The Heavy Water Components Test Reactor (HWCTR) is used to test prototype fuel elements for power reactors that are moderated with heavy water and fueled with natural or slightly enriched uranium. During the initial critical experiments in the HWCTR, it was observed that there were unexpected variations in nuclear reactivity. Investigations revealed that this effect was due to bubble of helium gas appearing and disappearing in the moderator. An examination of the expected operating conditions of the HWCTR and the solubility of helium in D2O showed that it was possible during normal operation for the helium content of the moderator to exceed saturation and thus for helium to appear as bubbles in the moderator. The possibility of helium bubbles appearing in the moderator because of solubility characteristics was eliminated by modifications to the process system so as to maintain the gas content of the moderator appreciably below saturation.

The thermal-neutron flux prevailing near the upper hole in the HRE-2 core wall was determined from measurements of the induced activity in a specimen cut from the edge of the hole. The specimen was removed following run 21 and was thus exposed to reactor neutrons during runs 13, 14, 16,17, 18. 19, 20, and 21. The neutron flux, calculated for an average core power level of 2 Mw, was 2.8 x10^13 neutrons/cm^2 sec. the core wall area from which the specimen was removed was located approximately 16-in. from the core center.

Summary: The use of dimensionless-parameter frequency response diagrams to determine accuracies of lumped-parameter approximations is demonstrated by two examples: calculation of the heat flux at the surface of a semi-infinite solid due to temperature fluctuations of an adjacent fluid; and the response of a counterflow heat exchanger to inlet fluid temperature perturbations. Dimensionless system parameters make it possible to use general-purpose plots to find the error in particular approximations as a function of the frequency of perturbation. Such plots are directly applicable to control-system stability problems, where the highest frequency of interest is usually apparent.

During the past year notable progress was made in several laboratories on design for linear accelerators in the energy range up to and above 1 Bev. Interest in linacs for this energy centers on two possible applications: first, as injectors for 300 to 1000 Bev synchrotrons, and second, as sources of intense meson beams. To review this progress, a conference jointly sponsored by the Brookhaven National Laboratory and Yale University was held at Brookhaven during the week of August 20, 1962.

Abstract; SM-1 Reactor Core I Rearranged and Spiked, and Core II with Special Components were analyzed under various off-design conditions to induce nucleate boiling. The steady state code, STDY-3, written for the thermal analysis of pressurized water cores, was employed for the analysis. The code performs a complete steady state parallel channel thermal analysis for both nominal and hot channels. Thermal characteristics of individual elements were investigated while changing the parameters of primary pressure or inlet temperature to introduce the phenomenon of nucleate boiling in the the core. Reduction of system pressures to 1000, 800, and 600 psia and increasing core inlet temperatures to 465 and 500 degree F were studied as the means to induce boiling in the core. This analysis indicates that SM-1 Core I Rearranged and Spiked can be safely operated at the reduced pressure of 910 psia without introducing extensive boiling in the core. SM-1 Core II with Special Components can be operated at 800 psia or at an inlet temperature of 500 degree F at 1200 psia.

From abstract: "This report summarizes the past year of study of fine, molded, multicrystalline graphites with particular reference to the interrelation among certain properties with the composition, fabricating techniques, and thermal treatments found to influence them."

This is the third quarterly report that documents a system of mass flow that can record measurements of homogeneous flow, slurries, highly corrosive fluids and multiphase fluids, additionally considering pressure drops, measuring external to the flow, ruggedness and reliability.

High speed data handling and computing systems are coming into increasing use in the automatic control of complex industrial processes. One of the next significant developments in reactor design is believed to be the application of high speed data handling and control systems to nuclear reactors. This document is a study of such a system intended for use with the Plutonium Recycle Test Reactor.

When the nucleus of an atom in a crystalline solid undergoes radiative neutron capture there is disruption of the crystal in the vicinity of the event due to energetic processes accompanying the nuclear transformation. This local disruption has been termed a "hot-zone" or "displacement spike". The chemical state of a transformed recoil atom immediately following transformation is unknown. Within a microsecond the "hot zone" has cooled sufficiently to "freeze" the recoil atom into a stable (or metastable) chemical state. A fraction of the metastable recoil atoms can undergo thermal annealing reactions, and the chemical nature of the metastable state can sometimes be inferred from annealing data. It is characteristic of these reactions that the recoil atoms tend to be reincorporated into the parent chemical form.

