Patent ID: 8325872
Filing Date: 2012-12-04
Classification: B63C,G21C,Y02E

Abstract:
1. A working method for doing works under an annular shroud support plate arranged substantially horizontally between an inner surface of a nuclear reactor pressure vessel and an outer surface of a shroud, the method comprising: conveying a working equipment with a folding/unfolding mechanism, a ballast tank, a vertical thruster and a horizontal thruster to a working position with the folding/unfolding mechanism held in a folded state, the conveying step including: unfolding the folding/unfolding mechanism and setting up the working equipment under the shroud support plate after conveying the working equipment to the working position; moving the set up working equipment along a lower surface of the shroud support plate and positioning the working equipment, while pressing the working equipment against the lower surface of the shroud support plate; and doing a work on the shroud support plate with the moved and positioned working equipment.