Core-control assembly with a fixed fuel support.

摘要

In a boiling-water nuclear reactor (10), a core-control assembly (22) comprises a control rod (60), a fuel support (62), a control-rod guide tube (64), a control-rod drive (66), and a control-rod-drive housing (68). The fuel support is welded to the control-rod guide tube. To remove (200) the control-rod drive, the reactor vessel (12) can be opened (202) and the adjacent fuel bundles removed (203) from the fuel support. Then the control-rod can be rotated while clearing the fuel support. The control rod is then rotated (205) to decouple its bayonet connection to the control-rod drive. The control rod can then be lifted (206) out of the reactor. This arrangement allows a control rod to be replaced without handling of the fuel support. In addition, the fuel support can be more securely installed since it does not need to be removed.