| 摘要 |
<p>Cruciform control rod can move vertically in the intermediate spaces between a group of four generally rectangular fuel element casings. The control is guided at the top by drum-shaped rollers, one in each or leaf of its cruciform section. Each of these rollers bears against one only of the adjacent fuel elements each diametrally opposite pair of these rollers bears against opposite sides of the slot between the fuel elements. Used partic. for boiling water reactions. By arranging the rollers offset from the centre line of the appropriate arm, so that each roller projects on one side and bears only on that side against the adjacent fuel element, jamming is prevented.</p> |
