Tube Alloys the features, science and idea behind the American Fat Man implosion-type nuclear weapon. He broke down the development tasks required to replicate it, identifying outstanding questions that required further research on nuclear weapons. On 3 October 1952, under the code-name "Operation Hurricane", the first British nuclear device was successfully detonated in the Monte Bello Islands off the west coast of Australia. The Sputnik crisis and the development of the British hydrogen bomb led to the Atomic Energy Act being amended in 1958, and to a resumption of the nuclear Special Relationship between America and Britain under the 1958 US–UK Mutual
Residual-current device to the appliance. The test button (8) allows the correct operation of the device to be verified by passing a small current through the orange test wire (9). This simulates a fault by creating an imbalance in the sense coil. If the RCD does not trip when this button is pressed, then the device must be replaced. Residual-current and overcurrent protection may be combined in one device for installation into the service panel; this device is known as a GFCI (ground fault circuit interrupter) breaker in the USA and Canada, and as an RCBO (residual-current circuit breaker with overload protection)