Loviisa 1 will undergo a normal refuelling outage and Loviisa 2 an inspection outage that is carried out every four years. The entire outage procedure is estimated to be completed in just over nine weeks.
"In addition to the normal periodic maintenance tasks and refuelling, the most significant work on Loviisa 1 includes replacement of main transformer and generator breaker, inspections and cleaning of two steam generators, and the maintenance of the reactor coolant pumps and the low-pressure turbine in accordance with the maintenance schedule. Moreover, the antimony-free mechanical seals will be changed in three reactor coolant pumps.
We will also continue the modernisation of the low-pressure turbine," says Pertti Salonen, Manager of Loviisa power plant’s Maintenance Unit.
The first antimony-free seals were introduced at the power plant in 2012 after some years of development and testing. Radioactive antimony is a substance normally found in the metal alloy of the mechanical seals of the reactor coolant pumps. During operation, it is released into the primary circuit pipelines and causes approximately half of the radiation dose of the workers at the power plant.
Changing the mechanical seals to antimony-free seals is part of the Loviisa power plant’s continuous improvement to lower the collective radiation dose of the personnel.
At Loviisa 2, the most significant tasks besides the normal periodic maintenance and refuelling are the inspections of the reactor and the primary circuit’s steam generators, the leak testing of the containment, the maintenance of two reactor coolant pumps in accordance with the maintenance schedule, the opening and maintenance of the low- and high-pressure housings, the replacement of the main transformer and generator breaker, and the modernisation of primary circuit pressure control.
In addition, the mechanical seals on two reactor coolant pumps will be replaced with antimony-free types, after which all of the reactor coolant pumps’ seals at the power plant will be antimony-free. A total of 930 contractors are involved in the annual outage and the Loviisa power plant’s ongoing modernisation projects.
