Patent Number: 061730262
Section: abstract

A power oscillation monitoring system and method for indicating instability of a nuclear reactor. The monitoring system facilitates monitoring reactor instability and maintaining a nuclear reactor in the stable state. In one embodiment, the monitoring system is implemented in a computer workstation having memory and a processor. The workstation is electrically coupled to neutron detectors, and a period based algorithm and a confirmation density algorithm are stored in the workstation memory. The processor contains a Period Based Algorithm (PBA) and a Confirmation Density Algorithm (CDA). Under the control of the system the PBA algorithm evaluates the periodicity of the neutron detector output signals to identify the presence of density waves in the reactor. The CDA utilizes the PBA output signals to identify confirmation density, which is the fraction of active neutron detectors in the core that reach a target successive oscillation period confirmation count. When the confirmation density exceeds an instability threshold setpoint, an instability signal is generated to facilitate suppression of the reactor prior to any growth in power oscillation amplitude. By providing suppression at these conditions, the development of significant power oscillations is avoided.