MOSCOW, November 17 (RIA Novosti) - The deaths of 20 people on board the Russian nuclear submarine the Nerpa were caused by a crew member entering the wrong data into a temperature sensor, the Kommersant paper said on Monday. (INFOgraphics)
The business daily said, quoting a source close to the investigation, that sailor Dmitry Grobov is suspected of having entered the wrong temperature data for the submarine's living quarters, which caused the fire safety system to release Freon gas.
The source said that according to information obtained from the sub's Rotor data block, similar to an aircraft's black-box, "the temperature...increased sharply all of sudden and the fire safety system reacted as programmed."
The daily said that at the time of the incident Grobov was on a scheduled watch and the access code to the fire safety system was written in pencil on the surface of the equipment.
The tragedy occurred late on November 8 while the Nerpa was undergoing sea trials in the Sea of Japan. Three submariners and 17 shipyard workers died in the accident. There were 208 people, 81 of them submariners, on board the vessel at the time.
However, former Navy officers have told the paper they doubt that Grobov was solely to blame as it is impossible for one person to activate the system, which is protected from unauthorized activation by multiple levels of confirmation.
The submarine's reactor was not affected by the accident, which took place in the nose of the submarine, and radiation levels on board remained normal.
Investigators earlier announced that they had brought criminal charges against the crew member, and that he faced up to seven years in jail.
"Military investigators have determined the person who activated, without permission or any particular reason, a fire safety system on board the submarine. He is a sailor from the crew, and he has already confessed," Vladimir Markin, a spokesman for the Investigation Committee of the Prosecutor General's Office, said on November 13.
The incident is the worst for the Russian Navy since the sinking of the Kursk nuclear submarine in 2000 when all 118 sailors died.
The construction of the Akula II class Nerpa nuclear attack submarine started in 1991, but was suspended for over a decade due to a lack of funding. Akula II class vessels are considered the quietest and deadliest of all Russian nuclear-powered attack submarines.
Based in the Russian Far Eastern city of Komsomolsk-on-Amur, the Amur Shipbuilding Plant has built 270 vessels, including the Nerpa and another 55 nuclear submarines since it was established in 1936.