Chevron response to fire threat probed Investigators suspect pipe's insulation masked danger before fire

Looking north towards the crude oil unit damaged in the fire. On the third day after the Chevron refinery fire, more residents sought legal advice and Chevron announced plans to open a help center at the Nevin Community Center in Richmond, Calif. just blocks from the refinery. less Looking north towards the crude oil unit damaged in the fire. On the third day after the Chevron refinery fire, more residents sought legal advice and Chevron announced plans to open a help center at the Nevin ... more Photo: Brant Ward, The Chronicle Photo: Brant Ward, The Chronicle Image 1 of / 1 Caption Close Chevron response to fire threat probed 1 / 1 Back to Gallery

Investigators looking into the fire at the Chevron oil refinery in Richmond suspect that heat insulation around a leaking pipe contributed to the disaster by masking the extent of the danger until it was too late, The Chronicle has learned.

By underestimating the size of the leak, initially believed to be about 20 drips per minute, officials kept operating the refinery's large crude unit, where crude oil is separated under heat reaching 1,100 degrees.

When the insulation was being removed to make the repair, what the company assumed was a small leak "broke loose" and a large amount of hot and volatile diesel-like hydrocarbon spurted out and quickly ignited, said Randy Sawyer, chief of the Contra Costa County hazardous materials unit.

The company has been criticized for running the plant for two hours Monday afternoon after a worker first spotted the leak. The company's account of the events, released Thursday, did not address the nature of the leak other than to say it was being evaluated at the time of the blast with fire crews on standby.

A company spokeswoman, Heather Kulp, characterized talk of the insulation's role in the fire as "purely speculative."

The company had previously cited the small volume of the leak in explaining why it did not act immediately to shut down the unit, which is the heart of the refining process. The apparatus superheats the crude, vaporizing most of it, allowing it to separate into different components that eventually are processed into various products such as gasoline, jet fuel and diesel.

Leak spotted after 4 p.m.

Sawyer said his investigators interviewed the first worker who spotted the dripping from the pipe after 4 p.m. and who took part in removing metal cladding and the heat insulation to expose the pipe, which led out from the crude unit.

"At the time of the fire, operations personnel were in the process of evaluating a reported leak with the assistance of Chevron Fire Department personnel," according to the company's account filed with Sawyer.

Sawyer said workers were taking the insulation off the pipe when the leak "broke loose."

"The piping isn't under very much pressure. It is possible a leak could be absorbed by insulation," he said.

Quick ignition

The hydrocarbon was hot enough to almost instantaneously ignite when it came in contact with the open air. Although an ignition source has not been identified, the fire flared so fast that crews had to abandon a Chevron fire truck parked nearby - it was consumed by flames.

"It's definitely not the same fire truck anymore," Sawyer said. "Everybody got out of there just in time - it happened pretty fast."

Two workers suffered minor burns, the refinery reported.

It took about 10 minutes for the crews to activate a countywide response alarm, a delay that Sawyer said was "not out of the ordinary" under such circumstances. "We would obviously like them to sound the alarm as fast as possible," he said.

Kim Nibarger, a refinery safety expert for the United Steel Workers who has faulted the company's handling of the leak, said the absorption potential of the insulation - or its acting as a shield to restrict the leak - should have been factored in when assessing the possible extent of the danger.

"You should err on the side of safety and not err on the side of profits - it doesn't pay to assume the best, you should assume the worst. You already know it's a problem," Nibarger said. "It can always get worse. I don't know of a situation where a leak has healed itself up."

Nibarger said the company should have started shutting down the crude unit before the insulation was removed, as a precaution if nothing else.

He said the chalk-like insulation probably acted like a bandage, applying pressure to the pipe while keeping the product warm.

'Why flirt with danger?'

"This isn't the first time we have been down this road - when you have a leak, you have an abnormal situation; why flirt with danger?" he said. "Too many times they have gambled with keeping it going, that's the problem. They are gambling with people's lives."

Nibarger said he had seen a photo of the fire truck that was damaged, which provides more evidence the company had no idea what the problem was. "They way underestimated what they were up against," he said.

Meanwhile, in response to an estimated 4,540 residents who sought medical care after Monday's fire, Chevron will open a claims office Friday in Richmond to process applications for payments to cover medical expenses and property damage.