Technical Descriptions of Nuclear,
Chemical, and Biological Weapons
Nuclear Weapons. Two basic types of nuclear weapons exist: atomic (fission) and thermonuclear (fission and fusion). Atomic weapons are devices that yield explosive energy derived from fission (uranium or plutonium design, or a combination of both). Thermonuclear weapons, which are many times more destructive than atomic weapons, use both fission and the fusion of isotopes of the hydrogen atom. This combination allows designers to get a higher yield than with a pure nuclear fission weapon (with uranium or plutonium) and at a much lower weight.
Atomic and thermonuclear weapons cause catastrophic damage with blast, high temperatures, and radiation. Thermonuclear weapons are the most destructive weapons ever created by humankind, but they are also the most sophisticated and difficult to manufacture or acquire.
The production of nuclear weapons requires an expensive infrastructure, sophisticated manufacturing capabilities, and a special isotope of uranium (U-235) or plutonium (PU-239) to achieve the chain reaction that results in its destructive power. U-235 can be obtained only through the enrichment of natural uranium; plutonium is produced in reactors and must be extracted from spent fuel by chemical processes. Both processes require specialized facilities.
Only nine nations (China, France, India, Israel, North Korea, Pakistan, Russia, United Kingdom, and United States) have built the required infrastructures (some with outside help) and currently acknowledge having nuclear weapons of one or both types (except for Israel, which does not confirm or demonstrate that it possesses nuclear weapons). In addition, South Africa until the early 1990s had a secret arsenal of six nuclear weapons. A number of other countries (Canada, Sweden, Switzerland, Taiwan, Australia, Brazil, Argentina, Libya, Iraq, Iran, and possibly Syria) have pursued nuclear weapon capabilities. Most have either turned back or have been forced to dismantle their efforts. Iran, North Korea, and potentially Syria remain of concern to the United States and the international community. Following the collapse of the Soviet Union in 1991, Ukraine, Belarus, and Kazakhstan inherited the Soviet nuclear weapons located on their now independent territories.