METHOD AND DEVICE FOR CHECKING DETERIORATION OF NUCLEAR REACTOR PRESSURE VESSEL

摘要

PROBLEM TO BE SOLVED: To provide a method and a device for checking the deterioration of an nuclear reactor pressure vessel in which the nuclear reactor pressure vessel is a direct subject to be non-destructively measured. SOLUTION: A magnetic yoke 201 having a magnetizing coil 202 is closely adhered to the inner or outer wall of the nuclear reactor pressure vessels 204 or 205. A plurality of magnetic flux sensors 601 to 604 are provided at the position where the magnetic yoke comes into contact with the nuclear reactor pressure vessel to individually measure hysteresis magnetizing properties of the closed magnetic circuits formed in the magnetic yokes and the nuclear reactor pressure vessels. The coercive forces are obtained from the hysteresis magnetizing properties measured by each magnetic flux sensor. The distribution of coercive force in the direction of thickness of the nuclear reactor pressure vessel is obtained from the coercive forces. The distribution of material deterioration in the direction of thickness of the nuclear reactor pressure vessel is checked using the distribution of coercive force. COPYRIGHT: (C)2003,JPO