The passive safety features are supplemented by a comprehensive range of automated 'active safety features.' The reliability of these features is based on their multiple redundancy, and on the fact that they operate independently of each other in separate locations.

For example, each nuclear facility has its own power supply. And the reactor cooling systems are designed to ensure that the heat generated by the reactor can be reliably removed under any operating conditions-even in the event of a very unlikely malfunction, such as a breach of a primary coolant line. The electronic reactor protection system is the 'nervous system' controlling all active safety systems. It constantly monitors and compares all the key operating parameters of the plant. Thus, if a parameter reaches a limit value, the reactor protection system automatically triggers the necessary protection measures without any need for input from plant operating personnel. For example, if necessary, the protection system may initiate a rapid shutdown and aftercooling procedure.


Cross-sectional view of a reactor building

Schematic of the physically separate locations of key safety systems

Internal power supply of a nuclear power plant