Nuclear reactor vibration monitoring apparatus and method of monitoring nuclear reactor vibration

摘要

Vibration of a jet pump installed in a reactor pressure vessel of a boiling water reactor is monitored. Ultrasonic waves are transmitted from an ultrasonic sensor installed on an outer surface of the reactor pressure vessel toward a throat and a diffuser of the jet pump. When the ultrasonic waves reach respective outer surfaces of the throat and diffuser, reflected waves are generated at the respective outer surfaces. The ultrasonic sensor receives those reflected waves. The ultrasonic signal process section obtains a distance in the horizontal direction between the throat and the diffuser based on a time difference of the reflected waves reflected from respective reflection surfaces of the throat and diffuser and a sound speed in reactor water in the neighborhood of the throat and diffuser. A relative vibration is obtained based on the change with time of the distance.

主权项

1. A nuclear reactor vibration monitoring apparatus comprising:
an ultrasonic sensor set on an outer surface of a reactor pressure vessel, the ultrasonic sensor transmitting ultrasonic waves and receiving reflected echoes thereof; an ultrasonic transmitter and receiver for controlling simultaneous transmission of the ultrasonic waves to each of a plurality of reactor internals undergoing relative vibration in the reactor pressure vessel and reception of respective reflected echoes from respective reflection surfaces of respective reactor internals; and an ultrasonic signal process apparatus for processing respective reflected echoes and calculating said relative vibration of the respective reflection surfaces of the respective reactor internals based on time differences between the respective reflected echoes reflected from the respective reflection surfaces.