Czechia's Temelín replaces main water-supply valve for cooling tower

At the Temelín Nuclear Power Plant, the main shutoff valve supplying water to a cooling tower has been replaced. This is the first phase of a planned modernization of the cooling towers. Energy sector staff will begin the main part of the project in 2029. Temelín spokesperson Marek Sviták informed journalists of the work in a press release today.

Among other things, replacing the valve will allow for longer and more thorough inspections of the cooling tower’s interior. Until now, energy sector staff had to complete them within 22 days. The inspection period can now be extended thanks to a special butterfly valve that technicians installed on the circulating cooling water pipeline. “Unlike the original, the new valve is sealed on both sides. This gives us more time to carry out inspections, maintenance and investment projects. The cooling towers are due to undergo extensive modernization in the coming years, during which we will replace their internal components,” said Jan Kruml, director of the Temelín Nuclear Power Plant.

Energy sector staff plan to begin modernizing the cooling towers’ internal components in 2029. The work will primarily involve replacing nearly 111.000 plastic cooling blocks, which ensure the most efficient cooling of the water in each tower.

The recently completed replacement of the 23-tonne valve, which has a diameter of 3.4 meters, is preparation for the planned major project. “The new valves will allow us to speed up the demanding modernization of the cooling towers, as well as the associated increase in efficiency and reduction in water consumption, by six years. This is another example of how we continually improve the plant so that we can operate it safely and efficiently for more than 60 years,” said Bohdan Zronek, a member of ČEZ’s board of directors and director of its nuclear energy division.

Replacing the valve took 20 days. Technicians used a special crane to lift it from a depth of five meters. “We took great care when connecting the new valve to the existing pipeline. It is secured with flange joints, and we had to tighten 76 nuts on each side,” said project manager Miloš Mojha.

The new valve has so far been installed on the system at Unit 1. Energy sector staff will modify the same system at the second generating unit next year.

The Temelín plant, one of two nuclear power plants in Czechia, supplies around one-fifth of the country’s electricity consumption. It has generated 14 terawatt-hours of electricity since the beginning of the year.