A proposed modification to the experiment off-gas system for the EGCR-LITR Capsule Experiment is evaluated by comparing the atmospheric radiation doses to laboratory personnel that could result in the event of an experiment failure while utilizing the present off-gas system to those doses that would result if various modifications to the existing system were effected. The modifications considered include the addition of an iodine vapor adsorber and a krypton-xenon adsorber. The addition of an iodine vapor adsorber to the off-gas system, which presently includes an absolute filter, reduces the atmospheric dose to the thyroid from 510 mr to 1.4mr. The total body dose is also reduced from 2.2 to 1.3 mr. The total body dose can be further reduced to 0.7 mr if a large krypton-xenon adsorber is included. Basd upon these calculated atmospheric radiation doses it is concluded that the addition of an activated charcoal iodine vapor adsorber will reduce the atmospheric hazard to an acceptable level.

This semiannual progress report and future reports will be published as two documents to permit a wider distribution of the unclassified material. The report numbers are assigned in sequence so that the two reports will fall together when filed by report number.

In a gas-cooled reactor operating at very high power density the thickness of the reflector may be determine by the requirement that the steel pressure vessel be protected from an excessive dose of fast neutrons, rather than by the usual requirements of neutron economy and power distribution. It is important the the reflector not be made thicker than necessary, since an increase in pressure vessel diameter can result in a marked increase in cost, as well as a decrease in the permitted gas pressure level.

A Lucite model of a multi-stage countercurrent hydroclone solvent extraction apparatus has been constructed and tested with Amsco-water. The diffusivity of Cs 134 tracer in aqueous chloride solution was measured to check the performance of the capillary diffusivity measuring system. The experimental data from four Druhm runs showed that 1/8in. thick graphite liners are usable for reactor temperatures above the boiling point of sodium.

Uranium extractions from carbonate solutions were effective and phase separation rates were rapid using a new commercial quaternary extractant, Alamine 336. Extraction coefficients were approximately proportional to the quaternary concentration. Addition of -0.5 mole tridecanol/mole quaternary to the solvent gave optimum extraction efficiency and phase separation rates.

The addition of a surface active agent to an aqeous-organic interface produced a resistance to mass transfer equivalent to slightly more than 1 cm of water. Five semicontinuous Druhm runs were made with 1/2in. thick MgO liners and terminated due to either failures of the UFe nozzle or a top gasket leak. In preliminary scale-up tests of the flame calcination equipment, a maximum feed rate equivalent to 720 g oxides/hr was achieved using a 3-in. i.d. magnesia reflector with an outside wall temperature of 1500°C.

The measured diffusivity of uranyl nitrate in water at 25ºC was 0.7*10^e cm^2/sec with about 40% average deviation. A program was started to develop nonnuclear uses for depleted uranium. Two continuous DRUHM reaction tuns were terminate due to erratic operation of the sodium metering system. In the second Fluorox run with crude UF, which lasted for 29 hr, a total material balance of 94.8% was obtained and 17.9& of the theoretical amount of UF was collected in cold traps and chemical traps.

The following is taken from ORNL-2257, Instantaneous Velocity Profile Measurement by Photography, by R. E. Lynch, L. D. Palmer, and G. M. Winn. This report is in in preparation status; and errors, inconsistances, and omissions in he language, as well as in the technical aspects, may exist. The technique of using phosphorescent particles to enable photographic determination of qualitative and quantitative instantaneous velocity profiles is covered by AEC Patent Application No. SN-710, 371 issued to F. E. Lynch, L. D. Palmer, H. F. Poppendiek, and G. M. Winn and entitled " A Method of and Means for Visualizing Fluid Flow Patterns.

Standard water treatment practices have proven adequate for scale and corrosion control on the secondary side of the ORR pool-cooling heat exchanger. Corrosion rates measured on specimens exposed to secondary water showed maximum corrosion rates of approximately 1 mpy during the first exposure period and these rates decreased during subsequent exposure.

Temperatures are given at which two liquid phases form in a synthetic homogeneous reactor fuel solution and its concentrates. The data show a two-liquid-phase boundary temperature of 332°C for the Particular HRT Fuel composition and a flat minimum temperature of 305°C for the initial solution concentrated between 300 and 329°C are presented to indicate solution stability in this temperature region. Some related comments on current HRT operations are given.

In certain phases uranium processing it is poss!ble for operating personnel to acquire internal deposits of uranium. This body burden can be acquired by injection, as in contamination of a wound, by ingestion, of by inhalation. In order to estimate internal exposures, some means of determining the location and extent of these internal deposits is essential.

