Nuclear Weapons

Effects

Nuclear detonations are the most devastating of all weapons of mass destruction [WMD]. They generate an array of deadly effects, including blast, thermal pulse, neutrons, x- and gamma-rays, radiation, electromagnetic pulse (EMP), and ionization of the upper atmosphere.

Depending upon the environment in which the nuclear device is detonated, blast effects are manifested as ground shock, water shock — “blueout,” cratering, followed by large amounts of dust and radioactive fallout.

The energy of a nuclear explosion has three forms: blast, thermal radiation, and nuclear radiation. The distribution of energy among these three forms will depend on the yield of the weapon, the location of the burst, and the characteristics of the environment.

For a low-altitude atmospheric detonation of a moderate sized weapon in the kiloton (equivalent to a thousand tons of high explosive) range, the energy is distributed roughly as follows: 50% as blast; 35% as thermal radiation (made up of a wide range of the electromagnetic spectrum, including infrared, visible, and ultraviolet light and some soft x-ray emitted at the time of the explosion), and 15% as nuclear radiation (including 5% as initial ionizing radiation consisting chiefly of neutrons and gamma rays emitted within the first minute after detonation, and 10% as residual nuclear radiation. Residual nuclear radiation is the hazard in fallout.

Because of the tremendous amounts of energy liberated in a nuclear detonation, temperatures of several million degrees centigrade develop in the immediate area of the detonation (this in contrast to the few thousand degrees of a conventional explosion).