From American Nuclear Society Meeting, New York, Nov. 1963. In computer-coupled automated activation analysis such as in the Mark II system, conventional methods of data readout impose a serious restriction on the minimum handling time per sample. A data coupler for operating between the data accumulation system and the computer tape unit was developed which contributes nothing to the handling time per sample, does not distort the data, and prepares the data for direct computer entry. In addition to activation analysis, the coupler may be used to obtain successive spectra separated in time by 0.16 sec in the study of short-lived isotopes.

To improve gamma discrimination and eliminate d-c cable leakage interference currents, mean square voltage fluctuation measurements have been made on neutron sensitive ion chambers.

Introduction. Under AEC contract the Martin Company has followed up the design and construction of the PM-1 and PM-3A nuclear power plants with R&D efforts seeking improved plant efficiency, increased core life and higher operating power. The Advanced PM cores have evolved step by step, with the addition of degrees of freedom to design latitude. A first replacement core, Core 2, has been designed to achieve 50 percent greater life than PM-1 through relatively minor design changes. Core 3 realizes the potential extensive modifications in the fuel element and control element configurations. This paper outlines an analysis effort undertaken to define what may be called a performance profile over a range of configurations of interest for Core 3. It should be emphasized that this is a parametric or concept study and not a final design effort. The results of this study clearly indicate that a lifetime of 100 Mw-yr can be obtained from a 7 ft pressurized water core. If employed as a 10-Mw heat source for present PM equipment, this core has a lifetime approaching that of the plant equipment, 90,000 full-power hours. Core 3 will be suitable for applications demanding up to 40-Mw operating thermal power.

Technical report discussing a series a experiments on the reactivity worth of gaps has been performed in the KAPL Solid Homogeneous Assembly (SHA). One objective of the program is to provide data against which calculated models can be checked. An immediate goal is to develop a method by which large void regions can be adequately treated within the framework of diffusion theory. This would enable the nuclear engineer to perform standard design calculations on systems containing such voids. Another objective of the program is to provide data which will allow the shutdown margin of split bed assemblies to be more adequately estimated. for this latter purpose not only the reactivity work of gaps is required by also the rate of change of reactivity with distance as a function of gap size.

Technical report discussing three principal areas: (1) some recent cross section measurements and their effect on fast reactor calculations; (2) the question of Doppler and sodium void reactivity effects in large fast power reactors and the conflicts inherent in simultaneous optimization of performance, breeding, and safety characteristics; (3) the matter of hybrid fuel cycles.

This study is part of a research into trace element physiology of fresh water snails. As an average, biological materials contain [approximately] o.0% (fresh weight) NaCl ; this means [approximately] 3540 mg Na/1 (in snails, 0.4% NaCl [approximately] ms/1). Under these conditions, the application of neutron activation plus gamma spectrum analysis for the study of most trace elements as a routine method, is difficult. We will narrow down the scope some more and consider only the interference between Na24 and Cu64.

Abstract: A description is given of the preparation and properties of a granular form of potassium hexacyanocobalt (II) ferrate (II) that is a highly selective absorbent for cesium ion. The material is suitable for use in a large-scale ion exchange column, and offers the possibility of isolating and concentrating Cs137 from fission product waste solutions that arise from the processing of nuclear fuels.

The ML-1 is a nuclearly heated, electrical power producing plant being developed for the U. S. atomic Energy commission and the U. S. Army by Aeroject-General Nucleonics. The power plant is a compact, water-moderated, gas-cooled, nuclear reactor, coupled in a single closed cycle to a gas driven turbine-compressor set and alternator. The plant is designed to produce power up to 500 Kw electrical,using 3 Mw thermal supplied by the reactor. It will operate 10,000 hours without refueling and have a plant life of five years. The total weight is less than 40 tons and no single package weighs more than 15 tons.

Abstract. The purpose of this paper is to present, in the light of 20 years of reactor-operation experience at ORNL, what is being done in preparation for operation of the HFIR (High Flux Isotope Reactor). This paper considers only the areas of staffing and training; development of operating and maintenance procedures; preoperational testing of water systems; and testing of remote handling tools. The preparatory work in other areas such as the hydraulic tests, neutron tests, etc., is not covered in this presentation.

