Drive device for in-core neutron instrumentation system

A drive device for an in-core neutron instrumentation system, the drive device driving a neutron detector of the in-core neutron instrumentation system for measuring neutrons in a nuclear reactor, comprising:

• a winding drum for winding a cable having the neutron detector mounted at a tip end portion thereof;
• a drive motor for driving the winding drum for winding/extending the cable;
• a base member on which the winding drum and the drive motor are mounted;
• a cover member mounted on the base member and housing the winding drum and the drive motor therein;
• and
• a safety circuit provided between a power supply of the drive motor and the drive motor, and for switching between a conductive state in which power can be supplied to the drive motor and a cut-off state in which power cannot be supplied thereto depending on a mounted state of the cover member.