LITR Fluoride-Fuel Loop. — The inconel loop was dismantled for removal of the samples and for recovery of the uranium by using the remote cutting tools installed in a half cell of the Solid State Building. Disassembly proceeded without incident. An electric-arc cutting technique was developed for removal of the stainless steel enclosure around the pump bowl. Fission power and maximum flux were determined by irradiating a simulated loop, by heat-balance calculations, by radiochemical analyses for fission products in the fuel, by measuring the activation of cobalt foils attached to the loop, and by activation of the loop tubing itself. The determination of the power by these various methods gave 2.5 to 2.8 kw during operation of the loop, and the maximum power density was 0.4 kw/cc. Chemical analyses of the fuel were carried out to determine U, Zr, and the major constituents of inconel: Ni, Cr, and Fe.

A direct titrimetric method for the determination of trivalent uranium in uranium trifluoride and mixtures of fused fluoride salts was developed. The method is based on the stoichiometric oxidation of trivalent uranium to the tetravalent oxidation state with an acidic solution of methylene blue. The sample containing trivalent uranium is dissolved at room temperature in an excess of standard methylene blue solution in a carbon dioxide atmosphere; the excess oxidant is variation of the method is 1.5 per cent for 5 mg quantities of trivalent uranium. The method was applied to various mixtures of fluoride salts containing both trivalent and tetravalent uranium.

From July 7 to August 31, 1955, 20 tons of uranium and 1,200 g of plutonium were recovered in 47 days of plant operation at an average rate of 833 lb/day of uranium and at a cost of $2.60/lb of uranium. Uranium and plutonium recoveries were, respectively, 99.9 and 95.5 per cent.

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 …

Quarterly report on the metabolic properties of various materials, biological studies of radiation effects, health chemistry, health physics.

The motivation for the measurement of the angular distribution of elastic scattering of medium energy protons and neutrons has been clearly presented by others. They have also listed the results obtained prior to their experiments at 31.5 Mev. This is a report on some results obtained with 30.6 Mev protons scattered from Be, C, and Al.

Tests on twenty identically prepared 26 gauge Chromel-Alumel thermocouples have been completed. It appears that wires of this material without protection are unsatisfactory mechanically and thermoelectrically for service in atmospheres of CO₂ at 1000°C.

Photographs and working drawings are presented for a small (approximately 4.25 X 7 X 9 inch) 300Kv pulse transformer having double-conical secondaries each with a corona ring at its greatest diameter. The pulser circuit is shown but no text is included.

To calibrate a pulse height discriminator, the amplitude of the calibrating pulse must be known. If the amplitude is known, the discriminator dial may be calibrated in terms of the input signal required to just trip it. This is the purpose for which the Discriminator Calibrator was designed. It produces pulses of variable but known amplitude with a rep. rate variable from 3 pps to 4000 pps. The main use of this unit at the UCRL is in conjunction with scalers at fixed counting locations.

The uptake of carbon dioxide by plant roots preparations has been demonstrated by various authors. In addition to confirming the fact of fixation, I have investigated the effect of a number of factors involved and the compounds in which the absorbed carbon appears, using carbon-14.

The basic scheme under consideration in this research on stability of closed-loop of the Mark I machine is one in which a voltage proportional to the magnitude of the rf fields in the cavity acts to control rectifier voltage output. It is recognized that such is not the only scheme for maximization of output which may be conceived, but only what seems to be a logical and direct way of attaining such an objective.

Abstract: During March 1958, representatives of the health and Safety Laboratory, New York Operations Office, visited Columbia University to make stray radiation measurement at the Van de Graff accelerator. A radiation survey was performed at the Van de Graaff electrostatic generator at Columbia University. The survey results do not indicate a particular need for additional shielding at this time. It is recommended that the analyzer area of the beam room should not be occupied during beam operations and the present interlock system should be modified by the installation of a photocell interlock as shown on the included plan.

This report summarizes the hazards associated with the operation of the Lynchburg Test Reactor (LTR) critical experiments. The LTR critical experiment program is outlined and the design of the experiment is described. The experiments will provide basic data to check two-dimensional calculational methods and provide information needed in the design of the LTR.

