This report describes the final design of the Fuel Element Rupture Testing Facility and summarizes the safeguards analyses of the design and plans for operation.

Describes the design criteria, design details, and final installation of a high precision temperature and intimate contact monitor.

Description of Purex plant process for irradiated uranium for the separation and decontamination of plutonium and uranium from each other and from fission products.

From objective: "The objective of this work was to design, develop, assemble, and test and automatic analyzing monitor for recording the prominent isotopes in reactor effluent cooling water."

The subject of this report is the generalized computer program written to solve problems involving steady fluid flow through heterogeneous, partially-saturated porous media.

From introduction: "This report is concerned with exploratory experiments designed to studies the efficiency of a number of scavengers for zirconium and niobium adsorption and to provide preliminary information on the best conditions to employ on the most satisfactory of those scavengers studied, namely Super Filtrol FO. The data in this report include data obtained through October, 1949, and are by no means considered to be final. The investigation is currently being actively continued."

Objective: "The laboratory equilibrium study RC-E-1 described in this report was carried out to obtain uranium equilibrium curves at various concentrations of nitric acid and of TBP."

This report analyzes Parian and Teflon that were exposed to solutions of 1AX, 1AS, and 1AF, ANL June 1, 1948 Flowsheet, under conditions described in the following report.

The following report provides results from laboratory tests on the corrosion resistance of various types of stellite facings on astenitic stainless steel T-347 to Redox streams.

This report discusses a proposed method for treating the effect of increasing critical mass of plutonium solutions, which occurs when hydrogen density is reduced by dilution with heavier nuclei.

Abstract: "A titrimetric method for the determination of fluoride in plutonium is reported. Prior to a steam distillation of the fluoride, the bulk of the plutonium is separated by precipitation of the sulfate. The fluoride in the distillate is titrated at a pH of 3.2 with 0.001 M thorium nitrate, using chrome azurol-S indicator. Applied to samples containing 1 to 15 parts per million fluoride, the recovery is 87% and the precision on the 95% confidence level is +/- 0.65 ppm."

Report discussing the details of a radiation burst in a spherical reactor using plutonium nitrate fuel that occurred on November 16, 1951 at Hanford Works.

Report summarizing physical studies on Redox solutions and metal waste solutions, including refractometric investigations.

Report discussing study on recovery of nitric acid in the uranium recovery process. The behavior of chloride ions and tributyl phophate is noted, and the quality of recycled nitric acid was tested. Stainless steel in the nitric acid recovery system was evaluated for corrosion.

The following report describes a chemical procedure to analyze fission products and long-lived rare earths in both untreated urine samples and the supernates from the precipitation steps in the TTA procedure for plutonium.

Introduction: "A limited test progress for the evaluation of type 347 stainless steel pipe which failed the Huey (?) test has been complicated. The tests reported herein were similar in scope to those reported in document number EW-20765, Corrosion Tests on Stainless Steel Plate, Waste Metal Recovery Process. Material tested was obtained on order number EWC-8553, National Tube Company Heat #3X9741. Lots 9789 and 9790."

During the canning of slugs for Production Test 313-105-3-M, a high number of rejects were caused by gas voids in the A1-S1 bonding layer. Since the heat treatment of the slugs in a molten salt bath resulted in a chemically altered surface, an investigation was made to determine the volume of gas evolved from salt-bath heat-treated slugs as compared to other types of slugs. This test was designed as a preliminary test to determine if there were a significant differences.

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.

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.

The remodeling, fabrication, and instrumentation of a high vacuum system are described. The faults encountered with the old system and their solution are outlined. Tests were made on diffusion pump oils and on the reduction of pump oil back diffusion. The measurement of high vacuum pressures by a cold cathode ionization gage at various points on a vacuum system are discussed.

A knowledge of the mechanical and physical properties of uranium is important in understanding and explaining its pile behavior. The effects of irradiation on the properties of uranium will be dealt with in another chapter. However, it is important to know and understand the pre-irradiation properties of uranium prior to investigating the effects of irradiation.

Metallographic examination of an irradiated powder metal uranium slug from PT-313-105-4M⁽¹⁾ was undertaken primarily as an evaluation of recently remotized metallographic equipment. It was, also, proposed to compare the grain size with values obtained ultrasonically on the same slug. It was further proposed to make a comparison, so far as limited data permitted, of post-irradiated powder metal uranium grain size with that to be expected from normal uranium similarly irradiated.

Two methods for calculating the *reduction in η due to spectral hardening have been used. In the first method it is assumed that the absorption cross section of U-238 is l/v. This indicates no change in η within the error of the calculation. In the second it is assumed that the scattering cross section of uranium is constant. A decrease in η of 3.0% at the centerline of the slug is indicated by this calculation. The assumption U-238 is a l/v absorber is regarded as the most reasonable of the two.

The erection of a concrete biological shield at Hanford, Washington presented several unique construction problems. This shield encloses the radioactive core of a reactor and is designed to protect operating personnel from the harmful effects of pile neutrons and associated gamma radiation. Permanent steel forms were erected to close tolerance around the reactor and filled with high density concrete by means of prepacked method. Prefabricated sections of the steel forms, or crates, were five to eight feet deep and weighed up to 18 tons each. During erection, the process holes through successive crates were kept within 0.012 in. of their nominal distance. The left side, top shield, and right side of this biological shield were constructed integrally to form a rigid frame. The front and rear crates, which contain numerous process holes, were keyed into the side and top shields so as to permit relative expansions of shield components and to provide for their lateral support. These massive steel and concrete walls provide considerable resistance to blast and earthquake forces, support numerous process facilities, contain pile gas, as well as protect personnel from nuclear radiation.