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

Oak Ridge criticality accident, 1958

compiled by Wm. Robert Johnston
last modified 14 September 2005

Date: 16 June 1958

Location: Oak Ridge, Tennessee, USA

Type of event: criticality accident with uranium solution


A leak in a tank containing uranyl nitrate solution (93% U-235) was discovered on 15 June. The leak was not properly logged. The following day other tanks were being drained into a 55-gallon drum; uranium solution from the leaking tank also entered the drum. The operator nearest the drum noticed yellow-brown fumes rising from the drum's contents; he retreated before seeing a blue flash as the criticality excursion occurred. Excursion power output rose for at least 3 minutes, then ended after 20 minutes. Eight people received significant doses: 461, 428, 413, 341, 298, 86, 86, and 29 rem.

Consequences: 5 injuries.


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