Uranium hexafluoride has the distinction of being the only stable gaseous compound of uranium known up to the present moment. Because of this property it is the only compound that can be used for processes of isotope separation, such as diffusion, thermal diffusion, centrifuge separation, distillation, and other of a similar nature. Here is a short description of the properties of UF{sub 6} and is intended for a reader interested only casually in this compound. UF{sub 6} is a very reactive compound and a very strong fluorinating agent. It is immediately hydrolized by water. In fluorinating reactions it is reduced to the green highly stable UF{sub 4}. It reacts instantaneously with hydrogen at room temperature. It fluorinates many metals; sodium and mercury are attacked in the cold, lead, zinc, tin and iron on heating; platinum and gold react only above 400 C. With organic compounds like alcohol, ether, benzene or toluene, immediate fluorination takes place with formation of HF and carbon or carbonaceous material. The compound forms colorless, very volatile, beautiful transparent crystals of high refractive index. Melting point = 69.5{sup o}; boiling point at 760 mm = 56.2{sup o}; D20{sup o} = 4.68. The crystals melt water pressure to …

None

None

There were no cases of unusual blistering of slugs being followed under Production Tests. Two normal production tubes were borescoped following trouble with discharge. In Tube 3188-D a distorted slug became stuck in the region of sharp curvature near the inner end of the rear gun barrel; this is the first time this phenomenon has occurred. Examination of irradiated slugs of rolled metal after normal exposure indicates that rolled material has no particular advantages over extruded material from the standpoint of blistering. However, no extensively blistered pieces were found in either the rolled metal are being held for more extended exposure. Inspection of a large number of Van Stone flanges in the D and F Piles has confirmed that the inlet flanges are in generally good condition but that the rear Van Stone flanges of tubes in the 0.140-inch orifice sone of both piles were badly corroded and generally contained deep pits that extended about half-way through the flange. The Van Stone test units are to be installed unshielded in the risor room at the rear of the D Pile, since the shielding required in the X Sample Room exceeded the allowable floor loading. Recent experimental observations indicate that solid …

Tracer studies employing uranium enriched in the isotopes U{sup 234}, U{sup 235} have been carried out in six human subjects; four males and two females. The uranium, 6 micrograms to 70 micrograms per kilogram of body weight was given intravenously in the hexavalent state as uranyl nitrate. Each individual of the series received a single injection of the metal except for one who was given two widely spaced doses. The first of these was when his condition was normal and the second after an acidosis had been produced by ingestion of ammonium chloride. Renal function tests including urinary catalase, protein, amino N to Creatinine N ratio and clearances of mannitol and p-aminohippurate were done before and after administration of uranium. Only at the 70 microgram per kilogram level in Subject 6 was there a slight rise in urinary catalase and protein suggesting that tolerance had been reached. The excretion of uranium was mainly in the urine, where from 70 to 85% of the administered dose appeared in the first twenty-four hours. Urine of the second twenty-four hours contained about 4% and the third twenty-four hour urine, 1.5% of the administered dose. Detectable amounts were excreted for at least two weeks.

None

None

None

None

None

Analysis indicates that, in order to achieve supersonic flight with nuclear powered aircraft, a reactor -power plant combination capable of operating at temperatures considerably in excess of current practice must be developed. It is pointed out that there exist two general avenues of approach toward the goal of attaining high temperature reactors and power plants. The first approach involves the continuation and augmentation of research along the lines pursued by the conventional turbo-jet engine manufacturer, namely a search for material coatings or materials that will retain structural strength in high temperature oxidizing atmospheres. The second approach seeks to take advantage of the peculiar characteristics of the compressor-jet engine that permit the operation of the high temperature components in a non-oxidizing atmosphere. The results of a preliminary design study of a supersonic aircraft powered by a high temperature sodium, liquid vapor compressor -jet engine are summarized. The analysis considered, in as much detail as was warranted by the limited experimental information available, the characteristics of the reactor, power plant and airframe involved in determining performance. This study has been conducted for the purpose of guiding future, long -t e r rn , research work along the lines of high temperature reactors …

None

Activities of the National Monitoring System are summarized for the period March 1 to June 15, 1953, during which eleven nuclear devices were fired at the Nevada Proving Grounds during Operation Upshot-Knothole. The program employed a world-wide network of 125 sampling locations. Each station collected samples of atmospheric dusts for radiometric analysis. A comparison is made of air concentrations and fall-out activities. Data are tabulated.

