PROCEDURE FOR REPAIR OF A LABYRINTH BOARD OF A DIFFUSER OF A PRIMARY PUMP OF A NUCLEAR POWER PLANT.

摘要

A repair procedure of a labyrinth joint of a diffuser (30) of a primary nuclear power pump (1), said diffuser (30) comprising a peripheral skirt (31) provided at its base with a circular bottom (32) consisting of a hole (33) provided with said labyrinth seal, characterized in that it consists of: - making a bore (40) of a diameter larger than the hole (33) in the circular bottom to remove a central portion (32a) of the bottom (32) and eliminate the labyrinth seal, - reduce, in the vicinity of the boring (40), the thickness of the remaining portion (32b) of the bottom (32), - form on the edge of the boring (40), a chamfer (36), - position at the level of said boring (40) a spare part (41) consisting of a central hole (42), the peripheral edge of this part (41) being provided with a chamfer (43), - performing at the level of the two chamfers (36; 43) a continuous and watertight welding bead (44) - level the flanges of the c welding ordón (44), and - make in the central hole (42) of the spare part (41) lips forming a new labyrinth seal.