Previous nuclear incidents and accidents: COSMOS 954

On 24 January 1978, COSMOS 954, a Soviet nuclear-powered surveillance satellite, crashed in the Northwest Territories. The crash scattered an enormous 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.

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 authorized its Committee on the Peaceful Uses of Outer Space to set up a working group to study nuclear-powered satellites.