because, for the thorium reactors to start functioning, we need plutonium which is a by product of uranium fission.. so, we need uranium for this reason..
also, if we use up our scientists on developing our own indigenous thorium reactor, it would take another 100 years to materialize but after this deal, India can buy thorium reactors from canada who are pioneers in building reactors... they already have functional thorium fast breeder reactors and is ready to lend the technology to India and N-deal is signed..!!