Patent ID: 9208905
Filing Date: 2015-12-08
Classification: F22B,G21C,Y02E

Abstract:
1. An auxiliary feed water system of a Pressurized Water Reactor comprising: an auxiliary feed water pipe connected to a subsequent stage of a main feed check valve in a secondary cooling water pipe; an auxiliary feed water pump that feeds auxiliary cooling water stored in an auxiliary feed water pit to the auxiliary feed water pipe; and an auxiliary feedwater valve that adjusts a flow rate of the auxiliary cooling water passing through the auxiliary feed water pipe; a water-level detection sensor that detects a water level of the secondary cooling water in the steam generator; a microcomputer programmed to execute a water-level-deviation calculation program that calculates a deviation between a preset target water level and a water level detected by the water-level detection sensor; the microcomputer programmed to execute a valve-operation setting program that sets an aperture of the auxiliary feedwater valve corresponding to a deviation of the water level; and the microcomputer programmed to execute a valve drive program that outputs a signal for driving the auxiliary feedwater valve corresponding to setting by the valve-operation setting program, wherein the valve-operation setting program acquires water-level time-response information corresponding to an aperture of the auxiliary feedwater valve in advance, determines a parameter in a non-minimum phase transfer function, which approximates a response to the water level by an inverse response from a set aperture of the auxiliary feedwater valve, based on the water-level time-response information, and sets the aperture of the auxiliary feedwater valve, taking into consideration a gain margin and a phase margin of frequency characteristics of the non-minimum phase transfer function in which the parameter has been determined.