California Emphasis Program Confirms Refineries in Good Shape

An examination of 11 refineries by Cal/OSHA's Process Safety Management Unit found they are properly managing the risks that caused the April 2010 explosion at the Tesoro refinery in Anacortes, Wash., in which seven workers died.

• By Jerry Laws
• Oct 18, 2010

In April 2010, in response to an April 6 explosion in a heat exchanger at Tesoro Corp.'s refinery in Anacortes, Wash., Cal-OSHA's Process Safety Management Unit checked 11 California refineries to make sure they were controlling the corrosion in their heat exchangers to prevent a similar incident.

The Division of Occupational Safety and Health (DOSH) of Washington state's Department of Labor & Industries issued a record $2.39 million fine on Oct. 4 to Tesoro Refining & Marketing Co. in connection with the Anacortes blast, saying the company had not properly tested the heat exchanger in the plant's naphtha hydrotreater unit. The explosion had killed seven workers. The Washington inspection report includes 40 willful violations and five serious violations assessed against Tesoro. The assessed violations allege Tesoro did not properly train or equip workers at the Anacortes refinery with PPE and did not inspect or test equipment properly. The report includes a Hazard Correction Form, with corrections to be completed by Oct. 19 (unless the company sought an extension of the deadline), posted on site, and sent to L&I.

DOSH tested the unit's heat exchangers after the explosion and found extensive cracking that Tesoro should have detected, the agency alleged. The exchangers are nearly 40 years old and had been subjected to extreme heat and pressure, wide temperature and pressure swings, extensive chemical exposure, and a near doubling of production over the years, according to DOSH.

"If Tesoro had tested their equipment appropriately and had followed their other safety requirements, we believe that they would have found the cracks that caused this explosion and, either by replacing the equipment or repairing it, prevented this from happening," said Dr. Michael Silverstein, assistant director of DOSH.

Tesoro is based in San Antonio. It operates a total of seven refineries, including one located in Martinez, Calif. The Cal/OSHA PSM Unit concluded its California Emphasis Program in September and on Oct. 11 released its report confirming the Martinez refinery and 10 other California refineries are properly managing their hydrotreater corrosion risks.

Clyde Trombettas, the PSM Unit's Northern District manager, said a cooperative relationship between the unit and refiners operating in the state helped to make the in-depth review possible.

"We wanted to know, what precautions do you have in place to make sure this type of event does not happen? Not necessarily specifically in the naphtha unit, but in other high corrosion-susceptible units, as well," said Trombettas.

Five employees from the unit spent six months examining documents and visiting the refineries to evaluate the processes and safeguards in place. Their report lists a series of processes used by the refineries to control and detect corrosion and high temperature hydrogen attack (HTHA), which is a long-term corrosion phenomenon that can weaken naphtha hydrotreater units.

The report says the Cal/OSHA inspectors found that major oil refiners commonly operate their equipment 50 degrees F above the carbon steel Nelson curve for C-1/2 Mo equipment (referenced in API 941, Steels for Hydrogen Service at Elevated Temperatures and Pressure in Petroleum Refineries and Petrochemical Plants). "However," it explains, "the equipment is prioritized for appropriate assessment, inspection and maintenance based on temperature, hydrogen partial pressure, operating time, thermal history of steel during fabrication, stress, cold work, age, presence of cladding. California refiners recognize that cumulative operating time above the Nelson Curve increases equipment susceptibility to HTHA."

The 11 California refineries' units on average have been in service for 25 to more than 30 years, but the metallurgy in every facility's unit "had been upgraded over time both in response to, then in anticipation of the effects of" corrosion, the report states. It concludes, "The California refining industry collectively meets the challenges presented by corrosion phenomena known for decades to exist in the Naphtha Hydrotreating process."

"Crude production is an inherently dangerous industry, but California's refineries are some of the safest in the nation due to the PSM Unit's multi-dimensional approach to refinery safety," said Cal/OSHA Chief Len Welsh. "Thanks in large part to the oversight of our PSM Unit, California's refiners use the most effective measures available to monitor corrosion, measures that were not used at the Tesoro plant in Washington State."

'PSM Constantly Changes'
Trombettas worked in refining before he joined the division 10 years ago. Its relationship with refiners was more adversarial then, he said, but the unit's members decided to change that. They felt they could continue to carry out enforcement while offering outreach and training. They encouraged refiners to participate, such as by allowing new compliance officers in the unit to receive two weeks of operator training to familiarize themselves with the equipment and processes.

"Doing that, they know that when an event occurs, they've got a compliance person who understands how a refinery operates. The refineries have really embraced that as well as we have embraced it," Trombettas said. "Even though we may have our enforcement activities that may sometimes muddy that relationship a little bit, it still continues on. This developing relationship in my mind is much better than just doing constant enforcement."

Because Process Safety Management is a performance-based standard, compliance personnel must define the benchmarks they want refineries to meet. A working relationship really helps there, he said.

"Fortunately, California refiners have a really good metallurgical department" and are skilled at corrosion control and non-destructive testing, he said. "We really have a good dialogue."

For example, unit personnel said a cracked line at the Valero Refining Co. refinery in Benicia, Calif., needed encapsulation and a post-weld heat treat. The refinery's management said maintaining it above 500 degrees meant the treatment was not needed, so a shutdown would not be necessary. They discussed it, and the refinery won the argument, he said.

The PSM Unit performs planned inspections and accident investigations. "The routine oversight of the PSM Unit has promoted the ability and readiness of Cal/OSHA and industry representatives to pick up the phone and ask questions of each other. This has resulted in a teamwork approach that is highly valued," said Terry Schulte, VPP coordinator for the Valero refinery in Benicia. "The Valero Benicia refinery's involvement in the VPP further enhances that working relationship."

Trombettas said personnel in the unit have a good idea now what went wrong at Anacortes because the chief metallurgist from Tesoro's corporate office gave them a briefing in September. "That's really huge," he said, "to have an employer be that comfortable to have someone coming in to give a presentation like that -- it really speaks highly of the regulated community here."

Trombettas said no other state conducted a similar review of its refineries following the Anacortes explosion because none of them has a dedicated PSM unit. Other states may have a team consisting of a few people, but they do not focus fully on process safety, he said.

"PSM constantly changes. What was good practice today, 10 years from now may not be good practice," Trombettas said. "So you have to constantly be up on training, understand new technology, understand new methods of doing things. It kind of behooves you to have some type of working relationship."

He said he has talked often this year with his federal counterparts, suggesting they follow the same approach.