Plutonium and the fission products can be removed from irradiated uranium by liquidmetal extraction by use of another metal immiscible with uranium. Metals studied have been silver, cerium, and lanthanum. Plutonium removal by silver is high, by the rare-earth metals moderate. In a l l cases volatile elements, including cesium, strontium, and barium, are removed. Rare earths are e5ciently removed. Ruthenium and molybdenum are largely unaffected. Experiments with synthetic fuels corresponding to long bum-up periods show improved removal of most elements. Repeated batch extractions indicate that a continuous process separating the fuel into uranium, plutonium, and fission-product fractions could be developed.

Development of the Gel-Addition Process for mixed urania-plutonia fuels has continued. UO^ sols have been prepared by the ORNL Formate Process. Gel spheres were made by drying sol droplets in a recirculating column containing a 2-ethyl hexanol bath. Carbon analyses at various steps show that at least half the carbon added (as urea and formate during sol preparation) remains in the sol. Gelation roughly triples the carbon level (C/U atoms ratio in gel = 1. 5). A study of the gelation bath composition showed that nitrated organics do not appear in sufficient quantity to constitute a hazard. Oxidation of Pu(IV) to Pu(VI) by nitrate has been confirmed to be first order in Pu(IV). Apparent half-times have been measured at 30 minutes and 10 minutes. Plutonium pickup by U0 2 gel has been found to be extremely rapid. In contacting runs lasting between 10 and 20 seconds, Pu/U+Pu reached several percent from Pu(IV) solutions. Ceramographic procedures have been developed for polishing and photographing unfired gel. Most gel samples examined show cracking, Capsule design for in-pile testing of mixed oxide is complete. Progress for the fourth quarter ending June 30, 1967 is reported. The project is supported by the U.S. Atomic Energy Commission under Contract No. AT(30-l)-37 14.

This report wae prepared a6 an account of Government sponsored work. Neither the United States, nor the Commission, nor any pereon acting on behalf of the Commission: A. Makes any warranty or represontation. expressed or implied. with respect to the accuracy. completeness. or usefulnesa of the information contained in this report, or that the use of any information, apparatus, method. or process dkciosed in this r e p r t may not infringe privately owned rights; or B. Assumes any liabilities with respect to the u~e of, or for damages resulting from the use of any information, apparatus, method. or process disclosed in this report. As used in the above, "person acting on behalf of the Commlaeion" includes any employee or contractor of the Commission. or employee of such contractor, to the extent that such employee or contractor of the Commirrsion. or employee of such contractor prepares. disseminates. or provides accesa to, any information pursuant to his employment or contract with the Commission. or his employment with such contractor.

This report was prepared as an account of Government sponsored work Neither the United States, nor the Commission, nor any person acting on behalf of the Commission A Makes any warranty or representation, expressed or Implied, with respect to the accuracy, completeness, or usefulness of the information contained in this report, or that the use of any information, apparatus, method, or process disclosed in this report may not infringe privately owned rights, or B Assumes any liabilities with respect to the use of, or for damages resulting from the use of any Information, apparatus, method, or process disclosed in this report As used In the above, "person acting oo behalf of the Commission" includes any employee or contractor of the Commission, or employee of such contractor, to the extent that such employee or contractor of the Commission, or employee of such contractor prepares, disseminates, or provides access to, any information pursuant to his employment or contract with the Commission, or his employment with such contractor.

This report was prepared as an account of Government sponsored work Neither the United States, nor the Commission nor any person acting on behalf of the Commission A Makes any warranty or representation expressed or implied, with respect to the accuracy, completeness or usefulness of the information contained in this report, or that the use of any information, apparatus, method, or process disclosed in this report may not infringe privately owned rights, or B Assumes any liabilities with respect to the use of, or for damages resulting from the use of any Information, apparatus method or process disclosed in this report As used in the above, "person acting on behalf of the Commission" includes any employee or contractor of the Commission, or employee of such contractor, to the extent that such employee or contractor of the Commission, or employee of such contractor prepares disseminates, or provides access to, any information pursuant to his employment or contract with the Commission, or his employment with such contractor