Construction of the Olkiluoto 3 reactor now continues inside. The 'roof' of the steel liner of the inner reactor containment - the dome section - was erected in place on September 6 and work now continues under it.
With the dome section of the steel liner erected in position, the reactor building now stands in its final shape and height of almost 60 metres. The dome weighs ca. 200 tons, is 14 metres long and has a diameter of 47 metres. Welding work on the dome will go on for a few weeks before the containment is completely weather tight. Working conditions will improve considerably under the roof, says OL3 Project Manager Jouni Silvennoinen.
The polar crane for the reactor building and the large "door", or cover, of the equipment hatch were also lifted and erected in position towards the end of the summer. The polar crane, with a lifting capacity of 32 tons, is used in the annual outages to lift the concrete slabs protecting the reactor building pools, the reactor pressure vessel head and the pressure vessel internals. The cover of the equipment hatch is eight metres in diameter, and the hatch is used to transfer the large components of the reactor coolant system, such as the reactor pressure vessel and the steam generators, in and out of the reactor building. The equipment hatch is kept closed when the plant unit is in operation and is only opened during the annual outages if large components need to be transferred.
Work has progressed also in the turbine island. The last major building areas are nearing completion, and the testing and commissioning of the first systems is becoming a near future target.
Manpower on the OL3 site now numbers about 4300 and is still on the increase. More than 15000 workers have so far attended the site induction training. In the past 12 months alone, more than 5000 people have been trained in the OL3 project.