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

Los Alamos criticality accident, 1958

compiled by Wm. Robert Johnston
last modified 14 September 2005

Date: 30 December 1958

Location: Los Alamos, New Mexico, USA

Type of event: criticality accident with plutonium solution


Plutonium solutions were inappropriately combined into a single vessel for mixing. When stirring of the tank began, a criticality excursion occurred which ended as the contents became more fully mixed. An operator who was viewing the tank received a dose to his upper body of 12,000 rem and died 36 hours later. Two others were exposed to doses of 134 and 53 rem but suffered no ill effects.

Consequences: 1 fatality (12,000 rem).


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