Chemical Processing Technology Quarterly Progress Report

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Download or read book Chemical Processing Technology Quarterly Progress Report, July-September 1961 written by and published by . This book was released on 1961 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Idaho Chemical Processing Plant did not operate on fuel recovery during the period since numerous repairs and modifications were being made to the extraction and U concentration equipment, Ba/sup 140/ production continued on schedule; substantial decontamination of the RaLa facility was achieved and desirable replacement or repair of in-cell equipment was accomplished in the interval between two successive runs. Aqueous Zr fuel processing studies continued with the obje tive of adapting the HF process to continuous dissolution a complexing in order to increase the capacity of the ICPP process while using as much existing equipment as possible to minimize costs. Dissolution rates for Zircaloy-2 in 10M(bar) fluoride dissolver solution proved to be adequate for continuous dissolution (as high as 79 mg cm/sup -2/ min/sup -1/) in an acid range which resulted in both controlled gas evolution and stable dissolver solutions. Preliminary results indicate the possibility of blending Zr raffinates from this process with larger volumes of Al raffinates to achieve stable waste solutions and avoid the necessity of constructing additional special alloy tanks for Zr waste. Supplemental studies on the sodium formate process for head end precipitation of Zr snd fluoride are reported, as well as results of corrosion tests on materials of construction considered for use in various zirconium processing applications. Other aqueous processing studies included the determination that 2.2M aluminum nitrate solutions, acid deficient to 1.0N/sup b/, could be used to scrub highly acid U extraction solutions without incurring the hazard of ammonium diuranate precipitation. Preliminary to processing organic moderated reactor fuel elements, it was discovered that carbonaceous films present on some elements were resistant to removal by Turco 4502 solution, and responded only to oxidation at 500 deg C; the possibility of processing without film removal was explored with satisfactory results insofar as dissolution of the fuel is concerned. Electrolytic dissolution of nichrome-containing fuels in HNO/sub 3/ appears promising and conditions predicted from earlier studies on stainless-steel dissolution were confirmed. Stability, density, and viscosity data are presented for representative product solutions from electrolytic dissolution of stainless-steel fuel of the APPR type. Results of additional chemical and radiation exposure tests on possible plastic insulator materials are presented. Factors affecting the formation of alpha alumina from amorphous alumina received additional study in the laboratory because of the severe attrition problem and related operational difficulties associated with the alpha form in the fluidized-bed calcination process. It was demonstrated that very little alpha alumina was formed by heating amorphous pilot plant product in air, moderate amounts were formed by heating in an airwater vapor atmosphere, and larger amounts were formed when the atmosphere also contained HNO/sub 3/ vapors. Temperature and method of alumina formation (i.e., conditions of pilot plant calciner operation) also affected the conversion but appeared to be interrelated so that no clear cut conclusion on individual effects could be drawn. Investigations of intermediates in the reaction, and structure and distribution of crystalline material in individual particles of calcine, are discussed. Pilot plant calcination studies showed a direct effect between feed Na content and alpha alumina formation rate. Hg was found to have no detectable effect on the process or product. Stripping of TBP from aqueous U streams was investigated because of difficulty associated with decomposition products of TBP, which form gummy deposits and interfere with the operation of product evaporators and pumps. Using tracer P, the TBP distribution coefficient between Amsco and water containing flowsheet quantities of HNO/sub 3/ and U was found to be sufficiently high (290 plus or minus ...