On Sunday, June 22, 1997, at approximately 10:07 a.m. Central Daylight Time, a violent explosion and large fire occurred at the Shell Chemical Company plant in Deer Park, Texas. The explosion was felt and heard over ten miles away, and the ensuing fire burned for approximately 10 hours. As a result of the explosion and fire, extensive damage occurred to the facility, and several workers received minor injuries. Nearby residential property was damaged. Major transportation routes adjacent to the facility were closed for several hours, and nearby residents were advised to remain indoors.
Under the terms of the EPA/OSHA Memorandum of Understanding for Chemical Accident Investigations, a joint chemical accident investigation team (JCAIT) was formed to investigate the accident and determine its root causes. A concurrent enforcement investigation was done by OSHA to determine if any violations of occupational safety and health laws had occurred.
The JCAIT determined that the immediate cause of the accident was the internal structural failure and drive shaft blow-out of a 36-inch diameter pneumatically-assisted Clow Model GMZ check (non-return) valve. The valve was located on a high-pressure light hydrocarbon gas line installed in the process gas compression (PGC) system of Olefins Plant Number III (OP-III). The check valve’s failure started a large flammable gas leak. The escaping gas formed a vapor cloud and eventually ignited, resulting in an unconfined vapor cloud explosion.
The learning objective of this course is, what lead to the above conclusion.
EPA/OSHAReview the quiz before studying the course.
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