Styrstavsanordning jämte kärnreaktoranläggning

摘要

The present invention refers to a control rod device for a nuclear reactor (1) having a core which comprises nuclear fuel and which is arranged to permit through-flowing of water. The control rod device (2) comprises a moveable control rod member (6) and a stationary guide member (7). The control rod member may be displaced axially into the core and comprises a control rod (8) with a neutron-absorbing substance. The control rod member is displaceable in the guide member between a first end position outside the core and a second end position in the core. A retarding device is arranged to retard the control rod member when it approaches the second end position. The retarding device comprises an eddy current brake having a first eddy current unit (31) on one of the control rod member and the guide member and a second eddy current unit (32) on the other of the control rod member and the guide member.