Primary side chemistry online monitoring at the Kozloduy Nuclear Power Plant (Units 5 and 6)

The Kozloduy Nuclear Power Plant (KNPP) is a Russian designed 1000 megawatt pressurized water VVER located in northern Bulgaria on the Danube River near the town of Kozloduy. A Primary Chemistry System (PCS) Online Monitoring (OLM) project was part of a Modernization Program being implemented at the Kozloduy Nuclear Power Plant (Units 5 and 6). Online monitoring of the plant's system chemistry can help pinpoint contaminant ingress and allow the rapid implementation of corrective actions. This allows plant personnel to operate the plant systems more accurately. Control of reactor coolant chemistry is enhanced by online measurement of species controlled within specified ranges. This is essential to the KNPP engineering and operations management for maintaining and protecting the integrity of power plant system components and improving plant availability. Westinghouse was awarded the contract by KNPP to provide this system on a turn-key basis. This included the design and fabrication of the primary side chemistry system, installation, testing (factory and site), training and follow-on support. The Westinghouse Primary Chemistry System is a state-of-the-art primary chemistry monitoring system that takes data in real-time of sixteen (16) essential chemistry parameters being continuously monitored on the primary side from three different sample streams. The chemistry conditions are provided within minutes of analysis to the reactor operators and the chemistry staff. The operator interface components are located in a chemistry laboratory to minimize radiation exposure and make access to the operator interface more convenient. The modules were constructed such that no additional building construction work will be required to move the equipment into the agreed upon locations by Kozloduy NPP and Westinghouse. Interlocks were designed into the system to protect personnel in the area and personnel working in the panel and to protect the equipment from damage. The system was also designed to minimize personnel radioactive exposure and to minimize radioactive wastes. The specific location of the Primary Side Chemistry System panels, their interconnections and interfaces with the overall plant computer system and the Operator interfaces in the Main Control Room make this project unique and first-of-a-kind. This paper will include a discussion on KNPP's operating experiences with the systems since both plant unit systems were commissioned in 2008. (author)