| 摘要 |
<p>The control rod (10) includes an upper absorber section (12) and a lower velocity limiter (14) comprised of a socket (24), a vane (22), a transition piece (20) and a set of fins (18). To adjust the weight of the control rod, lighter and heavier sets of fins (18a, 18b), as well as lighter and heavier transition pieces (20a, 20b) are provided. By suitable selection of the lighter and heavier sets of fins and the lighter and heavier transition pieces, the weight of the velocity limiter can be selectively adjusted in accordance with the weights of differently designed sections to obtain a predetermined control rod weight. Additionally, the heavier transition piece may have material removed therefrom to decrease its weight to provide an infinite adjustment of weight within a predetermined range of weights for the velocity limiter.</p> |
