Interest has been expressed in continuously monitoring the beta activity of the uranyl nitrate solution pumped to the RCU receiver tank, to facilitate operation at higher flow rates and with younger feeds. A beta scintillation detector has been developed which should make this feasible, and it is proposed that it be tested on stream for this use.

The development of methods which were successful in producing zirconium Hanford type process tubing by roll forming and inert are welding (He) flat strip to which appropriate rails had ben previously attached by resistance welding is described in this report. Grade 2 drip arc melted crystal bar material was used.

Engineering notes on limiting bore diameter, angular divergence in a linear accelerator.

Abstract: "Extraction equipment of the multistage mixer-settler type has been found useful for providing the intensive contact between phases that is required in processes involving complex compounds of the heavy metals. In this report, the factors of mixer-settler design and operation are discussed with reference to the known types of mixer-settler units. Following this review, a detailed description is given of mixer-settler units constructed and installed in this laboratory."

Progress on projects on experimental physics, theoretical physics, MTA Target-Physics Program, accelerator construction and operation, chemistry, biology and medicine, plant and equipment.

Semi-empirical modifications of age theory have been made to interpret the critical masses of proton moderated assemblies, which may or may not have reflectors of various substances, in particular, water or steel. Section I shows that critical masses of untamped water moderated systems can be calculated by use of an appropriate age and linear extrapolation length. Assuming that all captures and fissions take place at thermal, a familiar expression can be set up which contains the age and extrapolation length which are not well determined by theory. An age value suggested by theory, (Sec. II) is taken and ORNL criticality data (K343) are used to find the best extrapolation length. With these values the K343 critical mases can be computed to bout +-5%, which is their estimated experimental uncertainty; this for H/U-235 atomic ratios between 43 and 755. Section II contains a theoretical discussion of effects which the simple "theory" of Sec I neglects. It is indicated that several of these effects compensate to make a simple theory more useful than one would believe at first sight. to take into account reflectors of water, water shield by cadmium, or steel of various thicknesses, it proves sufficient to alter the extrapolation …

This technical report is a summary of unclassified theoretical work on propagation of one-dimensional shock waves and on the propagation of spherical shock waves in gases.

Two xenon extraction runs were made this month. It appears that a small design change in Trap #2 will be necessary so that a dry ice-trichloroethylene slurry can be used for coolant rather than liquid freon. For each of the runs this month the enriched generator was exposed for four hours in the est pile operating at 100 watts. A period of eight hours for cooling and xenon builidup was allowed before the collection and separation runs were started.

Through the efforts of the Hanford Engineer Works a quantity of neptunium-237 was separated from uranium waste solutions by a modification of the standard plutonium precipitation process, This material, as concentrates, was shipped to Argonne for final isolation and purification of the neptunium.

"These notes are intended to serve as a summary of the current knowledge of properties of materials. In the future some need may exist for related information on methods od testing, design and fabrication. This issue presents information on thorium with subdivisions..."

The angular distribution of fission fragments from the neutron-induced fission of several isotopes has been studied. Distributions were observed for thermal neutrons on U233 and U235, Lady Godiva leakage neutrons on U235 and U238, and 14 Mev neutrons on U233, U235, U238, Th232, and Np237. No anisotropy was observed for thermal neutron fission, whereas for Lady Godiva neutrons and 14 Mev neutrons the probability of fission along the axis of the neutron beam was determined to be higher than for fission in the orthogonal direction. Experimental results are given on pages 10 and ll.

The following report analyzes several reported incidents of uranium-rich zirconium-uranium explosions. This report offers notes designed to describe conditions sufficient to cause an explosion with an 80% wt. uranium alloy.

Dissolution of the large number of samples obtained from the natural uranium blanket of the Experimental Breeder Reactor after approximately 485,000 kw.-hr. of operation has been completed, and analysis of these samples for uranium consumed and plutonium formed is well along. An attempt is being made to distinguish quantitatively between uranium-238 and uranium-235 fission in the blanket area by determining the ratio of ruthenium-106 to cesium-137 in the fission products.

Due to some lack of knowledge of the energy per fission, there has been some uncertainty over the absolute power of the Bulk Shielding Reactor. This report analyzes measurements to state the absolute power of the BSR within a few percent.

Abstract: "The spectrum of plutonium has been observed over the temperature range of 2000 to 2600 C and a wavelength coverage of 3476 to 6888 A. The spectrum was excited in a modified King furnace."

Abstract: "This report describes the results of X-ray diffraction examination of reaction products from a series of experiments performed by Mallinckrodt Chemical Works as an acid in understanding the process of bomb reduction of UF4. UF4 is initially reduced to UF3 by magnesium at 560 C., and subsequently to metal at 600 C. MgF2 from the initial reaction forms a coating on the magnesium which retards the final spontaneous reaction."

Hanford uranium contains minute angular inclusions which affect the microstructure, reactivity, and other important factors controlling the serviceability of the metal. Small quantities of the inclusions have been isolated by chemical means, and the x-ray diffraction patterns and chemical analyses of the isolated materials have been determined. As a first step in the identification of the inclusions present in rolled uranium, a search was made for a chemical method of separating the inclusions from the matrix metal.

About twenty-five to thirty per cent of the uranium slugs canned in the Metal Preparation Section do not meet specifications and are rejected. These rejected slugs are recovered by a chemical process and prepared for re-canning. The current recovery process consists essentially of a sodium hydroxide-sodium nitrate bath for chemically removing the aluminum can and the bonding medium, followed by hydrofluoric acid and nitric acid baths to remove the remaining compound layer and to pickle the slugs before they are returned to the process canning line. Recent studies have indicated the possibility of using a more economical means of recovery. this includes the mechanical removal of the aluminum can and most of the bonding medium, followed by a chemical removal of the residual compound layer by a solution of sodium hydroxide.

From abstract: "The circumstances are described pertaining to an explosion in a TNX evaporator during the concentration of a uranyl nitrate-nitric acid solution. TBP and Amsco diluent were probably present in the evaporator charge. A laboratory program involving small-scale atmospheric and closed-vessel distillations of various mixtures of UNH, HNO3, Amsco, TBP, and water indicate that an exothermic reaction between TBP and UNH, or between TBP and HNO3, or both, was responsible for the explosion. The danger areas of temperature, TBP concentration, pressure, and heating rate are defined and recommendations are made for safe evaporator operation.

It is proposed to test gaps corresponding to deuteron energies in the range of 0.45 to 4.5 Mev. The accelerator to be modeled is a 48 mc/sec cylindrical cavity in the TM010 mode with [formula] repeat length, [formula] gap, 0.25 megavolt per cavity foot peak r.f. gradient and strong focusing magnets alternating polarity at each drift tube.

The decontamination of portable instruments by the Calibration Unit has presented a problem for some time. Most of the contamination is in the 100 to 500 c/m or 500 to 2000 d/m range. Higher levels of contamination can usually be reduced to these levels, but further cleaning proves quite difficult

The following report analyzes whether there is a difference between the neutron streaming in the "armor plate" and 347 stainless steel.

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.

Plus-minus ratios for pion production by 340-Mev proton bombardment were measured at 13 Mev, 18 Mev, and 42 Mev with the use of the spiral orbit spectrometer.