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FINALLY ! -- CSB -2019 Accident Report: Storage Tank Fire at Intercontinental Terminals Company

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MJCronin

Mechanical
Apr 9, 2001
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An important and significant accident report has jsut been released by the CSB, today...



The CSB determined that the cause of the incident was the release of flammable butane-enriched naphtha vapor
from the failed Tank 80-8 circulation pump, which accumulated in the area and ignited, resulting in a fire.
Contributing to the severity of the incident were the absence of a flammable gas detection system to alert the
operators to the flammable mixture before it ignited approximately 30 minutes after the release began, and the
absence of remotely operated emergency isolation valves (ROEIVs) to safely secure the flammable liquids in
Tank 80-8 and the surrounding tanks in the First & Second 80’s tank farm.

Elements of the tank farm design, including tank spacing, subdivisions, engineering controls for pumps located
inside the containment area, and drainage systems also contributed to the severity of the incident by allowing the
fire to spread to other tanks within the tank farm. The resulting accumulation of hydrocarbon and petrochemical
products, firefighting foam, and contaminated water in the secondary containment area ultimately contributed to
a breach of the containment wall and a release of materials to the local waterways.

Finally, the CSB determined that because of the atmospheric storage tank exemption contained in the OSHA
PSM standard and the flammability exemption contained in the EPA RMP rule, ITC was not required to develop
and implement a formal PSM program for Tank 80-8 and its associated equipment that could have provided a
process to identify and control the specific hazards that resulted in this incident, which also contributed to this
incident.


I believe that this CSB Report is highly significant because it points to a significant weakness in the OSHA PSM standard .... the atmospheric storage tank exemption

Please read the report for yourself ...... What do you think ?

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MJCronin
Sr. Process Engineer
 
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This certainly highlights what can go wrong with atmospheric tanks - and this gives clear reasoning why those tanks require the elevated planning and management. Especially if the increased requirements address a multitude of the contributing factors here. I'm not a tank/plant guy so I can't offer any more opinion than that.

I'm a machinery guy, so this did get me thinking about how the design of the pump might be improved for hazardous material service. A single mechanical seal without any leak detection, leak containment, or vibration monitoring system just seems inadequate. ATEX puts requirements on machinery design in flammable service - yet in the OSHA/UL/NFPA world, it seems all of the burden for safe selection, operation, and maintenance of machinery falls on the owner. (Trust me - the ATEX design process is far from perfect, but it at least has the mechanical designs categorized by their capabilities.)
 
Thanks for posting the link. Lots to read and digest.

As a tank builder I don't influence much of this, but I'm astonished by how close together these 15 tanks are, and that they all share a single containment. However looking at the Buffalo Bayou area on Google Maps satellite view, it appears to be standard industry practice to jam tanks together.

I'm afraid the cynic in me figures that the oil-and-gas lobby in Washington and Texas has been very effective in keeping regulations to a minimum.
 
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