Abstract; Test instruments developed at the Dr. Förster Institute, Reutlingen, Germany, were considered for possible application to Savannah River nondestructive inspection problems involving stainless steel and aluminum tubing. None of the equipment can solve these problems without modifications. Several instruments are recommended for further study in connection with their use with aluminum tubing. None will be considered for use with stainless steel at this time."

From abstract: "A composite ultrasonic unit was developed to indicate the size and location of non-bonded areas and the presence of non-transformed regions in flat uranium fuel elements clad with aluminum. A two-dimensional recorder was developed to yield instantaneous, permanent records of the non-bonded areas on electrosensitive paper. Panel lights indicate the presence of non-transformed regions that have not received proper heat treatment. Defects 1/8" in diameter are consistently detected at an inspection rate of approximately 50 sq. in./min."

From abstract: "There were significant increases in radioactivity in the environs of the Savanna River Plant during the period from January 1954 to July 1954. All of these increases were relatively small as compared to the maximum permissible concentration. Although fallout from Pacific tests was the main contributor to the increased activity, some of the increase was due to normal Plant operations."

From abstract: "Natural uranium plates that were irradiated to 600 and 1500 MWD/T were cut under water by a guillotine-type shear. Irradiation reduced the force required for shearing to 50 per cent of that required for unirradiated uranium. Measurements were made of radioactivity released to treated and untreated water in which the cut sections were stored."

From abstract: "A 'Growth Index' for predicting the dimensional behavior of natural uranium at low burnup was developed from X-ray diffraction measurements of preferred orientation."

Technical report. From Abstract: "An ion exchange process was demonstrated for the recovery of Pu238 from irradiated neptunium oxide. Three cycles of anion exchange proved adequate for the removal of fission products and for the separation of the neptunium and plutonium from each other."

Technical report. From Abstract: "Ultrasonic energy appropriately applied to the die or container of a laboratory-type direct extrusion press effected a marked increase in the free extrusion rate of lead and aluminum billets at a constant extrusion rate. the same results were obtained in extrusion cladding steel tubes with aluminum. Rate increases were generally 100 per cent or greater, and decreases in force were usually within the range of 10 to 20 per cent. Furthermore, the shape and slope of the extrusion curves were altered. The effect appeared to be attributable to a reduction of both die friction and container wall friction under ultrasonic influence."

Technical report. From Abstract: "Rate data are presented for the oxidation of neptunium (V) by vanadium (V) in nitric acid." From Summary: "Rates of oxidation of neptunium (V) were determined by a solvent extraction technique based on the difference in distribution coefficients for neptunium (V) and neptunium (VI)."

Abstract: Critical experiment studies were performed, varying the parameters U235, B10 and metal to water ratio, in the SM-2 7 x 7 core configuration with 38 stationary elements and seven control rods of the SM-1 (APPR-1) type. An experimental mock-up of the SM-1 was assembled using the basic SM-2 fuel plates. Excellent agreement between the SM-1 boron loading, determined by chemical analysis, and the SM-1 mock-up boron loading, for equivalent bank positions, was noted. Several SM-2 mock-ups, cold clean and midlife, were assembled and studied with regard to reflector effects, flow divider effects, relative control rod array worths, critical rod configurations, and relative power distributions. The results of these experiments indicate as satisfactory a U235 loading of 36.4 Kg and a B10 loading of 63.4 grams for the SM-2. Attention is drawn to numerous power peaks present in the active core. The open seven control rod array has a slight reactivity advantage over the closed seven array and consequent minor disadvantage with respect to "stuck rod" criteria.

Five continuous coatings were produced on zirconium coupons using an anodizing technique. These layers appear to be quite adherent and not subject to visible or audible failure caused by flaxion of the basis metal, Their abrasion resistance, though not investigated thoroughly, appears to be moderately good.

The results of this investigation indicate that maximum electric power generation can be obtained by selecting the turbine steam temperature within a range of plus/minus 30 degrees C. from an "idealized" steam temperature. This "idealized" steam temperature is shown to depend primarily on the maximum permissible uranium temperature. The minimum available condenser temperature and the temperature rise of the coolant in the pile effect the selection of the turbine steam temperature to lesser extent.