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.

Abstract. An a priori calculation of the radiolysis of oxygen gas in the pressure ; range 10-3 to 100 atm has been made. In the low background region (1- 100 atm) all track effects have been considered. The calculated G(O3) values seem to be in reasonable agreement with experiment if only one excited oxygen molecule is initially formed per ion pair. Effects of pressure, LET and dose rate have been discussed. The radiation-induced chain decomposition of O3 has not been considered.

From American Nuclear Society Meeting, New York, Nov. 1963. The need for control of the flow distribution and/or steam quality in boiling reactors is discussed. A quality control device is being developed which consists of an entrance venturi and an exit venturi for measuring the flow rates into and out of the channel, means for comparing the two flow rate signals, and a value for regulating the flow rate. This device can be used either as a constant quality device or as a controlled-quality device. Results are given of air-water studies of two-phase flow in a vertical venturi.

Montgomery and Chandrasekhar and Hulm suggested models for predicting Im and Hm of high-field superconducting solenoids. Montgomery's model for predicting the degradation effect of superconducting solenoids leads to a unique coil quenching characteristics if geometrically similar solenoids are considered. Experiments do not verify these predicted results. Chandrasekhar and Hulm's model leads to one unique coil quenching characteristic for all solenoids with identical wire type and turn distance; coils with identical load factor should display identical values im and Hm. An analysis of the surface currents in an ideal superconducting infinitely long solenoid demonstrated possible forms of shielding currents. Experiments with Pb coils with and without NbZr and compensation agree with results expected from this analysis, but contradict Chandrasekhar and Hulm's model. Measurements of individual turn resistances show behavior of a soft superconductor solenoid in the intermediate state.

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.

Abstract. The rate constants for the reaction of the hydrated electron eaq with a number of solutes and with radicals formed in water radiolysis are reported. Hydrated electrons were formed in the electron pulse irradiated solutions at concentrations in the range from 1 to 10 pM. Their reaction was followed by the decay of the optical absorption of eaq at 5780 A. Generally a 04 psec pulse of 15 MeV electrons was used. In the absence of eaq scavengers, second-order kinetics prevailed owing to the dominance of the reactions,eaq+eaq, eaq+H, and eaq+H202 when OH radical scavengers were present in alkaline solution. An analysis of the decay curves leads to values for keaq+eaq and keaq+H of 0.9~ 1010 and 3 x 1010 M-1 sec-1, respectively. With scavenger present in excess over [eaq], pseudo first-order kinetics were found and rate constants for a number of inorganic and organic compounds are reported. The agreement of these and other rate constants with diffusion-controlled reaction theory is discussed.

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.

The purpose of this paper is to describe a few of the suggested advanced concepts for fast breeder reactors and to compare these with the standard approach as to their potential advantage. I have attempted to estimate the economic effect of full technical success with each of the proposed concepts. The proposed concepts include: (1) single sodium system, (2) steam-cooled core concept, (3) direct cycle reactor using potassium as reactor coolant and working fluid, (4) molten plutonium-fuel alloy circulated and cooled by a jet of sodium, (5) settled-bed core, (6) molten salt concept, and (7) paste-fuel system.

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.

Abstract: This report is concerned with the application of an electronic data processing system to the unique combination of scientific and commercial data processing requirement of nuclear materials management. The organization and flow of data from the plant through the data processing equipment to the final report is the principle topic of the report. Included in the discussion, however, are topics concerned with the impact of conversion to electronic data processing on personnel, materials management costs, and on other plant organizations. Portions of the report are devoted to programming systems and decision-making abilities of data processing equipment which make these systems readily adaptable to nuclear materials management.

The variational method is applied to the monoenergetic time dependent transport equation to obtain a simple relation for the asymptotic decay constant in small pulsed assemblies. The results indicate that flat trial functions may be a reasonable representation of the flux distributions in the thin slab limit. This approach is superior to many of the usual transport approximations.

