United Kindgom tests its first atomic bomb to become the world's third nuclear power, code named Operation Hurricane
Operation Hurricane was the test of the first British atomic device on 3 October 1952.
A plutonium implosion device was detonated in the lagoon between the Montebello Islands, Western Australia.
The weapon was a close copy of the Fat Man (Nagasaki) weapon, although the design was modified to use a levitated pit. This increased the power of the bomb, but was actually done as a safety measure. There were concerns that without the gap between the tamper and the pit, a criticality accident could occur. The bomb used plutonium produced mainly at Windscale (now Sellafield) in Cumbria with a low Pu-240 content since hurried production led to short irradiation times. However, Windscale could not quite meet the 1 August 1952 deadline for manufacturing the inner core and the device also used some Canadian-supplied plutonium.
To test the effects of a ship-smuggled bomb (a threat of great concern to the British at the time), Hurricane was exploded inside the hull of HMS Plym (a 1,370-ton River class frigate) which was anchored in 12 m of water 350 m off Trimouille Island. The explosion occurred 2.7 m below the water line, and left a saucer-shaped crater on the seabed 6 m deep and 300 m across.