British Nuclear Tests at Maralinga - Minor Tests

Minor Tests

In addition to the major tests, a large number of minor trials were also carried out, from June 1955 and extended through to May 1963. Although the major tests had been carried out with some publicity, the minor tests were carried out in absolute secrecy. These minor tests left a dangerous legacy of radioactive contamination at Maralinga.

The four series of minor trials were codenamed Kittens, Tims, Rats and Vixen. In all, these trials included up to 700 tests, with tests involving experiments with plutonium, uranium, and beryllium. Operation Kittens involved 99 trials, performed at both Maralinga and Emu Field in 1953–1961. The tests were used in the development of neutron initiators, involving use of polonium-210 and uranium, and generated "relatively large amounts of radioactive contamination." Operation Tims took place in 1955–1963, and involved 321 trials of uranium and beryllium tampers, as well as studies of plutonium compression. Operation Rats investigated explosive dispersal of uranium. 125 trials took place between 1956 and 1960.

Operation Vixen was formulated to investigate what would happen to a nuclear device which burnt or was subject to a non-nuclear explosion. 31 Vixen A trials between 1959 and 1961 investigated the effects of an accidental fire on a nuclear weapon, and involved a total of about 1 kg of plutonium. Twelve Vixen B trials, between 1960 and 1963, attempted to discover the effects of high explosives detonating a nuclear weapon in a fire (typical of conditions which would occur in aviation accidents) and involved 22 kg of plutonium. They produced "jets of molten, burning plutonium extending hundreds of feet into the air." It was the subsequent disposal of the waste plutonium from these minor trials – Vixen B especially – which created the major radiation problems at the site.