Patent ID: 6735266
Filing Date: 2004-05-11
Classification: B23K,G21C,Y02E

Abstract:
A method for manufacturing a control rod for boiling water reactor, the control rod comprising a tie rod having a cruciform cross section, a handle attached to an axially upper part of the tie rod, a lower part support member or a velocity limiter attached to an axially lower part of the tie rod, and sheaths attached to tips of cruciform arms of the tie rod, each of sheaths having a U-shaped cross section, comprising the steps of:forming the tie rod which is provided with steps for fixing the sheaths at the tips of the cruciform arms; fitting the tips of each of the sheaths onto the steps of the tie rod; and fixing each of the sheaths to the tie rod by performing a laser welding with the sheath being fitted onto the tie rod, wherein a surface of the tie rod is irradiated with a YAG (yttrium aluminum garnet) laser beam or a CO2 laser beam in such a manner that an axial center position of the beam is shifted from an end face position of the step of the tie rod toward an axis center of the tie rod to achieve a continuous weld of at least a part of the tie rod in a longitudinal direction thereof.