The nuclear industry made a beginning with critical facilities and research reactors, and then moved
on to power reactors. Initially, the reactor size was small but was gradually increased to 700–
1600 MW range to realise the economy of scale. Lessons learnt from various incidents in nuclear
reactors have been incorporated into the designs of operating third-generation reactors. The fourth
generation of reactors where the goal includes breeding, utilisation of thorium, achieving high temperature for hydrogen generation and improving cycle efficiency is going through a developmental
process that could take a long time to realise. Public perception of nuclear energy has fluctuated
over time. The present perception is quite positive because of concerns arising from climate change.
At COP-28 in December 2023, 25 nations declared their intent to triple nuclear-installed capacity
by mid-century. At COP-29, six more countries joined the group of 25. India plans to triple nuclearinstalled capacity much earlier than mid-century. The Department of Atomic Energy (DAE), Government of India, has projected a target of 100 GW by 2050, which is more than ten times increase
compared to the present installed capacity.