September 15 (SeeNews) - Russia’s Atomstroyexport, hired to build Bulgaria’s Belene nuclear power plant, said the construction will cost 6.0 billion euro ($8.77 billion) in the worst-case scenario, state-run Bulgarian news agency BTA reported on Tuesday. Bulgaria awarded the construction works to Atomstroyexport for 3.997 billion euro last year. To this sum the inflation in the different countries, which will produce the equipment for the plant, should be included, BTA quoted Atomstroyexport Vice President Gennady Tepkyan as saying. According to recent Bulgarian media reports, however, the project for the country's second nuclear power plant would cost between 8.0 and 10.0 billion euro. Atomstroyexport and Bulgaria have still not agreed on what inflation they will calculate for the project, Tepkyan said, adding that Bulgaria has disagreed to apply Russia's inflation for the equipment made in Russia. To address this disagreement, Atomstroyexport has proposed to use the average annual inflation for the 27 member states of the European Union as reported by the bloc's statistics office Eurostat but Bulgaria has not answered yet. Construction works currently are 15 months behind schedule, Tepkyan said.