Performance Characteristics of a High-Temperature Servomechanism for Reactor Control Rods

Feasibility of servo operation, with supply gas and average part temperatures over 1000°F, for periods over two hours is well established. Performance required for vernier rod control in the Tory II-C reactor was nearly achieved with the first prototype design. Analytical study revealed characteristics of the pneumatic valve and motor significant in designing performance into systems of this type, and modifications to a roomtemperature motor predict improved resolution and dynamic stiffness for the second design. Analog model studies show the effects of supply-to-ambient pressure-ratio variation on valve-motor characteristics are tolerable for Tory II-C reactor controls.