| 摘要 |
PURPOSE:To perform nondestructive measurement, by irradiating X rays from the inside of a coating pipe, generating the characteristic X rays of component other than zirconium among the component of zircaloy, measuring the X rays by a detector, and obtaining the thickness of a linter from the relationship with the attenuation factor of the characteristic X rays. CONSTITUTION:A liner 2 comprising pure zirconium is provided on the inner surface of a coating pipe 1 comprising a zircaloy alloy. An X ray source 3 and X ray detector 4 are arranged in the coating pipe 1. An Am-241 radiation source 6, which is provided in the X ray source 3 radiates gamma rays, excites zirconium target 7, and generates characteristic KX rays 8. The rays are irradiated on the coating pipe 1 from a radiating port 5a. Then only component elements Fe, Cr, and Ni other than zirconium in the zircaloy alloy generate characteristic X rays 9. The characteristic X rays 9 are transmitted through a liner 2 and inputted in the X ray detector 4. The characteristic X rays 9 are attenuated when they are transmitted through the liner 2. Since the relationship between the attenuation factor and the thickness of the liner is known, the attenuation factor is obtained from the output of the X ray detector 4, and the thickness of the liner is obtained from this factor. |
