Stopford have featured again in this quarter’s Tank Storage Association newsletter issued today. This went out to 22 companies operating ~300 terminals in the UK and ROI. Stopford’s article focused on fire risk management. Below is our article or follow this link to the full newsletter.
Stopford Energy & Environment
Risk Management, Firewater – Fuel for thought
In the aftermath of the Buncefield Incident in December 2005, one of the recommendations for future improvement was the management of fire water.
In a significant loss of containment incident, the burning fuel level may approach the top of the bund wall. Continued application of cooling water may eventually cause the floating fuel to overtop the bund wall, spreading the fire beyond this containment boundary. In addition, any foam applied to knock out the fire will be lost, thwarting firefighting efforts.
The Incident Manager is left in an invidious position; continue to add cooling water, which risks spreading the burning fuel beyond the bund, or stop cooling, with potentially catastrophic failure of other assets, spreading burning fuel.
The current design of bunds is based upon the containment of the credible release scenario, but takes little account of managing the volumes of water required to tackle a major fuel storage facility fire. These volumes are substantial and, after initial operation of fixed systems, will be supported by the Fire & Rescue Service, in all likelihood using High Volume Pumps (HVP) each running at 7000l/minute.
PSLG and CIRIA recommend using ‘aqueous flow’ to remove water. The density difference between fuel and water means the water needs to be removed from bottom of the bund. The design challenges to achieve this are significant, though not insurmountable, in maintaining the secondary containment integrity and capacity, while simultaneously providing a high-volume water outflow. A pumped system would require an equal number of Fire & Rescue HVPs for water removal, alternatively direct recycling could be used. However, avoidance of a suction vortex is paramount to maintain separation, otherwise, to quote David Bowie, you may be “putting out the fire with gasoline”!
Flammable liquid storages need a new secondary containment standard to address these concerns. This should include: increased secondary containment capacity, a bottom entry overflow to tertiary containment, appropriately sized for the worst-case firefighting scenario. A piped water management system may ‘tick a box’ but it is unlikely to have any substantive benefit. While waiting for new legislation to be introduced, it is going to be business as usual… until the next major incident.
Stopford has undertaken research and prototype development of maintenance-free remotely-operated bund water removal systems.
 Safety and Environmental Standard for Fuel Storage Sites, PSLG Final Report, HSE, 2009; Section 233.
 Containment Systems for the Prevention of Pollution, C7386, CIRIA, 2014; Section 6.33 Figure 6.5
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