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Operation Totem was a pair of British atmospheric nuclear tests which took place at Emu Field, South Australia on 15 October 1953. They followed the Operation Hurricane test of the first British atomic bomb, which had taken place at the Montebello Islands a year previously. The main purpose of the ''Totem'' trial was to determine the acceptable limit on the amount of plutonium-240 which could be present in a bomb. The plutonium used in the original Hurricane device was produced in a nuclear reactor at Windscale. This plant did not have anything like the capacity to provide sufficient material for the British government's planned weapons programme, and consequently eight more reactors had been planned. These were intended to produce both electricity and plutonium, and the design was known as Pippa, (for Pressurised Pile Producing Power and Plutonium). Construction of the first one started at Calder Hall in March 1953. However, for cost reasons they were to operate in such a way that a higher proportion of plutonium-240 was to be present in the fissionable plutonium-239 product than in the Windscale-produced material. This was potentially a problem since plutonium-240 is prone to spontaneous fission, which would both present a criticality accident risk and reduce the likely yield of any weapon was containing it. Sir William Penney urgently obtained ministerial permission in December 1952, two months after the ''Hurricane'' shot, for the ''Totem'' tests to take place in October 1953. The ''Totem'' tests tried two designs with different proportions of plutonium-240 in the pit. Since the Royal Navy were unable to provide the level of support which they had in the ''Hurricane'' test, the Montebello Islands used for that shot were ruled out. Instead a new site, originally given the codename X200 but later renamed Emu Field, was selected following surveys by Len Beadell and the British Army Survey Corps. An isolated dry, flat clay and sandstone expanse in the Great Victoria Desert, it was 480 km north west of Woomera, South Australia. Because the site was on the Australian mainland, the Australian government required much more information than they had for the ''Hurricane'' test, including details of implosion principle behind the bomb's design and much more information about nuclear fallout and radioactive contamination. The isolated location and poor roads meant that only 500 tons of the 3000 tons of equipment needed for the test arrived by road, the bulk arriving via the airstrip quickly constructed on the site (about 17 kilometres north west of the test field on a lake bed at ). The main scientific party arrived on 17 August and the device for the first test arrived on 26 September to be followed three days later by Penney. The two nuclear explosions were preceded by five smaller tests which formed part of a series codenamed ''Kittens'', and which were performed without formal Australian Government approval. These did not produce nuclear explosions, but used conventional explosive and polonium-210, beryllium and natural uranium to investigate the performance of neutron initiators. ==Summary== The United Kingdom test series summary table is here: United Kingdom's nuclear testing series. The detonations in the United Kingdom's ''Totem'' series are listed below: Table notes: 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Operation Totem」の詳細全文を読む スポンサード リンク
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