Development of a High Temperature and Radiation Resistant Linear Motion Servo Actuator System for Nuclear Reactor Control Rod Application

This paper discusses major problem areas encountered in the design, construction, and development of a servo actuator system for positioning the control rods of a nuclear ramjet engine test reactor. The actuator discussed is 40 inch linear stroke, electropneumatic servo actuator capable of operating throughout the temperature range of 70°F to 1200°F part temperature, using air as the power supply, with temperatures ranging from 70°F to 1060°F. The discussion covers major components as well as the complete actuator assembly. Important details of the mechanical design and selection of materials are presented together with a summary of the measured. performance levels. The component and system test programs are described. Life data based on testing under the specified, room and high temperature environment conditions, is presented.