Professionalism/The Valero Refinery Fire

The Valero Refinery fire refers to the Mckee refinery propane fire that broke out on February 16, 2007. The refinery, built in 1933 by Shamrock Oil and Gas Corporation, was acquired by Valero in 2002. Since then, it has gone through major upgrades to expand its processing activities and increase its production capacity to 170,000 barrels per day. The refinery, located in Sunray, Texas (fig. 1), employs more than 450 individuals.

Figure 1. Sunray, Texas outlined in red

Background

The McKee Refinery had already experienced a tragic accident in 1956, which resulted in the death of nineteen firefighters. In the 2007 incident, a propane pipe leaked, leading to a fire that spread due to multiple mechanical failures (fig. 2). Fifteen minutes after the fire erupted, the management evacuated the refinery, preventing any fatalities. However, three workers were severely burned. The size of the fire and the high, shifting winds hampered the firefighters’ efforts. It took them more than twenty-six hours to put the fire out completely. The fire halted all operations at the refinery for two months. Once work resumed, the refinery operated at reduced capacity for over a year.

Figure 2. 2007 Valero McKee Refinery fire in Sunray, Texas

Two days after the incident, the United States Chemical Safety Board (CSB) initiated an independent investigation to determine the causes of the accident. After interviewing the workers and reviewing the company’s documents and data sheets, the CSB published a full report in July 2008 identifying the causes of the incident. The CSB issued a total of twelve recommendations to prevent such incidents from happening in the future. The recommendations were directed at the American Petroleum Institute (API), the United Steelworkers of America (USWA), Valero Energy Corporation, and the McKee Refinery. The API, the trade association for the oil and gas industry in the United States, was involved in this investigation. The API's industry standards failed to recognize freezing hazards, which were determined to be the root cause of this incident. FM Global cited "151 freeze incidents in industry with an average estimated gross loss of about $115,000 per incident from 1991 to 2000."

Sequence of Events

A section of a pipe in one of the units at the refinery was discontinued; all of the valves were closed, creating a dead leg, which is a section of the piping without any flow. A piece of scrap metal wedged itself under a valve gate and blocked one of the valves from closing properly. This piece of metal created a pathway for water to flow through the valve and build up in the dead leg. On February 15, 2007, the temperature dropped to 6°F in Sunray, Texas. The accumulated water in the pipe froze and expanded. This expansion led to a crack in the pipe elbow (fig. 3). When the temperature increased above the freezing point on February 16, the ice in the pipe melted.

Figure 3. Propane vapor release from cracked pipe elbow

High pressure, liquid propane then escaped from the cracked pipe, and the flammable vapor reached the boiler house. Nearby pipes ignited, and a second fire started. The secondary fire spread to a non-fireproofed support structure, which collapsed. The pipes supported by this structure failed and released large quantities of flammable vapor. The refinery managers immediately called for total evacuation of the site.

There were also two near-miss incidents. Three one-ton chlorine containers were 100 feet away from the unit. One container ruptured from the heat, and the plugs on all three melted. The chlorine gas released could have been fatal if operators had not been evacuated. There were also four butane storage spheres located near the unit. One sphere began to overheat because of the fire. If the wind were stronger on that day, the fire could have spread to these spheres, causing them to explode and release high-pressure butane vapor.

Related Incidents

1956 Shamrock Oil and Gas Corporation Fire

On July 29, 1956, a similar explosion occurred at the McKee Refinery, then owned by Shamrock Oil and Gas Corporation. During this incident, flammable pentane and hexane vapors were released from a spherical tank, similar to the butane storage spheres in the 2007 incident. While the root cause of this vapor release is unknown, speculations suggest that a line break or a pump leak led to the incident. A light wind was blowing that day and carried the vapors toward a tank with a small fire underneath it. The vapors ignited, and the fire reached the storage tank, which then overheated and exploded. Nineteen firefighters died, and thirty people were injured because of the fire. A statue in front of the Sunray City Hall commemorates the firefighters who died during the incident. According to the McKee Refinery's Fire Chief, Mike Roberts, "There wasn't much or certainly not enough known about [boiling liquid expanding vapor explosion] back then."

1947 Texas City Disaster

Another major fire occurred nearby nine years before the Shamrock incident. On April 16-17, 1947, two major explosions occurred in Texas City, Texas.. A French-owned ship, the S.S. Grandcamp, caught on fire on April 16, and exploded because of ammonium nitrate fertilizer. About 16 hours later, the S.S. High Flyer, another ship also containing ammonium nitrate, exploded. The explosions destroyed a plant owned by Monsanto Chemical Company, grain warehouses, and storage tanks at nearby refineries. According to Stephens (1997), the explosion of the S.S. Grandcamp represents the worst industrial disaster in U.S. history. The incident resulted in over 468 deaths, 100 missing individuals, and 3,500 injuries. A total of $500 million worth of petroleum products were ruined. Also, the destroyed Monsanto facility was valued at $20 million in 1947.

