On 24 January 1978, COSMOS 954, a Soviet nuclear-powered surveillance satellite, crashed in the Northwest Territories. The crash scattered a large amount of radioactivity over a 124,000 square kilometre area in Canada's north, stretching southward from Great Slave Lake into northern Alberta and Saskatchewan.
The clean-up operation was a coordinated event between the United States and Canada. Dubbed "Operation Morning Light", the clean-up effort continued into October 1978 and resulted, according to the Atomic Energy Control Board (now the Canadian Nuclear Safety Commission), in the estimated recovery of about 0.1 percent of COSMOS 954's power source.
Using special radiation sensors, Canadian and American teams flew over the contaminated area trying to detect parts of the power source on the ground's surface. In addition, decontamination teams worked on foot to locate radioactive bits of the downed satellite and to package and remove them in specially shielded canisters.
The experience of COSMOS 954 stimulated the awareness in Canada that a federal nuclear emergency preparedness and response plan was needed. The Three Mile Island incident a year later reinforced this need, and convinced officials that the time had come to set up a contingency plan to deal with peacetime nuclear accidents and events.
The crash of COSMOS 954 raised international policy questions. Soon after the satellite's crash, there was a call from the United States to prohibit satellites containing radioactive material from orbiting the earth. This was followed by similar calls from Canada and countries in Europe. In November 1978, the United Nations authorised its Committee on the Peaceful Uses of Outer Space to set up a working group to study nuclear-powered satellites.