Abstract: "The heat-treatment behavior of zirconium alloys containing 7 to 70 w/o uranium is described. The effect of oxygen contamination on the structure and hardness of these alloys is outlined. It is shown that in the initial stages pf transformation of beta zirconium-uranium solid solution into the low-temperature phases a potent hardening reaction occurs in alloys containing 20 to 70 w/o uranium. In this reaction the hardness may rise from 200 DPH characteristic of retained beta to values in excess of 400 DPH. Practical heat treatments have been developed which produce relatively soft alloys. The microstructures and hardnesses produces by these treatments are shown."

Abstract: The thermal distortion of a Y-shaped hafnium control rod heated by arrays of individually controlled radiation heaters was studied. The large axial and radial temperature gradients specified for this control rod were easily obtained with the radiation-heating method. The distortion, as measured with dial indicators, amounted to a 2-mil movement of the free end of the rod in the direction of the coolest blade.

Abstract: "Approximate melting points have been determined for five samples of uranium tetrafluoride representing incompletely converted uranium dioxide and covering the range from about 2 to 20 w/o UO2, using the method of differential thermal analysis. The results indicate the melting temperatures are in the range of 920 to 980 C. No significant correlation between melting point and UO2 content was observed, possibly because of calcite formation. Similar results were obtained on synthetic mistakes of UF4 containing from 10 to 40 w/o UO2."

"Characteristics of a pulsed, occluded-gas ion source, operating in a magnetic field, have been investigated. Mass spectra of hydrogen- and deuterium-loaded sources are presented. Constructional details of the source and its operating characteristics are discussed."

Abstract: "This report describes six electronics areas at the Radiation Laboratory (Berkeley and Livermore) that are being successfully used with various particle acceleration for nuclear research. The electronics equipment, consisting of pulse amplifiers, scalers, coincidence circuits, pulse-height analyzers, automatic recording equipment, high-voltage supplies, etc., is arranged in such a manner that most experiments can be quickly set up, and a number of people can run experiments simultaneously. Advantage and limitations of these areas are discussed."

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 …

The Hanford Test Pile is a heterogeneous, low power, graphite moderated natural uranium pile. The pile consists of an eighteen foot cube of graphite containing 292 charged channels in a square array with an 8-1/2-inch lattice spacing. This report describes the reactor and the operating procedures used, and presents the latest results of calibrations performed. These calibrations supersede other work which has been done on the Test Pile and contain refinements of most of the early calibrations.

Past experience has shown that the demand for increase separations plant capacity comes up very regularly. One of the variables which greatly affects plant capacity is cross-sectional area of the individual vessels. Larger areas permit greater flow rates as well as more space for the installation of heat transfer piping (shell and tube concentrators). Design considerations of the separations plants vessels have been based on both circular cylinder and slab geometries. A study has been made to determine other vessel geometries that will result in safe vessels from a nuclear safety standpoint and at the same time offer larger cross-sectional areas than right circular cylinders. Vessels of elliptic as well as annular cross sections have been considered. It is neither the intent of this study to discuss the effects of intersection, vessel piping, etc., nor the pros and cons of fabricating feasibility and structural strength of these different shaped vessels. The main purpose is to make comparisons of cross-sectional areas (capacity parameter) of safe vessels so that vessel shape may be evaluated as one of the parameters in any design study for separation plants.

Approximately 15,000 "P" Process Aluminum caps clad with aluminum-silicon on the face and sides have been successfully canned. These caps were fabricated by the Aluminum Company of America from clad plate stock. An increase in canned slug yield of about two percent was realized from using these caps and no significant process problems indicated that the additional cost of clad plate might be off-set by the elimination of the centerless grinding now required on the side of the cap base. Therefore, processing of at least 100,000 additional aluminum-silicon clad caps is recommended, and consideration should be given at this time to completely converting from the present cap design to the aluminum-silicon clad cap.

On May 2, 1955, a request for comments on the construction and design of proposed continuous calciners was submitted to this unit by W. M. Harty. This request was complied with and a letter containing comments and suggestions on the design and construction of these calciners was written to him on May 6, 1955. The major suggestions were: 1) that the shell of the calciner be made as thin as possible, using external ribbing for structural strength, and 2) that the material of construction be type 304-L stainless steel welded with type 308-L rod. The recommendation regarding design was based on work performed by Collins, Krivobok, and this unit, which indicated that thick sections, on the order of one inch, tend to crack when subjected to thermal cycling. Type 304-L stainless steel was recommended as the material of construction because of its resistance to weld and base metal cracking, and because recent investigations indicate that a neucleation of precipitated carbides occurs after extended service in the sensitizing temperature range. On May 25, 1955, this unit received a letter from W. M. Harty stating that, on the basis of design considerations, the calciners would be fabricated from one inch thick type …

The determination of various parameters such as thermal utilization, resonance escape probability, control rod calibrations and etc. is often accomplished by the measurement of the pile period due to some given perturbation. With the present thoughts being directed towards plutonium fueled reactors, it was felt worthwhile to discuss a few of the basic differences in pile neutron behavior due to the smaller fraction of delayed neutrons per fission of Pu239 and the larger fraction of delayed neutrons per fast fission of U238 than occurs from fission of U235 alone.

