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102 5.18 Wilday, A.J., The safe design of chemical plants with no need for pressure relief systems. In IChemE Symposium Series No. 124, 243-53, 1991.

EQUIPMENT FAILURE 195 Design for drainage to reduce corrosion by installing exchanger in a sloped orientation (consider the baffle design to allow fluids to drain). Use double tube sheets for heat exchan gers handling toxic chemicals or for materials where mixing must be avoided (see Figure 11.16). Consider fluid velocities, fluid properti es, contaminants (solids and dissolved materials), and impingement. Ensure the vapor pressure of the process fluid at the maximum heating media temperature is less than the equipmen t maximum allowable working pressure. Figure 11.13. Shell and tube heat exchanger (Mukherjee) Figure 11.14. Principle of plate pack arrangement, gaskets facing the frame plate (Alfa Laval)

7. Developing content of a job aid 75 teams. This review should aim to identify unforeseen issues with the practicality, accuracy, and fitness for purpose of job aids. A technical validation may involve safety specialist or process engi neer checking the job aid. Verification of jobs aids and proced ures through field-based observations cannot be overemphasized. Effective validat ion of job aids and procedures cannot be completed remotely. Workers using job aids and procedures should be consulted to ensure they are valid and practicable. The CCPS guide “Guidance for Writing Effective Operating and Maintenance procedures” [25] provides further guidance on procedure approval. 7.6 Keeping job aids up to date Job aids and procedures must be kept up to date. A “management of change” process or a Procedure Life-Cycle Managem ent Process should be used to manage changes to the design, operating system or chemistry of a process, and ensure that necessary changes are made to job aids an d SOPs. Triggers for updating job aids include: • Developing new facilities or work areas. • Introducing new equipment or updating the plant or equipment. • Changes to work due to incidents, and lessons learned from operational experience. • Changes to roles and responsibilities. • Learnings from a task analysis or a new HIRA. • Requirement for periodic review, i.e., this procedure is valid to three years after the date of issue. When job aids are updated there should be a formal process to identify and remove all out-of-date procedures to avoid the inadvertent use of old procedures. This can be helped by color-coding versions or using watermarks with the date of issue. All job aids should be updated by applying a formal process with final sign off and authorization. The update process must be efficient and able to produce timely updates. Long delays in the upda te cycle will create frustration with the process and discourage operators from inputting them.

376 PROCESS SAFETY FOR ENGINEERS: AN INTRODUCTION The automatic seawater deluge system, which was designed to extinguish such a fire, was unable to be activated as it had been previou sly isolated to protect divers carrying out inspection and maintenance on the platform supporting structure near the fire pumps submerged inlets. About twenty minutes after the initial explosio n, the fire had spread to the gas risers generating sufficient heat to cause them to fa il catastrophically. The ri sers, which carried very large quantities of gas from the seabed to the platform, were constructed of 610 and 915 mm (24 and 36 in) diameter steel pipe containing flammable gas at 138 bar-g (2000 psig). When these risers failed, the resulting release of fuel dramatically increased the size of the fire to a towering inferno. At the fire’s peak, the flames reached a height of 90 to 120 meters (300 – 400 ft) three to four hundred feet. The heat was felt from over 1.6 km (1 mi) away, and reflections in the clouds could be seen from 137 km (85 miles). The crew began to congregate in the platfo rm’s living accommodation area, which was the farthest from the blaze and seemed the least da ngerous, awaiting helicopters to rescue them. However, the fire prevented helicopters from landing. The accommodation was not smoke- proof and due to lack of training, people repeatedly opened and shut doors allowing smoke to enter. Some crew members decided that the only way to survive would be to leave the accommodation immediately. However, they found th at all routes to lifeboats were blocked by smoke and flames and, lacking any other instruct ions, they jumped into the sea hoping to be rescued by boat. Sixty-one men survived by ju mping. Most of the 167 fatalities occurred due to carbon monoxide and smoke exposure in the accommodation area. Two fatalities occurred from a rescue vessel as well. The gas risers that were fueling the fire were finally shut off about an hour after they had burst, but the fire continued as the oil on th e platform and the gas that was already in the pipes burned off. Three hours later the majority of the platform had burned down to sea level with the derricks and modules, including the ac commodation, sliding off and sinking to the sea floor below. Only the drilling part of the platform remained standing above sea level. Oil continued to burn on the sea due to leakage fr om Piper Alpha’s oil production risers (CCPS 2008). The investigation found that the immediate cause of this incident was failure of the Work Permit system to control maintenance and inspec tion work on the platform. At the beginning of July 6, a work permit had been issued for the maintenance of the standby condensate pump. The pump’s process connections had been isolated only by valve. A second work permit was issued for removal of the pump’s discharge pres sure relief valve for maintenance. (LBP 2018) When the pressure relief valve was removed, only four bolts instead of the full set required for operation were used to fasten the blind flanges fitted over the open ends of the connecting pipework, most likely just to keep the system cl ean. This pressure relief valve was located in the module above and out of sight of the pump . After removal, the pressure relief valve was taken to the platform workshop for inspection but had not been replaced by the end of the working day. When the Maintenance Supervisor returned th e Work Permit to the Control Room after he and his crew finished their shift, the Process Supervisors and Operators were in deep conversation. Consequently, he left the Work Permit lying on the desk without making any

356 Human Factors Handbook 26.5.6 Human Factors practice and principles in understanding error Individuals involved in incident investigations require relevant technical and Human Factors knowledge. This is so th at they are able to conduct effective incident investigations that allow identifi cation of underlying causes (root causes) and that enable effective long-lasting learning. Good Human Factors practice recommends that individuals involved in incident investigations possess the following knowledge and understanding: • Types of human failures including: o Action errors (slips and lapses). o Thinking errors (rule-based versus knowledge-based mistakes). o Non-compliance (routine, situat ion, or exceptional) [116]. • Capabilities and limitations of hum an beings e.g., cognitive bias, cognitive overload, mind traps. • Performance influencing factors e.g., people, work, technological and organizational factors. • Understanding of an “Open and Challenging Culture” and/or a “Just Culture”. Human Factors practice also recommends that individuals involved in incident investigations possess an “investigation mind set”. This means having an interest in finding the root causes and providing le ssons learned, with a strong focus on improving safety through the implementati on of recommendations that well help prevent recurrence. 26.6 Selecting preventive Hu man Factors actions This handbook does not cover culture (e .g., Safety Culture or Just Culture). However, many good Human Factors practi ces recommend a focus on culture and its underpinning elements. This is becaus e they contribute to a more effective incident investigation, and they allow for application of lessons learned. “Good” safety culture also reduces the likelihood of non-conformance or procedural non- conformance, and increases understanding of risk. One common pitfall of actions arising fr om investigations is to call for more training for the personnel involved even when the incident has occurred as a result of an action error. In order to identify improvements, it is important to: • Identify the root causes of error. • Assess if the causes are common to other tasks (e.g., all training is poor), and therefore whether the solution should be applied across all tasks/work environments, not just the one where error was detected.

162 Guidelines for Revalidating a Process Hazard Analysis should write each recommendation so that it “stands alone” and can be understood by someone who did not participate in the revalidation meeting. Each recommendation should state the issu e as specifically as possible, with reference to the particular piece(s) of equipment or procedure(s) involved and/or any applicable risk ranking, po licy, recognized and generally accepted good engineering practices (RAGAGEP), regulation, or law that prompted the recommendation. Well-written recommendations often include a brief explanation of the team’s concern and rati onale. This is frequently followed by any specific risk-reduction ideas the team thinks would help the person assigned responsibility for completing the reco mmendation. However, it is not the revalidation team’s responsibility to design the solution, as discussed in Section 7.2.3, Example 6. Follow-Up. As with any PHA recommendatio n, the recommendations coming out of the revalidation study should be resolved in a timely manner [2, p. 281]. Experience indicates that explicit, clea r documentation of responsibilities is essential to the successful resolution of recommendations. In general, organizations resolve recommendations in a two-phase process, and some resolutions require authorization from upper management. Phase 1 is the decision/authorization phase. When management receives the recommendations, it should quickly make an initial assessment of them within the bounds of any regulatory or organizational constraints. Some recommendations may be rejected because: (1) management is willing to accept continued operations with elevated risk, (2) management concludes the risk is already ALARP, or (3) management disagrees with the revalidation team’s rationale for making the recommendation. Note: The risk management procedures of some organizations requir e corporate management to review and concur with local management decisions. Management should convene a meeting with the revalidation team to explain their preliminary decision to reject any recommendations and give the team an opportunity to justify or explain the recommendation. Regardless of whether a recommendation is declined or implemented, these decisions should be documented in the facility recommendation tracking system. Declined recommendations should not simply be removed from the revalidation report. The recommendation implementation schedule is often set during this management meeting. Recommendation benefits (risk reduction), recommen- dation complexity, resource availability, and implementation opportunities (e.g., during a unit shutdown) should be cons idered when assigning the completion dates for a particular recommendation. The rationale for extended recommendation completion dates should be documented, along with any interim plans for risk mitigation.

