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

Mayak Enterprise criticality accident, 1953

compiled by Wm. Robert Johnston
last modified 21 September 2007

Date: 15 March 1953

Location: Mayak Enterprise, Russia, USSR

Type of event: criticality accident with plutonium solution


A criticality accident occurred in a plutonium processing facility. Plutonium separated from spent fuel rods was being processed in nitrate solution. Procedural errors in an unrecognized accumulation of 842 g of plutonium in one vessel, which became critical and brought the vessel contents to boiling. The operators transferred contents of another vessel to the first, ending the reaction. The accident was unrecognized for 2 days when one operator developed symptoms of radiation sickness. This operator had received a 1,000 rad dose, resulting in severe radiation sickness. He also sustained severe radiation burns on his legs, requiring amputation of both legs, but survived another 35 years. A second operator received a 100 rad dose; this worker and a third operator both developed radiation sickness.

Consequences: 3 injuries (1,000, 100, ? rad)


© 2004-2005, 2007 by Wm. Robert Johnston.
Last modified 21 September 2007.
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