The Temelín Nuclear Power Station

Elektrárna Temelín-1-ajThe Temelín Nuclear Power Plant is situated approximately 24 km from České Budějovice and 5 km from Týn nad Vltavou. Electricity is generated in two production units with VVER 1000 Type V 320 pressurised-water reactors. Process water is drawn from the Hněvkovice reservoir on the Vltava River; it was built as a part of the power plant project. The required quality of water is guaranteed by waste water treatment stations situated on the upper course of the Vltava River, namely at Větřní, Český Krumlov and České Budějovice. In spring 2003, the Temelín Nuclear Power Plant, with its 2,000 MW of installed capacity, became the largest power resource in the Czech Republic.

The investment design of the construction was issued in February 1979, while the initial power plant design was developed by Energoprojekt Prague in 1985, and construction of operating units was launched in 1987. After November 1989, under new political and economic conditions, it was decided to reduce the number of production units to only two. In the course of a period of great uncertainty, the reduced but technologically updated construction was completed, and in July 2000 the reactor was loaded. On 21 December 2000, the 1st production unit realised the first supply of electricity.

ETE - virtual tourStroll through the Nuclear power plant Temelín!

The technological schema of the power plant corresponds to the latest world parameters. The entire primary circuit including the nuclear reactor, four steam-generators, circulation pumps, etc. is located in a fully pressurised reinforced concrete containment facility hermetically enclosed in a protection envelope. A turbo-generator developing 1,000 MW output is situated in the secondary circuit. The reactor core contains 163 fuel assemblies, each with 312 fuel rods, and 61 regulating rods. Each steam-generator produces 1,470 tons of steam per hour with an output pressure of 6.3 MPa and temperature 278.5°C. The turbine works at 3,000 revolutions per minute.

Our nuclear power plant’s pressurised-water reactors are fuelled by UO2, uranium dioxide enriched by an average of 3.5% of the fission isotope U235. The fuel for the Temelín Nuclear Power Plant is supplied by the Westinghouse Company (USA), which also supplied the new instrumentation and control system.

Thermal energy released by the controlled fission of the uranium U235 nuclei is removed from the reactor core by the demineralised water of the primary circuit to four heat exchangers – steam-generators. Heat generation in the reactor can be regulated by control rods, and by changing the boron concentration in the coolant. The cooling water, sealed under high pressure in the primary reactor circuit, circulates by means of four cooling loops with steam-generators and pumps. In the steam-generators, water of the closed primary circuit passes its heat into the steam turbine circuit, i.e. the secondary circuit.

Elektrárna Temelín-2-ajThe secondary circuit is also closed and filled with demineralised water. In the steam-generators, the secondary circuit water turns into steam which is then carried to the turbine. There are two such turbines in the power plant, each powering a 1,000 MW alternator which generates electricity with 24 kV voltage. The entire turbine set for the Temelín Nuclear Power Plant was made by Škoda Pilsen. Downstream from the turbine, the steam condenses back into water on the cool surface of titanium pipes in three condensers. Condensation heat is then removed from the steam by the cool water of the tertiary coolant circuit flowing through the condenser pipes. The circuit is then led out into four cooling towers where the tertiary circuit water is recooled by natural air flow. What remains and is released in the atmosphere is pure water vapor.

An important part of the safety operation is formed by a high professional level of personnel. A full-range simulator of the unit control room situated in the Temelín Nuclear Power Plant has been built for the training of personnel. This exact mathematical model of the reactor, which imitates the primary and secondary circuit’s behavior, is located in a precise copy of the control hall of the reactor unit.

Many alterations to the original design course of the Temelín Nuclear Power Plant construction have been incorporated since 1990. These alterations were intended to raise the power plant’s reliability and safety to Western European standards. After 1991, 21 in-service inspections were carried out by International Atomic Energy Agency inspectors in the power plant, and recommendations focused on raising the reliability and safety of the power plant have been implemented in the course of its construction and commissioning. Trial operation of the 1st production unit was started on 10 June 2002. The 2nd production unit started its trial operation on 18 April 2003. In 2003, the Temelín Nuclear Power Plant produced 12.11 TWh of electricity with 13.4 TWh planned for production in 2004. By putting both production units into trial operation, together with the Dukovany Nuclear Power Plant, the share of the ČEZ Joint-Stock Company’s nuclear resources in the country’s electricity production increased to 42.5% in 2003.

Detailed information about the Temelín Nuclear Power Plant can be obtained in the information centre situated in the reconstructed Vysoký Hrádek Castle.

Temelín Nuclear Power Plant
Installed capacity 2 x 1,055 MW
Commissioned in 2002
Reactor Type VVER 1000




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