Assessment of radiation doses to Australian participants in British Nuclear Tests

Between 1952 and 1957, the UK exploded a total of 12 nuclear devices in Australia, and also conducted about 600 'minor trials' that did not involve a nuclear explosion. Over 16 000 Australian servicemen and civilians were involved in the UK tests in Australia. This paper reports the estimation of doses that the Australian participants received as a result of their involvement. Both the external and internal exposure pathways were considered. Most participants received very small doses: 79% of all participants received <1 mSv, and less than 4% received >20 mSv, the current internationally recommended annual dose limit to workers. The largest dose recorded was 133 mSv, received by aircrew conducting sampling in the nuclear cloud soon after detonation. Most doses >20 mSv were received by groups who entered the near vicinity of the explosions or fallout contaminated areas to collect samples or instruments soon after a detonation. Internal doses were a very small component of the total dose during the first few months after detonation, but thereafter inhalation became an increasingly important pathway due to the presence of unburnt nuclear fuel in fallout. (authors)