This quarterly progress report details ongoing work at the Oak Ridge National Laboratory as part of the Aircraft Nuclear Propulsion Project. Topics of discussion include reactor theory and design, shielding research, materials research, appendixes with information on ongoing analytical chemical studies.

From abstract: "This report describes the decontamination of Oak Ridge National Laboratory Purex Pilot Plant facilities and presents an appraisal of the decontaminating techniques and reagents which were employed."

Abstract: "Experiments were performed to characterize the types of nitro compounds that might be formed by reaction of Shell Spray Base with nitric acid, to determine the extent of their formation, if any, and their path under conditions of nitric acid recovery in the Purex Process. It is concluded that the instability of Shell Spray Base to nitration, under conditions to prevail in the plant, presents neither a disposal problem nor a safety problem."

Abstract: "A uranium-titanium constitution diagram is presented. There is complete solid solubility between titanium and gamma uranium above about 2100 F. Only one compound exists in the system. It has a hexagonal structure based on U2Ti. It has a fairly wide range of stability, particularly on the titanium side. Beta-titanium solid solution decomposes eutectoidally into alpha titanium and compound at 1150 F. Eutectoid composition is about 72 atomic per cent titanium. Gamma-uranium solid solution decomposes eutectoidally at 1325 F into beta uranium and compound. Eutectoid composition is about 6 atomic per cent titanium. Beta uranium and compound react peritectoidally at 1233 F to give alpha uranium. Solubility of titanium in alpha and beta uranium is low as is the solubility or uranium in alpha titanium."

As there is no accurate measurements of the energy distribution of neutrons emerging from large uranium blocks, it becomes of importance to see how much information of this kind can be derived from the slowing down distribution of the neutrons in a water tank.

A method for determining zirconium in plutonium-zirconium alloys was required as part of an investigation of alloys containing fissionable material, with possible use in nuclear reactors. Alloys of these two elements were brought into solution with a bisulfate fusion and the zirconium was separated by precipitation with p-bromomandelic acid. Determinations were completed by weighing the zirconium oxide obtained after ignition of the precipitate at 925 degree C. The precision of this recommended procedure was estimated in terms of the standard deviation for quadruplicate determinations, made with weight aliquots from dissolved alloy samples. The range for the standard deviation was 0.5 to 1.7 parts per thousand for samples from which aliquots each containing 9 to 15 mg of zirconium were selected. The complete recovery of zirconium from solutions of pure zirconyl chloride and plutonium trichloride was shown by the 95 percent confidence limits of 99.9 +- 0.3 percent for the average of four determinations, observed with samples containing 5 to12 mg of zirconium in the presence of 10 to 20 mg of plutonium. It was found the Mo, La, PU(III), and K2Cr2O7 do not interfere with zirconium determinations made according to the recommended procedures, but Pu(IV) does interfere slightly. It was …

Summary of the research progress meeting of June 12, 1952