Operation Totem was a pair of British atmospheric nuclear tests which took place at Emu Field in South Australia in 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 trial was to determine the acceptable limit on the amount of plutonium-240 which could be present in a bomb. In addition to the two main tests, there was a series of five subcritical tests called "Kittens". These did not produce nuclear explosions, but used conventional explosives, polonium-210, beryllium and natural uranium to investigate the performance of neutron initiators. Background During the early part of the Second World War, Britain had a nuclear weapons project, code-named Tube Alloys, which the 1943 Quebec Agreement merged with the American Manhattan Project to create a combined American, British, and Canadian project. The British government expected that the United States would continue to share nuclear technology, which it regarded as a joint discovery, after the war, but the United States Atomic Energy Act of 1946 (McMahon Act) ended technical co-operation. Fearing a resurgence of United States isolationism, and Britain losing its great power status, the British government restarted its own development effort, which was given the cover name "High Explosive Research". The first British atomic bomb was tested in Operation Hurricane at the Montebello Islands in Western Australia on 3 October 1952. Purpose and site selection The main purpose of the trial was to determine the acceptable limit of the amount of plutonium-240 that could be present in a bomb. The plutonium used in the original Hurricane device was produced in the nuclear reactor at Windscale, but the Windscale Piles did not have the capacity to provide sufficient material for the British government's planned weapons programme, and consequently eight more reactors were planned. These were intended to produce both electricity and plutonium, and the design was known as PIPPA, for pressurised pile producing power and plutonium. Although PIPPA produced less plutonium than a Windscale Pile, it also produced electricity which it could put back into the grid, whereas a Windscale Pile consumed GBP £340,000 a year worth of electricity to run its blowers. The electricity produced was more expensive than that of a conventional coal-fired plant, but this was offset by the value of the plutonium produced, which was about £100 per gram (£3,100 per