Recommendations

American Petroleum Institute

The bulk of the CSB recommendations were for the API to modify its industry standards. These recommendations included the following:

• Issuing API-recommended practices for freeze protection at oil refineries to inspect dead-legs and other freeze hazards frequently

• Increasing the radius around highly flammable chemicals in which fireproofing is necessary

• Reviewing the fire protection in refineries to enable safe and rapid isolation of process equipment that contains highly pressurized flammable gases

• Reviewing the storage facilities' standards to include an effective emergency deluge system at nearby facilities

Valero Energy Corporation

Other recommendations, directed at Valero Energy Corporation, included the following:

• Installing Remotely-Operable Shut-off Valves (ROSOVs) on all pipelines containing flammable materials

• Establishing a written program for freeze protection that includes identification, mitigation, and audit requirements

• Requiring fireproofing pipe rack support steel for units that contain flammable gases

• Replacing the chlorine used in cooling water treatment units with safer chemicals at all refineries

The CSB recommended Valero and the USWA to work together on improving fireproofing standards and to require discussion of this aspect in all process hazard analysis reports.

Lessons Learned

Transfer of Knowledge

One generalizable lesson from the 2007 catastrophe is the importance of the transfer of knowledge between generations. Thorough analysis of hazards based on previous incidents would have mitigated the risks and consequences of the 2007 incident. Previous incidents, such as the 1956 fire, could be incorporated in training modules to emphasize the importance of safety precautions. If similar catastrophes occur two generations apart, there could be a break in knowledge. Institutions should encourage the transfer of knowledge by ensuring a wide age distribution, holding training sessions led by experienced employees, and establishing mentoring programs and shadowing opportunities.

According to Argote & Ingram (2000), performance-based, experiential methods can effectively assess knowledge transfer within an organization. Indigenous groups exemplify the successful transfer of knowledge between generations. Sillitoe (1998) claims that indigenous communities often transfer knowledge through traditions and experiences instead of transferring them verbally. Indigenous groups rely on traditional knowledge to classify plants and animals and extract valuable resources. According to Posey (2000) and Sillitoe (1998), indigenous people encourage grassroots participation, instead of employing top-down management, and have an intrinsic concern for the well-being of future generations. Frequent performance-based evaluations and corporate encouragement of employee participation could improve generational knowledge transfer in the chemical industry.

Smart Maintenance Strategy

Valero had a policy to check pipes annually in the Fall. In February, temperatures in Sunray, Texas fall below the freezing point. The freezing water in dead legs was the root cause of the fire. If the pipes were checked regularly throughout the winter, operators would have identified the frozen pipe and the fire could have been avoided. Valero recognized the cracked pipe as a dead leg fifteen years prior to the 2007 incident. If a pipe is not being used in a system, it should be removed entirely. Also, the failure of the non-fireproofed support structure represents poor design, construction, and maintenance.

Preparing for the Worst

Over 300 employees worked at the refinery in 2007. Valero's management team successfully evacuated the entire refinery within fifteen minutes of the outburst. Emergency strategies are important, especially at refineries. Thanks to Valero's attentiveness and preparation, there were no casualties from the fire, which is a great improvement from the 1956 fire.

Conclusion

This incident exemplifies three sociological concepts. The refinery had been storing toxic chlorine gas for cooling water processing units, even though safer alternatives were available. These chlorine tanks were stored in close proximity to flammable chemicals solely for convenience. Because the company had been operating this way for years with no major accidents, the management’s tolerance for this safety risk increased. Therefore, the normalization of deviance concept explains Valero’s behavior.

While Valero’s management had been aware of the dead leg for fifteen years, the company did not have a strict policy to inspect dead legs, and no action was taken to remove the dead leg from the unit. Valero had been conducting a checkup once each fall but not during the winter, when freeze protection is a major concern. Valero’s passive approach to address these concerns exemplifies the status quo bias and the bystander effect.

Despite Valero’s apathy to multiple safety concerns, the management responded quickly on the day of the incident. Valero's management showed professional judgement in valuing the lives of the workers over the refinery’s production capacity. By evacuating the facility, the managers of the McKee Refinery avoided repeating history and prevented any fatalities.