Patent ID: 11935663
Assignee: SMR INVENTEC, LLC
Field: Engines, pumps, turbines (Mechanical engineering)
Classification: CPC G  Y | IPC G

Claim 0:
1. A control rod drive system for a nuclear reactor vessel, the system comprising:
a control rod drive mechanism mounted externally to the reactor vessel;
a drive rod mechanically coupled to the control rod drive mechanism and extending through the reactor vessel into an interior cavity of the reactor vessel holding a nuclear fuel core, the control rod drive mechanism operable to raise and lower the drive rod through a plurality of vertical axial positions;
a grapple assembly connected to the drive rod in the interior cavity of the reactor vessel and movable with the drive rod;
an electromagnet mounted in the grapple assembly;
a rod cluster control assembly comprising a plurality of control rods configured for removable insertion into the nuclear fuel core; and
a drive rod extension extending axially between the rod cluster control assembly and the grapple assembly, the drive rod extension comprising:
an axially extending actuator shaft having a top end including a magnetic block configured to releasably engage the electromagnet of the grapple assembly and a bottom end configured to releasably engage the rod cluster control assembly; and
a lifting head sleeve including a diametrically enlarged lifting head, the lifting head sleeve slideably receiving the actuator shaft therethrough for axial upward and downward movement;

wherein the electromagnet is operable to magnetically couple the actuator shaft to the grapple assembly at the top of the drive rod extension when the electromagnet is energized and uncouple the actuator shaft from the rod cluster control assembly at the bottom of the drive rod extension when the electromagnet is de-energized.