| 摘要 |
<p>A control cluster for a water cooled and moderated nuclear reactor, comprises a spider and rods suspended from the spider. Each rod contains neutron-absorbing material. In a lower portion of each rod, the material is a metal neutron absorber. In an upper portion, it is a stack of pellets of boron carbide B4C. In a middle fraction occupying a height lying in the range 35% to 45% of the total height, it is zirconium diboride ZrB2 isotopically enriched in boron 10 or hafnium diboride HfB2.</p> |
