Neutron Monitoring System and Rod Control System Upgrades for Plant Life Extension

Most nuclear power plants in operation were built in the 1970’s and 1980’s. Plants of this vintage would require extensive upgrade for the instrumentation and control (I&C) to be able to support plant life extension. The most challenging aspect of I&C upgrades for these plants is the upgrade of the neutron monitoring system (NMS) and the Reactor Manual Control System (RMCS). These are specialized instrumentation and would require high quality design and engineering products to ensure safe and efficient plant operation. GEHitachi (GEH) Energy’s nuclear business provides a Wide Range Neutron Monitoring System (WRNM) to replace the existing Source Range Monitors (SRM) and Intermediate Range Monitors (IRM), a Power Range Neutron Monitoring System (PRNM) to replace the Average Power Range Monitor (APRM), and a Rod Control Management System (RCMS) to replace the original Reactor Manual Control System (RMCS) in the GE designed Boiling Water Reactors (BWR). The WRNM, PRNM, and RCMS are based on the Nuclear Monitoring Analysis and Control (NUMAC) platform, which is a microprocessor based system that provides improved system performance with standard features such as improved HMI, selftest and automatic calibration. In addition to enhancing the system functions, these upgrades also help to support the challenges of plant life extension. This paper presents the designs and experience of these GE-Hitachi Nuclear Energy systems in support for nuclear plants life extension.