| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a control rod for regulating power that makes the average reactivity value over its lifetime equivalent to that of a shut-down control rod, while achieving the mitigation of problems about blade history, reducing the usage of hafnium, and eliminating the non-integrity and difficulties in the manufacture due to welding deformation or mechanical imbalance. <P>SOLUTION: The control rod CR includes: blades 1 made by confronting one piece of blade pieces 10 holding Hf plates 12 whose thickness in at least 1/4 segment is 1.5 to 2.5 mm with each other; a tie cross 4 arranged with a space secured along the shaft of the control rod CR to hold four blades 1 so that its cross section can be cruciform; a trap 13 arranged in a space between the confronted blade pieces 10 and filled with reactor water; water windows 3 arranged in at least 1/4 segment of each of the blade pieces 10, and forming partial hafnium loss sections; and a shaft center water region 5 arranged in a space between locations of the tie cross 4 with the shaft center water width CW of 10 to 40 mm in at least 1/4 segment of an effective part of the control rod CR. <P>COPYRIGHT: (C)2011,JPO&INPIT</p> |
