N UCLEAR HOLOCAUST In a single uranium fission about . × MeV ( MeV) of energy is liberated. If each nucleus of about kg of U undergoes fission the amount of energy involved is about × J. This energy is equivalent to about , tons of TNT, enough for a superexplosion.
Uncontrolled release of large nuclear energy is called an atomic explosion. On August , an atomic device was used in warfare for the first time. The US dropped an atom bomb on Hiroshima, Japan. The explosion was equivalent to , tons of TNT.
Instantly the radioactive products devastated sq km of the city which had , , inhabitants. Of this number , were killed and , were injured; more than % of the city’s structures were destroyed. High temperature conditions for fusion reactions can be created by exploding a fission bomb. Super-explosions equivalent to megatons of explosive power of TNT were tested in .
Such bombs which involve fusion of isotopes of hydrogen, deuterium and tritium are called hydrogen bombs. It is estimated that a nuclear arsenal sufficient to destroy every form of life on this planet several times over is in position to be triggered by the press of a button. Such a nuclear holocaust will not only destroy the life that exists now but its radioactive fallout will make this planet unfit for life for all times. Scenarios based on theoretical calculations predict a long nuclear winter , as the radioactive waste will hang like a cloud in the earth’s atmosphere and will absorb the sun’s radiation.
. . Controlled thermonuclear fusion The first thermonuclear reaction on earth occurred at Eniwetok Atoll on November , , when USA exploded a fusion device, generating energy equivalent to million tons of TNT (one ton of TNT on explosion releases . × MeV of energy).
A sustained and controllable source of fusion power is considerably more difficult to achieve. It is being pursued vigorously in many countries around the world (including India), because fusion reactor is regarded as the future