The Texas City Refinery Explosion

When systems and controls deteriorate, everything can come together in the worst possible way.

The Texas City Refinery is BP’s largest and most complex oil refinery, with a rated capacity of 460,000 barrels per day and production of up to 11 million gallons of gasoline a day. It also produces jet fuels, diesel fuels and chemical feed stocks.

The refinery has 30 process units spread over a 1,200-acre site and employs about 1,800 permanent BP staff.

On Wednesday March 23, 2005, the BP Texas City refinery experienced a catastrophic process accident - the startup of the isomerization (ISOM) unit (after a temporary downtime) led to an explosion.

It was one of the most serious United States workplace disasters of the past two decades, resulting in 15 deaths and more than 170 injuries.

According to the U. S. Chemical Safety and Hazard Investigation Board report into the incident:

Actions taken or not taken led to overfilling the raffinate splitter with liquid, overheating of the liquid and the subsequent overpressurisation and pressure relief.

Hydrocarbon flow to the blowdown drum and stack overwhelmed it, resulting in liquids carrying over out of the top of the stack, flowing down the stack, accumulating on the ground, causing a vapour cloud, which was ignited by an abandoned white pickup truck with the ignition on.”

Underlying Causes

These underlying causes of the incident were identified as follows:

• Over the years, the working environment had eroded to one characterized by resistance to change, and lacking of trust, motivation, and a sense of purpose. Coupled with unclear expectations around supervisory and management behaviors this meant that rules were not consistently followed, rigor was lacking and individuals felt disempowered from suggesting or initiating improvements.
  
• Process safety, operations performance and systematic risk reduction priorities had not been set and consistently reinforced by management.
  
• Many changes in a complex organization had led to the lack of clear accountabilities and poor communication, which together resulted in confusion in the workforce over roles and responsibilities.
  
• A poor level of hazard awareness and understanding of process safety on the site resulted in people accepting levels of risk that are considerably higher than comparable installations. One consequence was that temporary office trailers were placed within 150 feet of a blowdown stack which vented heavier than air hydrocarbons to the atmosphere without questioning the established industry practice.
  
• Given the poor vertical communication and performance management process, there was neither adequate early warning system of problems, nor any independent means of understanding the deteriorating standards in the plant.

Internal Control Observations

A Panel of Experts led by the former US Secretary of State James Baker analysed all aspects of the process, safety and internal control environment at all US BP refineries.

Amongst many observations they noted:

• BP had not provided effective process leadership and had not adequately established process safety as a core value across all its five U.S. refineries. While BP had an aspirational goal of “no accidents, no harm to people,” BP had not provided effective leadership in making certain its management and U.S. refining workforce understood what was expected of them regarding process safety performance.
  
• BP did not effectively incorporate process safety into management decision-making. BP tended to have a short-term focus, and its decentralized management system and entrepreneurial culture had delegated substantial discretion to U.S. refinery plant managers without clearly defining process expectations, responsibilities, or accountabilities.
  
• While accountability is a core concept in BP’s Management Framework for driving desired conduct, BP had not demonstrated that it had effectively held executive management and refining line managers and supervisors, both at the corporate level and at the refinery level, accountable for process performance at its five U.S. refineries.
  
• While all of BP’s U.S. refineries had active programs to analyze process hazards, the system as a whole did not ensure adequate identification and rigorous analysis of those hazards. The Panel’s examination also indicated that the extent and recurring nature of this deficiency is not isolated, but systemic.
  
• BP’s corporate management system did not ensure timely implementation of external good engineering practices that support and could improve process safety performance at BP’s refineries.
  
• BP had not instituted effective root cause analysis procedures to identify systemic causal factors that may contribute to future accidents. The Panel indicated that when true root or system causes were not identified, corrective actions may address immediate or superficial causes, but not likely the true root causes.

The Panel noted that many of the process deficiencies were not new but were identifiable to BP based upon lessons from previous events, including process incidents that occurred at BP’s facility in Grangemouth, Scotland in 2000.

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The Panel’s report noted in its summary:

The passing of time without a process incident is not necessarily an indication that all is well and may contribute to a dangerous and growing sense of complacency.

When people lose an appreciation of how their systems were intended to work, systems and controls can deteriorate, lessons can be forgotten, and hazards and deviations from operating procedures can be accepted.

Workers and supervisors can increasingly rely on how things were done before, rather than rely on sound engineering principles and other controls.

People can forget to be afraid.