CSB cites six safety issues in BP refinery explosion

By OGJ editors
HOUSTON, Oct. 28 -- Investigators from the US Chemical Safety and Hazard Investigation Board (CSB) Oct. 27 identified six key safety issues underlying the Mar. 23 explosions and fire at BP PLC's 446,400 b/cd Texas City, Tex., refinery. The incident, which was contained within the plant's 24,300 b/cd isomerization unit, killed 15 workers and injured 170 others (OGJ Online, Mar. 23, 2005).

The six identified safety issues were:

-- Trailers were placed in an unsafe location, too close to an isom process unit. All of the fatalities occurred in and around trailers that were as close as 121 ft from the release of flammable material from a blowdown drum. One trailer 600 ft from the explosions was heavily damaged, and 39 other trailers were either damaged or destroyed.

-- The unit's raffinate splitter should not have been started up due to existing malfunctions of the level indicator, level alarm, and a control valve.

-- The raffinate splitter tower had a history of abnormal start-ups that included recurrent high liquid levels and pressures.

-- On Mar. 23, a blowdown drum vented highly flammable material directly to the atmosphere. The drum was never connected to a flare since its construction in the 1950s. The previous owner of the refinery, Amoco Corp., replaced the isom unit blowdown drum in 1997 with identical equipment; Amoco refinery safety standards recommended connecting the drum to a flare when such major modifications were undertaken, but this was not done.

-- Between 1995 and Mar. 23, 2005, there were four other serious releases of flammable material from the isom blowdown drum and stack that led to ground-level vapor clouds, none of which ignited.

-- In 1992, the US Department of Labor's Occupational Safety and Health Administration cited a similar blowdown drum and stack at the Texas City plant as unsafe because it vented flammable material directly to the atmosphere, but the citation was dropped and the drum was not connected to a flare system.

In May, BP issued a statement blaming personnel mistakes for the refinery explosion. A BP investigative team concluded that personnel failures before and during start-up of the isom unit in the plant led to the explosion and fire (OGJ Online, May 18, 2005).

This month, BP agreed to pay more than $21 million in penalties under a settlement agreement with OSHA for violations connected with the explosion (OGJ Online, Oct. 10, 2005).

What happened
CSBIB investigators released three computer animations of the start-up of the isom unit, the vapor cloud formation, and the subsequent explosions. "The simulations showed a vapor cloud that blanketed much of the nearly 5-acre isom unit just before the cloud was ignited, most likely by an idling diesel pickup truck," investigators said.

The process simulation depicts liquid hydrocarbon flows through a complex of piping connecting a heat exchanger, a furnace, the raffinate splitter tower, and the blowdown drum. "As the temperature and fluid levels increase inside the tower, the animation shows pressure-relief valves directing overflow to the blowdown drum and attached vent stack," investigators said. "The drum rapidly fills, finally causing a geyser-like release of flammable liquids from the top of the vent stack. The vaporizing liquid falls to the ground, where it forms a vapor cloud."

Don Holmstrom, CSB lead investigator, noted, "The first rule of oil refinery safety is to keep the flammable, hazardous materials inside piping and equipment. A properly designed and sized knockout drum and flare system would have safely contained the liquids and burned off the flammable vapors, preventing a release to the atmosphere."

Investigators found evidence that BP evaluated connecting the raffinate splitter to a flare system in 2002 but ultimately decided against it, Holmstrom said. Following the incident, BP said it would eliminate blowdown stacks that vent directly to the atmosphere at all US refineries.

Investigators presented new details on the 16 previous start-ups of the raffinate splitter from 2000 onward. They found 8 start-ups with tower pressures of at least double the normal value and 13 start-ups with excess liquid levels. BP did not investigate any of these abnormal start-ups.

"Investigations of these incidents could have resulted in improvements in tower design, instrumentation, procedures, and controls," Holmstrom stated.

He said there was no supervisor with appropriate experience overseeing the unit's start-up. "Operators did not follow the requirements of start-up procedures, including opening the level control valve for the splitter tower," he said. "This omission allowed the tower level to rise rapidly for 3 hr to 15 times its normal level. Operators were misled by the malfunctioning level indicator on the tower and a separate high-level alarm, which failed to activate."

Investigators also stated that a number of equipment problems made it unsafe to start up the raffinate splitter. "Proper working order of key process instrumentation was not checked as required by the start-up procedure," Holmstrom stated, adding, "Managers turned away technicians and signed off on the instrument tests as if they had been done."

Investigators also found that BP's traffic policy allowed vehicles unrestricted access near process units. On Mar. 23, there were running vehicles, including a diesel pickup truck, as close as 25 ft from the blowdown drum. "A total of 55 vehicles were in the vicinity of the drum, investigators determined, and one likely served as the ignition source for the explosions," Holmstrom said.

CSB earlier this week issued two recommendations to leading US petrochemical trade organizations, calling on the American Petroleum Institute to develop new safety guidance that would establish minimum distances for occupied trailers away from hazardous areas of process plants. The board also called on API and the National Petrochemical & Refiners Association to immediately contact their members urging "prompt action to ensure the safe placement of occupied trailers away from hazardous areas of process plants," before the new API safety guidance is completed.

A final public report of the investigation is expected in 2006.

Related Articles

Union strike under way at US refineries, petchem plants

02/02/2015 The United Steelworkers Union (USW) has instituted a strike at nine US refining and petrochemical production plants following a breakdown in negoti...

