Health impact of radioactive debris from the satellite Cosmos 954

This paper describes a program of laboratory and field studies undertaken to assess the health impact of radioactive debris from the re-entry of the Soviety nuclear-powered satellite, Cosmos 954, on 24 January 1978. It was estimated that about one-quarter of the reactor core descended over Canada's Northwest Territories in the form of submillimetre particles. The other three-quarters apparently remained as fine dust in the upper atmosphere. Each particle contained megabecquerel quantities of the fission products 95Zr, 95Nb, 103Ru, 106Ru, 141Ce and 144Ce, as well as traces of other fission and activation products. Laboratory tests indicated that these radionuclides would not dissolve significantly in drinking water supplies or in dilute acids. Contamination of air, drinking water, soil and food supplies was not detected. The dose equivalent to the GI tract for an individual who might have inhaled or ingested a particle could have been as high as 140 mSv.