14 | 1 Introduction the top of the organization, and then carry through all levels, to the plant floor. Strong leadership stewarding each function is needed to direct resources to the most critical risks and opportunities, clarify expectations, listen and learn, create passion, and provide clear, consistent messages. As discussed in Chapter 2, Leadership is a core principle of process safety. The role of management and leadership will be discussed in more detail in Chapter 3. In a complex business with a high-risk profile that suffers from lack of leadership, cultural gaps will appear and can lead to process safety performance gaps. These in turn can lead to catastrophic incidents. Therefore, leaders in the chem ical, oil and gas, and related industries have no role more im portant than stewarding the PSM S and process safety culture in their organizations. What causes process safety cultures to fail? Roughton and Mercurio (Ref 1.18) state that in many cases these failures occur due to m anagement style. Their research identified two prim ary types of management styles: authoritarian management and participative management. Authoritarian managers stress productivity and often believe that people inherently avoid work. They operate by comm and and control, which m ay get tasks done. But they fail to motivate people because they do not fulfill basic human social and ego needs. Furthermore, this management style limits ingenuity, creativity, and problem-solving to only a few individuals, only partially utilizing the intellectual potential of the workplace. Participative managers recognize that people can be positively m otivated by the satisfaction of doing their job well. Accordingly, direct control and punishment can be successfully replaced by self-direction. Workers comm itted to their work seek responsibility rather than avoid it. They then exercise their

EQUIPMENT FAILURE 217 Figure 11.31. Tank collapsed by vacuum (CCPS g) An internal deflagration is possible if a flamma ble material is being stored. Static electricity is a common form of ignition. Static can be gene rated by the flow of fluid through pipes, or free fall of a liquid, or by the mixing of different phases in a tank, especia lly if one of the phases is non-conductive. The design for flammable liquids should avoid free fall of liquid by using a dip pipe or bottom feeding. Fill rates should be kept below certain levels until a dip pipe is covered. Guidance on fill rates to minimize gene ration of static electricity is provided in Avoiding Static Ignition Hazards in Chemical Operations (Britton). Inerting of the vapor space is another possible ignition control method. Tanks should be properly grounded to allow dissipation of static charges from all sources. Attached equipment should be bonded to the tank. NFPA 77, “Recommended Practice on Static Electricity”, (NFPA 77) contains information about the generation and control of static charges. The CSB video “Static Sparks Explosion in Kansas” describes an example of an explosion in a storage tank caused by static electricity. (CSB) Another important safeguard needed on flammable storage tanks is a flame arrestor to prevent the flames of an external fire from pr opagating into the tank through the atmospheric vent. A flame arrestor is a device that allows the gas to pass through it but stops a flame. Lightning strikes are another common cause of ignition in storage tanks. NFPA 780, “Standard for the Installation of Lightning Prot ection Systems”, (NFPA 780) provides guidance for protection of structures containing flammabl e liquids. A lightning strike could ignite vapors in the vicinity of the seal of a floating roof atmospheric storage tank. These are termed rim seal fires and are usually not catastrophic unless the roof fails simultaneously (e.g. roof sinks) resulting in a full-surface fire. Usually, floating roof tanks are fitted with a foam dam around the circumference and firefighting foam chambe rs to add foam just to the dam and not the

68 | 2 Core Principles of Process Safety Investigators found that audits conducted of the facility shortly before the incident revealed no deficiencies in the management system. These audits gave m anagem ent false confidence in their process safety performance and culture, and they failed to Learn to Assess and Advance the Culture identified no deficiencies. Particularly troubling was degree to which the plant failed to Understand and Act on Hazards and Risks, both in perform ing PHAs and MOCs. Investigators also noted indicators of other cultural deficiencies indicators, such as alarm s that sounded too frequently, indicating a Normalization of Deviance. Few if any companies have an ideal process safety culture. In fact, developing and m aintaining process safety culture is a continuing journey. Most com panies either have, or plan to m ake some initial improvements. These efforts should then be followed by additional culture improvements to help make the process safety culture more and more robust over time. Moreover, the same human forces that cause deviance from procedures and standards to be normalized can also cause culture to weaken. Small deviations from com m itm ent, leadership, trust, and so on can accumulate, ultim ately undoing prior efforts to im prove culture. Changes in personnel can have a similar effect, especially if com petency is compromised. Organizations that do not internalize and apply the lessons gained from mistakes, including others’ mistakes, will fail to advance the culture. They are likely to relegate them selves to static, and more likely declining, levels of performance. Process safety excellence requires the curiosity and determ ination necessary for the organization to be a learning, advancing culture. Knowledge, communications, and a questioning/learning environment are the key characteristics of a process safety culture

TOOLS AND METHODS FOR MANAGING ABNORMAL SITUATIONS 131 5.5.1 Standard Operating Procedures Standard Operating Procedures (SOP s) are one of the 20 fundamental elements in the CCPS’ Guidelines for Risk Based Process Safety (CCPS 2007a) and are required by many government agencies. Therefore, by expectation, SOPs are one of the many established process safety tools that most companies already have in place to prevent and if necessary, mitigate incidents. The scope of SOPs such as startup, normal operation, and shutdown can extend beyond the standard simple wording such as “start feed flow, heat up, open va lves, monitor level” content that appears in most written procedures. For example, Example Incident 3.8 – Distillation Column Startup from Chapter 3, Section 3.4.2.1 illustra tes the need for a better initial commissioning procedure in addition to a process startup procedure. SOPs should be structured to include safe operating range, provide warnings against exceeding the sa fe operating limits, and include recommended steps to bring the process back into safe status. However, since procedures are called “Standard Operating” Procedures, they often seem routine and do not specifically address the Abnormal Operating Situations. In order to address this, the ASM Consortium® conducted a research study to investigate procedure execut ion failures in abnormal situations (Bullemer, Kiff & Tharanathan 2010b). The study team examined data related to procedural operation failu res across a data set from 32 public and private incident reports. The ma in finding from this investigation was that the majority of the procedur al operations failures (57%) across these 32 incident reports involved execution failures in abnormal situations. The analysis of the top causes of procedure execution failures found: The most common failure was associated with lack of knowledge about appropriate responses to the occurrence of an abnormal situation while executing a procedure. The second most common failure was the failure to detect the presence of an abnormal equi pment or process mode while executing a procedure.

5.1 Senior Leader Element Grouping |167 leadership chain. Then, after shutdowns, leaders should acknowledge the correctness of the shutdown, while carefully avoiding any inadvertent signal that the shutdown was unfortunate or unnecessary. Indeed, shutdowns may be, after investigation, found to have been unnecessary. This could lead operators to second-guess them selves, or believe they need higher level approval to shut down the next time. Operators m ay also com e to view recovering from the shut-down – cleaning out equipment or performing a tedious start-up – as another disincentive to shut-down the next time. Leaders need to address this head-on by leaving no doubt that the operator’s actions were commendable and correct. Measurement and M etrics (Element 18) Metrics, sometimes referred to as Key Perform ance Indicators (KPIs) are common management tools to monitor conditions and drive im provement. As such, metrics are im portant parts of both the PSMS and process safety culture. Leadership should therefore establish an appropriate num ber of metrics, tracking both the PSMS and the culture. In recent years, API (Ref 5.2) and CCPS (Ref 5.3) have collaborated to suggest useful leading and lagging m etrics to use for these purposes. In determ ining measurements and metrics, leaders should also consider how they will be used. In the words of an anonymous industry manager who said, “What gets measured can be corrupted.” This reflects several ways that well-meaning m etrics can possibly have effects other than those intended. For exam ple: M easuring near-m isses: A goal to reduce near-misses could lead to near-misses not being reported. M easuring loss incidents: An incentive for reducing actual incidents could lead to covering-up incidents. • •

