Olkiluoto 1 reactor begins extended maintenance shutdown

The Olkiluoto 1 nuclear reactor in Finland will begin a 55-day maintenance outage on Sunday, operator Teollisuuden Voima (TVO) announced. The shutdown, significantly longer than usual, follows the completion of Olkiluoto 2’s annual maintenance on Friday.

TVO stated that the extended duration of Olkiluoto 1’s maintenance is due to several major projects, including repairs to the turbine condenser’s front chamber, renewal of reactor automation systems, high-pressure turbine servicing, replacement of electrical penetrations in the containment building, and a primary circuit pressure test. The work is scheduled to conclude on June 13.

Olkiluoto 2’s 10-day maintenance, which ended Friday, included fuel replacement and extensive inspections. TVO had previously detected indications of a minor fuel issue in the unit, but investigations during the shutdown confirmed no damaged fuel elements were present.

The Olkiluoto plant, which supplies roughly 30 percent of Finland’s electricity, consists of three reactors. This spring, two of the units are undergoing maintenance.