System of grouped and individual control of WWER-1000 reactor control rods

The upgraded SGIU-M system, which has been developed and manufactured by the Czech company SKODA Energo, Controls subsidiary, and has been installed at 3 Ukrainian nuclear power plants, is described. Connected to the control rod drives, the system feeds coils of the drive magnets and coils of the induction sensors of the rod positions. The system evaluates constantly the actual position of each individual rod and displays it in the main and backup control rooms. The control rod position is controlled either in the manual mode based on commands from the operator's console, or in the automatic mode based on commands of the automatic reactor power controller or of the emergency reactor protection system. The system maintains the rods in their actual position unless a command to change it is received. (P.A.)