The process is nuclear fission.
Substances are uranium, plutonium, thorium.
Advantages :
(i) For a given amount of fuel, the amount of energy released is extraordinarily large.
(ii) Nuclear power plants can be set up at any place.
Hazards:
(i) Improper nuclear waste storage and disposal result in environmental contamination.
(ii) Further, there is a risk of accidental leakage of nuclear radiation