Nuclear weapons and the United Kingdom weapons to be a joint discovery, but the American Atomic Energy Act of 1946 (McMahon Act) restricted other countries, including the UK, from access to information about nuclear weapons. Fearing the loss of Britain's great power status, the UK resumed its own project, now codenamed High Explosive Research. On 3 October 1952, it detonated an atomic bomb in the Monte Bello Islands of Western Australia in Operation Hurricane. Eleven more British nuclear weapons tests in Australia were carried out over the following decade, including seven British nuclear tests at Maralinga in 1956 and 1957. The British hydrogen bomb programme demonstrated
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)