In the event of a loss of containment, refineries and chemical plants depend on safety critical equipment to isolate the release, prevent escalation, and assist with emergency response. Even when considering potential catastrophic releases, these systems are often assumed to be available. However, safety critical equipment, including the power and electronics required to activate these systems, may be damaged by fires and explosions and may not be available to perform their required function. Proper analysis is necessary to determine the continued availability of safety critical systems in the aftermath of an event to prevent further escalation. Thankfully, this analysis can be performed using information available in a plant’s facility siting study or quantitative risk assessment. While current facility siting methodologies often focus primarily on loss of life, they can be easily modified to include the risk to safety critical equipment.
This paper outlines a method of screening safety critical equipment for blast and fire risk using data available in a facility siting study or quantitative risk assessment. The methodology addresses the specific failure modes and vulnerabilities of safety systems and develops a case study for a chemical facility. The case study identifies safety critical equipment warranting further study or requiring damage mitigation, and outlines solutions to improve the availability of these systems in the event of a fire or explosion in the facility.