Over the past six years, the hiring practices of the Reactor Operations Division of Argonne National Laboratory have been conducted to determine the highest level of personnel who would be willing to remain in the position of reactor operator. We have discontinued the hiring of personnel who have a bachelor's degree from an accredited institution or who are close to receiving such a degree. We now hire men from three general categories: (1) graduates from two-year technical institutes, (2) men who have had a number of years of experience in related operating jobs such as the petroleum industry or the chemical industry, and (3) men who have served in the nuclear programs of the armed forces. The following tests are given: (1) Wonderlic personnel Test, score above 43 percentile is mandatory, (2) Oral Directions Test, score above 80 percentile is expected, (3) mechanical Comprehension Test, score above 80 percentile is expected, (4) Arithmetic Reasoning Test, score above 60 percentile is expected, and (5) Primary Mental Abilities Test, used primarily as a check on the other tests given. Applicant is interviewed by at least three supervisors in the Division. All three supervisors must concur before an offer of employment is made.

A cladding failure monitor using the principle of detection of rare gas fission products in the cover gas system of liquid metal-cooled reactors, was developed which efficiently discriminates against AR41. This discrimination is accomplished by electrostatic precipitation of the rare gas daughter nuclides; since K41, the daughter of Ar41, is not radioactive, the activity of the precipitation is chiefly due to decay of various Rb and Cs fission products. The monitor equipment is described. Results of monitor testing in EBR-1 are reported; a simulated fuel road failure experiment was made which shows that the charged-wire cover gas monitoring principle should be useful in other sodium-cooled fast reactors systems.

Since 1943 when the oak Ridge Graphite Reactor was put into operation, literally thousands of individual irradiation have been performed in this reactor and in other ORNL research reactors. Over the years there have been many minor incidents caused by experiments. Such incidents have provided a basis cor continued improvement in experiment design review and safety-analysis procedures. The reports lists the Design Review and Safety Analysis (1) objectives, (2) principles and rules of design, and (3) limits of application of the review process. The report includes a review of 19 incidents at ORNL research reactors.

An apparatus has been developed which controls automatically the acidity of unbuffered solutions in the region from pH 4 to 10. A potentiostat is used to control the potential of an inert electrode on which the hydrogen gas-hydrogen ion reaction occurs in a solution saturated with hydrogen gas. The inert electrode acts as both a sensing element and a regulating electrode for the control of acidity. Current from the potentiostat passes through the inert electrode and an auxiliary polarizing electrode in an external compartment separated from the main cell by a salt bridge or porous plate. Transients which occur during the regulating action are presented and analyzed. The electrochemical pH-stat may be used to measure corrosion rates. Limitations of the device are discussed and a modification is proposed which makes use of a differential amplifier instead of a potentiostat.

Introduction. The reactivity difference associated with a reactor change can be simply related to the coincident changes in the neutron loss and generation rates. Unfortunately, in many instances these rates are difficult to measure directly during high-level operation; thus relativity values are normally found by other methods such as buckling calculations or low-level rising period measurements. However, with certain applicable control rod systems, it may be feasible to use heat generation rate in the rods as a measure of the reactivity-compensation effect. The neutron absorption rate in the Hanford reactor control rods can be determined under equilibrium conditions (and without disturbing these conditions) from the heat transfer rate to the control rod coolant. This information, when combined with a measurement of the change in reactor leakage caused by rod insertion, allows the calculation of control rod strength.

In contrast with previous EBR-1 reactor cores which were fueled with enriched uranium, the current Mark IV core is a 7 x 8-in. cylinder made of delta-stabilized plutonium alloyed with 1 1/4 w/o aluminum. The reactivity of the reactor is largely controlled by the movement of the entire outer blanket mounted on a hydraulic elevator with a travel of 80 inches. Partial meltdown occurred in November, 1955 during the last experiment scheduled for the core which was directed toward identifying the time constants associated with the components of the over-all reactivity coefficients. The incident is reported elsewhere. The changes in reactivity apparently come about as a result of changing from operation on the high temperature system to the low temperature system or vice versa. Continuous operation from day to day on either system does not effect any significant change in reactivity. Reactivity is not dependent on the duration of a run, but rather on the maximum power attained during that run.

