During World War II, two exiled German physicists wrote a paper about the possibility of constructing a “radioactive super-bomb” which was sent to appropriate agencies of the United Kingdom government. A committee was set up to explore building such a bomb and a research program was begun. Eventually, the U.K. entered into partnership with the United States and Canada in the Manhattan Project. The Project was successful and two of the new atomic bombs were dropped on Japan, ending World War II in the Pacific in 1945.
Following the war, the British continued with their own research on nuclear weapons. The first order of business was to secure plutonium for bomb production. In 1946, two reactors were built at an old ordinance factory at Sellafield in northwest England. The reactors were fueled with uranium, moderated with graphite rods and air-cooled. Facilities were built to extract plutonium from the spent fuel removed from the reactors. Reactor 1 was started in 1950 and reactor 2 was started in 1951. By 1952, sufficient plutonium was available to build a bomb. The United Kingdom exploded their first atomic bomb in October of 1952 on an island off the coast of Western Australia. They continued research and testing and in 1957 began a series of test of hydrogen bombs on islands in the Central Pacific.
In 1958, the United States and the United Kingdom signed the Mutual Defense Agreement. Part of the Agreement covered the sharing of information and mutual assistance in the further development of nuclear weapons as well as cooperation on all nuclear security matters.
In 1960, the U.K. cancelled its last nuclear weapon delivery system project and has collaborated with the U.S. on weapon delivery systems ever since. Lockheed Martin designs and manufactures delivery systems and then they are fitted with nuclear warhead designed and built in the U.K.
The U.K. has not carried out the number of tests of other nuclear powers such as the U.S., the Soviet Union and Red China. However, because of their special relationship to the U.S. and access to classified U.S. nuclear weapons research, they have been able to develop sophisticated nuclear warhead with much less effort than the other nuclear powers.
There has been political turbulence in the United Kingdom over the manufacture of nuclear weapons and policies for their uses. For a long time, the actual costs and risks of the weapons programs were kept secret from the citizens of the United Kingdom.
The U.K. has constantly kept at least one ballistic-missile submarine on patrol since 1969. They purchased Polaris missiles from the U.S. to arm the submarines. Eventually, the Polaris missiles were replaced by U.S. Trident missiles in the mid 1990s.They currently have four Vanguard submarines that provide their deterrence against a pre-emptive first strike attack by an enemy. Their stockpile of warheads is estimated to be around one hundred and fifty.
Photo of Sellafield from the air - www.visitcumbria.com:
