Resilience Against External Events Using Vulnerability Assessment and QRA

摘要

Greater frequency and severity of extreme weather and geologic events have increased the likelihood of emergency shutdowns and extended outages at processing plants in areas affected. These events have brought into question the resilience of Chemical Processing Plants and Oil and Gas Refinery operations against extreme weather and earthquakes. Vulnerability Analyses review a plant’s potential to be affected by considering supply chain and infrastructure effects that would impact continuity of operations as well as the availability and ability of operators and plant personnel to safely operate the facility. They also consider the resiliency to restart operations safely and expeditiously following emergency shutdowns. This paper presents a method using qualitative and quantitative assessment techniques within a Process Safety Management Framework. It includes a thorough review of the plant processes that would benefit from hardening or protection of equipment and systems to prevent storm or natural disaster damage, followed by resilient measures such as capital spares of key operating components to expedite re-establishing processing capability. Resilience also allows for consideration of the ability of the plant to withstand other extraordinary events, safety and security of plant equipment and personnel, and continuity of operations. The authors will discuss the practical application of hazard identification/vulnerability analyses and Quantitative Risk Assessment (QRA) to focus investment on the most vulnerable units of the facility to apply hard and/or soft resilience measures for industrial plants susceptible to extreme weather conditions or natural disasters: Hard Resilience: Focus on resistance. ‘Fail-safe’ – constructing units of operation and equipment to withstand sudden impact with the assumption that strength or protective enclosures will make them safer and less prone to failure. Hard resilience looks to strengthen individual units, process trains and selected assets. Soft Resilience: Focus on absorption. ‘Safe-fail’ – constructing and preparing process trains and units of operation that recover quickly from shutdowns and outages, assuming that infrastructure elements (power, water, supply chains) will fail and preparing for their inevitable failures. Reducing the impact of operational disruptions by taking the view that repairs and replacement of damaged units is part of a systematic continuity of operations plan. Case studies will be presented for application of QRA and technical evaluations that have benefitted Energy Infrastructure Clients and related Facilities through increased Reliability, Availability and Maintainability (RAM) and improved continuity of operations through applying both Hard and Soft Resilience Measures.