The Dukovany NPP - Implementation of measures for automatic detection and protection against OPC

I&C Energo has signed a contract for the implementation of a public contract for the development of a system which will automatically detect OPC - Open Phase Condition (phase interruption on power lines outside the plant or directly at selected internal consumption points at the Dukovany NPP). Proper detection of the occurrence of OPC leads to the elimination of nuclear safety risks.

Three-level protection will be built to ensure proper detection of the OPC and, if necessary, timely and selective disconnection of internal consumption from the OPC as close as possible to its occurrence.

The first level of protection will be ensured by detection and disconnection at the level of unit and reserve transformers. The second level of protection will be at the R6kV Category III feeders (working and reserve feeders).

The third level of protection against OPC will be ensuring the quality of Category II secured power supply in case of OPC in the higher network. For this purpose, a new logic will be designed which will be activated only if the first two levels are not successful in disconnecting from the OPC.

Modifications will have been made in 17 sub-units by 2031.