Technology of the End Cap Laser Welding for Irradiation Fuel Rods

Kim, Soo-Sung; Lee, Jung-Won; Koh, Jin-Hyun; Lee, Young-Ho

Journal of KWJS 2003;21(6):20-25.
Published online October 27, 2003.

[기술논문] 조사연료봉 봉단마개의 레이저용접기술

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Technology of the End Cap Laser Welding for Irradiation Fuel Rods

Soo-Sung Kim, Jung-Won Lee, Jin-Hyun Koh, Young-Ho Lee

Abstract

Various welding methods such as Gas Tungsten Arc Welding(GTAW), magnetic force electrical resistance welding and Laser Beam Welding(LBW) are now available for end cap closure of nuclear fuel rods. Even though the resistance and GT A welding processes are widely used in manufacturing commercial fuel rods, they can not be recommended for the remote seal welding of fuel rods in the hot cell facility due to the complexity of the electrode alignment, the difficulty in replacing parts in a remote manner and the large heat input for the thin sheath. Therefore, the Nd:Y AG laser system using optical fiber transmission was selected for the end cap welding of irradiation fuel rods in the hot cell. The remote laser welding apparatus in the hot cell facility was developed using a pulsed Nd:Y AG laser of 500 watt average power with an optical fiber transmission. The weldment quality such as microstructure and mechanical strength was satisfactory. The optimum conditions of laser welding for encapsulating irradiation fuel rods in the hot cell were obtained.