The service life of the Hanhikivi-1 nuclear power plant will be at least 60 years. To keep the plant in good condition throughout its life, there will be frequent inspections and maintenance work.
The power plant’s maintenance program will include condition monitoring and preventive maintenance of structures and components. During operation parts of the plant will also be renovated according to the best available knowledge to achieve an even higher safety level.
Some maintenance work can only be performed during annual outages, when the plant is shut down. During these outages some of the fuel will be replaced and necessary inspections and maintenance will be carried out.
The annual outages will be intensive periods of work. They will last between two weeks and one month. During those times, hundreds of external workers may be busy around the clock at the plant. In addition to actual maintenance crew and inspectors, many people will be needed for various support functions such as cleaning and radiation protection.
During short outages, fuel will be replaced and only the most important inspection and maintenance work will be performed. If possible, any extensive modifications and repair work will be scheduled for longer outages. These may include removing reactor internals or inspecting the reactor pressure vessel.
Target schedules for annual outages have usually been achieved at Finnish nuclear power plants, which has kept them among the world’s best-performing plants.