A day after Prime Minister Narendra Modi hailed the attainment of criticality by the Kalpakkam reactor, the Congress has also welcomed the milestone.In a statement on Tuesday, Congress general secretary Jairam Ramesh said the 500 MW Prototype Fast Breeder Reactor at Kalpakkam went critical yesterday, making India the only country other than Russia, which will have commercial fast breeders that will then enable the utilisation of our vast thorium reserves.“This reactor is the result of over three decades of dedicated, dogged, disciplined, and determined effort on the part of our nuclear energy establishment – the foundations of which were laid by the Bhabha-Nehru duo and so many other distinguished nuclear scientists and technologists who came later,” Jairam said, remembering his own visit to Kalpakkam in July 2008 and the interactions he had with Dr Baldev Raj and his team.“It was a most inspiring morning. It would have only been proper for the PM to have acknowledged in his post the continuity in this stupendous achievement,” Jairam said.Earlier today, External Affairs Minister S Jaishankar said Kalpakkam attaining criticality is a historic milestone for our civil nuclear program. “It is also a testament to our growing domestic capabilities paving the way for nation’s energy security,” Jaishankar said.