Abstract: The question of how crack-free, protective oxide films can form on zirconium during oxidation when the Pilling-Bedworth ratio is about 1.5 has been considered by a study of the relative plasticity of various forms of zirconia. Hot hardness measurements showed that doping mono-clinic zirconia with iron, nickel, or chromium resulted in softer (more plastic) structures and that yttrium additions slightly reduced the plasticity. Calcia-stabilized cubic zirconia was found to be more plastic than mono-clinic zirconia when tested at temperatures above 200 degrees C. The behavior of anion-deficient oxides indicated that they were more plastic than stoichiometric oxides even though the hardness values were identical at 23 degrees C. The former were free from cracks at the indentions, whereas, stoichiometric oxides exhibited extensive cracking around and between indentions. The behavior of actual, thick (72 microns) oxide films during tensile deformation of oxidized metal samples indicated that considerable plasticity occurs in the oxide at 500 degrees C but that the films are brittle at 23 degrees C. It was concluded that the plasticity of the oxide may be greater than that of the oxygen-contaminated substrate at elevated temperatures and may be the means by which epitaxial strains are minimized.

Summary. The analysis of the motion of a six-bar linkage is difficult because of the large number of variables involved and the large number of calculations that have to be made for each position of the linkage. If a digital computer is used to make the calculations required for a multi-position analysis of a mechanism, it is feasible to design by analyzing a large numbers of similar linkages and selecting the optimum configuration. In this paper expressions have been derived for the output angle as a function of the input angle and the transmission angle as a function of the input angle for any single-degree-of-freedom six-bar linkage for which the parameters are known An example showing the usefulness of a six-bar computer program as a mechanism design tool is discussed.

One-region buckling measurements that were made on a series of D/sub 2/O- moderated lattices of heavy uranium metal tubes in the Process Development Pile at Savannah River Laboratory are presented. The purposes of these measurements are to provide normalization points for lattice bucklings and to extend the study of natural uranium- D/sub 2/O systems. The dependence of buckiing on the moderator-to-fuel ratio is studied for two types of lattices.

Procedures for the separation and concentration of microgram to nanogram amounts of thallium from gram amounts to galena and meteorite metal, sulfide, and silicate phases were developed and are described. The thallium is extracted from aqueous bromide of chloride solutions of moderate acidity using diethyl ether. A device for elimination of the large volumes of solvent by dropwise evaporation is described. Organic matter in the residue is destroyed by treatment with aqua regia, and the thallium is the residue is converted to the nitrate for spectrochemical or mass-spectrometric examination. The presence of thallium in the residue is tested by Rhodamine B. test.

The Model Q-1212C Pulser is a single frequency (60 pps) generator whose output waveform is characterized by a rise-time of less than 4 mµsec and, depending upon the method of termination, an exponential decay having a time constant of 300 or 600µsec. The waveform approximates that produced by a radiation detector. The waveform approximates that produced by a radiation detector. The maximum available output from the instrument is 10 volts, positive or negative polarity, and is continuously adjustable by means of step switches and a 10-turn potentiometer. The potentiometer has a linearity of 0.1%.

From introductory paragraphs: "The central problems in neutron research are the understanding of nuclear structure and the study of the properties of nuclear particles, particularly the properties of the neutron. The most fruitful attack on these problems is the determination of the probability of interactions between neutrons and nuclei, i.e., the measurement of neutron cross sections. Ideally, this involves the study of all possible types of neutron interaction with all available nuclei at all neutron energies...The discussion in this paper will omit the interactions leading to neutron productions, and will be limited to the intersections of neutrons with stable nuclei."

During a visit to Professor H.G. Harb at the University of Wisconsin, it was apparent that he had succeeded in obtaining fresh, clean chemisorptive layers of titanium by sublimation and chat that this could be adapted into an effective high vacuum pump. Two previous techniques of obtaining a chemisorptive layer of titanium, namely catholic sputtering and evaporation from the liquid droplet, have been extensively investigated and reported. Each of these seem to have inherent difficulties in stability and continuity of operation that appear to be eliminated or effectively reduced by the sublimation procedure. A development program was started at Brookhaven National Laboratory to investigate the possibilities of each sublimation of titanium as opposed to evaporation from the liquid.

