Patent ID: 6882696

Claim:
A control rod for boiling water reactor, 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 the sheaths having a U-shaped cross section; wherein the tie rod is provided with steps for fixing the sheaths at the tips of the cruciform arms; and the tip of each of the sheaths is fixed to the tie rod by a laser welding which is performed with the tip of the sheath being fitted onto the step of the tie rod, the laser welding using a YAG laser beam or a CO 2 laser beam that is not irradiated directly on the sheath and is set 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 and irradiates a surface of the tie rod so that at least a part of the tie rod is continuously welded in a longitudinal direction thereof.