ANNULAR FOREIGN OBJECT SEARCH AND RETRIEVAL APPARATUS

摘要

An apparatus (10) is for foreign object search and retrieval in annular space (12) around a tube bundle (14) of a nuclear power steam generator (16). A lance drive (18) through which a stiff, nonbuckling lance (20) extends has a nose piece (22) extends into handhole (24) of the steam generator (16). The lance drive (18) is mounted in front of the handhole (24) by a support rail (26) to which the lance drive (18) is mounted. A lance guide (28) is connected between rear (30) of the lance drive (18) and a lance takeup drum (32). The lance drive (18) has external nosepiece (22) serving as a guide for the stiff, nonbuckling lance (20) as it exits from the lance drive (18). The nosepiece (22) has a series of roller bearings (36) through which the stiff, nonbuckling lance (20) passes to curve it into the annular space (12). The stiff, nonbuckling lance (20) consists of a plurality of substantially vertically extending, one piece hosebar supports (38) strung on supporting cables (40) in a manner similar to beads on a string. Each of the hosebar supports (38) has a convex front surface (42) and a concave rear surface (44). The convex front surface (42) fits into the concave rear surface (44) of the next adjacent hosebar support (38). With the surfaces (42) and (44) engaging in this manner, the stiff, nonbuckling lance (20) has a substantially increased vertical stiffness, so that it can extend for substantial distances from the nosepiece (22) into the annular space (12) without lateral support. A-54750