Important Process Safety Lessons
The Marathon Martinez Update
The U.S. Chemical Safety Board (CSB) has published an update to the fire that occurred at the Marathon Martinez Renewable Facility in November 2023. (There were no fatalities, but one person was very seriously injured.)
From a process safety point of view two features of this event caught my attention.
The incident occurred during a start-up, and
A manual bypass valve was incorrectly open and its status had been overlooked.
Start-Up
The following is from our book Process Risk and Reliability Management.
The start-up phase is often a hazardous time because the facility is in a dynamic state with conditions constantly changing. Also, operations personnel, even those with considerable experience on the unit in question, may not be familiar with start-up conditions. Ironically, the improvements in system reliability brought about by risk management programs may mean that many personnel have little or no familiarity with a full start-up because the facility can run for years without a full turnaround.
Manual Bypass
The furnace where the accident took place had a low flow interlock. Therefore, if the flow of liquid through the furnace tubes was too low, the furnace would shut down. However, there was an open manual bypass around the furnace. It appears as if the flow through the flowmeter was high enough to prevent the interlock from shutting down the furnace.
These initial findings all need to be confirmed as the investigation proceeds. But we can already see that there are some important process safety lessons to be learned.
