The Balkan state wants to build a second nuclear power plant in Belene, 250 kilometers (about 150 miles) from the capital, Sofia, and to modernize the Kozloduy NPP in the north of the country.
Atomstroiexport and the Czech Republic's Skoda are bidding for the construction project.
"We will use both active and passive safety systems that will allow accidents to be prevented and tackled without human intervention," Atomstroiexport said in a statement.
The Belene NPP was being developed jointly with the Soviet Union until Bulgaria suspended work on the project in 1992.
In the new bid, the company has put forward two proposals on construction of the plant in a shorter period and with lower costs. Two power units will be commissioned as part of the existing project by 2013 under the first proposal. The second proposal would see the plant constructed from scratch and the first power unit commissioned within seven years after the start of construction.
Atomstroiexport is a leading Russian organization implementing intergovernmental agreements to build nuclear facilities abroad. It is the world's only company simultaneously building five nuclear power units in China, India and Iran.
