RICHMOND — Investigators are trying to determine why the leaky pipe that sparked Monday’s massive Chevron refinery fire was not replaced during a round of maintenance last year on No. 4 Crude Unit and said the event ranks as among the most serious refinery accidents in years.
The team of U.S. Chemical Safety Board investigators painted a frightening picture of the seconds after the pipe released a 600-degree “gas-oil” liquid that created a highly flammable vapor cloud that quickly engulfed Chevron employees.
“Witness testimony collected by CSB investigators indicates that a large number of workers were engulfed in the vapor cloud,” said team lead Dan Tillema. “These workers might have been killed or severely injured, had they not escaped the cloud as the release rate escalated and the cloud ignited, shortly thereafter.”
The chemical board’s chairperson Dr. Rafael Moure-Eraso said: “Monday’s fire was a near-disaster for refinery personnel. The circumstances warrant a full and independent federal investigation to determine the root causes. Although fortunately no workers were killed, the overall impact of the incident ranks it as among the most serious U.S. refinery incidents in recent years.”
A pipe adjacent to the leaky pipe was reportedly replaced during the maintenance last year, but not the 8-inch one. Federal investigators plan to determine what procedures and industry practices exists for combustible material leak response froma running unit. Critics have questioned why Chevron did not shut down the crude processing unit while investigating the leak. The oil company’s officials have said shutting down the plant can cause other dangers and is not always the best decision.
Chevron did not immediately return an e-mail asking for comment.
The federal board also said the incident had serious repercussions on the surrounding community.
“Area hospitals told CSB investigators that they attribute hundreds of emergency room visits by community members to reported effects of the release and fire, with symptoms ranging from anxiety to respiratory distress,” said CSB board member Mark Griffon, who was accompanying the team of seven investigators that arrived in Richmond on Wednesday.
The group has conducted witness interviews and reviewed documents, and plan to let their structural and industrial safety experts visit the fire site Monday once the area has been deemed safe.
They plan to do independent testing of the leaking section of the pipe to determine the failure mechanism.
The federal investigators say Chevron and its workers, largely represented by United Steelworkers, have been cooperating and the oil giant has provided assurances that employees “will freely share their knowledge and investigative information.”