The new monitoring system has been installed by Doosan Škoda Power experts for the turbine at unit 2 of the Temelín NPP in the Czech Republic. The system measures the rotation time of the blades to the nearest billionth of a second. This one of many actions being taken to ensure the two Temelín units can operate for 60 years. The work is being undertaken during a two-month scheduled maintenance outage which began in mid-February.
Czech utility ČEZ is to invest CZK3.8bn ($181m) this year to upgrade the Temelín NPP where two VVER-1000 units have been in operation since 2000 and 2002. ČEZ has already invested almost CZK38bn in Temelín and work planned for this year includes completing the transition to a longer fuel cycle, continued modernisation of the control system and expanding the use of artificial intelligence and modern control methods.
During the current outage at unit 2, workers will complete some 18,000 tasks, including 80 investment events. Including suppliers, approximately 1,000 people will be involved in the shutdown. A two-month shutdown for unit 1 will begin in mid-October.
So far 16 special sensors have been installed by Doosan Škoda Power technicians on each of unit 2’s three low-pressure rotors of the second production unit. It is about the modernisation of the turbine blade monitoring system, which we have been using for ten years,” said Temelín Director Petr Měšťan. “Thanks to special sensors, we can monitor, even during operation, whether the vibration of the blades of the last stage impellers [rotating wheel discs that hold the turbine blades] is within the necessary limits.”
The sensors measure the rotation time of each blade over a metre long to the nearest billionth of a second. Acceleration or delay in the rotation of the blade signals its shaking. “Although Temelín is a relatively young power plant, new technologies are always being developed. And if it makes sense to us from the point of view of efficiency and safety, we use them to the maximum extent. This applies to turbine diagnostics as well as a number of other devices,” said Bohdan Zronek, ČEZ board member and Director of the Nuclear Energy Division.
