レーザを応用した炉内保全技術とそのPWRへの適用
Laser based maintenance technologies for PWR power plants
著者:
佐伯 綾一 Ryoichi SAEKI 佐野 雄二 Yuji SANO 黒田 英彦 Hidehiko KURODA 落合 誠 Makoto OCHIAI 田村 雅貴 Masataka TAMURA 河野 渉 Wataru KONO
発刊日:
公開日:
Laser based maintenance technologyLaser claddinglaser peeningLaser seal weldingLaser ultrasonic testingPWRStress corrosion cracking (SCC)underwater welding
概要
Toshiba has developed laser-based maintenance, inspection and repair technologies as countermeasures against stress corrosion cracking (SCC) in nuclear power reactors. Laser peening (LP) is a novel process for preventive maintenance, which improves residual stress from tensile to compressive on material surface by irradiation laser pulses in water. Laser-ultrasonic testing (LUT) is capable of detecting and sizing SCC having a depth of about 0.5 mm. Underwater laser welding can be fulfilled by making local dry environment with shielding gas around welding point. Laser cladding is realized with the laser welding technology, which forms a corrosion resistant layer of sufficient chromium (Cr) content to cover the surface susceptible to SCC. Laser seal welding (LSW) is expected to isolate the crack tip from corrosive water environment and to impede the propagation of the crack. The outline of the laser-based technologies and their applications in BWR and PWR power plants are described.
