Russia’s first Borey class strategic nuclear submarine will be commissioned in 2013, Defense Minister Anatoly Serdyukov said on Monday.

The Yury Dolgoruky submarine was expected to join the Russian Navy by the end of this year, but tests carried out during the latest sea trials revealed a number of technical flaws. Software glitches in the automated launch control system prevented further tests of the Bulava ballistic missile, the submarine’s main weapon.

“We are expecting the Yury Dolgoruky submarine to enter service in 2013,” Serdyukov told Russian lawmakers at a meeting on defense issues.

The second Borey class submarine, the Alexander Nevsky, could join Russia’s Pacific Fleet in 2014, the minister said.

The Borey class submarines are expected to form the core of Russia’s strategic submarine fleet, replacing the aging Project 941 (NATO Typhoon class) and Project 667 class (Delta-3 and Delta-4) boats. Russia is planning to build eight Borey and Borey-A class subs by 2020.

Two more Borey class submarines are under construction at the Sevmash shipyard in the White Sea port city of Severodvinsk.

A Borey class strategic submarine is 170 meters (580 feet) long, has a hull diameter of 13 meters (42 feet), a crew of 107, including 55 officers, a maximum depth of 450 meters (about 1,500 feet) and a submerged speed of about 29 knots.

All the Borey class strategic submarines will carry the Bulava ballistic missiles, up to 16 ballistic missiles with multiple warheads.