Chemical Processing Technology Quarterly Progress Report, October-December 1961

The ICPP processed Al fuel, prtncipally of the MTR-ETR type, durtng this quarter. Newly designed and installed processing equipment exhibited excellent operating performance. This included direct-air-pulsed extraction, stripping and scrub columns, and a cascade-controlled continuous evaporator in first cycle product concentration service. Aqueous zirconium fuel processing studies continued with the objective of adapting the hydrofluoric acid process to continuous dissolution-complexing to increase the capacity of the LCPP process while using as much existing equipment as possible to minimize costs. Six variations of hydrofluoric acid flowsheets were tested in a smallscale continuous dissolvers. Dissolution rates were found to be high in all cases and dissolution was easily initiated at temperatures as low as 36 deg C. Monel and Carpenter 2O(Nb) were found to be satisfactory construction materials, from the standpoint of corroston, if oxidizing conditions were carefully controlled. Additional studies are reported on the stability of blended Zr and Al process raffinates and on the nature of the solids which result from the sodium formate headend precipitation process. Electrolytic dissolution studies, dtrected at fundamentals of current utiltzation in a series''-type dissolver, demonstrated that high current utilization is obtained when the polarization resistance is small compared with the solution resistance. Factors affecting polarization resistance and solution resistance are clarifted. A decrease in current utilization observed with alternating current as compared with direct current may be offset by efficiencies in elimination of a-c-d-c converters required for the d- c system. Experimental results indicate the possible usefulness of several plastic and ceramic materials tn the chemical and radiation environment of an electrolytic dissolver. Fluidized bed calcination tests conducted in pilot plant and demonstrational waste calcination facility calciners demonstrated that alpha alumina formation was suppressed by addition of boric acid to the waste aluminum nitrate feed. A possible relationship between nozzle design and alpha alumina formation also was noted. Additional laboratory studies on the effect of environmental gas composition on alpha alumina formation were conducted, and pilot plant investigation of calciner off-gas particulate loading demonstrated the effects of nozzle operating conditions on particle attritton. Pulse column- development continued with the goal of spectfying and evaluating column control requirements through a study of pulse column dynamics. Use of porous Kel-F and porous stainless steel has provided means of separating and sampling the organic and aqueous phases from the experimental column. Pulse amplitudes tn an experimental air pulser were measured by electronic integration of a signal representing the square root of the output of a flow transducer in the pulser leg. Results of calibration runs agree to within 5% of the amplitude observed tn a glass pulser leg, and, for comparable conditions, to within 2 to 3% of values obtained by simulation on an analog computer. Additional basic process studies reported include an investigation of the distribution of U between TBP-Amsco and HNO/sub 3/ solutions as found in stripping and scrub column conditions and as influenced sis, or both, and limited P removal to a TBP equivalent of by ihe presence of dibutyl phosphate, a TBP degradation produci. Other basic studies involve development of a continuous recirculating dissolver, study of the effect of Si in Al alloy fuels on U losses, and determination of ion exchange properties and possible usefulness of local natural earth materials rn low-level waste treatment. (auth