AFP: Russia and Vietnam on Sunday signed a deal worth an estimated 5.6 billion dollars for the energy-hungry Southeast Asian country’s first nuclear power plant. Russian President Dmitry Medvedev witnessed the signing, part of an effort to boost ties with his country’s former Soviet-era communist ally. “This is a very important project,” he told reporters after the ceremony. An official with Russian state nuclear conglomerate Rosatom has told AFP the construction cost of a two-reactor plant is…