| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a control rod which can prevent cracks on the sheath thereof. <P>SOLUTION: A handle 5 with a cruciform cross-section is welded to the upper end of a tie rod 2, and a lower support member 6 with a cruciform cross-section is welded to the lower end of the tie rod 2. The upper ends of a plurality of hafnium members 5A are attached to the handle 5, and the lower ends of a plurality of hafnium members 5B are attached to the lower support member 6. A sheath 4 having the hafnium members 5A, 5B located within is welded to the tie rod 2, and the upper end and the lower end of the sheath 4 are welded to the handle 5 and the lower support member 6, respectively. A whole control rod 1 assembled as above is then uniformly heated to 300°C. The welded joint between the sheath 4 and the handle 5 of the heated control rod 1 and the periphery thereof is quenched by spaying cooling water thereto by means of a cooling water spray device. The tensile stress of the upper end of the sheath 4 is thus reduced. <P>COPYRIGHT: (C)2013,JPO&INPIT |
