Czech Case Studies (International Case Study on Organization and Detailed Technical Aspects of NPP Outage Decontamination)

The Dukovany nuclear power plant was put into operation in 1985-1987. These are 4 units of WWER-440 reactor type. The specific feature of the WWER-440 design is six reactor cooling loops, that means each reactor is connected to six circulating pumps and six steam generators (SGs). Equipment DEKOZ PG, as shown, was designed for the chemical decontamination of the SGs of the plant. It separates the primary part of SG from the remaining part of the reactor cooling loop, serves for filling and draining the decontamination solutions into and from SG separated section and ensures also their circulation. Used decontamination solutions are drained by compressed air from the SG into the liquid waste draining lines. The device does not allow the recovery of the used decontamination solutions.