An improved heat sink for space vehicles was proposed in ORNL-CF-59-1-21. Subsequent work on the problem has indicated that there is a substantial probability of a puncture of such a radiator by meteors. To meet this problem a modified geometry has been evolved for which the probability of a meteor puncture should be reduced by a factor of at least 100 relative to the radiator of the original proposal at the expense of an increase in radiator weight of possibly 30%. This memorandum outlines the approach to the problem and a series of similar promising solutions.

A preliminary study of dispersing agents for thorium oxide has been completed and several of the dispersants have possible uses. Also many of the industrial dispersing agents tested are not usable with thorium oxide due to induced behavior causing balling and caking. The effects of nitric acid concentration have been observed to also effect each dispersing agent.

Preliminary measurements of the corrosion of titanium were made in 13 M HNO3-0.05 M fluoride using 0.1 M H3BO3 as a liquid and vapor phase complexing agent. Titanium Ax-55 was attacked at average rates of 0.58 and 0.33 mils/month in the liquid and vapor. In dissolver solutions containing 0.5 and 1.0 M titanium, all rates were less than 0.1 mils/month.

Many elements exhibit anisotropic scattering at energies of interest in reactor calculations. A method is presented for the calculation of transport cross sections including the observed anisotropy.

Nitrate contained in raffinates from Canadian Blind River mills interferes seriously with thorium extraction by secondary amines. With primary amines, however, the effect is negligible and these compounds are the preferred process extractants.

The method of calculation of various quantities relating the temperature and the rate of heat removal of UO2 test elements is presented. Graphs of the appropriate quantities as a function of the rate of heat removal are included.

This memorandum summarizes the results of an analysis to determine the extent of displacement of the EOCR core due to blowdown in case of several postulated hot main gas coolant pipe failures. Results show that the core will be damaged for any hot pipe double-ended failure. Excepting the improbable case of no coolant flow existing proper to the break, the core will be damaged for any hot pipe fracture exposing a total flow area to the atmosphere equal to that of one pipe. Smaller breaks will probably be safe in this respect.

The compatibility of zirconium diboride, boron carbide, and boron nitride with type 304 stainless steel was evaluated as a function of temperature (1000-1200°C), time (1-3 hr). Appropriate loadings of the boron compounds and stainless steel powder were blended and fashioned into a compact powder metallurgically. Each compact was roll clad into a plate and subsequently heat treated at a temperature equal to the initial sintering temperature. Metallographic examination of the fabricated and heat-treated plates demonstrated that none of the systems were metallurgically stable. The instability was generally manifested by the (1) interaction of the discrete boron compounds with the matrix and (2) precipitation of a hypothetically boron-rich phase throughout the stainless steel matrix material.

In the preliminary stages of getting up a time-of-flight system for measuring neutron spectra from proton reactions, a study of the time dependence of the beam in the 86Inch Cyclotron was made. This study revealed the expected bunching of the protons to produce a short burst of beam on each cycle of the 13.4 Mc/s accelerating voltage. In addition to the 13.4 Mc/s structure, however, there was a 360 c/sec modulation of the beam pulses and a complicated pattern built upon that.

A series of neutron multiplication measurements with arrays of 1 by 8 by 10 in. slabs of 93.4% U235-enirched uranium metal have been made to provide data from which safety criteria for the storage of these fissile units can be established. Each slab contained 22.9 kg of U235. A maximum of 125 unites was assembled. The arrays studied were cubic lattices of the units and were usually parallelepipedal in shape.

The results of a parametric study on a gas cooled reactor are reported on herein. The system considered was a helium cooled, UO2 fueled arrangement with the fuel assemblies consisting of clusters of long cylindrical elements, each element covered b a stainless steel jacket. The axial power distribution was assumed to be a "chopped cosine" having an axial peak-to-average power 1.32.

The Turco 4501 process is recommended for the decontamination of the PRFR pilot leaching plant equipment. The caustic-tartrate-nitric acid process is recommended for the decontamination of the cell and the equipment exterior.

The nil-ductility-transition (NDT) temperature, as defined by the Naval Research Laboratory drop-weight test, was determined on the A212B carbon-silicon steel used in the pressure vessel of the N. S. Savannah nuclear reactor. Correlations were made with the Charpy-V-notch impact energy at NDT. Specimens taken at two different thickness location from materials used in the upper closure head of the reactor vessel yielded NDT temperatures of 0 - 20°F which correspond to Charpy-V-notch impact energies of 11-19 ft-lb. Testing of as-received material used in the lower closure head indicated that the NDT temperature was 50°F which was equivalent to an average Charpy-V-notch impact energy of 12 ft-lb. After normalizing and stress-relieving this material, in order to more closely approximate the final condition of the reactor vessel, NDT was reduced to less than 10°F.