Nuclear power plant

Nuclear power plant

VVER-1200 is a third-generation pressurised water reactor (PWR), in practice based on the proven VVER technology. This reactor plant type was developed by OKB Gidropress, a subsidiary of Rosatom.

The first VVER plants were built before the 1970s, and also in Finland, experiences of their use have been good. Fortum has two VVER-440 units operating in Loviisa; they have been used safely for decades.

In 2021 there were 64 VVER nuclear power units in operation globally and 17 at various stages of implementation.

 VVER-1200 is the latest development in the VVER plant family. The first VVER-1200 plants have built in Russia, e.g. in Sosnovy Bor and Novovoronezh. In addition to these, four units have been ordered to Turkey and two to Belarus, for instance.

VVER-1200 has been developed for both the Russian market and export. Its design complies with IAEA requirements as well as general provisions for European power companies.

The plant type will also meet the strict requirements or Regulatory Guides on nuclear safety set by STUK that comply with the Finnish law. The Regulatory Guides describe in detail the requirement for implementing safety.

The most important design parameters of the power plant are presented at the bottom of the page.

Management of major reactor accidents

A new important safety feature in the VVER-1200 nuclear power plant are the passive cooling systems in addition to active ones; the passive systems do not require electricity or any other external power to maintain operation.

The management strategy of major reactor accidents in VVER-1200 nuclear power plants is based on four safety functions:

  • Decompression of the primary circuit
  • Cooling the molten corium in the core-catcher, located at the bottom of the reactor pit
  • Hydrogen management or prevention of hydrogen explosions and
  • Removing residual heat from containment building.

These protective measures ensure the containment building remains intact and leak-free so the limits set for major reactor accident emissions are not exceeded.

The safety design of VVER-1200 nuclear power plants has from the beginning aimed at complying with the safety regulations of the International Atomic Energy Agency (IAEA), meeting European Utility Requirements and complying with Russian national regulations and national requirements. In addition to these, Hanhikivi 1 plant unit will meet the Finnish nuclear safety requirements.

The most important design parameters

The plant’s electric power is approximately 1 200 MW and thermal power approximately 3 200 MW. Typical to VVER power plants, the steam generators are horizontal. The plant’s intended service life is at least 60 years.