Safe Nuclear Power
Fennovoima is responsible for the safety and safe operation of its nuclear power plant during the entire life cycle of the power plant.
In the plant design, safety takes precedence over everything else. Due to the advanced technical solutions and multiple safety systems, in today’s modern nuclear power plants severe the possibility of a severe accident occurs less than once in a million years.
However, since the possibility of failures and accidents can never be completely ruled out, the modern power plant designs, such as the AES-2006, include several safety systems which prevent operational disturbances or human failures and errors developing into problems.
The AES-2006 nuclear power plant design is based on the defence-in-depth principle, which means that the power plant is secured with successive and independent safety systems, which are designed to be many times higher than the normal operational need is. In case of a failure of one safety system, the power plant has several independent back-up systems, preventing any major damage from taking place. With all the safety features it is extremely unlikely that an incident progress to a severe accident as it would require simultaneous deceiving of several independent safety systems.
The defence-in-depth approach can also be seen in the design of the power plant structures. For instance, the reactor core is covered with several consecutive protective shielding, each of which alone is capable of retaining any radioactive material within them. The power plant’s electricity supply has been secured as the plant has its own diesel aggregates, own reserve power plant as well as multiple connections to the national grid. Also rising seawater levels and pack ice have been prepared for in the design of the plant.
The AES-2006 light-water reactor has also several inherent safety features. For example the supply of cooling water is secured with own clean water reserve tanks for a long time. Even if for some reason the nuclear power plant's cooling ceases and the cooling water around the reactor core begins to boil, the reactor shuts down naturally when the cooling water is boiled out, as the chain reaction in the fuel is no longer able to continue.