Reactivity modulation of a boiling water reactor to stabilize thermal- hydraulic instabilities

摘要

To stabilize boiling water reactors against neutron flux oscillations caused by thermal-hydraulic instabilities, random core-wide reactivity perturbations are induced in the reactor either to suppress the onset of asymmetric (regional) mode oscillations or, in response to the detection of asymmetric mode oscillations, to stabilize the reactor in a symmetric (core-wide) oscillation mode. The reactivity perturbations are produced by effecting random changes in dome pressure, core flow or coolant enthalpy.