Trinidad ULSD plant won’t be built in 2015, Petrotrin executive says

01/28/2015 Trinidad and Tobago’s state-owned Petrotrin has announced that its $500 million ultralow-sulfur diesel (ULSD) plant cannot be commissioned because ...

Vietnam advances Dung Quat refinery expansion plans

01/26/2015 Binh Son Refining & Petrochemical Co. Ltd. (BSR), a subsidiary of state-owned Vietnam National Oil & Gas Group (PetroVietnam), has unveiled...

Varo Energy plans upgrades for Swiss refinery

01/23/2015 Varo Energy BV, a midstream company owned by The Carlyle Group and Vitol Group, plans to invest more than 50 million Swiss francs ($56 million) thi...

Kuwait lets contract for Mina Abdullah refinery

01/22/2015 Kuwait National Petroleum Co. (KNPC), through a subcontractor, has let a contract to Mushrif Trading & Contracting Co. for work related to its ...

Contract let for Aramco’s Jazan refinery, terminal project

01/21/2015 Saudi Aramco, through a contractor, has let a contract to Alderley FZE, Dubai, a division of Alderley PLC, Wickwar, UK, to provide metering systems...

EPA approves revisions to California’s refinery emission regulations

01/20/2015 The US Environmental Protection Agency has issued a final rule approving revisions to portions of California’s state implementation plan (SIP) that...

LyondellBasell expands roles of three senior executives

01/20/2015

LyondellBasell has expanded the roles of senior executives Timothy D. Roberts, Patrick D. Quarles, and Kevin W. Brown.

Senators introduce amendment to end corn ethanol mandate

01/20/2015 US Sens. Dianne Feinstein (D-Calif.), Patrick J. Toomey (R-Pa.), and Jeff Flake (R-Ariz.) introduced legislation to remove the corn ethanol mandate...
White Papers

Pipeline Integrity: Best Practices to Prevent, Detect, and Mitigate Commodity Releases

Commodity releases can have catastrophic consequences, so ensuring pipeline integrity is crucial for p...
Sponsored by

AVEVA’s Digital Asset Approach - Defining a new era of collaboration in capital projects and asset operations

There is constant, intensive change in the capital projects and asset life cycle management. New chall...
Sponsored by

Transforming the Oil and Gas Industry with EPPM

With budgets in the billions, timelines spanning years, and life cycles extending over decades, oil an...
Sponsored by

Asset Decommissioning in Oil & Gas: Transforming Business

Asset intensive organizations like Oil and Gas have their own industry specific challenges when it com...
Sponsored by

Squeezing the Green: How to Cut Petroleum Downstream Costs and Optimize Processing Efficiencies with Enterprise Project Portfolio Management Solutions

As the downstream petroleum industry grapples with change in every sector and at every level, includin...
Sponsored by

7 Steps to Improve Oil & Gas Asset Decommissioning

Global competition and volatile markets are creating a challenging business climate for project based ...
Sponsored by

The impact of aging infrastructure in process manufacturing industries

Process manufacturing companies in the oil and gas, utilities, chemicals and natural resource industri...
Sponsored by

What is System Level Thermo-Fluid Analysis?

This paper will explain some of the fundamentals of System Level Thermo-Fluid Analysis and demonstrate...
Available Webcasts


The Alternative Fuel Movement: Four Need-to-Know Excise Tax Complexities

When Thu, Jun 4, 2015

Discussion on how to approach, and ultimately embrace, the alternative fuel market by pulling back the veil on excise tax complexities. Taxes may be an aggravating part of daily operations, but their accuracy is crucial in your path towards business success.

register:WEBCAST



On Demand

Prevention, Detection and Mitigation of pipeline leaks in the modern world

Thu, Apr 30, 2015

Preventing, detecting and mitigating leaks or commodity releases from pipelines are a top priority for all pipeline companies. This presentation will look at various aspects related to preventing, detecting and mitigating pipeline commodity releases from a generic and conceptual point of view, while at the same time look at the variety of offerings available from Schneider Electric to meet some of the requirements associated with pipeline integrity management. 

register:WEBCAST


Global LNG: Adjusting to New Realities

Fri, Mar 20, 2015

Oil & Gas Journal’s March 20, 2015, webcast will look at how global LNG trade will be affected over the next 12-24 months by falling crude oil prices and changing patterns and pressures of demand. Will US LNG production play a role in balancing markets? Or will it add to a growing global oversupply of LNG for markets remote from easier natural gas supply? Will new buyers with marginal credit, smaller requirements, or great need for flexibility begin to look attractive to suppliers? How will high-cost, mega-projects in Australia respond to new construction cost trends?

register:WEBCAST


US Midstream at a Crossroads

Fri, Mar 6, 2015

Oil & Gas Journal’s Mar. 6, 2015, webcast will focus on US midstream companies at an inflection point in their development in response to more than 6 years shale oil and gas production growth. Major infrastructure—gas plants, gathering systems, and takeaway pipelines—have been built. Major fractionation hubs have expanded. Given the radically changed pricing environment since mid-2014, where do processors go from here? What is the fate of large projects caught in mid-development? How to producers and processors cooperate to ensure a sustainable and profitable future? This event will serve to set the discussion table for the annual GPA Convention in San Antonio, Apr. 13-16, 2015.

This event is sponsored by Leidos Engineering.

register:WEBCAST


Careers at TOTAL

Careers at TOTAL - Videos

More than 600 job openings are now online, watch videos and learn more!

 

Click Here to Watch

Other Oil & Gas Industry Jobs

Search More Job Listings >>
Stay Connected