On January 12, 1953, an explosion occurred in the Savannah River pilot plant which has been used since November, 1951 by du Pont personnel to train operators and to test equipment for their new Purex production plant. The explosion occurred in an evaporator in which a uranyl nitrate solution containing some organics was being concentrated to a high degree to remove nitric acid. This memorandum reviews the facts surrounding the incident as obtained from the official Preliminary Technical Report'', and by talking to du Pont personnel. These facts are interpreted as fast as possible and the current design for the Hanford Purex production plant is re-evaluated in the light of these data.