Database of radiological incidents and related events--Johnston's Archive

Siberian Chemical Combine criticality accident, 1978

compiled by Wm. Robert Johnston
last modified 14 September 2005

Date: 13 December 1978

Location: Siberian Chemical Combine, Russia, USSR

Type of event: criticality accident with plutonium metal


The accident occurred in a facility which processed plutonium metal ingots. Ingots were placed in stainless steel cans within a glovebox. In violation of procedures, one operator asked a second operator to assist him in transferring ingots amongst containers to speed the process. The second operator, unattended, erroneously transferred two ingots to the same container. The first operator returned and transferred two more ingots to this same container, for a total plutonium mass of 10.68 kg. While transferring the fourth ingot, a criticality excursion occurred, producing an energy release that either expelled the fourth ingot or prompted the operator to instinctively withdraw it, ending the excursion. The operator saw a flash of light and felt an instantaneous heating of his hands and arms. The operator received a whole body dose of 250 rads, with a localized dose to his hands of over 2000 rads. Seven other glovebox operators received doses of 5 to 60 rads.

Consequences: 1 injury.


© 2004, 2005 by Wm. Robert Johnston.
Last modified 14 September 2005.
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