Patent ID: 8848857

Claim:
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, wherein the cylindrical structure is a jet pump, the device body is provided with an access device configured to bring the device body to the cylindrical structure and to detachably hold the device body, the access device includes: an access-device holding part engageable with the device body and holding the device body; an operation pole extending to an operation floor; and a rotating and driving part interposed between the access-device holding part and the operation pole, the rotating and driving part being configured to rotate the access-device holding part with respect to the operation pole around an axis disposed substantially perpendicular to a longitudinal axis of the cylindrical structure, and the access device is configured to hold the device body in substantially a same direction as a longitudinal axis of the operation pole or a direction substantially perpendicular to the longitudinal axis of the operation pole.