European Nuclear Society
e-news Issue 9 Summer 2005
http://www.euronuclear.org/e-news/e-news-9/cez.htm

2005 ANNIVERSARY
20 YEARS OF DUKOVANY NPP IN THE CZECH REPUBLIC

Attachment to Press Release, information material

Twenty years ago Unit 1 of Dukovany NPP achieved 100% of rated power

This year the Czech nuclear industry celebrates the twenty years of the day when the first of the four Dukovany’s nuclear reactors was put into operation. The Nuclear Power Plant (NPP) has been operated successfully since its commissioning, as we can infer from the various national and international assessment studies. In this period of anniversary, we ought to remember a few significant dates.

In the first year of operation, Dukovany NPP’s Unit 1 produced 2.4 billion KWh (TWh) and reached already 59.7 billion KWh (TWh)by the end of 2004. Such amount of electricity would be sufficient to supply all Czech households at their 2004 consumption level for over 50 months.

In 2004 the Czech Republic’s total electricity generation amounted to 84.3 billion KWh (TWh) and the share of Dukovany NPP’s four Units was 16.2%. Together with the second nuclear power plant of the country, Temelín NPP, the nuclear share in total electricity production in the CR was 31.2%

About Dukovany NPP

History
The history of the Dukovany NPP dates back to 1970 when the former Czechoslovakia and USSR signed an intergovernmental agreement on the construction of two 1760 MW-nuclear power plants: one at Jaslovské Bohunice in Slovakia and the second at Dukovany in South Moravia. The Dukovany site was chosen because of the nearby pumping hydro power plant in Dalesice with the balancing reservoir Mohelno, both located on the Jihlava River. The hydro system serves as a reservoir of cooling water for the nuclear power plant.

Construction started in spring 1974
The construction of the NPP started in April 1974 but works were suspended between 1976 and 1978. During this period, the design was modified to fit the updated model of the VVER 440 –V213. It was a very successful model of PWR reactors based on previous Russian operating experience. The construction resumed in late July 1978. The Czech national companies played a dominant role in the construction of the NPP, and the manufacture and montage of the equipment. 85% of all equipment was made in the Czechoslovakia incl. reactors, steam-generators, turbines, etc. Companies such as Skoda, Vitkovice and Kralovopolska were the main suppliers.

In full capacity in 1997
The pressure vessel was fitted in the structure of Unit 1 in November 1982 and the first criticality was achieved in February 1985. Full power was achieved one month later. Next three Units were subsequently commissioned in 1986 and 1987. Dukovany NPP reached its full power of 1760 MW in July 1987. From the beginning of its operation in 1985 to the end of 2004 the nuclear power plant produced more than 238 billion KWh of electricity.

Nowadays
Over the whole period of its existence the Dukovany nuclear power plant has featured high reliability, low rate of failures and high safety. The major asset of the NPP is its contribution to fighting climate change. It saves 17 million tons of CO2 a year that would be otherwise released into the atmosphere by burning 11 million tons of coal in thermal power plants.

Nuclear is the cheapest power source
Nuclear reactors are operated at full power in the long term for technical and economic reasons. Refuelling is performed once a year and during this process approximately one fifth of the fuel in the reactor is replaced. Since 1985 Dukovany NPP has changed its fuel cycle from a 3-year cycle to a 5-year cycle and such a change has reduced the volume of spent nuclear fuel by 5.3 tons per Unit and per year. Such a modification has a significant economic impact, resulting in cutting down fuel and storage costs. By the end of 2004, Dukovany NPP had already saved more than 6 billion CZK.

The advanced nuclear fuel with a 5-year cycle was used at Dukovany NPP for the first time in 2003 in Unit 2 and later on in Units 1 and 4. This year, during the refuelling of Unit 3, a completely new type of fuel is used for the first time. This new fuel is characterised by reduction of Uranium 235 enrichment from 4.38% to 4.25% while maintaining the same fuel assembly performance. Full transition of all four Dukovany Units to the 5-year cycle will be accomplished by 2008. The Russian company TVEL from Elektrostal factory (near Moscow) is a fuel supplier for Dukovany NPP and the contract for the advanced fuel is valid until 2011.

Nuclear Safety
Nuclear safety is a basic requirement of the Dukovany NPP operation. It consists of a set of technical and organisational requirements, aiming to ensure that the nuclear fission process and corresponding release of radioactivity remain under control whatever the conditions. Apart from nuclear safety, the power plant staff closely supervises radiation safety. Radiation protection of human beings and of the environment is ensured by protecting them against consequences of ionising radiation and contact with radioactive substances.

Trained and highly qualified personnel
The outstanding operation of Dukovany NPP is not only a result of designers, builders and manufacturers’ efforts. A highly trained and qualified operation personnel is working at Dukovany NPP. Every employee has to successfully go through health examinations and regularly repeated psychological tests. Provided that he/she fulfils all general qualification requirements, he/she is trained in the Training Centre for the job. The most specific training is provided for the licensed operators in main control rooms whose expertise is examined every two years by a state examination committee of top experts in the nuclear sphere. All in all 17% of workers have trade and craft qualification, 49% high school qualification and 33% university education.

Among the best performers
According to expert assessments, Dukovany NPP belongs to the best performers among nuclear power plants worldwide. With regard to a number of parameters and indicators, Dukovany NPP is above the European average. Nuclear operators worldwide use performance indicators of WANO (World Association of Nuclear Operators), based on which Dukovany Units are in the first 20% of all reactors.

Public acceptance
The population living near the nuclear power plant is in favour of nuclear power. According to an opinion poll, about 90 % of the inhabitants living in a zone of 20 kilometres around the plant back the operation of the nuclear power plant.

Future
As it was proved, the equipment of Dukovany NPP is capable of being operated much longer than 30 years than initially designed. Lifetime analysis and the aging of equipment showed that the lifetime of the vital parts, particularly reactor vessels are from 70 to 140 years (on different Units). Other equipment is in a similar shape. That is why the CEZ management decided to extend the lifetime of Dukovany NPP to forty years, i.e. to 2025, at least. Based on this decision a Harmonisation Programme has been developed which sets up a number of particular projects (80) incl. equipment, licensing, documentation, PR, personnel, competitiveness and management.

Performance Indicators (source WANO)

EDU = Dukovany NPP, ETE = Temelín NPP

Capacity Factor

Unplanned Capacity Loss Factor

Unplanned Automatic Scrams per 7,000 Hours Critical

Dukovany NPP has had no scrams for more than four years at any of the four Units

Collective Radiation Exposure,
Man-Sieverts per unit

Dukovany NPP is Among Absolute Best NPPs Worlwide

Dukovany NPP - Basic Data

Significant Dates of Dukovany NPP Units

Dukovany NPP - Technical Parameters of Units

Production History of Dukovany Units (GWh)
1985 - 2004

© European Nuclear Society, 2005