This is the fifth quarterly report that documents a system of mass flow that can record measurements of homogeneous flow, slurries, highly corrosive fluids and multiphase fluids, additionally considering pressure drops, measuring external to the flow, ruggedness and reliability.

This article presents data on the effects of gamma radiation on the physical properties of a number of different classes of plastics materials of construction which were screened to determine their capabilities and limitations for service in applications where ionizing radiation exists. The irradiations were carried out in air at ambient temperature at normal atmospheric pressure to various gamma radiation doses up to 1*10^9 r depending upon the stability of the materials to radiation exposure. The different classes of materials and materials within a class are compared.

The wide use of liquid oxygen as an oxidant in rocket engines has resulted in an increased interest in low-temperature heat transfer. Storage tanks for this type of application, being uninsulated, contain a boiling-liquid low-temperature sink, which is susceptible to environmental heat inputs and subsequent liquid loss by vaporization. Such losses are difficult to predict due to the complex combination of ambient conditions which exist, and the lack of knowledge concerning their combined effects. Heat transfer in this field is difficult to analyze primarily because of its transient nature. This is a result of such factors as: (1) the growth of an insulating frost layer on the outer surface of the container, with its accompanying energy transfer to the system; (2) the temperature dependent convective air pattern that surrounds the container, (3) the transfer of radiant energy to the system, and (4) the mechanical failure of the frost itself with subsequent sloughing from the container wall. A lack of knowledge regarding the coefficient of diffusion of water vapor through air and the thermal conductivity of frost in this depressed temperature range further complicates the predictions of heat transfer.

Quarterly report describing progress on a project to develop and evaluate high-temperature tungsten alloys. This report discusses initial experiments to compare different alloy combinations.

In the past several years the use of neutron monitors for Pu concentration monitoring has been expanded in the Chemical Processing Department. Most of these monitors have been quite successful, and considerable effort is being made to improve the operation of both existing and future monitoring systems. One of the major improvements has been the development and use of a transistorized pre-amplifier or impedance matching circuits. This unit solves several problems associated with the use of boron trifluoride (BF3) neutron detectors in process monitoring; e.g., vacuum tube pre-amp failure because heat is not being conducted away.

The Heavy Water Components Test Reactor (HWCTR) is a pressurized reactor, cooled and moderated with D2O, and has the capability of testing fuel assemblies under operating conditions of coolant flow, temperate, and pressure that are typical of those proposed for modern power reactors. The report contains (1) description of the four systems used for failed element detection, (2) discussion of the laboratory analyses of water samples used a as backup for the fuel failure instruments, (3) description of 3 monitors, Cyclic Air Sampling Monitor, Stack Gas Activity Monitor, Health Physics Building Monitors, (4) normal full power activity readings, (5) discussion of the experience during fuel failure.

Abstract: New experimental data and literature data are utilized to determine the upper temperature of usefulness of zirconium alloys. Three basic engineering assumptions are used; (1) service life requirements are on the order of four years; (2) tubular fuel cladding for rod-type fuel is considered with a maximum wall thickness of 1.27 cm; and (3) heat fluxes are above 157 watts/cm. The inter-relation of three basic factors, corrosion rate, corrosion embrittlement by hydrogen and oxygen, and strength are considered. An upper limit for an acceptable corrosion rate for long-term service of 1 mg/dm/day is set primarily by the effect of heat-transfer on corrosion. For the best alloys anticipated, this requirement (even without considering transient conditions) limits cladding surface temperatures to less than 540 degree C. Oxygen embrittlement of the alloy substrate by oxide film dissolution is not expected to be a limiting factor. Corrosion hydrogen embrittlement was studied in detail and found to limit acceptable service to cladding surface temperatures of less than 525 degree C for established experimental alloys. Hydrogen embrittlement may not be a limiting factor if alloys corrosion resistant enough to be acceptable above 600 degree C could be developed. Zirconium alloys designed for high strength to …

The evaluation of the inductance of an electrical component is often important in understanding and operating an electrical circuit. Inductance is defined by several equations, the most common being e= -L d1/dt . This equation defines inductance as the constant which relates the back emf produced in an element to the time-rate-of-change of current.