History 8 Electrical and Instrumentation Room Explosion

Case History 8 Electrical and Instrumentation Room Explosion 

On October 30, 1998, a flammable gas release led to gas migration to a non-electrically classified Electrical and Instrumentation (E l) Room. The flammable gas was ingested into the exterior heating and ventilation inlet duct. When the 480 volt primary power switch, within the E l room was remotely shut off, an explosion resulted. The E l module explosion led to a subsequent fire in adjacent production buildings. There were no injuries to personnel. The root cause of the incident was determined to be the failure of management systems 

At 1 14 p.m., the operator received a radio transmission from the PCC (Process Control Center) informing him that a low gas alarm had been received. Immediately, the operator was informed of two more gas alarms. Upon reaching the E l module, the operator noted the sound of gas escaping somewhere inside the production module. At approximately 1 22 p.m. he climbed the stairs to the E l control room and opened the door to check the fire and gas alarm panel which indicated a high gas atmosphere in the production modules. The operator then requested the Emergency Response Team be put on standby and went to inform three contract workers, in the area of the danger. 

Once the contract personnel were safely off pad, the operator moved to a safe observation and contacted the PCC operator to order a process shutdown. The PCC operator acknowledged and replied that the shutdown signal had been sent. At approximately 1 28 p.m. an explosion occurred in the E l module and soon after, fire was noted coming from the adjacent process modules. 

The root cause of the incident was determined to be the failure of management systems to adequately understand and address the hazards. 

---