This article presents data on the effects of gamma radiation on the physical properties of a number of different classes of plastics materials of construction which were screened to determine their capabilities and limitations for service in applications where ionizing radiation exists. The irradiations were carried out in air at ambient temperature at normal atmospheric pressure to various gamma radiation doses up to 1*10^9 r depending upon the stability of the materials to radiation exposure. The different classes of materials and materials within a class are compared.

The design of NPR shows large quantities of carbon steel pipe and fittings in the front and rear face areas. These are also the area where the most work must be done during an outage, and consequently lower radiation levels are needed here than elsewhere in the piping system. A single pass decontamination of the front and rear piping without going through the entire loop is desirable. Because of the quantities of chemicals and available down time, an effective shorty interval process is needed. This report gives some recent laboratory data on this subject.

High speed data handling and computing systems are coming into increasing use in the automatic control of complex industrial processes. One of the next significant developments in reactor design is believed to be the application of high speed data handling and control systems to nuclear reactors. This document is a study of such a system intended for use with the Plutonium Recycle Test Reactor.