186 | 14 REAL Model Scenario: Population Encroachment As the meeting progressed, Anna asked the group if they should cover any other topics. Wai-Kee said, “This discussion has been great for improving awareness and communication, but I think we should try to answer the question you posed in your in-depth analysis of the West, Texas incident. What additional barriers can be added to improve safety?” “Maybe we should review the facility siting analysis as a first step?” Andrew suggested. Wai-Kee thought this was a good idea. He knew that safety had been a big concern when the facility was originally built, but so much had changed since then. Wai-Kee nodded approvingly and closed the meeting, saying, “Let’s go ahead with these ideas and see if there is room for improvement.” Seeing how much effort was going into making the current site even safer, Mei had an idea. “Do you think there is a way that we can convince the government that we are a safe and trusted neighbor, so that we do not have to move?” she asked. Wai-Kee said, “Let’s bring that to Chen and Winston, and see what they think. Personally, I think we should at least try. We’ve been a good neighbor and have never had a serious incident since we were founded. “I understand the desire to move us,” he added, “but there are enormous safety issues in moving, not to mention the financial consequences.” 14.6 Prepare Wai-Kee, Mei, and Anna took a couple of weeks to follow up on the ideas presented at their meeting. One of the critical action items was to ask Chen and Winston for their feedback on the possibility of negotiating with the government to avoid a move. Wai-Kee was skeptical that they would receive a positive response, but much to his surprise, Chen said that he wanted to make every effort to convince the government that the move was unnecessary. “Moving should be our last option,” he said. “If we can come up with ways to make the facility safer and show that we are proactive rather than reactive, we have a chance to change their minds.” Given their marching orders, Wai-Kee, Mei and Anna quickly went to work on developing a plan. Wai-Kee and Anna worked on improving the safety of the facility. Considering all the chemicals stored there, the explosivity potential of ammonium nitrate was the biggest hazard. Anna had confirmed that there were no incompatible materials and that good housekeeping procedures were being followed. But they decided to go one step further. To convince the government that the company was committed to safety, they proposed to isolate the ammonium nitrate in its own blast-resistant

Piping and Instrumentation Diagram Development 116 Table 7.15 Aut omatic valves on P&IDs. Simplistic presentation Detailed presentation Control valve FV FVP/I FY Switching valve KV KVS VentIAIn some types of actuators (i.e. diaphragm and piston actuators), there are two energy streams as the actuator driver: instrument air and DC electricity. In these actua­tors, instrument air moves the main actuator element to push the valve’s stem. But the instrument air is initiated to the actuator through one solenoid valve or an arrange­ment of solenoid valves, which are functioning via DC electricity. If either of these gets lost, the actuator fails to function. Losing instrument air is known as a power loss and losing DC electricity is known as a signal loss [1]. To what type of failure does the failure position of an automatic valve refer? Losing instrument air or losing DC electricity? If failure position of an automatic valve is mentioned without any specifics, it is generally because of power loss. However, to prevent any confusion, it is better to clearly mention if the failure position is for power loss or signal loss. The letter P at the beginning of acronym for failure position shows it is for power loss, and an S represents signal loss (Table 7.14). A process engineer generally wants to have an auto­ matic valve with the same failure position for power loss and signal loss. Complications can arise if a design process engineer asks for a failure positions in signal loss differently than in power loss. The automatic valves generally report the failure position in cases of power loss unless another option is needed. ●Actuator Driving System Showing the driving system of valve actuators on the P&IDs are different for each company. Some decide to show all the details of the driving mechanism, and others show only a brief schematic of the system and refer the reader to other documents for details of the system. Table  7.15 shows different ways of displaying auto­matic valves on P&IDs in regard to their driver system. Chapter 13 discusses actuator driving systems in more detail. The symbol of a multi‐port valve in the detail of drivers does not refer to process multi‐port valves. These valves are common in the hydraulics industry Table 7.14 Failur e case acronyms regarding different types of driver loss. Driver loss type Name of drive loss Representing acronyms Instrument air Power loss PFC, PFO, PFL, PFI DC electricity Signal loss SFC, SFO, SFL, SFI

5 TOOLS AND METHODS FOR MANAGING ABNORMAL SITUATIONS Previous chapters in this book stress the importance and value of recognizing and managing abnormal situations in chemical processes and provide many actual example inci dents to fortify those lessons. Several management tools have b een mentioned, with focus on preventing or minimizing abnormal situations. This chapter further illustrates and provides guidance on applying these tools for managing abnormal situations when they occur. Process plant operators are familiar with many of these tools and often use them in their normal job responsibilities. However, by increa sing their knowledge about the tools and their importance, it is possib le for the operators to identify opportunities to improve performance on the job by proper use of those tools and methods, especially during an abnormal or stressful situation. There are several available tools an d methods to help predict and/or identify abnormal situations, and thus prevent them from escalating to serious or major incidents. These tool s are usually well recognized in the process industry, but with advancem ents in computer applications and technologies, new tools and methods ar e continuing to evolve that are likely to provide further risk reductio n in the future. This book will primarily cover the existing and curr ently available tools but will also discuss some new technologies as appropriate. This chapter is structured to cover tools and methods that are associated with the eight subject areas that are listed next in Section 5.1. These tools and methods are then disc ussed in more detail in Sections 5.2 through 5.9 in this chapter.

426 PROCESS SAFETY FOR ENGINEERS: AN INTRODUCTION EO 2013, Executive Order 13650 Improving Chemical Facility Safety and Security, White House, Washington, D.C., August 1. Ellis, Ralph, 2016, "Fire that led to Texas fertilizer blast set on purpose, officials say", cnn.com. CNN. Retrieved May 11. FEMA 2008, National Incident Management System, https://www.fema.gov/pdf/eme rgency/nims/NIMS_core.pdf. HSE 1999, “Emergency planning for major acci dents: Control of Major Accident Hazards Regulations”, Health and Safety Executive, U.K. KDA, https://agriculture.ks.gov/divisions-progra ms/dwr/floodplain/resources/historical-flood- signs/lists/historical-flooding/coffeyville. Listo, https://www.listo.gov/es/node/344. NFPA 400, “Hazardous Material Code”, National Fire Protection Association, Quincy, MA. NFPA 495, “Code for the Manufacture, Transporta tion, Storage, and Use of Explosives and Blasting Agents”, National Fire Protection Association, Quincy, MA. OSHA 1998, 29 CFR 1910.109, Blasting and explos ive agents, Occupational Safety and Health Administration, Federal Register 33450, June 18. Ready.gov, https://www.ready.gov/busine ss/implementation/emergency.

FIRE AND EXPLOSION HAZARDS 61 Flash point is the primary characteristic to classify the relative flammability of liquids; however, organizations define flammability differently. Refer to Chapter 7 for further information on chemical hazards da ta sources. (NFPA, OSHA b, UN) NFPA 30, “Flammable and Combustible Liquids Code” o A Class I Liquid is a combustible liquid with a closed-cup flash point not exceeding 38°C (100°F.) o A Class II Liquid is a combustible liquid with a closed-cup flash point at or above 100°F (37.8°C) but below 140°F (60°C). A Class III Liquid is with a closed-cup fl ash point at or above 140°F (60°C) OSHA and the UN “Globally Harmonized System of Cl assification and Labeling of Chemicals” o Flammable liquid: not more than 93°C (199.4°F) The relationship between these terms is illustrated in Figure 4.7. If a flammable liquid is above its flash point, it will evolve flammabl e vapors. The upper and lower flammability limits define levels at which the resulting fuel/oxygen vapor concentration is either too rich or too lean (respectively) to burn. If the fuel/oxygen vapor concentration is in the flammable range and it is exposed to an ignition source meeting the minimum ignition energy for that fuel, then combustion will occur. If the fuel/oxygen vapor concentration is in the flammable range and it is above its autoignition temperature, it will ignite without the presence of an ignition source. Autoignition temperature - The lowest temperature at which a fuel/oxidant mixture will spontaneou sly ignite under specified test conditions. (CCPS Glossary) Minimum oxygen concentration - The concentration of oxidant, in a fuel-oxidant-diluent mixture below which a deflagration cannot occur under specified conditions. Limiting Oxidant Concentration (LOC) is synonymous with the term Minimum Oxygen Concentration (MOC). (CCPS Glossary) Minimum ignition energy (MIE) - The minimum amount of energy released at a point in a combustible mixture that caused flame propagation away from the point, und er specified test conditions. The lowest value of the minimum ignition energy is found at a certain optimum mixture. The lowest value is usually quoted as the minimum ignition energy. (CCPS Glossary)

