Hitachi, Ltd.

Shizuo Matushita

Kiyotomo Nakata

Shizuka Shimanuki

Shigeki Kasahara

Michiyoshi Yamamoto

Hideya Anzai

A method and an apparatus for estimating the remaining service life of an object by measuring the physical quantity of a sample and which are applicable to a nuclear reactor. A plurality of model samples are experimentally prepared by preliminarily disposing a material having substantially the same composition as the object to be subjected to the estimation in an environment substantially the same as the object and measuring the physical quantities of the model samples in relation with exposure times. From this experiment, a relationship between the exposure time and the physical quantity under such an environment is obtained. Further, a critical exposure time which will cause an unstable fracture of a material of an actual sample, which is made of a material substantially the same as the object and placed in substantially the same environment as the object, is preliminarily obtained from the relationship between the exposure time and the physical quantity for the model samples. The physical quantity of the actual sample is then measured. Subsequently, an actual exposure time corresponding to the physical quantity of the actual sample is obtained by using the relationship between the physical quantity and the exposure time. Thereafter, a difference between the critical exposure time and the actual exposure time is calculated to obtain a remaining service life of the object.

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Hitachi, Japan

Shizuo Matushita