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TRANSCRIPT
BUNCEFIELD
Tenth Year Anniversary Where are we now?
Outline
Background – Incident description – Containment failures – Overall consequences
Major Incident Investigation Board (MIIB) Process Safety Leadership Group (PSLG) Have we learned the lessons? Summary
Background
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Hemel Hempstead, England – Three operating sites with a consent to store 194.000
tones of hydrocarbon fuels
http://www.buncefieldinvestigation.gov.uk/images/index.htm
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7 pm, Dec 10
• Tank 912 started receiving unleaded motor fuel from the pipeline
3 am, Dec 11
• The level gauge for Tank 912 recorded an unchanged reading. Filling of the tank continued
05:20 am
• Tank 912 was completely full and started to overflow. Protection systems did not work
5:38 am • Vapor from the escaping fuel is first visible
5:46 am
• Vapor cloud reached a height of about 2 m and was flowing out in all directions
6:01 am
• First explosion occurred, followed by more explosions and a fire that engulfed over 20 storage tanks. Fire continued until Dec 15
Timeline
Overfilling of Tank 912 resulted in the flow from the breather holes at the top of the tank
The flow was very efficiently fragmented, and created relatively small droplets falling freely through air around the tank
The free fall of fuel droplets through the air also leads to entrainment of air and mixing between the air and fuel vapor
5 http://www.buncefieldinvestigation.gov.uk/images/index.htm
Background – Vapor Cloud Generation
Background – Vapor Cloud Dispersion and Ignition
Vapor dispersion Vapor can move with wind, and mix with air
further – The vapor concentration reached the point where it
could support an explosion
Possible ignition sources Fire pump house Emergency generator Car engine
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Background – Containment Failures
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Two sets of alarm system: 1. Automatic tank gauging (ATG) system 2. Independent ultimate high level switch ATG system was showing a static level reading after 3 AM No ultimate high level alarm was received
Primary containment failed
http://www.buncefieldinvestigation.gov.uk/images/index.htm
Background – Containment Failures
Pipe penetrations
Bund joints (crack formation)
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Secondary containment failed
http://www.hse.gov.uk/comah/buncefield/buncefield-10-years-on.pdf
Background – Containment Failures
Tertiary containment – Ensures that liquids could not
be released outside the containment region
– Pollutants from fuel and firefighting liquids leaked from the bund, flowed off site and entered the groundwater
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Tertiary containment failed
http://www.hse.gov.uk/comah/buncefield/buncefield-10-years-on.pdf
Background – Overall Consequences
Overall financial impact likely to exceed £5Billion
No fatalities
43 people injured in the incident, none seriously
10 http://www.buncefieldinvestigation.gov.uk/images/index.htm
Major Incident Investigation Board (MIIB)
Identified areas for improvement and gave several recommendations in the following areas: – Design and operation of fuel storage sites – Emergency preparedness for, response to and recovery
from incidents – The explosion mechanism advisory group report – Land use planning and the control of societal risk
around major hazard sites
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Control of Major Accident Hazards (COMAH) Competent Authority (CA) Developed a guidance in response to MIIB
recommendations: – CA guidance on emergency planning arrangements for
COMAH establishments CA designated emergency response arrangements
as a priority topic for inspection and developed further guidance to assist its inspectors in ensuring all COMAH businesses meet the requirements
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Process Safety Leadership Group (PSLG)
Created in September, 2007 Addressed specific topics related to the MIIB
recommendations – In 2009 the PSLG published the Safety and
Environmental Standards for Fuel Storage Sites • Key improvements required by PSLG:
– A review of the risks associated with filling large petrol storage tanks
– Ensuring large petrol storage tanks do not lose containment
– Ensuring effective leadership and an understanding of the risks associated with the management of sites that store petrol
– A review of how emergency services and industry respond to major incidents
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Progress Against the PSLG Recommendations
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Systematic Assessment of Safety Integrity Level Requirements
Risk assessment done by operators to re-evaluate the risks associated with overfilling a petrol storage tank
Better understanding of automatic protection systems
Document the risk assessments to demonstrate the Competent Authority (CA) how the operator manages the major accident hazard risks
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Protecting Against Loss of Primary Containment
Primary objective: Level detection in the tank
Operators have to assess their tank capacities and ensure that normal operating level, overfill level and alarm systems are appropriate
Test the protection systems In 2008, the industry
committed to install automatic overfill protection systems
16 http://www.hse.gov.uk/comah/buncefield/buncefield-10-years-on.pdf
Engineering Against Escalation of Loss of Primary Containment
Understanding of where an explosive atmosphere might occur
