System for sealing the nozzle of a steam generator

A collapsible nozzle dam for a system for sealing the nozzle of a steam generator, said nozzle dam comprising:

• a base portion receivable through the manway;
• a number of pivoting arms attached to said base portion extendable to reach the periphery of a nozzle larger in diameter than the manway and foldable to fit through the manway;
• and
• a foot assembly for each said arm on the distal end thereof, each foot assembly including means for automatically engaging the periphery of the nozzle for supporting said base portion in the nozzle when said arms are extended, said means for automatically engaging including at least one wedge bolt subassembly comprising a threaded shaft receivable by threaded holes in the nozzle ring and a pin removably insertable in said threaded shaft.

An installation pivot arm for transporting a collapsible nozzle dam, said installation pivot arm comprising:

• a support with a proximal end securable to a manway of a steam generator and a distal end securable to a nozzle ring;
• nozzle dam attachment and positioning means;
• and
• means for articulating said nozzle dam attachment means and said nozzle dam attached thereto to between a position proximate the manway and a position over a nozzle for transporting the nozzle dam from the manway to the nozzle.

A collapsible nozzle dam for a system for sealing the nozzle of a steam generator, said nozzle dam comprising:

• a base portion receivable through the manway;
• a number of pivoting arms attached to said base portion extendable to reach the periphery of a nozzle larger in diameter than the manway and foldable to fit through the manway;
• a foot assembly for each said arm on the distal end thereof, each foot assembly including means for automatically engaging the periphery of the nozzle for supporting said base portion in the nozzle when said arms are extended;
• a post extending from said base portion;
• a tension leg assembly for each foot assembly, each tension leg extending between said post and its associated foot assembly;
• and
• means for providing compliance between at least one foot assembly and at least one tension leg assembly.