 The detailed engineering of the design was implemented at Larsen & Toubro 's submarine design center at their Hazira shipbuilding facility . Tata Power SED built the control systems for the submarine . The steam turbines and associated systems integrated with the reactor were supplied by Walchandnagar Industries . The lead vessel underwent a long and extensive process of testing after its launch in July 2009 . The propulsion and power systems were tested with high @-@ pressure steam trials followed by harbor @-@ acceptance trials that included submersion tests by flooding its ballast tanks and controlled dives to limited depths . INS Arihant 's reactor went critical for the first time on 10 August 2013 . On 13 December 2014 , the submarine set off for its extensive sea trials . 
 The detailed engineering of the design was implemented at Larsen & Toubro <a href='null_genetive' title='1'><mark>'s</mark></a>submarine design center at their Hazira shipbuilding facility . Tata Power SED built the control systems for the submarine . The steam turbines and associated systems integrated with the reactor <a href='uninflect' title='2'><mark>were</mark></a> supplied by Walchandnagar Industries . The lead vessel underwent a long and extensive process of testing after its launch in July 2009 . The propulsion and power systems <a href='uninflect' title='3'><mark>were</mark></a> tested with high @-@ pressure steam trials followed by harbor @-@ acceptance trials <a href='null_relcl' title='4'><mark>that</mark></a>included submersion tests by flooding its ballast tanks and controlled dives to limited depths . INS Arihant <a href='null_genetive' title='5'><mark>'s</mark></a>reactor went critical for the first time on 10 August 2013 . On 13 December 2014 , the submarine set off for its extensive sea trials . 
The detailed engineering of the design was implemented at Larsen & Toubro  submarine design center at their Hazira shipbuilding facility . Tata Power SED built the control systems for da submarine . The steam turbines and associated systems integrated w the reactor was supplied by Walchandnagar Industries . The lead vessel underwent a long and extensive process of testing after its launch in July 2009 . The propulsion and power systems was tested with high @-@ pressure steam trials followed by harbor @-@ acceptance trials included submersion tests by flooding its ballast tanks and controlled dives to limited depths . INS Arihant  reactor went critical for tdafirst time on 10 August 2013 . On 13 December 2014 , the submarine set offf fa its extensive sea trials .