The April 1962 Criticality Event in the Recuplex Facility

On Saturday morning, April 7, 1962, at 10:59 a.m., an accidental nuclear excursion occurred in the plutonium waste recovery facility (Recuplex) of the 234-5 building. The nuclear excursion was the first and only one to have occurred in any production facility at Hanford. This excursion did not result in any mechanical damage or spread of contamination. Three employees received overexposures to gamma and neutron radiation of 110, 43, and 19 rem, respectively. In each case, the overexposure was recognized promptly, and following medical observation and testing, the men were released to return to work.