WWER-type reactor plants
Water-cooled water-moderated power reactor (WWER) belongs to the most prevailing type of light water reactors. Water is used as coolant and moderator in the reactors of this type. Operation of WWER and PWR reactors is based on this principle. The WWER is not an analog of PWR referred to this type, because there are essential differences both in design and materials used.
WWER distinguishing features:
- Usage of horizontal steam generators that never encountered with such problems as fretting, PWSCC, fouling, denting, etc.
- Usage of hexahedral fuel assemblies
- Absence of bottom penetrations in the WWER vessel
- Usage of high-capacity pressurizers.
Development of WWER-type reactor plants of a wide power range (from 300 to 1700 MW) is the mainstream activity of OKB "GIDROPRESS”.
OKB”GIDROPRESS” is a world leader in the number of implemented WWER-type reactor designs. 73 WWER Units have been constructed in all. During last 10 years 8 WWER Units have been constructed and commissioned in Russia and abroad.
Safety is a convincing argument in favor of the choice of state-of-the-art WWER reactors. In last WWER-type reactor designs the newest safety approaches are implemented based on the principle of defense-in-depth, several safety levels and optimal combination of multichannel passive and active safety systems.
The lessons of “accidents of the century” at “Three Mile Island” NPP (USA, PWR-type reactor) and Chernobyl NPP (USSR, RBMK-type reactor) are taken into account in WWER nuclear power plants. Based on the results of assessment of causes and consequences of the accident at “Fukushima” NPP (Japan, BWR-type reactor), the additional safety analyses (stress tests) have been performed with account of external extreme impacts. The analyses results are taken into consideration in new designs of reactor plants with WWER; some additional measures are implemented at operating NPPs on the basis of these analyses. It allows assuring further reliable development of domestic nuclear power engineering and WWER technology export.
At present WWER reactors developed at OKB “GIDROPRESS” are operated at 20 NPPs in Russia, Ukraine, Armenia, Finland, Bulgaria, Hungary, Czech Republic, Slovakia, China, Iran and India. They are 23 WWER-440 Units with the total power of 10120 MW and 34 WWER-1000 Units with the total power of 34000 MW. Novovoronezh NPP Unit 6 of 1200 MW with the first Generation 3+ reactor plant in the world has been commissioned. Activities are under way on extension of the first generation reactor equipment service life.
In the immediate future the Russian nuclear power units will be supplemented with the new WWER-1200 and WWER-1000 reactor plants being in preparation for start-up and designed by OKB “GIDROPRESS”: Leningrad-2 NPP Unit 1, Rostov NPP Unit 4.
Today several nuclear power units to be equipped with the WWER plants designed by OKB “GIDROPRESS” are under construction abroad: in India, China and Belorussia. Each of the designs is unique, and each of the power plants has its own peculiarities. All the designs have the following common features: high quality standards of work and maximum requirements for the safety level.
Woks on development of the reactor plants for NPP in Finland, India, Iran, Hungary and Bangladesh have been already started. For implementation of WWER-1200 and WWER-TOI reactor plants the State Corporation “Rosatom” has selected sites in Egypt and Jordan. All the designs are based on WWER technology proved by operational experience.