Vegitation submerged during Dam formation and water accumulation leads to Decay which causes Methane formation and Metahne contribution to Green House effect is far worse than CO2 emmission. Once BBC printed a full article on this.
Hydroelectricity is not a consistent source as BASE LOAD. Electricity supply varies depending upon Rain pattern.
A certain % of Nuclear energy is boon especially down south of India.
Look at narmmada project of Gujrat , it is huge project and electricity generated at proper narmada Dam will be just 1500 MW.
Today it is easy to see 1 Nuke reactor generating 1000 MW.
These people like "SRINIVASAN" have very little overall understanding and they talk in isolation. But it is misleading the masses.
Let him come to a debate , he will be stripped in no time.