Description: 9 > ? ( ing schedule included MTR, ETR, and other aluminum-type fuels that were processed through the TBP headend at 75 to 100% of flowsheet rates and through the Hexone second and third cycle extraction system at up to l5O% of flowsheet values, achieving an over-all recovery of 99.60%. In carrying out basic studies on aqueous zirconium processing, results obtained during the potentiometric titration of zirconium-fluoride-nitric acid solutions with sodium hydroxide were explained by a mechanism in which the untitrated zirconium fluoride species is converted to a fluozirconate and further hydrolysis proceeds via a fluozirconate route. A modified Zirflex flowsheet for processing 2.5% U-Zr alloy fuels is proposed as a result of bench scale dissolution studies on unirradiated PWR plates that showed that dissolver solutions could be stabilized by adding aluminum nitrate and nitric acid. that higher ammonium fluoride concentrations increased the dissolution rate, that higher hydrogen peroxide concentrations lowered the dissolution rate and decreased solution stability, and that ammonia removal by boiling with or without air sparging had little effect on the reaction. Density curves for Zirflex solutions are reported. First tests of the pilot plant for continuous dissolution of zirconium-type elements have indicated that the dissolution rate is approximately four times as great as predicted on the basis of batch dissolution rates and comparison with the rate ratio for batch vs. continuous dissolution of aluminum, which was used to establish the dissolver size. The continuous dissolution rate for a 2% zirconium- 98% uranium element was approximately proportional to the acid feed rate and reached l9O kg/day at an acid feed rate of 36 l/hr (11M nitric acid, 0.30M hydrofluoric acid, and 0.35M aluminum nitrate). Development of new waste treatment methods is influenced by waste volumes and the associated storage costs involved. A survey of current and proposed ...
Date: July 13, 1960
Creator: Slansky, C.M.; Warzel, F.M. & Bower, J.R. Jr. ed.
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Partner: UNT Libraries Government Documents Department