Khabarovsk (Russia), July 27 (RIA Novosti) The first stage of sea trials of Russia’s Nerpa nuclear attack submarine, which was damaged in a fatal accident during previous tests, has been successfully completed, the Amur shipyard said Monday. The vessel, which will be leased to the Indian Navy by the end of 2009, resumed sea trials July 10 in the Sea of Japan following extensive repairs.

“The first set of sea trials has been successfully completed according to schedule,” a shipyard official told RIA Novosti.

“The sub is back at the Bolshoy Kamen in the Primorye Territory, and it is getting ready for the second stage of the scheduled testing,” the official said, adding that some equipment for performance checking and adjustment work will be installed on board the submarine.

On Nov 8, 2008, as the Nerpa was undergoing sea trials in the Sea of Japan, its on-board fire suppression system went off, releasing a deadly gas into the sleeping quarters. Three crewmembers and 17 shipyard workers were killed. There were 208 people on board the vessel at the time.

Following the repairs, which cost an estimated 1.9 billion roubles ($60 million), the submarine was cleared for final sea trials before being commissioned with the Russian Navy.

India reportedly paid $650 million for a 10-year lease of the 12,000-tonne K-152 Nerpa, an Akula II class nuclear-powered attack submarine.

Akula II class vessels are considered the quietest and deadliest of all Russian nuclear-powered attack submarines.