Activities of the National Monitoring System are summarized for the period March 1 to June 15, 1953, during which eleven nuclear devices were fired at the Nevada Proving Grounds durirg Operation Upshot-Knothole. The program employed a world-wide network of 125 sampling locations. Each station collected samples of atmospheric dusts/or radiometric analysis. A comparison is made of air concentrations and fall-out activities. Data are tabulated. (C.H.)

In connection with the Upshot-Knothole test series in network consisting of 95 U.S. and 26 forcign stations was set up. Of the 11 devices detonated, ranging in yield from 0.2 to 60 kt, highier activity was found for lower bursts than from air drops. Information relating to the optimum spacing of stations in a gummed film network and the possibility of missing local areas of intense fallout are discussed. (W.D.M.)

None

This report is a summary of the physics design work performed on the Engineering Test Reactor. The ETR presents computational difficulties not found in other reactors because of the large number of experimental holes in the core. The physics of the ETR depends strongly upon the contents of the in-core experimental facilities. In order to properly evaluate the reactor' taking into account the experiments in the core, multi-region, two-dimensional calculations are required. These calculations require .the use of a large computer such as the Remington Rand Univac and are complex and expensive enough to warrant a five-stage program: 1. In the early stages of design, only preliminary two-dimensional calculations were performed .in order to obtain a rough idea of the general behavior of the reactor and its critical mass with tentative experiments in place. 2. A large amount of work was carried out in which the reactor was approximated as one with a uniform homogeneous core. With this model, detailed studies were carried out to investigate the feasibility and to obtain general design data on such points as the design and properties of the gray and black �control rods, the design of the beryllium reflector, gamma and neutron heating, the …

This volume continues with discussions of shielding provided for the heat exchanger building, concrete biological shield, top area and bottom area shielding, canal shielding, water shielding requirements during fuel element exchanges, and supplementary shielding requirements.

None

Hardness measurements of specimens quenched from the beta yields alpha phase at different cooling rates support the proposed martensitic beta yields alpha transformation for urnnium. Specimens held in 635 and 600 deg C isothermal baths prior to subsequent quenching to --5 deg C require more than 10 and two seconds, respectively before diffusion mechanlsms for beta yields alpha transformation commence. Once started, about 500 seconds are required to complete transformation by diffusion at these temperatures. Specimens quenched prior to tais hold time transform in part martensitically. Relationships are calculated for hardness as a function of grain size and cooling rate, and for grain size as a function of cooling rate. Metallographic examination confirms the hardness trends and reveals that widely varied grain structures can be produced by controlled cooling from the beta phase. Finally, a schematic time- temperature-transformation curve is sketched from the hardness data obtained. (auth)

An over-all description of the background material on the use of electrical arcs for heating of powders is presented as well as a summary of experimental studies on the arc calcination of thoria. Favorable results have been indicated both with heating thoria powder in an arc heated gas and with thoria formed into a consumable electrode. Use of a consumable electrode produces thoria particles 0.1 to 0.01 mu in diameter. It is recommended that additional electrodes be fabricated and further arc calcination tests be run to produce a quantity of product sufficient for evaluation. (auth)

Failures of standard fuel element jackets (1245 aluminum alloy) after relatively short Hanford reactor exposures are occurring at high reactor power levels. Metallographic examination of fuel element jackets from short exposure ruptures shows the cause of failure to be rapid intergranular corrosion. This type of attack has been reproduced in laboratory tests by exposure to water at temperatures above 200 C, or to steam at temperatures higher than 300 C. Flow disruptions due to misalignment of the fuel elements within the reactor process tube, worn tube ribs, etc., are believed to cause the high local jacket temperatures necessary for the occurrence of intergranular corrosion.

A preliminary study of the volatility behavior of molybdenum indicated that MoF/sub 5/ was converted to MoF/sub 6/ by F/sub 2/; MoF/sub 6/ and Tc fluoride are absorbed on NaF at 100; technetium fluoride is more strongly held than molybdenum fluoride on NaF; MoF/sub 6/ may not be completely trapped by a dry ice trap. The behavior of volatile fission product fluorides was such that (a) Ru and Nb fluorides were volatile from fused salts during fluorination, (b) Mo and technetium were not volatile during hydrofluorination but were in excess F/ sub 2/> 100 deg C(auth).

None