344 INVESTIGATING PROCESS SAFETY INCIDENTS A series of questions that can be used to help identify key learning opportunities is provi ded below in Table 16.1. Table 16.1 Questions for Identi fying Learning Opportunities

Pipes 91 6.7.10 Other Special Pipe Routes A U‐shape on a P&ID does not actually represent the installing of a U‐shaped pipe. If a piece of pipe with spe- cial routing will be provided by a vendor, the data sheet will show the details of the pipe. However, if the special pipe route will be fabricated by Piping staff in field, it should be mentioned in the P&IDs through a note. It is common to ignore the note and show the real pipe rout - ing on the P&ID by relying on the knowledge of the pipe modeler. 6.8 Piping Movement A piping circuit can be moved slightly during operation because of different reasons. One cause of a moving pipe circuit is thermal expansion and the other is equipment movement. Because of the high temperature of service fluid or temperature variation of ambient air, thermal expan-sion can expand the piping circuit. Such expansion can lead to breaks in the pipes if there are no provisions to handle that. Equipment movement is another reason for pipe movement. If a piece of equipment connected to a pipe is moving, then pipe will move. Again, if this pipe move-ment is not planned for and stopped in time, the pipe will be break. There are two main types of equipment that may cause movement: rotary machine vibration and set-tlement of big footprint equipment. Equipment like pumps, compressors, and centrifuges may continuously vibrate. This vibration will transfer to all connected pipes if it is not mitigated. However, with today’s technology and placement of equipment on the skids, the vibration of equipment is rarely a problem. The well‐known example of a big footprint equipment are large tanks. Tanks with a large diameter are consid-ered big footprint equipment. Several years after tank fabrication, one side of the tank may settle higher or lower than the other side of the tank. This may lead to a marginally tilted tank and the connected pipes are dis - placed and will eventually break. Tanks settle due to the nonhomogenous nature of the soil and the imperfect foundation of the tank. Such settlement is not uncom-mon and can often be seen in buildings throughout the world. A few years after a new house is built, some cracks can appear in different locations of the house, and this is a result of the settlement of the house. There are two ways that pipe movement can be mitigated: 1) Shifting movemen t: By placing expansion loops on a pipe circuit, the unwelcomed movement of pipe is transferred to the elbows, which can handle those movements better than a straight pipe. Expansion loops could be in the form of horizontal U‐shapes (Figure 6.54). 2) Isol ation of equipment: By isolation of the pipe circuit from the moving equipment, the movement will not be transferred to the pipe circuit. Flexible connec - tions are used to isolate a piece of equipment. Flexible connections have symbols, and they are shown in Figure 6.55 and should be tagged as a SP item in the Normally closedMin. Min. Figure 6.52 Min. length of a not e to eliminate dead end. FC Fit Readable Figure 6.53 Min. length of a not e for control valve stations. Figure 6.54 Expansion loop in pipes. Figure 6.55 Fle xible connection on a large bore pipe connected to a tank.

CONSEQUENCE ANALYSIS 305 Figure 13.15 Wind roses (Grange 2014) Estimate the discharge rate of sulfur dioxid e vapor (molecular weight of 64.1) at 25°C (77°F) and 200 kPa gauge (29 psig) pressure from a 25 mm (1 in) hole assuming a discharge coefficient of 0.61. Show your results. A propane cloud is ignited in an area of the facility with few pieces of equipment and no surrounding structures. A second propane cloud ignition occurs in a process unit with rows of equipment so close together that the sunlight barely shows through. What differences are expected in the explosion strength? Estimate the airborne rate for a 10 kg/s (22 lb/s) overflow release of acetone (molecular weight of 58.1) at 25°C (77°F) through a 51 mm (2 in) at 10 m above the ground into a 100 m2 (1076 ft2) diked area with wind speed of 3 m/sec (6.7 mi/hr). Show your results. Estimate the concentration at the transition distance where jet mixing has diminished for a 2 kg/s (4.4 lb/s) release of ethylene (m olecular weight 28.1) at 25°C (77°F) through a 100 mm (3.9 in) diameter pipe with wind speed of 3 m/s (9.8 ft/s). (Note you will need to estimate the density of ethylene at atmo spheric pressure at 25°C (77°F).) Show your results. Estimate the downwind distance to an ERPG-3 concentration of 25ppm for a release of 2.9 kg/s (6.4 lb/s) of sulfur dioxide vapor us ing ALOHA. Select a location of Ann Arbor, Michigan. Use: Wind Speed of 3 m/s (9.8 ft/s) at 10 m (33 ft) Measurement Height, Wind from W, Open Country, Cloud Cover of partly cloudy, Air Temperature of 25°C (77°F), No Inversion, Humidity of medium, Source height at ground level. Provide a screen shot of the Toxic Threat Zone. Estimate the distance to 6.9 kPa (1 psi) ov erpressure from an explosion of 15 kg of acetylene with a heat of reaction of 190.92 kJ/mol. Use the TNT equivalency method. Show your results.

98 PROCESS SAFETY IN UPSTREAM OIL & GAS 5.2.5 SIMOPS The hazard of simultaneous operations was previously mentioned in Chapter 4 and is covered in detail here. Simultaneous operations refers to two or more distinct activities occurring at the same time and in close proximity to one another. Well construction and production are two distinct activities and ar e thus considered SIMOPS. Project work during production is also SIMOPS. Conversely, producing from two adjacent wells are not distinct activities and are not c onsidered SIMOPS. The term combined operation is also used, but IADC notes they are different, with combined operation normally meaning two separate facilities working adjacently (e.g., a drilling rig beside a production facility). Regardless of the term used, this is a SIMOPS activity and requires appropriate controls. While each individual activity may be managed safely, the potential for interaction between the activities significantly increases the risk unless the interaction is actively managed. Guidance is available for SIMOPS during well construction from API Bulletin 97 (API, 2013b), which provides guidance on the interface between an operator’s manageme nt system and the drilling contractor’s safe work practices (see also Section 4.3.1). While these have an offshore tone, the principles of an adequate operator-con tractor interface are equally applicable onshore. While API 97 is designed for well construction and production activities, the framework also works for project ac tivities adjacent to production or well construction. The hazards are different, as are the necessary control measures, but the active management of the interface is similar. Key Process Safety Measure(s) The key process safety measures are typically the elements of an interface document including the following. ●A statement of management system principles ●An overview of the two or more activities ●Hazard Identification and Risk Analysis including key safety barriers ●Safe Work Practices including permits ●Management of Change ●Conduct of Operations including a responsibilities chart (e.g., RASCI) ●Emergency Management 5.2.6 Vents and Flare Risks There is a risk of thermal and toxic exposure to material from vents and flares. Onshore production facilities normally have a flare to burn off any emergency release of flammable or toxic vapors. The fl are collects releases from pressure relief

8 • Emergency Shutdowns 150 Figure 8.3 Example timeline for an ab normal operation resulting in an emergency shut-down to a different, safe state. 8.5 Start-up after an emergency shutdown The start-up after an emergenc y shutdown—transient operating mode Type 10, Table 1.1—is defined as “the time when preparing for and resuming operations after the emergency shutdown period” (Table 2.2). These start-ups were illu strated in Figure 6.2, the transient operating modes associated with emergency operations. If the emergency shutdown time occurred due to an incident with harm to people, the environment, or property, then all special restart and

94 | 3 Leadership for Process Safety Culture Within the Organizational Structure Do Not Allow “Not-Invented-Here” Leaders should encourage improvement ideas the sam e way they encourage bad news. The not-invented-here syndrom e has no place in a strong culture. Good ideas for process safety can com e from anywhere: from any employee, any other unit or com pany site, other companies, and even from regulators and Non-Governmental Organizations (NGOs). Recognizing ideas that really make a difference is good, but in a strong culture, all ideas should be recognized whether used or not. Trust, but Verify In 1987, USA President Ronald Reagan and USSR General Secretary Mikhail Gorbachev signed an arms-reduction treaty based on m utual trust, enhanced by verification. While not everything in the PSM S needs to be verified, a sampling of them should be. Management should decide which PSMS activities deserve such checking, and then devise an independent and documented way of achieving the verification. Candidates for verification may include: Closure of action item s from audits, incident investigations, PHAs/HIRAs, MOCs and PSSR, emergency drill critiques, etc., Lagging and leading metrics; and Training, i.e. that trainees achieve their learning goals. Coordinate and Collaborate Process safety has m any diverse elements representing a wide range of functions and competencies. While the PSMS is intended to closely integrate these functions, few com panies have achieved com plete integration in practice. This is because m any com petencies, such as mechanical integrity, overlap with other • • •

