The following report provides a general summary of some methods that could be used to convert hexafluoride into tetrafluoride, but is mainly devoted to the work done on the conversion of tetrafluoride to tetrachloride.

Abstract: "A precise potentiometric method for the determination of uranium in essentially pure uranium oxides is described. Ten gram samples of oxides are reduced in a Jones reductor and titrated potentiometrically to U+4, using platinum and tungsten electrodes. A weighed amount of solid Bureau of Standards potassium dichromate is then used to oxidize at least 99 percent of the uranous ion, and the oxidation is completed by titration with 0.01 N potassium dichromate using calomel and platinum electrodes. This method, which is based on a primary chemical standard, has a precision of +/- 0.015% on a single determination at the 95 percent confidence interval."

This report follows experiments conducted to determine an alloy addition agent for uranium which would subsequently increase the yield strength and creep resistance of uranium.

Report presenting background and instructions on completing spectrophotometric determination of silicon in zirconium, which relies on the solubility of silicon tetrachloride in a small amount of nitric acid solution and the complexing of fluorides with boric acid.

The following report follows a correction on a previous report (CP-1381) on the value of the magnitude of the gamma effect.

Report discussing two methods for "the elimination of sulfate and second group interferences in the extraction of tuballoy from residues which have been processed by the pyrosulfate fusion method." Advantages for one of the methods are mentioned.

It has been suggested by many workers in the power reactor field that a more efficient utilization of natural uranium may be obtained in thermal reactors if the Pu produced in a fuel cycle were used to enrich a subsequent cycle in which the irradiation-depleted-uranium would be reirradiated. The work described here was done for the purpose of evaluating the reactivity value of the Pu enrichment under the assumption that all plutonium produced is, after chemical separation, fabricated into separate fuel elements and not alloyed with recycled uranium. It has been suggested that the reactivity value of the Pu decreases with exposure to such an extent that highly burned plutonium should be discarded. We, therefore, wish to look at two of the variables affecting the limiting exposure: the reactivity value of the fuel as a function of exposure and temperature and the fraction of potential fissions which would be discarded as a function of exposure. Though the residence time of the Pu fuel before reprocessing, refabrication, and recycling depends upon the relative decrease in specific power, decrease in reactivity due to fission product build-up, the lifetime of the fuel elements before failure, and the cost of reprocessing, only the first …

Neutron attenuation in the old pile shields is dependent more and more on the slowing down characteristics of the iron as the hydrogen is baked out of the masonite. For neutrons above 1 or 2 Mev, iron does a good job by inelastic scattering. However, below this energy attenuation can be done only by the gradual moderation by elastic scattering to thermal energies with subsequent capture in the iron. Since iron is heavy and thus a poor moderator, there is a good possibility that many neutrons of intermediate energy will leak out of a burned out shield. Also, iron has a large dip in its cross section at 25 Kev which might allow a large burst of neutrons at this energy to leak out. Measurements using a lucite moderator with gold foil detectors indicate a large leakage of neutrons of intermediate energy, but interpretation of these measurements is difficult. These considerations prompted an attempt to get a rough idea of the energy distribution of the leakage neutrons through pure iron using a simple qualitative theory.

Average coefficients of thermal expansion of the temperature range 25 C to approximately 425 C are reported for numerous types of graphite. The dependence of thermal expansion on crystal orientation and crystallite size and the effects of oxidation and cold test hole irradiation are discussed. An empirical relationship between thermal expansion and the initial rate of physical expansion under cold test hole irradiation is formulated.

The power and estimated reprocessing load are tabulated for existing and proposed United States and United States-built reactors of 10 Kw or greater thermal power.

During normal operation the NPR will function as a closed system and the coolant will be maintained at a high degree of purity. Periodically, however, the system will have to be opened for fuel element discharge and/or decontamination. During these periods the reactor will be operated on single pass cooling. The use of deionized and deoxygenated water as the single pass coolant is not economically feasible due to the large quantities of coolant that will be required. At present it appears that filtered water will be used for this purpose. Since filtered water contains substantial amounts of dissolved solids (approximately 100 parts per million), and since it is saturated with air, this type of operation will have to be investigated with regard to corrosion problems. A particularly serious problem will be present after the system has been decontaminated, since the high temperature oxide films will have been removed and the bars metal surfaces will be exposed to the coolant.

This report is a record of experimentation conducted intermittently over a period of two years and directed toward preventing deposition of transport corrosion products on fuel elements and other critical components in high-temperature, circulating water nuclear reactor. It includes the postulated mechanism for deposition, a description of experimental equipment, experimental data, results obtained from the experiments, and recommendations for future study.

