A helium coolant side-stream purification system consisting of parallel sections for radioactive and non-radioactive de-contamination was designed for the proposed Pebble Bed Reactor Experiment. Primary equipment components are two gas coolers, gas heater, charcoal delay trap, CuO oxidizer, Molecular Sieve adsorber, and full flow filter. The charcoal delay trap is sized to provide a hold-up of 30 minutes for Kr isotopes, 6hr hold-up for Xe isotopes, and 99.9% retention of iodine isotopes resulting in "de-contamination factors" varying from l for Kr85 to 556 for I131. Non-radioactive de-contamination will result in a steady state concentration of CO2 in the coolant of 20.8ppm or less.

A literature study has been made of rates for the reaction of oxygen with high-purity artificial graphite. Values from a number of sources have been expressed on a common basis which provides approximate correction for the retarding effects of oxygen diffusion in the graphite pores. The corrected rates can be correlated by the equation k = 7.24 x 10^9 exp (-22 100/T), where k has units of weight fraction oxidized per hour and T as in °K. Effects of oxygen concentration, solid and gas-phase contaminants, and radiation on the observed rates are discussed. Methods for estimating rates and spatial distribution of heat release during graphite oxidation are presented. These should be of value in analyzing the hazard of a graphite fire following a coolant system rupture in a gas-cooled, graphite-moderated reactor.

A development program is being carried out in the pilot plant to improve the equipment involved in monitoring, metering and pumping process streams. The equipment under development includes an alpha monitor, a gamma monitor, a waste water monitor, a liquid flow rate meter, a canned rotor pump, a diaphragm pump, air lifts and a pressure tank pump. This report presents the present status of the testing program.

Methods for the noncorrosive removal of volatile fission products and UO2 dust from carbon steel and stainless steel have been developed. Procedures for applying these methods to the decontamination of the EGCR charge and service machines are described.

A conductometric titration method described by Goldstein was adapted for use in a remote analytical facility. The results obtained by mean of experiments made prior to this adaptation indicated that methanol is the most satisfactory medium in which to determine excess sulfuric acid in uranyl sulfate solutions that stimulate Homogeneous Reactor type fuel. When methanol is used, the complexation of hydrolyzable ions with sodium fluoride, as described by Pepkowitz, Sabol, and Dustin, is not required.

EXPIRE is a calculation which predicts the reactivity-lifetime, instantaneous and integrated effective multiplication constants and instantaneous and integrated effective multiplication constants and instantaneous conversion ratio for heterogeneous reactors. The concentration of all the isotopes of interest from Th232 to Am243 are calculated as a function of time using the average reactor power density and a uniform flux distribution. The equations have been programmed for the IBM-704 computer and the average running time is approximately two minutes per reactor lifetime.

A portable shield has been designed, developed, fabricated and shop tested to provide the HRT with a facility for direct dry maintenance operations. It provides temporary replacement for any one of the lower roof plugs and should permit many operations to be performed without flooding the reactor cell with water.

The effect of adding small quantities of fuel or poison to the HRT has been estimated using perturbation theory. The results have been reduced to a single relation and a set of graphs which make the estimation of added reactivity relatively simple. The perturbation theory results are compared with multigroup results and reasonable agreement is demonstrated; however, there is some question concerning the prompt neutron lifetime.

The theory of mass transfer into a flowing fluid is utilizes to estimate the effect of gas film resistance on overall rates of transfer through a porous septum. The expressions developed for the mass transfer ratio...

The preparation of essentially pure dimethyl selenide for the Isotype Separations Group, Chemistry Division, is described. The compound was prepared by warming a mixture of selenium, sodium hydroxide, sodium formaldehyde sulfoxylate in aqueous solution for several hours at 50°C and then adding methyl iodide. Dimethyl selenide was removed by distillation.

The calculation of concentration transients caused by mixing in the interconnected three-body system of the fuel dump tanks, core and blanket has been coded for the IBM-704. The system of equations includes material balances, the dependence of critical temperature on core and blanket concentrations, and the effect of temperature (density) changes on flow rates. The controllable flow rates, the fuel dump tank weight and the initial conditions are input variables. Outputs include core and blanket concentrations, critical temperature, concentration ratio and power ratio. The code has been used to compute transients during a number of operating situations.

Experimental determination of heat-transfer coefficients, burnout heat fluxes, and friction factors have been made for swirl flow of low-and moderate-pressure water through electrically heated aluminum, nickel, and copper tubes containing full-length Inconel twisted tapes. For nonboiling conditions, swirl-flow heat-transfer coefficient were successfully correlated with both the Froude modulus (the ratio of inertial to centrifugal forces) and a grouping of the Grashof and Reynolds moduli (ratio of buoyant to inertial forces).