Much attention has been given to the application of zirconium and zirconium alloys to process tubing for reactors. The properties of this material which make it attractive for such use are, as compared to aluminum: lower neutron absorption; higher design strength; and better corrosion resistance in hot water. Installation of process tubes in HAPO reactors requires that gas tight and water tight joints be maintained between the gunbarrel and process tube, and the process tube and nozzle, respectively. With aluminum tubes this is accomplished by forming a Van Stone flange at the ends of the tube and clamping the flanges between the gunbarrel and nozzle with suitable gasketing. No changes would be required in the existing pile components to install zirconium or zirconium alloy tubes if Van Stone flanges could be formed on these tubes. other methods have been tested, however, which eliminate the necessity for a flange. These will be discussed later.

The introduction of aluminum in hot process water has been studied extensively and numerous reports have been issued on the subject. The conclusions reached have been largely empirical and can only be used to state what is happening under the given conditions existing in the corrosion experiments. It is only with difficulty and a great deal of uncertainty that these empirical results can be used to predict what will occur under a different set of conditions. If the fundamental mechanism of aluminum corrosion in water were known, it is possible that more accurate predictions could be made and that steps might be taken to affect the controlling factors and thus reduce the severity of corrosion. To keep the system as simple as possible one would attempt to study the corrosion mechanism by corroding aluminum in pure water. However, this is undesirable because of the extremely low corrosion rate of aluminum in pure water and the large water supply and treatment facility required to supply sufficient high purity water for circulation about the corrosion samples.

A report about mechanical properties of dilute uranium alloys are being investigated in an effort to develop a high-strength alloy for fuel elements. Elevated temperature tensile tests were made on two dilute uranium-aluminum alloys, and several ternary alloys were arc melted.

Changes made in the Thorex process flowsheet were a decrease in the extraction column acidity to decrease thorium losses and the addition of a second thorium solvent-extraction cycle to provide the increased decontamination required when thorium irradiated to 2000-4000 g of U233 per ton is processed. Bonded slugs could not be dissolved by the Thorex flowsheet procedure. Various laboratory scale studies on feed preparation, first-cycle variables, and radiation damage to the solvent are reported.

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.

From abstract: "The 'Nuclear Test Gauge', a slightly subcritical assembly for quality control of reactor components, was designed, constructed, and placed in operation. calibration experiments demonstrated that the sensitivity of the unit is adequate, and that the speed of testing is increased y a factor of ten over that of a critical test pile."

The EBWR loading requires a total of 888 plates. It is anticipated that approximately 1000 plates will have to be produced to obtain the number of acceptable plates required for the loading. To the end of this quarter, 568 cladding billet cores acceptable with respect to chemical composition and physical soundness had been cast; this number represents 78% of the total number of cores cast. Approximately 75% of the Zircaloy-II stock required has been rolled, and about 55% of the cladding components required have been finished. The anticipated number of 495 cladding billets required for the thin (0.210") natural and enriched plates have been assembled, welded, sealed, and jacketed in steel. A total of 310 cladding billets have been rolled to fuel plates; of this number, 142 have been completely finished, and the remaining 168 are in the finish processing stages. The stability of the equipment for measuring the clad thickness of EBWR fuel plates has been improved by placing the phototube and the anthracene scintillator crystals in an insulated box with a temperature regulation of the order of 0.1°F.

In some recent experiments the ion density in a plasma was measured as a function of radial distance from a d-c arc source of ions for the magnetic field intensities from 2500 to 14000 oersted. The diffusion coefficient appeared to very inversely as the square of the magnetic field strength, D~1/H2. The absolute value of D was shown to be approximately that which would be predicted by the collision diffusion theory when account is taken of the shorting effect of the end walls. The purpose of this report is to continue the examination of ion diffusion in a plasma and field experimentally the relation between the diffusion coefficient and the neutral gas pressure for a constant magnetic field.

This quarterly progress report of the Aircraft Nuclear Propulsion Project at ORNL records the technical progress of the research on circulating-fuel reactors and ether ANP research at the Laboratory under its Contract W-7405-eng-26. The report is divided into three major parts: I. Reactor Theory, Component Development, and Construction, II. Materials Research, and III. Shielding Research.

Reactivity measurements conducted in the Hanford Test Pile are interpreted to yield resonance integrals for uranium, uranium oxide, thorium and thorium oxide. The experiments were made using cadmium filters and are discussed in terms of the multiplication factor of the Hanford Test Pile.

The work of the Laboratory has greatly expanded into applications of nuclear energy which are significant for national defense and security, but are not directly connected with weapons development. It was felt, therefore, that a description of the non weapons activities of the Laboratory would serve a useful purpose at this time. For classification reasons, it has been necessary to issue the report in three parts; the third part concerns power reactor experiments.

The work of the Laboratory has expanded into applications of nuclear energy which are significant for natural defense and security, but are not directly connected with weapons development. It was felt, therefore, that a description of the nonweapons activities of the Laboratory would serve a useful purpose at this time.. For classification reasons, it has been necessary to issue the report in three parts; this is the first and is concerned with controlled thermonuclear reactions.

The experiments described in this report were designed to explore the feasibility of precipitating plutonium from 35 percent TBP in Gulf BT using peroxide, fluoride, sulfide, sulfite, sulfate, cocalate, hydroxide, iodate and phosphate ions from anhydrous, dilute and concentrated aqueous sources.