Abstract: This monthly progress report covers the activities of the Army Gas-Cooled Reactor System Program for April 1959. The program includes a water-moderated heterogeneous reactor (Gas-Cooled Reactor Experiment I), a graphite-moderated homogeneous reactor (Gas-Cooled Reactor Experiment II), a mobile gas-cooled reactor (ML-1), and the coordination of the Gas Turbine Test Facility. [It reports] the progress of each project, the associated tests and data evaluation, the applicable design criteria, and the fabrication of reactor components" (p. 1).

Report containing a description of the Oak Ridge National Laboratory's High-Flux Isotope Reactor (HFIR) and its operation.

Report issued by the Oak Ridge National Laboratory discussing a Health Physics Instrument Manual. Descriptions, characteristics, and applications of different instruments are presented. This report includes tables, illustrations, and photographs.

Report issued by the Oak Ridge National Laboratory discussing a review of the Radioisotopes Program during 1964. Research and experimental projects conducted during 1964 is presented. This report includes tables, illustrations, and photographs.

Report that "describes the equipment, technologies of use, and reliability of an ultrasonic tester - designated UT-4 - capable of detecting very small defects in the brazed closures of reactor fuel elements" (p. 2).

Report reviewing literature that concerns "the compatibility of stainless steels and nickel-base alloys with various gases which might be present in or around a high temperature nuclear reactor" (p. 2).

Report containing the procedures and results of tests made to determine the corrosion resistance of materials in a simulation of Hanford Laboratories' N-Reactor secondary system water environment.

Report describing ongoing progress made at the Oak Ridge National Laboratory's Thermonuclear Division.