| 摘要 |
<p>In a fuel assembly for a nuclear reactor, spacers are used for keeping together and fixing fuel rods (7) and control rod guide tubes (8), if any, in the fuel assembly. To be able to improve the cooling of the fuel rods in the fuel assembly during operation, sub-spacers (5,6) are arranged for controlling the cooling water flow in the fuel assembly. With sub-spacers formed as inner sub-spacers (5) and outer sub-spacers (6), which are placed alternately along the fuel assembly (1), it is possible to create a cross flow which alternately acts between the inner and outer regions in the fuel assembly, whereby the cooling water is mixed with an essentially maintained low pressure drop. The cross flow also provides short distances between the turbulence regions which arise after each spacer, which is expected to lead to a high DNB margin and a low pressure drop.</p> |
