Construction of the Olkiluoto 3 nuclear power plant in Finland has reached a new milestone with the installation of the reactor pressure vessel in the reactor building.

According to Areva, the 420 ton component was first transported from its storage hangar to just outside the reactor containment, and then lifted into the reactor building before its final vertical introduction into the reactor pit.

The operation came after the completion of the reactor dome in September 2009 and will “kick off a flurry of installation activities for heavy nuclear components”, says Areva. The reactor pressure vessel measures 10.6 m in height and 5.3 m in diameter and was installed using the permanent polar crane and a large movable crane.

Areva is building the EPR project in a joint venture with Siemens. The two companies are in dispute with the plant’s owner, Finnish utility TVO, over project delays.

Installation and start-up testing of electro-mechanical systems at the project site will also now begin. Areva and Siemens said in early June that fuel loading would start at the end of 2012.

Total manpower on site is now 3900.