An Advanced Digital ROD Postion Indication System for Pressurized Water Reactors

A new digital Rod Position Indication (RPI) System is described. It is a replacement for analog RPI systems in pressurized water reactors. The new RPI system provides substantial improvements in plant availability, system maintenance, fault tolerance and control room man-machine interface. A new sensing technique reduces systems complexity and eliminates time consuming costly adjustments. A fault tolerant, redundant microprocessor based system architecture and extensive embedded diagnostics ensure plant availability and reduce the need for system maintenance. Reduced electrical interconnection requirements frees many containment penetrations for alternative uses. All external interfaces are designed for low installed cost. Display of rod position, alarms, and diagnostic information are provided in analog and digital formats on a compact color CRT in the control room.