The attached memo by G. N. Krouse of Sturm-Krouse, Inc. gives results of a preliminary analysis of the deflections of beam holes due to thermal expansion and internal pressure in the vessel. A partial solution of the problem is suggested. Based on preliminary pressure-temperature data the following deflections were derived: Movement of horizontal beam tubes = 0.046 in. Movement of Engineering facility tubes = 0.117 in. Vertical motion of the vessel at the horizontal beam tubes due to thermal expansion may be eliminated by locating the supports in that plane. That also will reduce the expansion at the point where the slant tubes pierce the vessel wall.

This manual represents the recommendations of the Instrumentation and Controls Division committee on Electrical and Electronic Symbols and Drawing that have been issued to date, and supersedes the previously issued ORNL Electrical Symbols List and CF-58-12-141, Electrical and Electronic Drawing Standards for Wiring and Device Coding and Applications.

An approximation is derived for the time constant which characterizes the rate of energy loss of fast ions moving through a plasma. Using particle and energy-balance equations a simple approximate criterion is derived for the estimation of the importance of energy degradation during plasma buildup in a DCX type machine. Next, there is derived the steady-state ion energy distribution for a case in which energy losses are to electrons at a given temperature and particle losses are by charge exchange. The distribution function is used to compute loss rate, upper critical current, ionization rate, and other functions of interest. Quantitative application is made to DCX-2 under various conditions of operation of carbon and deuterium arcs.

This memorandum presents a description of several additional miscellaneous HRT core maintenance tools, not in an earlier report (1). These tools were used in the removal of the cut up diffuser plates, probing the core wall, gauging the size of the holes, and other simple tasks. Function, design, and operation are described for the following items.

The use of the DD^3 amplifier with the RIDL 200- and 400-channel analyzers has been found advantageous for certain applications. In order to use the DD2, certain modifications to the input circuits of the Analog-to Digital Converter Unit are necessary. In addition, the modifications improved the linearity of the analyzer in the low channels. Using the analyzer with the RIDL Type 30-7 Scintillation Pulse Amplifier, it was noted that non-linearity of as much as 5 or 6 channels was present below channel 20. With the modifications made and with the use of the DD2, this non-linearity has been reduced to less than 1/2 channel.

Departures from the usual precipitation method produced crystalline uranium peroxide in several forms. Three types of segregated needles were used in the preparation of three pellets for pellet-type elements. Densities of the pellets ranged from 93 to 97% of theoretical, depending on conditions of precipitation.

The ORNL analog computer was used to simulate four widely different experiment conditions in the small EGCR in-pile loops. Various control and safety systems were evaluated in each case. Curves are included which show the response to postulated accidents and component failures. The results indicate that one standard control and safety system will probably be adequate for a wide variety of test conditions.

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%.

A mathematical model is presented for the prediction of heat transfer coefficients for fully developed turbulent flow of fluids in circular pipes by analogy to the transfer of momentum. There is also presented an empirical velocity distribution equation derived from existing experimental data for use in the analogy model. Heat transfer coefficients for fluids with Prandtl numbers ranging from 0.01 to 100 and Reynolds numbers ranging from 5x10^3 to 10^7 are presented in tabular and graphical forms for both the case of constant heat flux at the pipe wall and the case of constant temperature at the pipe wall. The heat transfer coefficients computer in this investigation are compared with existing experimental dat, and a discussion of the parameters affecting the heat transfer characteristics of fluids in turbulent motion in circular pipes is presented.

Some results have been obtained which may be of use in studying the escape of fission fragments from slurry particles which contain fissioning material. Assuming that the fission fragments are of fixed range H, that they are generated uniformly and isotopically in a sphere of diameter D, the escape probability , mean path length, and path length distribution function have been derived.

An investigation is made to determine the adequacy of presently used analog circuits in solving dynamic fluid flow heat transfer equations. A mathematical analysis is made of dynamic heat transfer in pipes with zero losses, with losses proportional to pip temperature, and with heat inputs. The results of this analysis are compared with analog results by means of generalized temperature versus time graphs. The analog circuit is found to be adequate for most conditions, but sometimes requires modification when heat inputs are considered.

The solution of the monoenergetic Boltzmann equation in an infinite homogeneous, nonmultiplying medium with linearly anisotropic scattering and an isotropic plane source is given and compared with the corresponding solution for isotropic scattering. The effective source strength for the asymptotic flux turns out to be the same as that for isotropic scattering to first order in Σa/Σ.