CSB releases interim report on Chevron refinery fire

The Chemical Safety & Hazard Investigation Board last week released an interim analysis of the Aug. 6, 2012 refinery fire at a Chevron refinery in Richmond, Calif. The fire started when a corroded pipe ruptured in a crude oil processing unit. CSB identified several failures that led to the fire: “Missed opportunities to apply inherently safer technologies, a failure to recognize and correct workplace hazards, and the lack of industrial safeguards,” reported C&EN’s Jeff Johnson on Friday. CSB’s report is available here, and a Chevron internal report is available here.

One notable set of images in the CSB report is on pdf page 11. The set includes four photographs taken from across the Bay that show the initial hydrocarbon vapor cloud that formed when the pipe burst, followed by the black smoke from the fire. Amazingly, no one was killed when the leaking material ignited. From CSB’s video about the incident and its findings:

A decision was finally made to begin an emergency shut down of the crude unit. But it was too late. Suddenly, the pipe ripped open. A vapor cloud formed and rapidly expanded, as the large inventory of hydrocarbons in the distillation tower started to vent through the ruptured pipe. The vapor cloud immediately spread over hundreds of feet, engulfing all 19 people who had gathered nearby. The firefighters and operators struggled to escape through the dense hydrocarbon cloud, unable to see. They had to feel their way out, some on their hands and knees. At approximately 6:30 p.m., two minutes after the huge vapor cloud formed, the hydrocarbons ignited. One firefighter was trapped inside a fire engine when it was suddenly engulfed in flames. He radioed for help. … But when he received no response, he assumed everyone else was dead. To escape the inferno, he fled through what witnesses described as a wall of fire.

That fire engine was destroyed by the fire.The Chevron report argues that the white vapor cloud itself was not flammable. Instead, material still leaking from the pipe either auto-ignited or dislodged a light fixture, exposing wiring that could have ignited the stream.¬†¬†Chevron’s internal report also says, “The response and assessment after the discovery of the leak did not fully recognize the risk of piping rupture and the possibility of auto-ignition” (Causal Factor 1, pdf page 21).

From pdf page 36 of the CSB report, here’s a graphic that illustrates the number of times someone at Chevron said the pipe should be replaced, and the refinery didn’t do it:
CSB-Chevron-key events

Last but not least, here’s CSB’s video:

Author: Jyllian Kemsley

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2 Comments

  1. I wonder what the pressure is like on oil refineries regarding a production shutdown, and also the maintenance priorities. Was their (from their perspective) a good reason for not replacing the pipe?

  2. @CJ: I only read parts of the reports and what I did read, I read quickly. That said, no, there don’t seem to have been reasons for not replacing the pipe. It doesn’t seem like anyone said, “This pipe wall is getting thin and we need to replace it but we won’t because of X and Y.” It was more that poor communication/training/etc. meant that the people responsible for the pipe did not recognize how perilously thin it had become. Other parts of the line were inspected and replaced at various points. The one stretch kept getting overlooked, despite 100% inspection requirements.