ASYMMETRIC FILTER OF NEUTRON SIGNALS FOR DETECTING POWER OSCILLATIONS IN BOILING WATER REACTORS

摘要

This invention introduces a new method for detecting power oscillations that may occur in Boiling Water Reactor (BWR) cores. According to this invention, the Average Power Range Monitor (APRM) is enabled to detect power oscillations even when the signals from the Local Power Range Monitors (LPRMs) that make up the APRM signal are not in-phase and tend to cancel out. The asymmetric filtering algorithm that is the core of this invention is applied to the individual LPRM signals before they are summed up to make a new APRM signal. The new APRM signal will increase when oscillations occur, regardless of the instability type, and can thus be used for detecting reactor instability and enable the operator or automatic reactor protection systems to actuate and prevent reactor fuel damage.

主权项

1. A method for creating an average power range monitor signal for a boiling water reactor from summing up the individual local power range monitors, where the signals from said local power range monitors are filtered using asymmetric filtering algorithm; the said algorithm is asymmetric in the sense that it responds faster when the input signal to the filter is rising in time and slower when the input signal is declining in time.