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Louisiana Refinery Accident Database

Marathon Ashland Petroleum (3165), Garyville

LDEQ Accident Report

Pollutants Released

Accident Classified As: Reportable Quantity

Cause of Problem: Human Factors

The Coke Drum was at a higher pressure than normal after the drum swap because HV-0705 was not opened from 40 to 70% prior to the swap. When swapping the offline drum to the blowdown tower, a much larger surge of flow occurred than normal due to the higher drum pressure. This caused the Blowdown Settling Drum to pressure up and its pressure control vent to open to the flare. There were no known offsite impacts. It appears that the operator failed to follow appropriate drum swap procedures, causing the incident to occur.

Discharge Preventable - Yes

The release could have been prevented by following the Coker Drum Swap procedure.

Notes/Remedial Actions

An incident investigation was conducted to determine the cause or causes of the incident. Per this investigation, the root cause was identified as a failure to complete/follow the steps in the Coke Drum Swap procedure. Multiple recommendation items have been identified to prevent a recurrence of this event. The MPC process control department has been tasked with implementing alarms and designing an interlock or control logic to prevent a quick increase in pressure to the Blowdown Settling Drum during a Coker Drum Swap (anticipated completion 9/15/14). The coke drum swap procedure will be modified by 7/7/14 to ensure the outside operator has verified and communicated with the board operator that each step of the procedure has been followed and completed. A training and auditing program will be instituted by 12/2/14 for field and board operators about the importance of procedural compliance.