Inspection hole plug

摘要

[Problem to be Solved] To easily perform assembly at the time of plugging an inspection hole. [Solution] An inspection hole plug 1 that plugs an inspection hole of an outer casing 136 surrounding a tube bundle in a steam generator includes: a base 2 fixed to the outer casing 136 and having an opening 21 that serves as the inspection hole; a fitting member 3 that plugs the opening 21 of the base 2; a fitting unit 4 that guides rotational movement of the fitting member 3 in a circumferential direction along an inner peripheral edge of the opening 21 of the base 2 and restricts the rotational movement by an axial movement of the fitting member 3 parallel to a central axis R of the rotational movement to fit the inner peripheral edge of the opening 21 of the base 2 and an outer peripheral edge of the fitting member 3 to each other; a holding member 5 into which a shaft portion 31 extending from the fitting member 3 along the axial direction is inserted and that is provided to be capable of abutting on the base 2; and a fastening member 6 that is screwed onto the shaft portion 31 of the fitting member 3 and holds the fitting member 3 at a position axially moved by fastening thereof with the holding member 5 abutting on the base 2.