Table C-1 continued HF Competency Performance/ Knowledge Criteria Level 1 - Operator Level 2 - Supervisor* Level 3 - Manager** Overarching concepts, principles, and knowledge Supporting human performance Understands how to support human performance Understand different types of human performance (Skill- based, Rule- based/Procedure-based and Knowledge-based performance) and error within each type of performance Can select appropriate solution to support human performance Able to assess effectiveness of solutions designed to support human performance Supporting human capabilities Understands how to support human capabilities Understand the demands of tasks and understands limits to human capabilities (e.g., cognition limits) Can suggest solutions which would enhance human capabilities – aid cognition, avoid cognition bias Able to assess effectiveness of solutions/aids designed to aid human capabilities Safety critical task analysis Ability to perform Safety critical task analysis Can contribute to Safety critical task analysis Can perform Safety critical task analysis and identify task specific needs Can review effectiveness of Safety critical task analysis and its application

112 GUIDELINES FOR MANAGING ABNORMAL SITUATIONS 5.2 PREDICTIVE HAZARD IDENTIFICATION Table 5.2 provides an overview of some of the most frequently used tools for hazard identification an d their corresponding strengths and weaknesses. Table 5.2 Hazard Identification Tools Common Tools and Methods Strengths Weaknesses HAZOP, FMEA Systematic approaches to predict events based on potential scenarios and identify the existing and/or required safeguards. Resource-intensive What-If Structured What- If, Checklists Focuses on known prior failure mechanisms or team experience. Often less time is required, as questions are more relevant to the process being evaluated. Can be easily modified for reviewing abnormal situations. Strongly dependent on the expertise of the checklist developer and the applicability of the checklist to the types of hazards involved in the process being reviewed Event Trees, Fault Trees, Bow Ties Provides detailed path from cause to final outcome, each branch of which can potentially be a point that mitigation can address. Logic and mathematics can be easily misapplied by someone who is not a specialist in the technique.

Piping and Instrumentation Diagram Development 12 bit behind because CADD obtains documents from the Process group for drafting. The Piping group generally does not have much involvement with P&ID development until late stages, mainly in pipe distribution drawings. The other contri-bution of the Piping group is placement of drain and vent valves in different locations. The Electrical group does not have much involvement in P&ID development. They, however, need to add the required electric power of equipment on P&ID sheets. The Civil group could end up having no involvement in the P&ID development unless the containers are of a concrete type. Based on the previous section, it can be surmised that the workload of the Process group will decrease after the IFD version of P&IDs, while the workload of the other groups will increase. 2.4 P&ID Set O wner In an engineering company, each document has an owner and a P&ID is no different. The owner of a docu-ment is neither the person who has the sole liability regarding the content of that document nor the sole per - son who uses that document. However, a person or group should be assumed as the go‐to person for issues regarding that document. The ownership of a document may be changed at certain times. A P&ID is not different than other documents; how - ever, the owner of P&ID has a critical role due to the importance of P&ID during the design phase. It is natu-ral tendency for companies to assume that the Process group is the owner of the P&IDs – which is not always the case. In smaller projects in which process activities are limited, the Mechanical group could be assumed to be the P&ID owner. In projects that are executed on an  aggressive schedule, the P&ID owner could be the Project Engineering group. Even sometimes when the Process group is selected as the P&ID owner, the own-ership of the P&ID can be transferred to the Piping group or Project Engineering group after IFD revision of P&ID. This can be done based on the logic that after IFD gate, the Process group will not be the main player of the game in P&ID development. The other reason could be, as some people say, that “if the P&ID remains in the hands of the Process group, then P&IDs will never be finished because the Process group tends to keep changing them!” Within the Process group, the P&ID development could be handled in a nonstructured way, or it can be put on the shoulders of a P&ID administrator or a P&ID coordinator. In large projects, the responsibility of a P&ID administrator is handling the nontechnical aspects of P&ID development and also ensuring uni-formity in P&IDs. 2.5 Required Quality of the P&ID in Each S tage of Development During the evolution of the P&ID, more details with more accuracy are shown on the P&ID. At the early stage of P&ID development, a person may not see any small‐bore, 2” pipe, but in the last stage of P&ID development, IFC revision of that, all 2” pipes should be shown. In the early stage of a project, the length of a vessel could be mentioned at 5000 mm, but the same leng th would be seen on an IFC revision of P&ID as 5200 mm. But how can one sa y an issued P&ID as IFA has been produced according to quality standards? Each com-pany has its own standard of quality for the P&IDs in each stage of development. However, a general under - standing may exist and can be used as guideline. Because we are not still familiar with all of the elements on a  P&ID, such a guideline cannot be explained here. A guideline of acceptable quality of P&IDs is discussed in Chapter 18. 2.6 P&ID Evolution During the development of the P&IDs, different parties cooperate to increase the quality of the P&IDs. Therefore, P&IDs evolve during the design stage of projects. P&IDs evolve in three ways: additions, deletions, and changes. Different individuals from different groups do either or all the “P&ID development actions” on P&ID sheets in the form of “markups”every day or every few days. From time to time, the marked‐up P&ID sheets are sent for redrafting to implement all the markups and to produce a clean copy of the P&ID. Some companies have specific rules regarding the marking up of the P&ID to make life easier for the Drafting group. A typical guideline is shown in Table 2.1. At the early stages of P&ID development, all the addi- tions, deletions, and changes should be done to make sure the P&ID is the best fit for the considered purposes. Later during P&ID development, only the additions, deletions, and changes that are musts, and not necessarily preferences, should be done. 2.7 Tracking Changes in P&IDs Do we need to keep track of changes or not? How can we keep track of constant additions and changes?

290 Human Factors Handbook Figure 22-5: Decision-making in emergency situations. (Adapted from a decision-making model [58] )

Application of Control Architectures 289 14.9 Monitoring Parameters So far, our discussion has been about “automatic con- trol. ” However, not all parameters in plants are controlled automatically. Basically, the main types of control in each plant can be divided into two groups: “automatic con-trol, ” and “manual control. ” In automatic control, a system takes care of the control while in manual control, an operator collects the infor - mation from the plant and takes corrective actions based on that. The information that an operator needs for manual control can be obtained by reading the sensor and/or the data provided by the lab from the samples provided to them. We like to control everything automatically, but there are some cases where we need manual control. There are cases where there is no “sensor” for a parameter, or the available sensor is expensive. Another case is when a control task needs more judgment by a human. In such cases, we can also use manual control as long as the pro-cess parameter is not very “agile” and moves sluggishly (although these days, “expert systems” have been designed to be used in such cases). In such cases, we may decide to rely on manual control rather than automatic control. For each piece of equipment, different process param- eters (including pressure, temperature, flow rate, level, and composition) can be defined. However, not all of them are equally important. All of the defined parameters for each piece of equip- ment need to be checked against the need for monitor - ing. The type of “monitoring” is determined based on the level of criticality of each parameter. If the parame-ter is critical, it should be automatically controlled. If it is not critical but very important, it can be visually checked in the control room through an indicator, and an operator can take action if the parameter is out of the normal band. If it is mildly important, it can be vis - ually checked by the rounding (field) operator through a field indicator. And for a relatively unimportant parameter, there may be nothing, or only a “measuring point” somewhere in the plant for the rounding opera-tor to use his portable indicator, to check the parameter occasionally. Therefore, for “very important” and “critical” parame- ters, automatic control is required, whereas other param-eters are operator‐ or manually controlled. This concept is shown in Table 14.12.The decision on the level of criticality of each param- eter depends on the type of equipment, the commodity type, the level of harshness of the environment, and the level of skillfulness of the operators. However, Table 14.13 can be used as a guideline. Desired Ratio FY RSP FC FCSP÷Ratio control: A Sensor signal from one loop goes as RSP to the other loop.Single Loop control: A Sensor signal goes to the controller. Figure 14.32 Single loop versus r atio control. FTFT FYFC < FTFT FY<FC FCOverride control: Multiple controller signal from different location go to selector.Selective control: Multiple sensor signal from different locations go to selector.Figure 14.33 Selec tive versus override control.

