Engineering excellence after Buncefield2 July 2009
The explosion at the Buncefield terminal in December 2005 quite literally sent shock waves through the fuel storage sector, and the ramifications are still being felt today as the industry strives to meet stringent new operating and safety standards to prevent such an incident happening again. Martyn Lyons, Managing Director of Simon Storage, considers the impact of the new requirements, and at how innovative engineering solutions could provide the key to compliance.
As an established leader in the design and development of bulk liquid and gas handling systems, Simon has been an active participant in the work being undertaken by the Process Safety Leadership Group (PSLG) and its predecessor Buncefield Standards Task Group (BSTG) following Buncefield. In addition to taking a lead role in identifying and defining how operating and safety standards could be improved, Simon is investing more than £2 million in improvements at its own UK facilities over the next three years, even though the company has an award-winning safety record. As well as upgrading existing facilities where necessary, 50,500m³ of recently completed new tankage, associated fittings and tank bunds across Simon’s two Immingham terminals have been designed and built in full compliance with the safety and environmental recommendations of the BSTG. Also, following an internal review and completion of its LOPA (Layers of Protection Analysis) studies, Simon has implemented the higher standard SIL (Safety Integrity Level) 2 systems and automatic shutdown systems on its gasoline receipt systems, over and above the TSA and UKPIA commitment to SIL 1. Whilst it does not disagree that SIL 1 provides an adequate level of safety integrity, Simon is keen to ensure that its systems meet – and even exceed – expectations now and for the foreseeable future.
A key contributor to the post Buncefield committees and groups, Simon has committed itself to improving industry-wide standards of control at fuel storage sites and revising current procedures to protect people and the environment both on-site and off-site. The BSTG’s Initial Report in October 2006 detailed ‘Quick Win’ recommendations, which were unanimously accepted by the industry. These ranged from installing fire safe tank shut off valves and fail safe operation of remotely operated shut off valves, through to examination of secondary containment bunds to ensure fire resistance of bund joints and provision of suitable tertiary containment measures. Simon Storage implemented all the recommendations by the agreed deadlines and additionally embarked on a programme of fitting automated fail safe shut down systems on all facilities handling gasoline.
Stringent new standards
After its initial recommendations, BSTG started to look in more depth at hardware and software issues that could be improved or modified. The group’s final report, produced in July 2007, once again placed a major emphasis on containment, including protecting against loss of containment using high integrity systems and procedures, and engineering against loss of secondary and tertiary containment. This was followed in February 2008 with the introduction of the Containment Policy, which sets stringent new standards for new build and existing facilities storing and handling gasoline and other fuels. Indeed, the Policy represents some of the most significant requirements to affect the industry in recent years and the need to comply is driving development of innovative engineering and automation solutions.
Assessing the risk
The new containment standards take into consideration the type of fuel and infrastructure of the site, as well as how close the site is to near-by communities; the highest standards will apply to sites where the public and the environment are most at risk. The Environmental Agency has visited all fuel storage sites in the UK and categorised them as 1, 2 or 3 (1 being sites where the most urgent action is needed) depending on the risk they pose to the environment based on quality of containment, location and sensitivity to environment.
The Containment Policy identifies and outlines requirements for primary, secondary and tertiary containment systems. Primary systems are most important as they are responsible for ensuring fuel does not escape from vessels where it is normally contained in the first place, whereas secondary and tertiary systems prevent pollutants from escaping the site and contaminating the environment, should primary containment be lost.
Primary means of containment include tanks, pipes and vessels that hold liquids as well as fitted devices such as alarms and emergency shut down systems that allow safe operation and prevent spillages from storage tanks. Secondary means of containment are enclosed areas around storage vessels or bunds, correctly sized and sufficiently liquid-tight to hold any escaping liquids and any water or chemicals used in fire-fighting, to reduce consequences of any spills that may occur. Tertiary means of containment include drains designed to limit the passage of chemicals off site, or raised kerbs to prevent liquids that have breached the bunds from escaping into the general area around the site. These are largely planned as contingent measures, should the primary and secondary means of containment fail.
The engineering costs of complying with the Containment Policy are already proving prohibitive for some companies, who have or are withdrawing from their terminals storing and handling fuels. For others, the challenge will be balancing the considerable expense of achieving impermeability against ongoing operational and maintenance costs, as well as other safety, health, environment and regulatory driven expenditure. Simon has developed specialised engineering expertise in expanding and upgrading both its own and third party bulk liquid and gases facilities. The company also has experience in engineering within exacting compliance and regulatory environments and is now applying this capability to the development of innovative solutions to meet Containment Policy requirements. Whilst the most obvious answer is to lay concrete within bunds and under tanks this clearly involves high costs, and the disruption to business while the work is carried out means that such a project would inevitably have to be phased. With this in mind, Simon’s in house engineering team is currently considering alternative options, such as the use of clay, butyl lining systems or impervious matting systems.
Long term challenge
At its own facilities, Simon will continue to pursue standards above and beyond industry regulations and recommendations. In addition, the company’s industry experience and insight into changes following Buncefield means that it can also provide training and assistance to help third parties implement actions required to reach the new standards. This activity can be conducted at the customer’s own premises and can cover: LOPA, Containment Policy and Automatic Shutdown Solutions and technical assistance with other products falling within the Buncefield scope. Implementing improvements to prevent another Buncefield type incident undoubtedly represents a long term engineering challenge for the fuel storage sector, but rising to that challenge is vital to make the industry not only safer and more environmentally friendly, but also fit for the future.