Drilling worktable for manufacturing tube support plates and method of manufacturing tube support plates using the same

A drilling worktable for manufacturing tube support plates of a steam generator constituting a primary system of a nuclear power plant, the drilling worktable comprising:

• a plate having a drill insertion groove formed to face a position at which a heat transfer tube insertion hole is to be drilled in a member to be processed;
• the plate further comprising:
• a seating section formed on an upper surface of the plate so as to protrude upward;
• and
• a groove section through which the coolant, supplied when a drill unit drills downward of the seating section, is discharged,
• wherein the drill insertion groove comprises an opening portion opened at one side of an upper surface of the drill insertion groove for discharge of the coolant.

A drilling worktable for manufacturing tube support plates of a steam generator constituting a primary system of a nuclear power plant, the drilling worktable comprising:

• a plate having a drill insertion groove formed to face a position at which a heat transfer tube insertion hole is to be drilled in a member to be processed, wherein the plate further comprises:
• a seating section formed on an upper surface of the plate so as to protrude upward,
• a groove section through which coolant, supplied when a drill unit drills downward of the seating section, is discharged,
• at least one coolant discharge hole configured to guide drainage of the coolant introduced into the groove section, and
• a coolant merging hole communicating with a lower end of the coolant discharge hole, so that the coolant is merged from the coolant discharge hole into the coolant merging hole to be discharged out of the plate.

A method of manufacturing tube support plates of a steam generator constituting a primary system of a nuclear power plant using a drilling worktable for manufacturing tube support plates, wherein the drilling worktable includes a plate that supports a member to be processed, wherein the plate comprises:

• protruding seating sections formed on an upper surface of the plate so as to protrude upward and directly support the member to be processed;
• and
• a drill insertion groove formed as a recess into the upper surface of at least one of the protruding seating sections so as to face a position at which a heat transfer tube insertion hole is to be drilled in the member,
• groove sections disposed on an upper surface of the plate and between the protruding seating sections that are adjacent to each other, a lower surface of the groove section defined by the upper surface of the plate, the method comprising:
• fixing the member to be processed on an upper surface of the protruding seating sections of the plate;
• drilling the heat transfer tube insertion hole in the member to be processed using the drill unit, wherein the heat transfer tube insertion hole faces the drill insertion groove that is recessed into the upper surface of the protruding seating section;
• and
• supplying coolant during drilling, so that the coolant flows from the drill insertion groove into the groove sections.