46 exchange, distillation, and separation . Also, more recently, AIChE has sponsored the RAPID (Rapid Advance ment in Process Intensification Deployment) Institute. (Ref 3.10 RAPI D) The institute’s purpose is to create a dynamic network of partners who collectively build a sustainable ecosystem, through developing and commercializing new process intensification technolo gy. While the focus of process intensification in genera l, is on improving process efficiencies and economics, many of the technologi es described can also improve the inherent safety of processes by reducing in-process inventories resulting from their application. Process intensification includes th e following novel techniques and designs to minimize the size, inventory, and energy consumption of process equipment (Ref 3.17 Reay; Ref 3.20 Stankiewicz): Equipment: oSpinning disk reactors, osc illatory-baffled reactors, membrane reactors, microreactors. oCompact and micro heat exchangers oNon-reaction equipment, such as packed bed contactors and centrifugal absorbers. Methods: oIntensified mixing providing hi gher shear and mass transfer rates (spinning disk, induction-heated, inline mixers) oIntensified separation techniques (centrifugal, membrane, adsorption) oAlternative energy sources: centrifugal fluids, ultrasound, solar energy, microwave, electric fields, plasma technology. oOther methods: supercritical fluids, nano fluids, process synthesis, electrolysis A few examples of process minimiza tion will be presented here. See Kletz (Ref. 3.12 Kletz 1984; Ref 3.13 Kletz 1991), Englund (Ref. 3.5 Englund 1990; Ref 3.6, Englund 1991a; Ref 3. 7, Englund 1991b; Ref 3.8 Englund 1993), IChemE and IPSG (Ref. 3.1 IChemE), Lutz (Ref 3.15 Lutz 1995a; Ref 3.16 Lutz 1995b), CCPS (Ref 3.2 CCPS), Stankiewicz (Ref 3.20 Stankiewicz), and Reay, Ramshaw and Harvey (Ref. 3.17 Reay) for more examples.

171 the reactor when high temperature or high pressure indicates abnormal operation outside the sa fe operating limits. A passive safeguard (pipe size, orifice, limited pump capacity) could be considered to limit available energy. Low temperature can be dangerous if the energetic mate rial “pools” unreacted in the reactor and then the reaction in itiates. The pooled material could have enough potential energy to result in catastrophic releases. When dealing with flammable materi als, selection from inherently safer design options may vary accord ing to the site and process. For example: Use non-flammable materials, if this is still an option at this stage of the life cycle. Design the vessel to with stand the maximum pressure generated (i.e., inhe rent robustness). Additionally, a number of active an d passive layers of protection should also be provided as approp riate for the storage and handling of flammable materials, including us ing inerting vessels, installing explosion suppression and directing relief vents to a safer location (Ref 8.61 NFPA 2014), (Ref 8.60 NFPA 2018), (Ref 8.17 CCPS 2010), (Ref 8.20 CCPS 2003a). 8.5.2 Equipment Some engineers specify the maxi mum allowable working pressure (MAWP) for pressure vessels, co nsidering the intended operating temperatures and pressures only. While this saves on vessel thickness, it can result in a vessel design that is not tolerant of process upsets resulting from control system, comm unications, or utilities failure. If these process upsets potentially resu lt in process safety incidents, protection layers are required to re duce the risk. An inherently safer choice is to minimize the use of laye rs of protection by designing robust equipment. For example, if the ve ssel MAWP is higher than the maximum achievable pressure, a SIS to shut down the pressure sources on high pressure are not necessary. The proper specification of process equipment should consider potential overpressure scenarios, such as those listed in API Standard 521: Pr essure-relieving and Depressuring Systems.

15.6.1 Minimization MIC was an intermediate in carbaryl production. The facility could have stored less, as evidenced by the fa ct that MIC stocks had been reduced b y 7 5 % w i t h i n a y e a r o f t h e i n c i d e n t . F u r t h e r m o r e , b y c h a n g i n g t h e release diameter—the parameter reflecting chemical inventory—from a standard 50-mm orifice to 30 mm, the CEI-hazard distance, calculated using Dow’s Fire and Explosion Hazard Classification Guide (Ref 15.7 XX Dow 1994b) and Dow’s Chemical Exposure Index Guide (Ref 15.6 Dow 1994a) would be reduced by 28%. If th e MIC inventory (or release rate) had been minimized, the incident potential would have been reduced (2nd order IS measure). 15.6.2 Substitution Carbaryl was manufactured by reacti ng phosgene and methylamine to produce MIC, which was then re acted with alpha-naphthol. An alternative process reacts the phosge ne and methylamine in a different order to avoid the production of MIC. In this alternate process route, phosgene is reacted with alpha-naph thol, and then the intermediate—a less hazardous chloroformate—is re acted with methylamine (Figure 15.12). Application of the substituti on principle at the process route selection stage could have played a role in averting the incident consequences (First order IS measure). 15.6.3 Moderation Moderation of the storage conditio ns (temperature) would have been enabled by the refrigeration system ha d it been operating. Rather than being stored at 0°C or lower, as standard procedures required, the MIC was actually at ambient temperature — obviously much closer to its boiling point of 39.1 °C. With the co ntaminant presence leading to an exothermic reaction and elevated MIC temperatures and vapor generation, it is not clear how pressure might have been effectively moderated. However, a 90% reduction in the operating pressure involved would have resulted in a 60% decrease in the CEI-hazard distance. 420

DETERM INING ROOT CAUSES 211 limitations. For example, th e fishbone diagram is not particularly useful for complex incidents where many causes are interrelated. The knowledge and experience of the investigation team is important in any root cause analysis, but especially so when applying the 5 Whys. In simple, low risk incidents, flaws tend to be diminished as the analysis is simpler, and there is less tendency to skew results. Conversely, complex high risk incidents increase the possibility that the analysis may fail to identify some causes, and care is necessary to avoid bias. Investigators might inappropriately start the analysis with their ultimate cause in mind and then look for signs that they are right rather than comp letely understanding what happened. However, with training , practice and understanding its weaknesses, it is possible to overcome most of the 5 Whys’s drawbacks and correctly identify the root causes of an incident. Table 10.1 Strengths and W eaknesses of the 5 W hys Technique Strength W eakness Simple, easy to teach and use Requires skill as: selection of poor/meaningless causal factor may invalidate the analysis one poor/meaningless why? may invalidate the analysis No rules regarding line of questioning Lack of rules regarding line of questioning can introduce investigator’s bias Starter tool - can instill discipline of searching for true root cause Investigation team may focus on a single causal factor or stop too soon at a symptom Can identify multiple root causes Investigation team may stop at single root cause – requires persistence to seek multiple root causes Not data driven Requires knowledgeable investigation team, otherwise the cause(s) is unknown Results may be (un)intentionally biased by the investigation team: tendency to use deduction rather than facts (observation & analysis) lack of rigor to te st for sufficiency Less time-intensive Not repeatable - different investigation teams may come up with different root causes Can be used alone or in combination with other methods Other techniques are better for complex incidents Best suited to simple or minor incidents May not find all root causes for complex investigations

354 INVESTIGATING PROCESS SAFETY INCIDENTS An example of a process safety bulletin is provided in Figure 16.6, which uses a bowtie diagram to visu alize the barriers th at failed and the associated causal factors. Figure 16.6 Process Safety Bulletin Example

PROCESS SAFETY INCIDENT CLASSIFICATION 147 Detailed Description The Petrobras P-36 was a semi-submersible produc tion platform buoyantly supported by four columns and two pontoons. An emergency drain tank located in one of the support columns had been shut down and isolated. The isolation valve leaked as it was no t properly blinded off and hydrocarbons slowly leaked in and overpressured the tank causing the first physical explosion. A main cooling water pipe for the installation was located adjacent to the emergency drain tank and was ruptured in the explosion. More than one thousand alar ms were triggered. Cooling water was flowing through the pipe for normal cooling and when ru ptured it leaked water into the column and very quickly led to a noticeable tilt. The ruptured pipe also provided the firewater for the structure and the control system had been designed to make it difficult to shut-off the cooling water line as this would stop firewater supply. As the emergency response team arrived to inve stigate the initial physical explosion in the column, they accidentally ignited flammable vapo rs released from the physical explosion of the tank and a second explosion occurred fatally injuring eleven firefighters. The column was normally a safe location with no hydrocarbons intended to be present, so the emergency response team did not test for flammable vapors before entering. Flooding of the column short-circuited the seawater pump located at the bottom of the column in the pontoon. The sea chest valve to the ocean located at the bottom of the column is always open as it supplies the cooling water continuously. It is a manual valve and once the area flooded it could not be accessed. P-36 continued tilting, and the remaining staff were safely evacuated. Salvage operations were attempted for five days but were unsucce ssful. P-36, valued at $496 million, sunk in 1300 m (4265 ft) of seawater. Lessons Hazard Identification and Risk Analysis . The risk of a drain tank to contain hydrocarbons and thus violate the policy of no hydrocarbons in the columns was not identified. Conduct of operations. Multiple doors designed to seal ballast compartments were left open. The union cited poor training of contractors. Additionally, the single isolation valve provided for the emergency drain tank failed to provide positive isolation (as a redundant valve would have). The valves to the ocean at the bo ttom of the column were designed to fail-open which resulted in flooding of the column and pontoon. Measurement and Metrics. A Petrobras executive stated, in regard to positive financial performance, “the project successfully rejected ... prescriptive engineering, onerous quality requirements, and outdated concepts of inspection ...”. It is clear that focusing on financial metrics distracted from the value of oper ational risk and process safety metrics. Introduction to Metrics Metrics are measurements. In 1970, the U.S. OSHA required employers to maintain a log of recordable occupational injuries and illnesses per a set of definitions they provided. This common method of measure led to industry comparing safety performance and motivation to

