PURPOSE: To eliminate sodium adhering to the inner surface of component penetration hole efficiently without damaging the inner surface of penetration hole.

CONSTITUTION: On a door valve 3 fixed on a shield plug 1, a container vessel 11 is placed. In this container vessel 11, an extension tube 13 reaching the component penetration part 2 is inserted air-tightly by way of a shaft seal 8. To the extension tube 13, an operation part 14 is connected at the upper part and sodium elimination part 12 is connected at the lower part. To the extension part 13 and the container vessel 11, a gas system nozzle 15 is connected. In the sodium elimination part 12, a sealing plate to sweep off sodium adhering to the inner surface of the component penetration hole 2 and an endoscope to observe the adhesion state and elimination state of sodium are placed.