A process running in normal running conditions, while dangerous, is the safest time for any refinery, but when there is a startup or shut down condition, that is the cause of very tense times.
One perfect point in case is Tesoro refinery disaster in Anacortes, Washington April 2, 2010. That accident occurred during startup of the refinery’s “naphtha hydrotreater unit” after a maintenance shut down. A nearly 40-year-old heat exchanger violently ruptured, causing an explosion and fire that killed seven workers – the largest loss of life at a U.S. refinery since 2005.
With that in mind, the U.S. Chemical Safety Board (CSB) released an important safety video into the fatal explosion and fire at the Tesoro refinery.
The CSB’s 14-minute safety video entitled “Behind the Curve” includes a 3D animation of the events that led up to this tragic accident as well as interviews with the CSB’s investigators and chairperson.
“The CSB is seriously concerned by the number of deadly refinery accidents in recent years,” said CSB Chairperson Dr. Rafael Moure-Eraso. “We have concluded that extensive improvements must be made in how refineries are regulated at the state and federal level.”
The CSB’s investigation found an immediate cause of the tragedy to be long-term, undetected High Temperature Hydrogen Attack (HTHA) of the steel equipment, which led to the vessel rupture on the day of the accident. The CSB found the industry’s standard for determining vulnerability of equipment to HTHA, to be inadequate.
“High temperature hydrogen attack, or HTHA, is a common hazard that has long been known within the petrochemical industry,” said Investigator Lauren Grim in the video. “However, Tesoro engineers and corrosion experts did not believe it could occur within the heat exchanger that ultimately failed.”
The CSB’s investigation report, approved in May 2014, found a substandard safety culture at Tesoro, which led to a complacent attitude toward flammable leaks and occasional fires over the years.
In addition, the CSB found that the complexity of the startup procedure typically required more than just one outside operator. Yet operating procedures did not end up updated to account for the role of additional personnel during the hazardous non-routine work.
The CSB made recommendations in these areas to the industry group that issues guidance on HTHA, the American Petroleum Institute, as well as to Tesoro.
“The CSB found that if Tesoro had a strong safety culture, it would have addressed the ongoing leaks and defined a reasonable number of essential personnel for the startup activity,” said Investigator Dan Tillema in the video. “Had Tesoro done these things, we concluded that fewer workers would have been present on the night of the accident, and lives would have been spared.”
The CSB’s final report also recommended the governor and legislature of the State of Washington significantly strengthen the oversight of refineries.
The Board called on the state to require refineries to:
• Conduct more comprehensive hazard analyses and damage mechanism reviews
• Document the effectiveness of process safeguards
• Increase the role for worker representatives in process safety management
• Have company safety reviews examined by technically competent regulators
“Seven lives were lost at Tesoro, Moure-Eraso said. “It should not have happened. Companies, workers, and communities would all benefit from a more rigorous regulatory system that is focused on continuously lowering risks.”