Operation Totem

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Obelisk at the Totem One test site
Obelisk at the Totem One test site

Operation Totem was a pair of British atmospheric nuclear tests which took place in October 1953. The only ones conducted at a temporary site in Australia, Emu Field, they followed the Operation Hurricane test of the first British atomic bomb which had taken place at the Monte Bello 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 Monte Bello 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.

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 fallout and radiation 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. 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 tests were preceded by a series of five smaller tests which part of a series codenamed Kittens, and which were carried out without Australian government approval[1]. These did not produce nuclear explosions, but used conventional explosive and polonium-210, beryllium and natural uranium to investigate the performance of neutron initiators.

Contents

[edit] The Totem 1 (T1) test

A rehearsal for the first test took place on 1 October but rain delayed the actual test, originally scheduled for a week later, until 14 October. The yield was bigger than expected and only a little below the maximum planned in safety assessments.

[edit] Specifics

  • Time: 21:30 on 14 October 1953 (GMT)
  • Location: Emu Field, Southern Australia
  • Test Height and Type: Tower, 100 feet (31 m)
  • Yield: 9.1 kt

[edit] The Totem 2 (T2) test

The second test was also delayed because of poor weather. The yield was much bigger than the expected 2-3 kilotons, but again less than the estimated maximum of 10 kilotons.

[edit] Specifics

  • Time: 21:30 on 26 October 1953 (GMT)
  • Location: Emu Field, Southern Australia
  • Test Height and Type: Tower, 100 feet (31 m)
  • Yield: 7.1 kt

[edit] Fallout

Efforts were made to prevent nomadic Aboriginal People from entering the area around the test site, but there were thought to be no (or at most very few) people in such a dry and inhospitable environment. The chief scientist at the Australian Department of Supply, W. A. S. Butement asserted that "I am given to understand that the area is no longer used by Aborigines". The precautions consisted of warnings sent to pastoral stations in August 1953, warning notices around the perimeter of the test site, and aerial and ground searches, usually within 20 miles of the site, which were made with increasing frequency as the test firings approached. The 1985 Royal Commission into British nuclear tests in Australia determined that the area was still being occasionally used and the efforts have been criticised as inadequate. [2]

Before the tests, the height of the radioactive cloud resulting from the explosions was estimated at 12,000 feet, (+/-1000 feet). This led to safety criteria for making the decision to detonate the device that the wind direction from ground level up to 10 000 feet should not lie between 330 and 130 degrees and that no rain was forecast closer than 200 miles downwind. However the cloud from the Totem 1 shot rose to 15,000 feet, drifting east and crossing the coast 50 hours later near Townsville.

Following the Totem 1 test, a black mist rolled across the landscape at the Wallatina and Welbourn Hill stations in the Granite Downs 175 km from the test site and led to unacceptably high levels of radioactive contamination of these locations. There is controversy surrounding injuries received by Aboriginal People from fallout, and in particular from this mist. Approximately 45 Yankunytjatjara people were reported to have been caught in the mist at Wallatina and fallen ill, and over half may have died.[2]

The 1985 Royal Commission concluded that "Aboriginal people experienced radioactive fallout from Totem 1 in the form of a black mist or cloud at or near Wallatina. This may have made some people temporarily ill. The Royal Commission does not have sufficient evidence to say whether or not it caused other illnesses or injuries".

The Totem 2 cloud rose even higher, to 28,000 feet because of condensation of moisture entrained in it, and whilst the wind direction below 12,000 feet was an acceptable 10 degrees, at 20,000 feet it was 270 degrees. However high winds dispersed the cloud so that it had dissipated to the point where it could not be tracked beyond around 500 km east of the test site.

[edit] Aftermath

A few days after the conclusion of these tests, the British Government formally requested a permanent testing site from the Australian Government, which led to the agreement on the use of the Maralinga test site in August 1954. However the next trial was back at the Monte Bello Islands in May 1956. Operation Mosaic was a pair of tests as part of the development of thermonuclear weapons. The first trial at Maralinga was in September 1956, with the Operation Buffalo series.

[edit] References

[edit] Footnotes

  1. ^ A toxic legacy: British nuclear weapons testing in Australia. Australian studies in law, crime and justice. Retrieved on 2007-12-24.
  2. ^ a b Roger Cross and Avon Hudson (2006). Beyond Belief: The British Bomb Tests: Australia's Veterans Speak Out. Wakefield Press, 23-25. ISBN 978-1862546608.