A satisfactory ion-exchange-polarographic method was developed for the determination of either chromium(VI) or total chromium in Homogeneous Reactor fuels. Total chromium is determined as chromium (VI) , i.e., chromate, and in the same way as is chromium(VI), after chromium in the lower valence states is oxidized to chromate by potassium permanganate. Chromate is separated from all interfering metal ions in the fuel by ion exchange on a Dowex 50 resin column. The Chromate in the effluent is determined polarographically in approximately 0.75 M sodium hydroxide solution as supporting electrolyte. A well polarographic wave is obtained for the chromium (VI) chromium (III) reduction at a half-wave potential of -0.85 volt vs. the S.C.E. The relative standard deviation of the data for 2 μg of chromium (VI) per ml was 2%; for 4 μg of total chromium per ml, it was 3%. An ion-exchange-polarographic method was developed also for the determination of chromium(III). Chromium (III) is separated from all interfering ions in the fuel by ion exchange on a Dowex 1 resin column. The chromium (III) in the effluent is determined polarographically in a 1M ammonia-1M ammonium chloride supporting electrolyte. The wave obtained at a half-wave potential of -1.42 volt vs. the …

Bench scale studies have been made of the recovery of uranium from acid leach liquors (and slurries) by solvent extracting with di (2-ethylhexyl) phosphoric acid in an organic diluent. Uranium may be stripped from the organic solvent by either alkaline or acidic reagents, the former having been studied in greater detail. On the basis of these tests, a recovery process may be considered which shows promise both from the standpoint of operation and chemical costs. Under proper conditions, vanadium can also be extracted by the di (2-ethylhexyl) phosphoric acid and stripping again may be accomplished with either acidic or alkaline reagents. Preliminary studies have been made of these possibilities. In addition to di (2-ethylhexyl) phosphoric acid, some other organophosphorus acids, have been cursorily examined in respect to their extraction and/or stripping performance.

Much of the shielding work carried out with the Bulk Shielding Reactor (BSR) has yielded data of particular interest for the design of swimming pool type reactors, However, it is often difficult for a reactor designer to locate such data since it may be recorded in a report primarily concerned with shielding problems. Therefore, this memorandum presents a bibliography of reports from the Bulk Shielding Facility arranged according to the application of data to the various aspects of reactor design.

Semiannual Progress report of the Oak Ridge National Laboratory Chemistry Division providing updates on various projects, experiments, and other work in inorganic and physical chemistry, nuclear chemistry, organic chemistry, chemical physics, chemistry of separation processes, radiation chemistry, and reactor chemistry.

This quarterly progress report of the Aircraft Nuclear Propulsion Project at ORNL records the technical progress of the research on circulating-fuel reactors and ether ANP research at the Laboratory under its Contract W-7405-eng-26. The report is divided into three major parts: I. Reactor Theory, Component Development, and Construction, II. Materials Research, and III. Shielding Research.

Thorium nitrate, recovered from irradiated thorium metal processed in the ORNL Thorex Pilot Plant, was converted to thorium oxide and then to the fluoride in one pilot-plant-scale and two laboratory-scale runs. Activity distributions, decontamination factors, and safety of the process are treated. (D.L.C.)

High heat flux electrical cartridge heaters were tested with direct air cooling under simulated ORR Loop conditions. The cartridges and the heater design were found to be satisfactory. A gas cooled of concentric pipe design utilizing air, water, and air-water mixtures as the coolant was also evaluated and found to be satisfactory.

An investigation is made to determine the adequacy of presently used analog circuits in solving dynamic fluid flow heat transfer equations. A mathematical analysis is made of dynamic heat transfer in pipes with zero losses, with losses proportional to pip temperature, and with heat inputs. The results of this analysis are compared with analog results by means of generalized temperature versus time graphs. The analog circuit is found to be adequate for most conditions, but sometimes requires modification when heat inputs are considered.

A conductometric titration method described by Goldstein was adapted for use in a remote analytical facility. The results obtained by mean of experiments made prior to this adaptation indicated that methanol is the most satisfactory medium in which to determine excess sulfuric acid in uranyl sulfate solutions that stimulate Homogeneous Reactor type fuel. When methanol is used, the complexation of hydrolyzable ions with sodium fluoride, as described by Pepkowitz, Sabol, and Dustin, is not required.

Methods for the noncorrosive removal of volatile fission products and UO2 dust from carbon steel and stainless steel have been developed. Procedures for applying these methods to the decontamination of the EGCR charge and service machines are described.

EXPIRE is a calculation which predicts the reactivity-lifetime, instantaneous and integrated effective multiplication constants and instantaneous and integrated effective multiplication constants and instantaneous conversion ratio for heterogeneous reactors. The concentration of all the isotopes of interest from Th232 to Am243 are calculated as a function of time using the average reactor power density and a uniform flux distribution. The equations have been programmed for the IBM-704 computer and the average running time is approximately two minutes per reactor lifetime.

Multigroup one-dimensional calculations were done recently to obtain estimates of critical masses, power density distributions and fissioning spectra for some homogeneous molten salt reactors having outer reflectors and central "islands," placed inside the currently proposed MSRE vessel. For a 5-inch-thick outer reflector and 1-ft-diamter island, both beryllium, the calculated critical mass is 108 kg; 40 percent of the fissions occur at thermal, and the maximum power density of 3.9 times the core mean power density occurs at the island-salt interface. If the reflector thickness is increased to 10 inches, the critical mass is reduced to 34 kg; 67 percent of the fissions occur at thermal, and the peak power density of twice the core mean again occurs at the core island-salt interface.

The absorption in lead of Bremsstrahlung X radiation from a Sr^90 TiO3 pellet in the proximity of Hastelloy "C" was measured. The tenth value layer of the more energetic components of the X-ray continuum was determined to be 1.60 inches.