INVESTIGATION M ANAGEM ENT SYSTEM 61 • When appropriate, discuss empl oyee interviews and potential discoveries with an attorney before and after the interview to properly provide legal protection. • Have a plan in place for how to interact with outside agencies, including the media. 4.2.3.1 Use and Limits of Attorney–Client Privilege Some documents created by an incident investigation team may be subject to disclosure to: • government agencies under thei r regulatory authorities, and • plaintiff’s lawyers under the ru les of discovery that govern litigation. Communication with counsel is critical as there are a variety of issues that counsel may be dealing with that the investigator is not. The appropriate use of the at torney–client privilege duri ng an investigation can help promote frank and open communication between the incident investigation team and legal counsel, and through legal counsel to management. The primary advantage of the attorney–client privilege is to allow and legal analysis of the situation to be protected. If outside experts are needed to assist in the in vestigation, legal counsel will be responsible for retaining the expert. The experts may then assist counsel in the defense of any legal actions th at may follow. When documents are prepared at the request of counsel or wh en communications are transmitted to counsel in order to obtain legal advice, the extent of protection afforded by Attorney-Client Privilege de pends on the legal jurisdiction. The attorney–client privilege exists so clie nts can communicate frankly with their attorney. Usually, the attorney can prov ide sound representa tion without the substance of those communications becoming public. In most European countries, however, the concept of privilege is extremely narrow and in the United States, judges may apply privileges sparingly. Therefore the investigation team should ensure they have clear guidance from the counsel on how to conduc t communications in acco rdance with privileges appropriate for involved jurisdictions. Note that, if a document is cons idered privileged information, the organization may want to severely restrict access to that document to maintain that privilege. Because there are many at tacks on the use of the attorney–client privilege, each investig ation team member should treat any

50 GUIDELINES FOR MANAGING ABNORMAL SITUATIONS 3.3.1 Commitment to Process Safety Commitment to process safety and prevention of process safety incidents begins with the manage ment leadership team and their establishment of a Process Safety Culture that supports ri sk identification and safe work practices. Estab lishing organization roles and Workforce Involvement along with shared responsib ilities sets the foundation for identifying and preventing abnorm al situations. For example, the leadership team will need to provide expert resources, sufficient time, and the required funds for the necessary risk assessments to be appropriately completed otherwise an abnormal situation could result in a significant unanticipated hazardous event with serious consequences. 3.3.2 Understand Hazards and Risk The RBPS elements associated with the understanding of abnormal situations are contingent on identifying the risks with a Hazard Identification and Risk Analysis (HIRA) study conducted when the system is designed or when modifications are made. Tools that may help anticipate potential abnormal situations during these phases are included in Chapter 5. Where the hazards have been identified, these are then incorporated into the RBPS elements Process Knowledge Management and Operating Procedures , (Section 3.3.3) and to improve understanding of the procedures, Workforce Involvement (Section 3.3.1) is a key element to ensure the accuracy, practicality, and relevance of the procedures. The element Workforce Involvement further requires developing an d communicating a written plan of action regarding worker participat ion that should include management of abnormal situations. 3.3.3 Manage Risk Safely managing expected or unexpec ted events is a key responsibility of frontline personnel. If a proc ess has been designed following RAGAGEP and specific industry stan dards, the likelihood of unwanted events progressing to a serious consequence is greatly reduced. However, there may be those abno rmal situations that were not anticipated or included in the safe design of the process. These possible events can best be identified an d safely managed if the frontline operating team has been involved in the HIRA of the process; participates in writing, reviewing, and training on Operating Procedures

272 Human Factors Handbook Individuals can be trained and coached on how to avoid the “group-think” phenomenon during decision-making. Chap ter 16 discusses tactics to avoid group- think within task planning. Some techniqu es to avoid group-think in operational decision-making, include: • Increase awareness – increase individuals’ awareness of group-think, what it is, and why and how it occurs. • Bring in subject matter experts – when the topic is of high importance, subject matter experts can help with understanding issues, such as alternative options, and consequences. • Independent group member – individuals outside of the working group can provide a fresh perspective on the topic and also act as a “cold eye” by challenging the group members’ views. • Psychological safety – environment in which people feel safe to speak up and share ideas, even if these ideas are against the norms or consensus. • Engage in open discussion – create a culture when individuals are encouraged to critically analyze a situation and provide feedback. • Document the decision made – once a decision had been made, a team member should document: o The current situation and associated problems. o All possible solutions. All issues relating to each solution. o The recommended solution and its rationale. o A high-level implementation plan: when, who, how.

146 PROCESS SAFETY FOR ENGINEERS: AN INTRODUCTION Figure 9.1. P 36 Platform shown during dry tow (ANP 2001) Figure 9.2. P 36 attempted salvage operations (NASA 2008)

46 PROCESS SAFETY IN UPSTREAM OIL & GAS Example Incident: Ocean Ranger The Ocean Ranger semi-submersible sank offshore Canada in 1982 due to heavy weather and strong waves. A porthole failed and this allowed seawater from waves up to 65 feet (20 m) high to reach the vital ballast water control system. The seawater soon caused the control sy stem to operate unpredictably and a list developed. The rig was abandoned but none of the 84 crew members survived. RBPS Application Asset Integrity and Reliability emphasizes that critical operational and safety systems integrity be maintained – and this is more than simple reliability estimations for the system itself. The syst em should be protected against failures caused by other systems or the external environment. Contractors are prominent in operations, maintenance, well construction, workover, intervention and decommissioning activities. They have specialist knowledge and equipment to enable challe nging tasks to be performed safely and efficiently. It is necessary to align the process safety program of the company with its contractors to ensure that all aspects are addressed and that everyone knows their responsibilities. API and IADC provide guid ance for interface agreements that help to formalize this process. RBPS Element 12: Training and Performance Assurance Training refers to practical instruction on the job and task requirements and methods for operators, maintenance workers, supervisors, engineers, leaders, and process safety professionals. Performance assurance verifies that the trained skills are being practiced proficiently. Upstream work is challenging, and a high degree of skill is needed to perform tasks correctly. Numerous upstream incide nts identify weaknesses in training and job execution as underlying causes, includ ing, for example, the Black Elk incident Example Incident: Black Elk The Black Elk incident in 2012 offshore in the Gulf of Mexico was an example of poor contractor management and co mmunications. Multiple contractors were working on the platform. The incident involved welding on a line into a tank system. This caused an internal explosion that ejected three tanks off their bases, resulting in three fatalities and injuries to others. The incident was investigated by BSEE (2013). They identified issues with contractor management – poor communication and culture, poor safe work practices, improper hot work control, and failure to actuate stop work authority, amongst other issues. RBPS Application Contractor Management aims to ensure contractors are aware of all hazards and have training in required safe work practices. This is key in upstream operations where many different contractor s interface on a daily basis.

