Developing a New Neutron and Reactivity Monitoring System for Paks NPP

The Reactivity Monitoring System and the Refuelling Neutron Monitoring System of Paks NPP are aged and need to be reconstructed. Since both systems are based on neutron flux measurements, the new system is to be served by the same detectors and measurement instrumentation. In order to provide data during refuelling, start-up and at full power, a full range system is required, i.e. the detectors and the associated instrumentation should cover the full range of neutron flux measurements from 0% to 100% of reactor power. Additionally, the new system is required to operate continuously, to maintain a measurement archive, and to provide data for the Process Computer and the VERONA core monitoring system. In order to cover the full neutron flux range, Photonis CFUL08 type fission chamber was chosen. The interface module will serve all three operation modes of the detector: pulse, Campbell (AC) and current (DC) modes. In order to obtain high reliability and dependability, the system will be built from independent and redundant components.