ŠKODA PRAHA a.s

The project of construction of nuclear power plants was launched in Czechoslovakia in 1978. Due to experienced staff, ŠKODA PRAHA a.s. was assigned as the general contractor for the technological part of the Czechoslovak nuclear power plants. For this reason, SKODA PRAHA a.s., added to its team of experts new employees, in order to take care of design, quality inspection, equipment testing and operation of nuclear power plants, and also other organizational staff. Because of the political system at that time, the designers of the Czechoslovak nuclear power stations were forced to build these plants equipped with the Soviet type technological equipment of the primary circuit. At that time, it was the WER reactor. From this reason it was necessary to modernize this relatively outdated equipment, which had to be provided with the assistance of all firms participating in deliveries of equipment for the nuclear program. SKODA PRAHA a.s., also took part in hundreds of design modifications, and thus to a significant extent, contributed to the improvement of the technical properties of power generating units with WER reactors. During development of the new procedures for conducting cleaning operations, functional tests of systems, and unit-wide staged testing conducted in putting into operation the Jaslovske Bohunice nuclear power station in Slovakia and the Dukovany nuclear power station in the Czech Republic, ŠKODA PRAHA a.s. also came out with its own \\\\\\\"know-how\\\\\\\" for the WER 440 type of reactor.

Currently ŠKODA PRAHA a.s. is the main contractor for the technological part of the construction of the Temelin nuclear power station in the Czech Republic and acts in the same position for the construction of the Mochovce nuclear power station in the Slovak Republic.

Construction of the NPP Temelin began in 1986, and by a decision of the Czech government, the originally planned construction of 4 WER 1000 type units was reduced to 2 units. As mentioned previously, the initial design for the project with two WER 1000 reactors was the Russian design for a nuclear unit of a series of unified WER 1000 nuclear units, which are currently operating in some countries of the Commonwealth of Independent States (Rovno NPP, Zaporozi NPP, Balakovo NPP, etc.) This initial design was modified between 1984 -1988 by the Czechoslovak general designer Energoprojekt Praha in cooperation with the general contractor for the technological equipment, which was SKODA PRAHA a.s., and ATEP Moscow -the Russian design organization, so that technological equipment of Czechoslovak origin could be used. Based on a decision of the investor, i.e. CEZ (Czech utilities), significant changes in the design were adopted in order to increase nuclear safety. The most significant changes were related to the control system, reactor core itself including change of its regulation and control, electric technological part and electric cabling, and also into air-conduction systems of fire protection in the primary circuit of the NPP. Furthermore, some of the machines and equipment were replaced.

ŠKODA PRAHA a.s. modernized the control systems. As mentioned previously, the structure of the original I&C was based on the Russian-type design, and a design change was made in order to allow wider usage of the Czechoslovak automation techniques. Aiming to increase the nuclear safety of both units and also to increase the economic efficiency of the production of electrical energy, a tender for I&C delivery was announced, in which the U.S. company Westinghouse was selected.

Automatic Systems for the Control of Technological Processes for both units is divided into four operational sets. Another operational set (the off-unit Central Information System) serves for both units and helps to ensure communication with the computer systems of the other operational sets. ŠKODA PRAHA a.s, became the final contractor of I&C, when it concluded a contract for delivery of I&C equipment for both units of the NPP, with WEC as the subcontractor, in 1993. So, it is possible to state that in the case of the I&C modernization for both units, the original equipment is being completely replaced and substituted with distributed digital measurement and control technology. Only one sub-system of the original system remained without hardware and software change, which is the automated diagnostics system of the secondary circuit\\\\\\\'s technological equipment. Condensers with titanium pipes were first time used in the Czech Republic for the construction of the NPP Temelin. Using titanium markedly, the service life of this equipment can be extended and has a positive influence on both the chemical composition of the condensate and the regime of the transfer of heat. By mastering their own pipe-fitting technology, the employees of ŠKODA PRAHA a.s. have significantly enriched their technological expertise. In the aforementioned scope, it is obvious that these equipment modifications comply with conditions for the realization of a modern unit of the WER 1000 type which fulfills the demanding IAEA requirements in terms of nuclear safety and efficiency of operation.

Documentation of as-built technological units is by means of computer controlled videophotogrammetry. As a result of this method, an archive of digital photos is created, which supported by a simple browser, enables moving in the scanned area, including the coordinate data of any point on the photos. In addition, the archive can be also used for the subsequent creation of 3D computer model or for drawing common designs. This aforesaid technology is supported by PDMS and DIGI AB software, developed by CAD CENTRE Cambridge, UK. Compared to the manual data processing, using this method enables more accuracy, quality and work efficiency, which has a favorable impact to the final price.

Besides these contracts, ŠKODA PRAHA a.s. has been significantly involved in the modernization to increase nuclear safety at the Mochovce nuclear power station in the Slovak Republic, which is also equipped with Russian twin VVER 213 reactors with outputs of 2x 440 MW. The first Modernized Unit of NPP Mochovce was successfully put into operation in July 1998. Among other contracts completed further belong the modernization of Dukovany nuclear power station in the Czech Republic and the Jaslovské Bohunice nuclear power station in the Slovak Republic. The following is an overview of nuclear power stations constructed in the territory of the former Czechoslovakia, in which ŠKODA PRAHA a.s. took part or is still taking part:
- Jaslovske Bohunice, Slovakia 4 x 440 MW 1985
- Dukovany, Czech Republic 4 x 440 MW 1987
- Mochovce, Slovakia 4 x 440 MW underway
- Temelin, Czech Republic 2 x 1000 MW underway