Report documenting the progress of the Army Gas-Cooled Reactor Systems Program to develop a mobile, low-power, nuclear power plant for Military field operation.

This technical report presents measurements of the thermal expansion of five titanium carbide type cermets from 68 to 1800F. These cermets are designated by Kennametal, Inc., as K 138A, K 150A, K 152B and K 162B. They contain from 64 to 80 weight percent titanium carbide, 10 to 30 weight percent metal binder and 6 to 10 weight percent other carbides. The metal binders are cobalt, nickel, and nickel and molybdenum. An attempt was made to calculate the thermal expansion of each type cermet from thermal expansions of the constituents. The expansion of the mixture was computed by weighting and expansions of the constituents according to (1) weight percent of the constituents, (2) volume percent of the constituents and (3) according to a value developed for mixtures by P. S. Turner. It was found that expansions computed according to volume percent and by Turner's method agreed with measured values with +- 5 percent. The values calculated by weight percent were from 5 to 11 percent higher than the observed values. The thermal expansions of these cermets are compared with the expansions of a group of metals and alloys.

A digital-to-analog converter is described which is a part of a system that converts punched-tape digital data to analog data in a series of points drawn by an x-y plotter. The converter is designed to plot accurately tapes that contain information other than coded numerical coordinates. Operation of the converter is also described along with format requirements and power supplies. (J.R.D.)

This report covers the S-I-5-B-M fuel irradiation in the GETR Maritime Loop during the final quarter of fiscal year 1962 plus the month of July 1962 to conclude the irradiation program. The data are summarized in Section II.