Operation Totem

Totem
Obelisk at the Totem One test site
Information
Country	United Kingdom
Test site	Emu Field, SA, Australia
Period	1953
Number of tests	2
Test type	tower
Max. yield	10 kilotonnes of TNT (42 TJ)
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Previous test series	Operation Hurricane
Next test series	Operation Mosaic

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 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.