Report documenting ongoing research and developments at the Oak Ridge National Laboratory's Gas-Cooled Reactor Project.

Report issued by the Oak Ridge National Laboratory discussing progress and work conducted by the Chemistry Division.

Report containing a series of reports from members of the Oak Ridge National Laboratory's Neutron Physics30 Division.

This technical report describes development work done on method of particle separation by the Biology Division of the Oak Ridge National Laboratory and the Oak Ridge Gaseous Diffusion Plant during the period January 1 to June 30, 1963, under the Joint National Institute for Health-Atomic Energy Commission Zonal Centrifuge Development Program. The central effort has been to develop zonal centrifuge systems for the separation of cells and sub-cellular particles, including viruses, and bio-colloids, including proteins and nucleic acids.

The thermophysical properties of Armco iron such as thermal conductivity, electrical resistivity, and Seebeck coefficient have been extensively investigated and reviewed up to 1000 degrees C. Few investigations of such properties have been made on high purity iron. If such a study is made using the same apparatus to determine the properties of two purity levels of iron, then several significant intercomparisons can be made which add meaning to data on a single material. The systemic errors for a single apparatus are the same, therefore comparison of a property of two similar materials is more significant. A comparison of the property changes with temperature and purity can show the effects of impurities on the mechanisms contributing to a property and allows prediction of the properties of iron as a function of purity. For these reasons a study was initiated on the high-purity iron for comparison to Armco iron.

The experimental details, mathematical models, and typical data for a rapid comparative method for thermal conductivity measurements are presented. The method consists of measuring the temperature change of a small silver sphere after it is brought in contact with a small disk-shaped specimen which was initially at ta higher temperature. This temperature change was calibrated in the range of 50 to 400 degrees C by making measurements on samples of know thermal conductivity. The accuracy of this technique was shown to be between than +-10% with a reproducibility of at least +-2.5%. Using known transport mechanisms for heat conduction in solids and the temperature dependency of the electrical conductivity, a means to judiciously extrapolate thermal conductivity data obtained between 50 and 400 degree C to high temperature is presented.

Grade CGB graphite is a nuclear graphite which is basically an extruded petroleum coke bonded with coal tar pitch. No carbon blacks are used and the low-permeation graphite is finished through a series of impregnations and heat treatments with a final heat treatment of all components to 2800 degrees C. A listing of the results obtained is given in Table 1. The results at 51 degrees C are considered questionable. There was a slight contamination of the 90% Pt 10% Rh-Pt thermocouples at 910 degrees C but it was not sufficient to doubt the validity of the 910 degrees C results. However, the results obtained at 1015 degrees C should be disregarded because of severe thermocouple instabilities. In addition, the electrical resistance of the core heater at 603 degrees C indicated the thermocouples had a -10 to -15 degree error which is sufficient justification to disregard the 605 degrees C data.

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.

Sanderson & Porter have carried out a series of studies over the last four years which indicate that the pebble-bed reactor way be an attractive way to obtain low-cost power. At the request of the Atomic Energy Commission, two design studies have been carried out on this concept at the Oak Ridge National Laboratory. The first of these a preliminary design of a 10-Mw(t) reactor experiment, the PRRE, was initiated September 10, and a report on the study was issued November 1960. The second phase of the work, a conceptual design study of a 330-Mw (e) central station, was initiated November 1, and is the subject of this report.

A carrier containing 138.99 liters of solution, uranium concentration 202.04 g/liter with an isotopic concentration of 97.3% U-233, was prepared for shipment. The total uranium was 28,062 +/- 60 g (95% confidence level) and the U-233, 27,305 +/- 66 g (95% confidence level).