Accident: Motiva Enterprises Sulfuric Acid Tank Explosion
Location: Location: Delaware City, DE
Accident Occurred On: 07/17/2001 | Final Report Released On: 08/28/2002
Accident Type: Hot Work - Explosion and Fire
Investigation Status: The final report on this investigation was approved on August 28, 2002.
On July 17, 2001, an explosion occurred at the Motiva Enterprises refinery in Delaware City, Delaware. A work crew had been repairing a catwalk above a sulfuric acid storage tank farm when a spark from their hot work ignited flammable vapors in one of the tanks. This tank had holes in its roof and shell due to corrosion. The tank collapsed, and one the contract workers was killed; eight others were injured. A significant volume of sulfuric acid was released to the environment.
Work with NACE International (National Association of Corrosion Engineers) to develop API guidelines to inspect storage tanks containing fresh or spent H2SO4 at frequencies at least as often as those recommended in the latest edition of NACE Standard RP 0294-94, Design, Fabrication, and Inspection of Tanks for the Storage of Concentrated Sulfuric Acid and Oleum at Ambient Temperatures.
Revise API tank inspection standards to emphasize that storage tanks with wall or roof holes or thinning beyond minimum acceptable thickness that may contain a flammable vapor are an imminent hazard and require immediate repair or removal from service.
Ensure that API recommended practices address the inerting of flammable storage tanks, such as spent H2SO4 tanks. Include the following: - Circumstances when inerting is recommended. - Design of inerting systems, such as proper sizing of inerting equipment, appropriate inerting medium, and instrumentation, including alarms.
Communicate the findings and recommendations of this report to your membership.
Ensure that regulations developed for the recently enacted Jeffrey Davis Above ground Storage Tank Act require that facility management take prompt action in response to evidence of tank corrosion that presents hazards to people or the environment.
In light of the findings of this report, conduct periodic audits of storage tank mechanical integrity and design, Unsafe Condition Reports, hot work, management of change, and accountability systems at Motiva oil refineries. Ensure that the audit recommendations are tracked and implemented. Share the findings with the workforce.
Communicate the findings and recommendations of this report to the workforce and contractors at all Motiva refineries.
Implement a system to ensure accountability for mechanical integrity decision making. Include the following specific items: - Review of inspection reports by subject area experts, such as metallurgists or equipment design engineers, to ensure adequate analysis of failure trends and suitability for intended service. - Establishment of a planning system to ensure the timely repair of equipment. The Center for Chemical Process Safety (CCPS) publication, Plant Guidelines for Technical Management of Chemical Process Safety, Chapter 3, ?Accountability Objectives and Goals,? presents a model for such a system.
Review the design of existing tankage that contains or has the potential to contain flammables to ensure that, at a minimum:: - Inerting systems are installed where appropriate and are adequately sized and constructed. - Emergency venting is provided.
Ensure that management of change reviews are conducted for changes to tank equipment and operating conditions, such as: - Tank service and contents - Tank peripherals, such as inerting and venting systems.
Revise the refinery hot work program to address the circumstances that require use of continuous or periodic monitoring for flammables.
Upgrade the refinery Unsafe Condition Report system to include the following: - Designation of a specific manager with decision-making authority to resolve issues. - Establishment of a mechanism to elevate attention to higher levels of management if issues are not resolved in a timely manner. - Identification of a means to ensure communication of hazards to all potentially affected personnel. - Work with the Paper, Allied-Industrial, Chemical & Energy Workers International Union (PACE) Local 2-898 to design and implement the improved system.
Work with the American Petroleum Institute to develop API guidelines to ensure that storage tanks containing fresh or spent H2SO4 are inspected at frequencies at least as often as those recommended in the latest edition of NACE Standard RP 0294- 94, Design, Fabrication, and Inspection of Tanks for the Storage of Concentrated Sulfuric Acid and Oleum at Ambient Temperatures.
(Superseded by 2019-01-I-TX-R7 from the Intercontinental Terminals Company (ITC) report)
Ensure coverage under the Process Safety Management Standard (29 CFR 1910.119) of atmospheric storage tanks that could be involved in a potential catastrophic release as a result of being interconnected to a covered process with 10,000 pounds of a flammable substance.
Work with Motiva management on the design and implementation of an improved Unsafe Condition Report program.