations indicate that exposure to the environment has caused the conversion of relatively insoluble actinide oxides to the more soluble actinyl oxides and actinyl carbonate coordinated complexes. This process has led to dissolution of actinides from discrete particles and migration to the surrounding soil surfaces, resulting in a dispersion greater than would be expected by physical transport of discrete particles alone.
Electron beam techniques have been used to characterize uranium-contaminated soils at the Fernald Site, Ohio. Uranium particulates have been deposited on the soil through chemical spills and from the operation of an incinerator plant on the site. The major uranium phases have been identified by electron microscopy as uraninite, autunite, and uranium phosphite [U(PO3)4]. Some of the uranium has undergone weathering resulting in the redistribution of uranium within the soil.
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