Cooling unit for nuclear reactor control rod driving apparatus

A cooling unit cooling a coil assembly that generates electromagnetic force for driving a nuclear reactor control rod comprising:

• a coil surrounding a driving shaft of the nuclear reactor control rod so as to generate the electromagnetic force;
• a coil housing surrounding the coil so as to enclose the coil;
• a cooling shroud-shell forming a cooling flow path between the cooling shroud-shell and the coil housing, whereby a cooling fluid for cooling heat that is generated in the coil passes through the cooling flow path;
• and
• a plurality of cooling fins disposed on the cooling flow path in a radial direction so as to allow heat to be effectively exchanged between the coil and the cooling fluid that flows through the cooling flow path,
• wherein the coil housing is a hollow tube haying an inner surface and an outer surface, wherein a wiring passage is formed between the inner surface and the outer surface of the coil housing, and wherein the wiring passage extends along a central axis of the coil housing and is a part through which lead wires for supplying electric power to the coil passes.