Annual outages completed at Olkiluoto
The annual outages of Olkiluoto were completed on Friday, 10 June at 04:08 when the Olkiluoto 1 plant unit (OL1) was connected back to the national grid. The annual outages lasted for a total of six weeks.
The annual outage for OL1 started on 8 May. In addition to refuelling, preventive maintenance activities and inspections, the most significant work packages included, for example, the replacement of pumps and valves in the shutdown cooling system, renewal of electrical bushing assemblies in containment, inspection of the reactor pressure vessel bottom, maintenance activities in the service water channel and concreting one of the service water channels as well as replacement of impellers in feedwater pumps, installation of a new recirculation line and a pressure test of the reactor primary circuit.
The annual outage for OL2 consisted of refuelling and various annual preventive maintenance activities, inspections, repairs and tests. The refuelling outage of OL2 started on 24 April and ended on 3 May.
In addition to TVO's own personnel, this year up to 1,300 employees of external contractors took part in the annual outage works. A little less than three hundred experts in special fields took part in the annual outages from abroad.
The refuelling and maintenance outages carried out at the plant units on alternating years are designed to ensure that a good level of production and operability is maintained at the Olkiluoto nuclear power plant at all times.
Teollisuuden Voima Oyj has produced electricity for its shareholders, Finnish industrial and energy companies, safely and reliably for over 40 years. Nuclear electricity generated at TVO's Olkiluoto plant covers approximately one sixth, increasing to nearly one third once Olkiluoto 3 is completed, of the electricity consumption in Finland. Climate-friendly nuclear electricity not only benefits society but also reduces the environmental impact of energy production. Moreover, the world's first final disposal facility for spent nuclear fuel is under construction in Olkiluoto.