CCI’s Modern Technology Goes the Distance at Dukovany

Located in the Czech Republic southeast of the town of Tøebíè, the Dukovany Power Station boasts 1,760 MW of installed power, making it the second-largest power plant in the country. After CCI’s installation of several pressurizer relief valves more than five years ago, the plant reports that the valves continue to demonstrate trouble-free performance and superior control.

The Dukovany power plant comprises two double units, including four VVER 440 pressurized-water reactors that were commissioned in the mid-1980s. These four VVER units cool from the Jihlava River . Operating mainly as a base-load station, the nuclear power station annually supplies over 20% of the total electricity generated in the Czech Republic . In 18 years of operation, the Dukovany plant generated over 220 TW hours of electricity.

In 1997, CCI-AG in Winterthur, Switzerland designed and manufactured upgraded pressurizer relief valves used for overpressure protection of all four Dukovany reactor coolant systems. Installed five years ago, these advanced pilot-operated SV50 relief valves have proven to enhance valve reliability and provide consistent, leak-tight shutoff.

Demonstrating outstanding durability and dependability, these valves are tested once per year during unit shutdown at a primary circuit pressure level of 70 bar. Thus far, the valves have consistently operated without problems.

In fact, CCI-AG’s Tobias Zieger recently paid a visit to the Dukovany site, where he verified that the valves continue to perform exceptionally well. Using infrared photography, Mr. Zieger studied the valves’ thermal distribution during operation and confirmed that high temperature is isolated to the valve inlet and that the unwetted parts remain cool, meaning that the valve is tight.

During this site visit, Dukovany’s senior technical manager Mr. Charvat expressed his satisfaction with the SV50 relief valves and mentioned providing a positive reference to a nuclear station outside the Czech Republic that is considering CCI’s SV50 valves. Mr. Charvat also remarked that the annual maintenance and testing of the upgraded valves, performed by local technicians, has proven to be truly user friendly and problem free. Due to the excellent training offered by CCI, local personnel are able to perform any necessary maintenance without requiring CCI’s involvement. These technicians were taught by CCI’s valve experts and received maintenance certification after their week-long training at CCI’s facility in Winterthur, Switzerland .

Extending his appreciation to Mr. Zieger, Mr. Charvat offered the highest level of recognition – an invitation to return for discussion regarding applications where CCI can further contribute to the Dukovany Nuclear Power Station’s success.

European governments and the U.S. Department of Energy are assisting in the modernization of VVER facilities found throughout Eastern Europe, which are similar in design to Western Pressurized Water Reactors. CCI has played a significant role in upgrading these Russian VVER nuclear power reactors to Western standards, and use of CCI’s SV50 pressurizer relief valves is on the rise as these advanced valves continue to demonstrate their longevity and value in plants like Dukovany. Pressurized Water Reactors in the U.S. , Western Europe, and South Africa are upgrading to these valves. CCI’s technology also includes primary over-pressure protection safety valves, main steam safety valves, system medium-actuated main steam isolation valves, Herion pilot-control solenoid valves, and DRAG® control valves, which are some examples of other CCI solutions being used to modernize VVERs.

Published in SOLUTIONS Spring 2004