The effects of competition between resonances of different isotopes were investigated. Flux and reaction rate calculations on a Pu/sup 239/-- U/sup 238/ system revealed that U/sup 238/ exhibits both self-shielding and interference effects, the latter becoming noticeable at enrichment of a few per cent. Gold activation was also found to be depressed by the presence of U, but was insensitive at low enrichment values, Investigation of the Pu/sup 239/ resonance integral showed an asymmetric effect involving both interference between potential and resonant scattering and interference with resonance absorption in another isotope. The interference scattering arising in each resonance level had a notable effect on the average change in the Doppler coefficient. (D.C.W.)

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 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.

Abstract. A brief review of the development of the subject of lattice defects in solids is given. The relation of this problem to field theory methodology is discussed; the defect is regarded as a particle imbedded in the phonon field. One may then discuss scattering states in the field, or “dressed” states of the particle. Specific application is then made to a defect in a simple cubic crystal including interactions between the defect site and its six nearest neighbors. Scattering solutions and scattering cross-sections are calculated and show that vacancies can cause strong resonant scattering, or pseudo-localized modes, at frequencies well below the Debye frequency. Applications to thermal conductivity and other experiments are discussed briefly.

Abstract. The determination of the infinite multiplication factor, k∞ , from measurement son a small test sample was investigated by both theoretical and experimental techniques. Theoretical relations were developed to calculate the error in the measurement due to a mismatch between the flux ratios in the critical assembly and those of the test sample. Experiments were carried out at the Hanford Laboratory of the General Electric Company with the PCTR, to obtain values of the multiplication factor for comparison with the theoretical results. Calculations with two-group theory gave results that agreed with the experimental results when the test sample, with natural uranium fuel, was surrounded by a buffer region of the same material. When this buffer region was loaded with highly enriched fuel, the errors in the measured values were not predicted by the two-group theory. Three-group theory relations were derived which gave calculated values in agreement with the experimental values and indicated that a mismatch of the epithermal neutron group leads to the measured differences in the value of k∞ for the two buffer types.

Abstract: The current-carrying capacity of Nb- Zr wire has been studied under conditions of swept magnetic field and fixed wire current and of fixed magnetic field and swept wire current. The effects of wire movement, thermal environment, copper coating of the wire, and rate of sweep of wire current or magnetic field have been determined for these conditions of test.

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.

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.

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.

Abstract: Recent developments in techniques for low-voltage radiography have found application for the examination and evaluation of minute details in small or thin specimens. Utilization of x-ray tubes and helium chambers with thin windows for maximum transmission of soft x rays and bare film with dark-room exposure techniques have allowed very high contrast radiographs to be produced on low-contrast materials. These conditions, coupled with very high resolution photographic emulsion detectors, have resulted in the observation of detail approximately 1 {micron} in size. Useful examination of the plates and subsequent reproductions have been made at magnifications as high as 500X. This contact system offers the advantage of evaluation of a relatively large area, as compared to the restricted field of observation of projection microradiography. Included among the subjects have been graphite-coated UC₂ particles, graphite, beryllium, paper, and other organic specimens.

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.

Summary. In October 1960, increases in the fission product activity of the primary coolant of the SM-1 power plant indicated that a fuel element failure had occurred. Low power tests were run first to determine the nature and magnitude of the defect. Flux tilting experiments were then performed to determine the general location of the failed element. Finally, the primary coolant flowing through each of the fuel elements was sampled at low reactor power for relative iodine activity to determine the exact location of the defective element.. The element was found and replaced. Upon return to power, the fission product activity dropped back to its normal full power value.

In fast reactor safety studies, it is imperative to know the effects of temperature excursions on the fuel elements. Previous controlled out-of-pile experiments on the behavior of uranium fuel elements under meltdown or near-meltdown conditions have been performed using direct electrical resistance heating or furnace heating. As a step toward obtaining more complete information on reactivity effects accompanying fuel meltdown, the behavior of irradiated EBR II and Fermi A samples under transient nuclear heating in TREAT has been studied. The experiment results obtained indicate that effects of prior irradiation can produce significant effects upon reactivity changes produced by meltdown of metallic fast reactor fuel pins.