Patent ID: 6574295
Filing Date: 2003-06-03
Classification: G21C,Y02E

Abstract:
A boiling water type nuclear reactor use control rod which comprises a tie rod having substantially cross shaped cross section, a plurality of sheathes having substantially U shape cross section and attached to the respective sides of the tie rod, a plurality of neutron absorption rods disposed inside the respective sheathes, a handle which is disposed at one ends of the sheathes in the axial direction of the control rod and a lower portion supporting plate or a dropping speed limiter which is disposed at the other ends of the sheathes in the axial direction of the control rod, wherein at least one of the handle, the lower portion supporting plate and the dropping speed limiter is provided with a sliding structural body which is constituted by a pin, a pin hole into which the pin is inserted and a roller which rotates around the pin in the axial direction, and at least one groove is sized to promote water flow in a clearance between the pin and the pin hole and is arranged adjacent the clearance.