VIBRATION MEASURING APPARATUS FOR NUCLEAR REACTOR INTERNAL STRUCTURE AND VIBRATION MEASUREMENT METHOD THEREFOR

摘要

A vibration measuring apparatus for nuclear reactor internal structure includes a holder which has an opening contact on a surface of a pressure vessel of a nuclear reactor; a vibrator accommodated in the holder so as to transmit or receive an ultrasonic wave; a couplant with which the holder is filled up; and, a bias component applies a biasing force to the vibrator in the direction of the opening; The couplant is a solid state of metal material at normal temperature and change to liquid stage by heat transfer from the pressure vessel.