REACTIVITY ADJUSTING METHOD FOR STABILIZING BOILING REACTOR FOR THERMAL AND HYDRAULIC INSTABILITY

摘要

PURPOSE: To obtain various selectable automatic suppression functions capable of suppressing thermal-hydraulic instability of a boiling water reactor and stabilizing the reactivity of a core. CONSTITUTION: This nuclear reactor is constructed of a pressure vessel 10 holding a core 12 and steam separating-drying equipment 14, a recirculation pump 16 extracting a coolant from a downcomer area through a recirculation pipeline 20 and sending it into a lower plenum 22 through a recirculation pipeline 24 and a flow control valve 25, a pressure relief valve 33 protecting a main steam pipeline from an excessive pressure, a feed water pump 36, a controller 40 operating in response to various inputs so as to regulate operations of the pumps 16 and 36 and a turbine control valve 28 in accordance with an operating state and on a real-time basis, a local output region detector assembly 42, a vibratory output detecting device 44 and a reactivity regulator 52 receiving automatic suppression function(ASF) signals. A dome internal pressure, a core flow rate or coolant enthalpy is changed in a random manner by this construction and thereby the nuclear reactor is stabilized.