Both units at Fortum’s Loviisa nuclear power plant are back in production after completion of their annual outages. Unit 2 had a short annual outage that lasted 23 days and ended on 27 August. The extensive four-year outage of Unit 1 lasted 39 days and ended on 9 October.
The annual outage of Unit 2 was delayed by 2.5 days. The reason for the delay was the repair work of the fault detected during periodic inspections on the secondary circuit and the additional time required for valve testing. The annual outage of Unit 1 was initially extended by five days due to delays in pre-planned inspection and maintenance work and repairs to the diesel generator. In addition, the annual outage was delayed by another four days when a technical fault was detected in one of the control rods during tests carried out during plant start-up on Friday, 4 October.
"The ramp-up of the plant was suspended in order to determine the cause of the fault and take the necessary corrective measures. The fault was quickly located and the mechanism of the control rod in question was replaced in its entirety. After this, we were able to start up the plant and carry out the necessary tests again," says Sasu Valkamo, Senior Vice President of Loviisa power plant.
”Safety is our guiding star also in annual outage. Annual outages can sometimes uncover maintenance needs or defects that weren't anticipated, potentially delaying their completion. The equipment and systems are carefully inspected before the plant unit is returned to the network after annual outage”, Valkamo says.
During the annual outages, about a quarter of the fuel in both reactors is replaced. In addition to refuelling, both units underwent various preventive maintenance, inspections, repairs and tests.
”During the annual outage the first batch of Westinghouse Electric Company nuclear fuel has been loaded into Unit 2 in August. Cooperation with Westinghouse guarantees a reliable Western alternative for fuel deliveries to the Loviisa power plant”, Valkamo says.
In addition to the approximately 660 permanent employees at the power plant, approximately 700 employees of contractor companies participated in the annual outage.
