A new reactor for Russia

Kalinin 3 is now scheduled to begin commercial operation in 2004, according to plant director Stanislav Ivanivich Antipov. "The schedule has been approved by Minatom. Physical start-up is now set for 6 December this year with grid connection in April 2004," he said in an interview with NEI. Output from the new unit has been included in the energy balance calculations for next year and it is expected to produce 3.5TWh.

Antipov said plans for the construction of Kalinin 4 had also been approved. "In March 2003 a declaration was signed confirming the intention to begin construction of unit 4. The regional government has agreed to the units being built on its territory and Minatom is ready to provide the finance. Nevertheless, we understand that work will only begin after Kalinin 3 is completed as well as Kursk 5, Balakovo 5 and Volgodonsk 2. This is expected to be in 2008."

DESIGN CHANGES

He explained that unit 3 differs significantly from the first two units. "Units 1 and 2 are small series VVERs. Only four have ever been built two at Kalinin and two at South Ukraine. Unit 3 is a 320-series VVER. But it is being constructed in accordance with strict new safety standards." There are three main features that differ from the original design. These relate to the automatic process control system (APCS), the nuclear fuel and the turbine unit.

"The APCS was changed and now incorporates the latest technical upgrades," Antipov said. "The new systems allow the acquisition of more information and can carry out diagnostic procedures for all processes including the system itself. It is the first automatic control system of Russian design to be installed in a Russian nuclear power plant. It is similar to the systems used in the N4 series in France. It is also being installed at China's Tianwan plant and at Bushehr in Iran."

The fuel (uranium dioxide) for unit 3 will be 'more reliable' with different physical and mechanical properties which will give increased burn-up. While uranium dioxide fuel has been used traditionally at Russian NPPs with VVER reactors, the construction of fuel assemblies used at Kalinin differs from those used at other plants. These 'alternative' fuel assemblies were developed by the Mechanical Engineering Design Office and have been used at Kalinin 1 and 2 for more than five years already, although they will be loaded into the new reactor for the first time. The main peculiarity of these fuel assemblies is that they are strengthened by additional angles, which increases their rigidity and capacity to resist distortion. As a result the new fuel assemblies can stay longer in the core, and so burn-up is increased. For example, several fuel assemblies have been in the core of unit 1 for five years already. The new fuel assemblies are supplied by the Electrostal plant.

Another modification involves the turbine units. These operate at 3000 revolutions per minute. New modernised turbine governing systems and turbo-generator diagnostic systems have also been incorporated.

ENVIRONMENT

Antipov explained that the construction of unit 3 required the building of cooling towers to supplement the use of the natural lakes used for Units 1 and 2. The lakes are classed as first-category fisheries and contain many valuable types of fish. Russian environment protection requirements concerning these lakes are very strict, especially in summer time. Cooling towers were chosen to prevent overheating of the lakes and the severe penalties this would have incurred if all three units were cooled using water from these lakes.

Some 1000 people will be working at unit 3, including those such as maintenance units who will be shared with the other two units. However, 200 young specialists from higher schools have been specially trained. "The plant does have a simulator for unit 3, but because of upgrades and changes in the automatic process control system it is now being updated to fit with the third unit," Antipov explained. However, he believes the plant overall has very experienced and reliable staff. "Kalinin has the highest capacity factor within Rosenergoatom, at an average of 85.5%. One unit was 87% but the other was lower because of the length of the maintenance. In 20 years we have had no serious problems or failures and no events above zero level on the INES scale, nor have we had any gaseous emissions above10% of permissible norms."
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