Chemical explosion in USSR

On 29 September 1957, eleven days before the Windscale accident, there was a chemical explosion in a Soviet plant treating active wastes, situated in the Urals. No mention of the accident was made in Soviet media at the time, but an exiled scientist, Z. A. Medvedev collected information and published it in the west (Medvedev, 1976, 1979). A further study, using Medvedev s data and oblique references to the effects of the disaster in Soviet ecological literature, was made by scientists at Oak Ridge (Trabalka et al., 1980). After the elapse of 32 a, 

The release thus consisted of the more refractory fission products, 

Nuclide Half- life Release Percentage of total release 

The initial hazard was gamma radiation from fallout activity, but the long-term hazard was the deposition of 90Sr and its entry into food chains. Nikipelov et al. (1989) stated 

The term global fallout appears to refer to the peak level reached in the early 1960s rather than to that in 1957. 

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