Reactor Vessel Internals (RVI)

Mitsubishi completed the world's first all-in-one piece replacement of the upper and lower reactor internals at Ikata Unit 1 in Japan. This innovative replacement process enables the extraction of the existing reactor internals from the reactor vessel and containment without cutting into smaller pieces. This in turn enables the replacement to be achieved in a shorter time duration with significantly reduced worker dosage. Since Ikata 1, MHI has performed 3 additional RVI replacements at Japanese plants.