Ensure that emergency equipment is reachable and effective
Emergency plans and arrangements have also been reviewed and updated – Synergy between emergency services, relevant agencies and
bodies • Understanding of their role and responsibilities
For new sites – Closed Circuit Television (CCTV) – Gas detection of flammable vapor clouds
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Engineering Against Escalation of Loss of Secondary and Tertiary Containment
Immediate improvements have been implemented – Gaps sealing around pipework that enters the bund – Assessing and improving the integrity of concrete bund
wall joints • Fire proof steel plates where appropriate
Learn the hazards of chemicals and treat them in the right way – “Environmental Risk Tolerability for COMAH
Establishments” was developed by a joint industry/regulator group
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Operating With High Reliability Organizations
Personnel must be involved at all levels within the organization
Existing operating and management procedures have been reviewed and are maintained to reflect current good practices, i.e.: – Communication between fuel storage terminals and site, – Control room design – Alarm management – Shift working arrangements – MOC
Adoption of leading and lagging indicators to assess how effectively risks are being controlled
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Delivering High Performance Through Culture and Leadership
The CA, industry and unions developed a package of standards and training courses for all levels of staff in both COMAH and non COMAH businesses – Oriented towards all the organizational structure of the
company – Help leaders to develop appropriate competence in
process safety and to establish a proactive process safety culture
• Many companies who operate fuel distribution terminals and refineries have put their staff through this training
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Have we learned the lessons?
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Similar Incidents as Buncefield in the US
Sunoco Leak – October 17, 2006 ExxonMobil, Billings, MT – October 16, 2007 Silver Eagle oil Refinery – January 12, 2009 Caribbean Petroleum, Puerto Rico – October 23,
2009
Sunoco Leak – October 17, 2006
An estimated 220,000 gallons of crude oil spilled onto the ground at Sunoco’s oil refinery in South Philadelphia, PA
The oil spill occurred at a storage tank on the Sunoco tank farm, and remained on site, within a containment area surrounding the tank
Reinforced the importance of providing secondary containment for bulk storage
containers as required by the Oil Spill Prevention regulations
Caribbean Petroleum, Puerto Rico, US – October 23, 2009
The liquid level in the tank could not be determined because the facility's computerized monitoring system was not fully operational
The operators used a mechanical gauge on the tank's exterior wall to monitor the fuel level in the tank, and the employees in the facility's control room were not aware of the situation
A 5-million gallon Aboveground Storage Tank (AST) overflowed into a secondary containment dike
The gasoline spray aerosolized, forming a large vapor cloud, which was subsequently ignited in the wastewater treatment (WWT) area of the facility. The CSB announced that a malfunctioning tank fuel gauge led to the explosion
The outcome of this incident resulted in significant damage to 17 of the 48 petroleum storage tanks and other equipment onsite and in neighborhoods and businesses offsite
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What Have we Learnt From Buncefield?
Many changes have been done to learn from the past and prevent incidents; although, there have been similar incidents after Buncefield
Learn the hazards of chemicals and treat them in the right way – Gasoline can explode
Explosion mechanisms Facility siting studies should account for possible
detonation scenarios – Are we currently accounting for what is outside of our
facilities? e.g., tree lines in Buncefield acted as a detonation tube
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What Have we Learnt From Buncefield?
Emergency preparedness and response has been a key factor to minimize the consequences of an incident
Installation of redundant instrumentation, tank fail-safe controls
Information sharing between local government, emergency response services and local communities
Land-use planning
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References
COMAH Strategic Forum, The Buncefield Major Incident, 11 December 2005.
COMAH, Buncefield: Why did it happen? The underlying causes of the explosion and fire at the Buncefield oil storage depot, Hemel Hempstead, Hertfordshire on 11 December 2005, 2011.
Health and Safety Executive. Prosecution resulting from Buncefield explosion. Available from: http://www.hse.gov.uk/news/buncefield/
COMAH, Competent authority guidance for inspectors on emergency arrangements for COMAH establishments. 2012.
Health and Safety Executive. Chemical and Downstream Oil Industries Forum. Available from: http://www.hse.gov.uk/aboutus/meetings/committees/cif/resources.htm.
Chemical Safety Board and Hazard Investigation Board, Final investigation report. Caribbean petroleum tank terminal explosion and multiple tank fires. 2009.
National wildlife federation. Assault on America: A decade of petroleum company disaster, pollution and profit. Available from: http://www.motherjones.com/files/NWF_OilSpillsExplosions_pages.pdf.
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Acknowledgements
Dr. Mannan MKOPSC Steering Committee
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