BEST PRACTICES IN PROCESS SAFETY Ming Yang Department of Chemical Engineering, School of Engineering, Nazarbayev University ming.yang@nu.edu.kz

OUTLINE Introduction Best Practices Dynamic Risk Management Inherently Safer Design Trevor Kletz in a 1978 article entitled “What You Don’t Have, Can’t Leak” Concluding Remarks/Harsh Environments

Bhopal (1984), Piper Alpha (1988)

Phillips 66 (1989), Westray (1992)

Toulouse (2001), BP Texas City (2005)

Buncefield (2005), BP Horizon (2010)

INTRODUCTION Process Safety Occupational Safety Prevention and mitigation of process hazards in processing facilities Release of chemicals or energy (fires, explosions, toxic materials); breach of containment Occupational Safety Prevention and mitigation of hazards with a focus on the individual “Slips, trips and falls” Health issues → OH&S Difference may be meaningless to an individual impacted by a process incident or an occupational incident Whether focus is on process or on occupational hazards is determined, in part, by nature of the industry and relevant safety legislation Process safety does focus on an integrated approach by considering loss to People, Property, Production, Environment

RISK MANAGEMENT Risk (AIChE) A measure of economic loss or human injury in terms of both the incident frequency and the severity (consequences) of the loss or injury

Manage the Residual Risk D. McCutcheon Planned Reviews Management Activities To track company actions against policy. Identification of Hazards Reduce the Risk Risk Analysis/ Assessment A GENERIC FRAMEWORK FOR RISK MANAGEMENT Risk Analysis/ Assessment Activities To track, look for and analyze and assess hazards or concerns that arise and challenge policy. Yes Can the risk be reduced? Is the risk acceptable? No Yes No Management Activities To ensure company activities keep risks under control. Manage the Residual Risk Discontinue the Activity

RISK MANAGEMENT Knowledge uncertainty Physical scope Analytical scope Various techniques Physical scope Definition of system boundary for assessment Analytical scope Nature of hazards under consideration Perception, in addition to Event likelihood & Severity of consequences

Incident Pyramid G. Creedy/CSChE

DYNAMIC RISK MANAGEMENT A dynamic risk management framework is to ensure continuous improvement of the risk management process based on real-time process performance revised using process and failure history. The application of the dynamic risk management framework enhances the risk-informed decision-making process by constantly monitoring, evaluating and improving the process performance. Dynamic risk management approach helps to identify and control risk at earlier stage

Figure 3 shows a simple schematic illustration of how the proposed DRM approach is incorporated into the safety system and compares it with the traditional approach. In the traditional safety system design, variable deviations from their predefined thresh- old limits are monitored to activate control systems, alarms, and emergency shutdown devices (ESD). However, compared to this conventional single variable-based safety system design approach, the application of the proposed DRM approach ensures continuous updating of the events probabilities based on new evidence from: (i) monitoring of multiple correlated process variables; (ii) failure and incident histories; and (iii) process and operational changes. As highlighted in Fi

INHERENTLY SAFER DESIGN INHERENT SAFETY PASSIVE ENGINEERED (ADD-ON) SAFETY ACTIVE ENGINEERED (ADD-ON) SAFETY PROCEDURAL (ADMINISTRATIVE) SAFETY Active safety. ... The first, mainly in the United States, refers to safety systems that help avoid automobile accidents, such as good steering and brakes. In this context, passive safety refers to features that help reduce the effects of an accident, such as seat belts, airbags and strong body structures.

Principles of Inherent Safety (EARLY) Minimization (Intensification) Minimize amount of hazardous material in use (when use of such materials cannot be avoided – i.e. elimination)

Principles of Inherent Safety (EARLY) Substitution Replace substance with less hazardous material; replace process route with one involving less hazardous materials

Principles of Inherent Safety (EARLY) Moderation (Attenuation) Use hazardous materials in least hazardous forms; run process equipment with less severe operating conditions (e.g. T and P)

Principles of Inherent Safety (EARLY) Simplification Simplify equipment and processes that are used; avoid complexities; make equipment robust; eliminate opportunities for error

With respect to stability, an inherently safer option to a bicycle is a…

Unmanned platforms, relocation of accommodation modules and lifeboats, compact heat exchangers

CONCLUDING REMARKS/ HARSH ENVIRONMENTS Freezing temperatures, extreme winds, corrosive sea spray and remoteness of operations Best practices in process safety Dynamic Risk management Inherently safer design Risk management – uncertainty/perception Inherently safer design – four fundamentals