11. 5. 2020

The Temelín Unit 1 restored electricity production, despite the coronavirus, the technicians kept to the planned deadlines

This afternoon Temelín Unit 1 started producing electricity. The operators shut it down for refueling on March 13. The outage lasted for 59 days and the technicians e.g. replaced a quarter of the fuel, inspected the turbine and safety systems during it. Due to the coronavirus, they had to adjust the timetable before it started, but in the final, they kept the deadlines, despite many health-protective measures. Together with the Dukovany power plant, all six nuclear units are currently in operation.

A part of the employees are working from home, all those at the power plant mandatory wearing the cloth face masks, there was the need to ensure border crossings for foreign suppliers, measuring body temperatures, ubiquitous disinfection, change of shift mode. These are just examples of how one of the Temelín plant's most demanding outages in its 20-year history looked like.

"The decision fundamentally not to change the outage, i.e. to ensure the refueling and all checks and important activities in a situation of unclear development, with measures against the coronavirus becoming increasingly strict, was right but extremely difficult for the power plant's Director. All the staff proved to be professional and responsible as far as possible,”

says Bohdan Zronek, member of the ČEZ Board of directors and Director of the Nuclear Energy Division.

Temelín's Unit 1 began to produce electricity again at 50 % of the reactor rated power. Currently, the Temelín plant's operating personnel are increasing the Unit output. At 80 % of reactor rated power, additional the tests will be run, during which the technicians will verify the power distribution in the reactor core.

"We are also closely monitoring other technologies, such as the turbine generator, where a large range of activities was carried out during the outage. And, at its operation, tenths of a millimeter are deciding. The first days will show us, whether it will be necessary to tune the setting of the turbine generator,"

added Jan Kruml, director of Temelín NPP.

Abroad, the coronavirus pandemic caused extensions of outages at some power plants.

“Safety and Health are always crucial for us. We were prepared to adjust the scope of work and the level of preventive measures operationally. This was not necessary in the end, even though we are still ready for any changes,”

says Bohdan Zronek.

During the outage, the technicians replaced 42 out of 163 fuel assemblies in the reactor. Important outage activities included inspections of safety systems, of the turbine, or reactor pressure vessel inspection. The latter confirmed that the reactor pressure vessel is in very good condition and allows safe operation for decades to come. Just several weeks took the generator switch replacement. A device worth several hundreds of millions of crowns separates the power plant from the transmission system. The electricity supply to the transmission system also depends on its condition. The replacement was part of the regular modernization of the plant.

Along with Dukovany, all six nuclear blocks are currently in operation. The Temelín Unit 2 outage is planned to start on June 12.