Preventive maintenance/repair device and preventive maintenance/repair method for cylindrical structure

Abstract

A preventive maintenance/repair device 10 of the present invention includes: a device body 11 , and holding mechanisms 13 a and 13 b connected to the device body 11 , the holding mechanisms 13 a and 13 b being configured to hold the device body 11 on an outer circumferential surface of a cylindrical structure 19 . Further, the device body 11 is equipped with a traveling and driving part configured to be circumferentially movable along the outer circumferential surface of the cylindrical structure 19 . Furthermore, each of the holding mechanisms 13 a and 13 b is equipped with a maintenance/repair mechanism 16 configured to maintain and repair the cylindrical structure 19.

1 . A preventive maintenance/repair device for use in maintaining and repairing a cylindrical structure of a cylindrical shape among reactor internal structures installed in a reactor pressure vessel, the preventive maintenance/repair device comprising:
 a device body;   a holding mechanism connected to the device body, the holding mechanism being configured to hold the device body on an outer circumferential surface of the cylindrical structure;   a traveling and driving part disposed on the device body, the traveling and driving part being configured to be circumferentially movable along the outer circumferential surface of the cylindrical structure; and   a maintenance/repair mechanism disposed on the holding mechanism, the maintenance/repair mechanism being configured to maintain and repair the cylindrical structure.   
   
   
       2 . The preventive maintenance/repair device according to  claim 1 , wherein
 the holding mechanism includes: a pair of arms each having a shape along the outer circumferential surface of the cylindrical structure; guide rollers respectively disposed on distal ends of the pair of arms; arm cylinders configured to respectively drive the pair of arms; and links connected between the arms and the arm cylinders, the links being configured to transmit drives of the arm cylinders to the arms.   
   
   
       3 . The preventive maintenance/repair device according to  claim 2 , wherein
 each of the arms of the holding mechanism is separable into a proximal arm body and a distal arm end, and   in order to hold the device body on an outer circumferential surface of another cylindrical structure of a different outer diameter, the arm end can be replaced with another arm end of a different length with respect to the arm body.   
   
   
       4 . The preventive maintenance/repair device according to  claim 2 , wherein
 each of the arms of the holding mechanism is separable into a proximal arm body and a distal arm end, and   in order to hold the device body on an outer circumferential surface of another cylindrical structure of a different outer diameter, the arm body can be replaced with another arm body of a different length with respect to the device body.   
   
   
       5 . The preventive maintenance/repair device according to  claim 1 , wherein
 a distance sensor is disposed on an outer surface of the device body on a side opposed to a surrounding structure.   
   
   
       6 . The preventive maintenance/repair device according to  claim 1 , wherein
 the maintenance/repair mechanism includes an equipment configured to maintain and repair the cylindrical structure, and an equipment cylinder configured to drive the equipment in a longitudinal direction of the cylindrical structure.   
   
   
       7 . A preventive maintenance/repair device for use in maintaining and repairing a cylindrical structure of a cylindrical shape among reactor internal structures installed in a reactor pressure vessel, the preventive maintenance/repair device comprising:
 a device body;   a holding mechanism connected to the device body, the holding mechanism being configured to hold the device body on an outer circumferential surface of the cylindrical structure;   a traveling and driving part disposed on the device body, the traveling and driving part being configured to be circumferentially movable along the outer circumferential surface of the cylindrical structure; and   a maintenance/repair mechanism disposed on the device body, the maintenance/repair mechanism being configured to maintain and repair the cylindrical structure;   wherein the device body is provided with a thruster driving part configured to move the device body in water.   
   
   
       8 . A preventive maintenance/repair method using a maintenance/repair device for use in maintaining and repairing a cylindrical structure of a cylindrical shape among reactor internal structures installed in a reactor pressure vessel, the preventive maintenance/repair device comprising:
 a device body;   a holding mechanism connected to the device body, the holding mechanism being configured to hold the device body on an outer circumferential surface of the cylindrical structure;   a traveling and driving part disposed on the device body, the traveling and driving part being configured to be circumferentially movable along the outer circumferential surface of the cylindrical structure; and   a maintenance/repair mechanism disposed on the holding mechanism, the maintenance/repair mechanism being configured to maintain and repair the cylindrical structure;   wherein   the device body is provided with an access device configured to bring the device body closer to the cylindrical structure so as to attach the device body to the outer circumferential surface of the cylindrical structure and to detach therefrom the device body, and   an operation pole is connected to the access device,   the preventive maintenance/repair method comprising the steps of:   mounting the access device and the operation pole on the device body;   sending the device body into the reactor pressure vessel in a hanging manner through the operation pole and bringing the device body closer to the cylindrical structure;   holding the device body on the outer circumferential surface of the cylindrical body by the holding mechanism;   removing the access device from the device body, after the device body has been held on the cylindrical structure by the holding mechanism; and   performing a maintenance/repair operation to the cylindrical structure by the maintenance/repair mechanism.