Introduction. Sorption of gases by surfaces is the primary step in many heterogeneous processes. Because sorption processes are in general pressure-dependent, and very fast at normal pressures, low pressure system are mandatory. In gas-metal interaction studies the flash filament technique with ribbons and filaments and Wagener's technique with evaporated films allow observations at the requisite low pressures. However, these method have two major drawbacks: (1) Since the pressure changes during the sorption experiment, pressure-dependent parameters can only be obtained from indirect evidence; (2) The pressure change in the sorption cell during the experiment may cause significant interaction between the sample and the rest of the system and thus experimental data must be corrected for this effect. These drawbacks have been eliminated in a new approach based on a flow system in which the sample is exposed to constant pressure. This new technique has been employed for the study of adsorption and absorption of gases by filaments and evaporated films. This method can also be used for studying gas-metal solution equilibria.

A sector gauge was developed for routine measurement and recording of wall thicknesses between the ribs and at the top of installed aluminum reactor power tubes. The basic criteria selected for the device were that it would measure and record wall thickness over the length of the tube with an accuracy of plus or minus 2 mils at an average rate of 3 min per tube. An eddy-current measuring system was used in the device.

Training of Consumers Public Power District (CPPD) operating personnel for the Hallam Nuclear Power Facility (HNPF) was carried out under two formalized training programs. Both programs were organized and directed by Atomics International (AI). The first program was conducted in 1960 while he HNPF was under construction. The second program was begun in September 1961, prior to the initial HNPF dry critical loading experiment, and was completed in February 1963. The conventional portion of Sheldon Station has been a commercial power plant since July 1, 1961. Sheldon Station CPPD personnel were utilized extensively as instructors for the two formalized HNPF training programs and as responsible engineers for numerous test of the HNPF. CPPD shift personnel constituted the principal operating force throughout HNPF construction, reactor startup, and testing.

The radiation chemistry of ammonia, pure or with various additives, was studied by Co60 gamma radiation. The kinetics of aniline formation by the irradiation of homogeneous benzene-ammonia mixtures was determined together with the kinetics of hydrazine formation in the case of pure ammonia. The effects of dose, intensity, temperature, and specific additives were determined.

The Plutonium Recycle Test Reactor is a research and development tool supporting the Plutonium Recycle Program and the research activities at Hanford. The present organization directly associated with the PRTR is composed of Operating, Technical Assistance, Maintenance, and Engineering Groups. Liaison with research groups utilizing PRTR facilities is accomplished through the Technical Assistance Group. the other three groups serve the PRTR in the manner suggest by the group name. This paper limits its interest to the staffing experience of the Operating Group.

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 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.

The Heavy Water Components Test Reactor (HWCTR) was built for the Atomic Energy Commission by the Du Pont Company to satisfy a need for fuel testing in the AEC's Heavy Water Power Reactor Program. The reactor was designed to provide a realistic test environment for full size fuel candidates. The report contains sections on (1) the containment building, (2) vertical cross section of the reactor vessel, (3) core layout, (4) low power physics tests and comparison with calculations, (5) rod worths, (6) temperature coefficients, (7) flux shapes, and (8) the operating philosophy of a test reactor.

Abstract. The kangaroo rat is readily tamed and has certain characteristics that make it unique and of interest in highly specialized research programs. Studies were conducted on its ability to exist on a dried diet with only a bare minimum of water and that obtained from succulent plants. Hematological studies indicate that the kangaroo rat exhibits a different hematological distribution of cells than the mouse or rat. The lymphocyte constitutes 81.4% of the total leuokocytes. The hematocrit has a value of 46 to 48 in spite of the high degree of water conservation practiced by the animal. The response to ionizing radiation of this species does not differ from that reported for the mouse or rat. Behavior studies indicate that the digging characteristics of the kangaroo rat are similar to those of the gerbil. Furthermore, the animal shows definite psychotic tendencies under the influence of psychotomimetics like LSD-25 and psilocybin. An evaluation of the physiological responses of isolated tissues from this animal as well as its responses to anesthetics is being undertaken to evaluate its further usefulness in the laboratory.