Abstract: A control rod position detector including a permanent magnet that is attached on a control rod inserted in a reactor pressure vessel, where the permanent magnet is capable of moving together with the control rod, and a plurality of reed switch mechanisms that are arranged in the reactor pressure vessel at regular intervals in an insertion direction of the control rod. Each of the reed switch mechanisms is provided with a pair of reed switches that are placed so as to overlap with each other in the insertion direction of the control rod. The pair of reed switches are connected to a common wiring. The common wiring is connected to a detector that detects a position of the control rod based on signals from the reed switches.

Abstract: The object of the present invention is to provide a control rod position detector that is capable of avoiding and preventing a situation which makes impossible a detection of a position of a control rod inserted in a reactor pressure vessel. A control rod position detector of the present invention includes: a permanent magnet 10 that is attached on a control rod 4 inserted in a reactor pressure vessel 1, the permanent magnet 10 being capable of moving together with the control rod 4; and a plurality of reed switch mechanisms 31 that are arranged in the reactor pressure vessel 1 at regular intervals in an insertion direction of the control rod 4, the reed switch mechanisms 31 being operated by a magnetic flux of the permanent magnet 10. Each of the reed switch mechanisms 31 is provided with a pair of reed switches 13 and 14 that are placed so as to overlap with each other in the insertion direction of the control rod 4. The pair of reed switches 13 and 14 are connected to a common wiring 11.

Abstract: There is provided a reactor control rod which is capable of suppressing an excessive frictional force acting on passive state oxide films formed on the surfaces of neutron absorber elements, and also reducing the possibility to cause electrochemical problems, and a method of manufacturing the same. The reactor control rod comprises a wing having a sheath which has a substantially U-shaped cross-section. A top end structure is secured to a longitudinal top end of the sheath. A bottom end structure is secured to a longitudinal bottom end of the sheath. An opening portion of the sheath is secured to a central structure. A neutron absorber element is made of neutron absorbing material. The neutron absorber element is charged in the sheath. A supporting rod through hole is formed in the neutron absorber element, so as to penetrate the neutron absorber element. A supporting rod fitting hole is formed in the sheath. A load supporting rod is inserted into the supporting rod through hole.

Abstract: A control rod driving hydraulic system of a control rod driving system of a nuclear power plant, in utilization of condensate as a control rod driving water comprises a water pressure control unit arranged for each control rod and a water pressure supply unit for commonly supplying water pressure to all control rods. The water pressure supply unit comprising a pump mechanism operatively connected to a condensate supply source for driving the control rod driving water, a filter mechanism operatively connected to the condensate supply source and the pump mechanism for filtering the condensate as the control rod driving water, a valve unit for regulating quantity of flow of the control rod driving water, and a valve unit for regulating pressure thereof. The filter mechanism including at least one hollow fiber filter unit for purifying the control rod driving water. The hollow fiber filter unit includes a backwash regeneration equipment.