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Interactions of tailings leachate with local liner materials found at Canonsburg, Pennsylvania.

Description: The mill tailings site at Canonsburg, Pennsylvania is the first mill site to receive remedial action under the Department of Energy's Uranium Mill Tailings Remedial Action Program. Part of this remedial action will require excavating the 53,500 m/sup 3/ (70,000 yd/sup 3/) of tailings on the site having a specific activity exceeding 100 pCi/g, and encapsulating these contaminated tailings in a clay-lined cell. As part of the remedial action effort, Pacific Northwest Laboratory has been studying the interactions of tailings and tailings leachate with locally occurring clays proposed for liner materials. These studies include physical and chemical characterization of amended and unamended local clays, chemical characterization of the tailings, column studies of tailings leached with deionized water, and column studies of clays contacted with tailings solutions to determine the attenuation properties of the proposed liner materials. Column studies of tailings leached with deionized water indicated that the Canonsburg tailings could represent a source of soluble radium-226 and uranium-238, several trace metals, cations, and the anions SO/sub 4/, NO/sub 3/, and Cl. Of these soluble contaminants, uranium-238, radium-226, the trace metals As and Mo, and the anions F and SO/sub 4/ were present at levels exceeding maximum concentration levels in the tailings leaching column effluents. However, local clays, both in amended and unamended form were effective in attenuating contaminant migration. The soil amendments tested failed to increase radium attenuation. The tailings leaching studies indicated that the tailings will produce leachates of neutral pH and relatively low contaminant levels for at least 200 years. We believe that compacting the tailings within the encapsulation cell will help to reduce leaching of contaminants from the liner system, since very low permeabilities (<10/sup -8/ cm/s) were observed for even slightly compacted tailings materials.
Date: April 1, 1984
Creator: Dodson, M.E.; Gee, G.W. & Serne, R.J.
Partner: UNT Libraries Government Documents Department

Review of safety issues that pertain to the use of WESF cesium chloride capsules in an irradiator

Description: Since the recovery of the fission product cesium-137 began in 1967, about 1500 capsules, each containing an average of about 50,000 curies of cesium chloride, have been produced. These capsules were designed to safely store this gamma-emitting fission product, but they are now considered to be a valuable source for irradiators. The capsules were designed to have a large margin of safety in their mechanical properties. Impact, percussion, and thermal tests have been conducted that demonstrate their ability to meet anticipated licensing requirements. Although this document is not intended to develop or evaluate accident scenarios, an examination of the effects of heating a capsule to 800/sup 0/C for up to 90 min was completed. At 800/sup 0/C, the salt volume would be expected to exceed the initial capsule volume in a few (up to 1/3) of the WESF capsules. Under these conditions, the inner capsule would expand to accommodate the salt volume and the gas pressure. The strength and ductility of the capsule are more than adequate to permit this expansion with a safety margin of at least a factor of three. Capsules have now been stored in the WESF pool for 10 years, and 15 capsules have been used in the Sandia Irradiator for Dried Sewage Solids facility for nearly 5 years without any capsule failure. This experience, along with available laboratory and production data, gives reasonable assurance that the capsules can be safely used in properly designed commercial irradiators. This is especially the case when one considers current and future evaluation programs designed to assess the long-term effects of corrosion and mechanical properties degradation.
Date: July 1, 1984
Creator: Tingey, G.L.; Wheelwright, E.J. & Lytle, J.M.
Partner: UNT Libraries Government Documents Department

Photovoltaic module encapsulation design and materials selection. Volume II

Description: This is Volume II of Photovoltaic Module Encapsulation Design and Materials Selection: a periodically updated handbook of encapsulation technology, developed with the support of the Flat-Plate Solar Array Project (FSA), managed for the Department of Energy (DOE) by the Jet Propulsion Laboratory. Volume II describes FSA encapsulation technology developed between June 1, 1982, and January 1, 1984. Emphasis during this period shifted from materials development to demonstration of reliability and durability in an outdoor environment; the updated information in this volume reflects the developing technology base related to both reliability and encapsulation process improvements.
Date: June 1, 1984
Creator: Cuddihy, E.
Partner: UNT Libraries Government Documents Department

Reducing hot-short cracking in iridium GTA welding using four-pole oscillation

Description: Hot-short cracking, an intrinsic problem in iridium welding, has been reduced using four-pole magnetic arc oscillation. For given batches of iridium, reject rates have been reduced from 26% to 2%. The mechanics of the four-pole oscillator, the microstructural effects and the causes for improvement are discussed.
Date: January 1, 1984
Creator: Scarbrough, J.D. & Burgan, C.E.
Partner: UNT Libraries Government Documents Department