The Nuclear Club

What are the nuclear powers? In addition to the United States, Russia (which has "inherited" strategics and tactics heads from the former USSR), France, United Kingdom and India, in 1998 the Pakistan has been added to the nuclear club, in May of that year he performed the test of the first Islamic atomic. It is important that Islamabad has a score of nuclear weapons with a yield, or the explosive power of between 9 and 40 kiloton. Pakistan did not stop to realize, however, inefficient, and heavy heads depleted enriched, whose mass is such as to restrict the range of ballistic missiles (the Ghauri, developed from Islamabad), but has also pointed to the use of plutonium. Moreover this material is used preferably from Hiroshima forward since for an atomic bomb requires about 15 kilograms of uranium 235, or four to six kilograms of plutonium.

Ever since the Enola Gay dropped its deadly cargo on Hiroshima in August 1945 membership of the nuclear club has become a symbol of world power.

July 16, 1945: The United States explodes the first atomic bomb at Alamagordo in the deserts of New Mexico. Known as the "Trinity" test, it confirms the power of the H-bombs which are dropped on Hiroshima and Nagasaki three weeks later.

1949: The Soviet Union joins the nuclear club by exploding its first atomic weapon. So begins the nuclear arms race between the US and the USSR.

1952: Britain gets on the nuclear wagon by detonating a device in the atmosphere over Christmas Island in the Pacific. Many British servicemen who were present say they were not given protective suits and claim their health has been affected by radioactivity.

1954: The United States conducts the "Bravo" nuclear test off the Marshall Islands in the Pacific. Fallout from the 15 megaton explosion affects Japan and the US later pays $15m in compensation.

1957: The US conducts the first underground nuclear tests in a mountain tunnel 100 miles from Las Vegas.

1960: France becomes an atomic power by carrying out tests in the Pacific's Tuamotu Archipelago.

1962: The year of the Cuban missile crisis sees the largest number of nuclear tests, almost 200. The US and the USSR account for 95%.

1963: The US and the Soviets sign the Limited Test Ban Treaty which imposes a moratorium on underwater and atmospheric tests. Nearly 100 countries have since signed the treaty.

1964: Chairman Mao gives the go ahead for China to explode its first atomic weapon in the Lop Nor desert in Sinkiang province.

January 1966: Two US planes carrying nuclear weapons collide over Palomares, Spain. The accident and the subsequent settlement claims cost the US $182m.

1974: India begins underground testing.

1985: The Soviet Union announces it is ending nuclear testing.

1992: The US conducts its last nuclear test. The "Divider" test takes place in an underground bunker in the Nevada desert.

1995: France continues nuclear testing on the Pacific atoll of Mururoa despite international condemnation, especially from Australia and New Zealand.

1996: The United Nations General Assembly approves a comprehensive nuclear test ban treaty after China comes on board. Only India votes against the document.

April 1998: Britain and France ratify the test ban treaty. The US, Russia and China have signed the document but not ratified it. Neither India or Pakistan have signed it.

May 1998: India explodes five nuclear devices at Pokhran, its testing site in Rajasthan.

Analysts believe that Pakistan is in possession of over half a tonne of plutonium and has begun to conduct research to achieve a thermonuclear bomb, the H bomb, which, based on what is called schema Teller Ulama, used as initiator for melting atomic species fuze, the so-called primary, consisting of a nuclear fission bomb. Pakistan has a key role in nuclear proliferation: the first was a regional power to join the Nuke club, in response to India occurred in 1974, when they detonated in the desert of Thar, the Smiling Buddha,an implosion bomb in less than 10 kiloton, the plutonium. India is a nuclear power greater than Pakistan with which it faces. It has pure fission weapons, plutonium, with a yield of 12 kt, arms up to 20kt fission strengthened, made with plutonium for weapons, and even tested a thermonuclear power of 200-300 kiloton. But not all. India also has a micro-nuclear, weapons or tactics of power between 0.1 and 1 kiloton: the perfect weapons for nuclear terrorism, the same on which the father of Pakistan's atomic,the one discussed and arrested (for creating a network for the illegal transfer of nuclear technology to Libya, Iran and North Korea) Abdul Qadeer Khan had bet,because they can be used in a H bomb and it's for the intrinsic military significance. And these low yield bombs are the perfect weapon for nuclear terror.

The nuclear club has seen the presence of South Africa, which has dismantled its depleted enriched tested, but mostly sees the presence of Israel. The Jewish state, like India and Pakistan has not signed the Treaty on the Non-Proliferation Treaty, and has a relatively sophisticated arsenal that includes different types of nuclear weapons.

The technology to build a nuclear bomb is not overly sophisticated and is now within the reach of many States. What is more difficult, however, come into possession of fissile material (plutonium or highly enriched uranium) in the amount (critical mass) to achieve a device that uses high explosives to compress and combine the sub-critical masses.

Fissionable material, which can generate a chain reaction, is obtained with the process of enrichment or separation of two different isotopes of natural uranium: uranium 235 and uranium 238. The natural uranium is composed predominantly (99.3%) from U238 and the rest (0.7%) from uranium-235. The two isotopes behave very differently. A nucleus of U235 when it is hit by a neutron breaks (not always, but almost) in two and the beginning of the fission reaction releasing enormous amounts of energy. By absorbing a neutron depleted 238, or the so-called depleted uranium, is generated instead of plutonium, which does not exist in nature.

Enrichment is the process that leads to generate, based on natural uranium, the material usable for nuclear power, reactor grade (enriched to 2-3%) and for purposes of war (weapon grade, up to 90%) the process can occur in several ways: gaseous diffusion of uranium hexafluoride (UF6), centrifugation, separation aerodynamics and electromagnetic separation. The latter method led to the Hiroshima bomb and was the system chosen by Iraq, which had installed special particle accelerators (the colutroni) in Osirak reactor destroyed by Israeli raids "mission Opera" in 1981. The fissile material can also be derived from the fuel of a nuclear reactor. This is the process (re-) that leads from the spent fuel to recover plutonium that can be used for civilian or military.

Table of nuclear arsenals by country, published by the "Times" it is based on sources from the Strgegic Institute for International Studies and Globalsecurity.org

Russia 5.200

US5. 400

China 130

India 50-60

Pakistan 60

Uk 160

France 300

Israel 200