A spectrometer has been used with a hollow prism electrically heated to 70 C to measure the refractive indices of solutions of uranium hexafluoride in bromine trifluoride and uranium hexafluoride in bromine pentafluoride. The refractive indices of the two binary systems have been expressed as a function of composition.

This report is a summary of the neutron attenuation data which have been obtained at the Brookhaven shielding facility on a mock-up of the fuel-rod-unloading plug used in the KAPL Reactor. Before this program was initiated, a number of small scale tests had been made in the ORNL lid tank on carbon steel mock-ups of components of the rotating plug. The results of the tests indicated considerable neutron streaming through the vertical steel and air members of the plug. However, the lid tank source strength and dimensions did not permit the tests to be extended to the full plug height. In view of the concern aroused by the ORNL tests and the absence of fundamental information on the transmission of neutrons through steel and the addition height (12') available here resulted in a request for BNL to construct and test a mock-up of a sector of the SIR top plug in accordance with KAPL specifications.

Quarterly report of the Chemistry Division at the University of California Radiation Laboratory providing updates for each department about current findings and ongoing research.

This memorandum is the first in a series reporting progress in the program of critical experiments in the ORNLArmy Package Power Reactor Project. The critical assembly, designated as CA-25, is analogous to the APPR design core and consists of 45 fuel boxes, in a 7 x 7 array with the corners removed, contaIned in a large water tank. Two sides of each box are slotted for the insertion and positioning of any desired loading of eighteen plates of fuel, structural material, and poison. The array is submerged in water to provide a moderated and reflector. Enriched uranium metal, in two-mil-thick foils 2.5 x 22 in, is encased in type 304 stainless steel sheets, 2.7 x 23 x 0.0105 in., to form fuel plates. Stainless steel plates, 2.7 x 23 x 0.025 in. are used to simulate additional steel in the APPR core. It is, therefore, possible to maintain an essentially constant metal to water ration in the assembly when the fuel content is varied. The fuel is distributed as uniformly as possible in all boxes and a symmetrical distribution of materials is maintained in the core at all times. Fuel plates containing half-width (1.25 in) uranium foils are provided for …

We have recently completed measurement of resonance escape probability in the BNL reactor and in several slightly-enriched uranium light water moderated lattices. In addition, WAPD has made available to us data from other slightly enriched uranium-water lattices, so that about 18 lattices in all have been done.

" A reliable, efficient and economical method is needed to remove radioactive halogens such as iodine and bromine and particulates from air in many atomic energy installations. One method we have developed which is particularly suited to reactor containment vessels or other large confined areas is foam containment. In this method an ether lauryl sulfate foam containing an iodine reactant is generated, rapidly filling the entire containment volume. This provides a tremendous surface area to which the encapsulated gases and particles can diffuse and be removed."

An R.F. joint tester was designed to determine the relative heating and tendency toward arching at high RF current density (100 amps/linear inch) of a 12 inch diameter circular copper butt joint in vacuum with several types of inserts and at various amounts of axial loading, ranging from a very small contact pressure to one of 1400 pounds per linear inch of joint.

The study was undertaken with the objective of observing the distribution in the rat of organic compounds of phosphorus labelled with the P32 isotope as tracer. The fate of several of these compounds was studied in animals bearing tumors. The distribution of inorganic phosphate in animal tissues is well known but was included in this work for comparison with the organic phosphorus compounds.

Technical report. From Abstract : "The silver-1,10-phenanthroline system has been studied and the stability constants determined for the 1:1 and 2:1 complexes using the silver electrode. This known system was then used to study the complexes of 1,10-phenanthroline with other metals. The log βn values found for the over-all stoichiometric stability constants are as follows: Ag, 5.02, 12.07; Mn, 3.88, 7.04, 10.11; Cd, 5.93, 10.52, 14.30; Zn, 6.83, 12.05, 16.92. The stoichiometric stability constants determined for copper are log k2 = 6.42 and log k2k3 = 11.05."

Technical report. From Introduction : "The nuclear volume dependent isotope shift of optical spectral lines has long been a very useful means for studying the changes in the nuclear size or shape for different isotopes of heavy elements."

Quarterly progress report on various research projects conducted at the University of California Radiation Laboratory.

Three types of stainless steel (309 SCB, Carpenter 20, 304-L) were exposed to both the liquid and vapor phase of each of three types of solutions. The time of exposure totaled ten days during which the specimens were cleaned and weighed periodically. The three synthetic D-12 waste solutions contained respectively chrome-high chloride, chrome-low chloride and high chloride sans chromium. The solutions were renewed at each weighing.