CASE STUDIES/LESSONS LEARNED 169 flight, there had been at least two reported problems with the auto throttle. More details are awaited as the cockpit voice recorder was only just recovered (31 March 202 1) at the time of writing. In contrast to these incidents, de spite suffering dual engine failure when it struck a flock of birds after taking off from New York City’s La Guardia Airport in 2009, US Airways Flight 1549 landed successfully on the Hudson River. This was a si tuation where Captain Chesley Sullenberger used his basic piloting skills and significant experience, rather than relying on instruments. 7.1.2 Incident Overview – Air France AF 447 This case study concerns an incident that occurred on June 1, 2009, involving Air France flight AF 447. This Airbus A330-203 crashed into the Atlantic Ocean about 3 hours 45 minut es after take-off from Rio de Janeiro Galeão Airport bound for Paris Charles de Gaulle Airport, leading to 228 fatalities. The aircraft was at a cruise altitude of about 35,000 feet when it encountered turbulence and a high-level cloud mass. The autopilot and autothrust “disconnect ed” and the pilots were unable to control the aircraft, which crashed into the ocean about 4½ minutes later. The French Bureau of Enquiry and An alysis for Civil Aviation Safety (BEA) investigated the accident and rele ased the final report in July 2012, three years after the crash (BEA Final Report 2012). The report identified the blocka ge of pitot tubes, which were responsible for speed measurement, as th e first of a series of events that led to the accident. Three sets of pito t tubes on the aircraft are used to determine key flight parameters including speed and altitude. Ice blockage of the pitot tubes caused i nconsistencies in the aircraft speed measurement, which resulted in dise ngagement of the autopilot and led the airplane to a stall position. The crew failed to recover the aircraft from the stall position. 7.1.3 Speed Measurement on A330 Aircraft The airspeed on most aircraft, including the A330, is deduced using two sets of pressure data from outside th e aircraft. The firs t is taken from a static pressure sensor, oriented flus h along the aircraft surface and the second is from a dynamic sensor comprising a forward-facing tube,

5.4 Worker-Related Element Gr ouping |193 Know the safeguards that protect the facility, its employees, and its neighbors from those hazards, Have a system to know that these safeguards are being m aintained effective, Know enough about the technology to understand what they are approving and what they are asking their team and em ployees to do; and Know who has the technical knowledge for consultation when difficult questions arise. Training and Performance Assurance (Elem ent 12) Training is the practical instruction in job and task requirements and methods. Training helps build the skills and abilities that individuals need to perform their jobs or prepare for new jobs. The skills and abilities for which training is needed for a given position are identified through the com petency element just discussed. The training elem ent also includes performance assurance, to confirm that training successfully imparted the required skills, leading to com petency. This relationship is illustrated in Figure 5.2. Figure 5.2 Relationship between training and competency Specify Competencies (Plan) Provide Training (Do) Assure Performance (Check)Develop Personnel (Act)• • • •

4. Supporting human capabilities 41 4.7 Key learning points from this Chapter Key learning points include: • It is important to understand the demands of tasks and human capabilities to know how best to aid human performance. • Key human capabilities include the ability to: o Be attentive o Be vigilant o Remember (Memory) o Recognize and process information (Cognitive) o Think and make decisions

|239 7 SUSTAIN IN G PROCESS SAFETY CULTURE As discussed throughout this book, humans are wired to norm alize deviance. This can be beneficial when deviance leads to innovation, but harm ful when deviance leads to operation outside safe operating, m aintenance, and technology limits. Deviance can also occur in culture. For this reason, achieving a strong process safety culture is more of a journey than a destination. Normalization of deviance can and likely will occur, even in the high-level effort to improve process safety culture. Com panies lose their sense of vulnerability and can tire of continuous improvement efforts (Ref 7.1), no m atter how beneficial. B ut as m uch as some m ay desire, process safety culture cannot be treated as a project that can be checked-off as complete. This chapter discussed ways for leadership at all levels to sustain a process safety culture im provement effort, and ultimately sustaining a strong process safety culture. So how can we sustain process safety culture? 7.1 Definition of Sustainability Sustainability has become a popular business term with two distinct definitions: Essential Practices for Creating, Strengthening, and Sustaining Process Safety Culture, First Edition. CCPS. ©2018 AIChE. Published 2018 by John Wiley & Sons, Inc.

5.3 Corporate Change Models | 61 In this model, leaders facilitate the learning process, actively driving individual learning toward corporate improvement. Leaders support employee learning by providing time and learning resources, promoting an environment that encourages questioning, and showing visible support. Leaders also facilitate change in response to learning. The model treats any learning brought to the organization as a gift that must be captured. Employees are encouraged to report hazards and weak barriers, to seek opportunities to improve human factors, and to identify inherently safer options. Sharing is a key dimension of the model. This emphasis not only facilitates communication among team members but also helps drive better solutions by involving people with diverse perspectives and skill sets. The model considers the process of learning to be one of sustainable action. Learning occurs only when the process, operations, and culture change so that the improvement will persist over time. Repsol’s Guiding Principles touch all four quadrants of Figure 5.1. The model’s over-arching theme is that learning must be intentional, driven by corporate needs, supported by open communication, and permanently maintained by intentional action. 5.3 Corporate Change Models This section presents a representative selection of corporate change models that apply to a variety of changes and corporate cultures. As in the previous section, we identify the characteristics of each model that apply to the combined model we seek. 5.3.1 Lewin Kurt Lewin’s 1948 pioneering work described organizational change in three simple stages (Levasseur 2001): • unfreeze • change • refreeze. The unfreezing step includes recognizing the need for improvement. This is best accomplished by understanding what will make the people across the company want to change. The process includes obtaining data about where

13. Operational competency development 145 Learning opportunities enable an individual to progress from “learner/partially competent” to “fully competent”. An indi vidual’s competency can be categorized as: • “Competent” to conduct the safety critical task, safely without supervision. • “Partially competent” where further development is required, through the following: o Training (e.g., refresher training, training, training and supervision); o Coaching; and o On-the-job performance, until competency can be demonstrated. 13.2.2 Individual competency - learning methods Individual competency may be developed through three main learning methods. These methods are provided in Table 13-1. Table 13-1: Learning methods for developing individuals Learning method Description Information- based This type of method introduces operators to the core competency, and provides (for example) knowledge of processes, safety principles, and hazards (e.g., a training course). Demonstration- based This type of method allows operators to observe or watch the required skills, actions, and strategies. It helps operators think about how they will use these new skills in their work (e.g., an apprenticeship). Practice-based This type of method helps operators understand and organize their learning. It helps operators to practice their new skills or knowledge within a workplace environment, which helps them to practically assimilate or inco rporate their new skills into their work (e.g., on-the-job experience). For more information on individual training methods see Table 13-1 and for group/team training methods, see Table 13-2.

52 Guidelines for Revalidating a Process Hazard Analysis of the analysis. The advantage of summarizing responses is it allows the PHA leader to use the checklis t as a brainstorming tool. Evaluating the answers to lists of qu estions is relatively straightforward. When reviewing the documentation from What-If/Checklist analyses, consider: • Were all the questions answered as intended (i.e., are there question-by-question or summary responses)? Failure to respond to a question is an omission. • Are the answers detailed enough to provide insight and justification for the response? Sometimes a simple yes, no, or not applicable response is appropriate, but that should not be the norm. • Do the responses make sense fr om a technical perspective? • Has the RAGAGEP underlying the checklist changed significantly since the checklis t was last used? Outdated checklist questions could solicit outdated responses. • Are there cases where elevated risks were identified, but the team did not include a recommendation? Perhaps the team judged the elevated risks to be ALARP, but the reasons for that determination should be evident. Example – Summarized Checklist Responses PHA Team A grouped the human factors checklist questions (See Appendix F.) into topics and had a th orough discussion regarding process controls. Although each question was not specifically answered, the team documented process safety concerns (with recommendations) regarding interlock systems that are normally bypassed and lack of an emergency shutdown panel. PHA Team B answered each human factors checklist question with the same response: “No issues.” In these examples, even though Team A did not document the answer to every individual question, its analysis appears more accurate and complete than Team B. It is entirely possible that Team B completed a thorough Checklist Analysis. However, Team B’s documentation would be more persuasive if it included some description of the engineered or administrative safeguard(s) that resulted in their “No issues” determination. (See also the discussions of PHA documentation in Chapter 8.)

Piping and Instrumentation Diagram Development 340 16.8 Showing Safety Instrumented F unctions on P&IDs Up to now, we have learned how to show different SIS elements on P&IDs. Now we want to learn how to show a whole function. Let’s have a look at the two examples below. In the first example, when the level gets too high, the SIS action could be to close the inlet valve and open the outlet valve (Figure 16.13).In the second example, to protect a pump from cavita- tion, we can implement a safety feature to shut down the pump when the NPSHA is too low, or the pressure of the vessel is too low (Figure 16.14). There are two issues regarding this type of representa- tion of SIS functions: one is crowdedness, and the other is confusion in the interpretation of the SIS function. Showing such simple cases on a P&ID is very easy, but more complicated SIS functions, when they involve “and/or” functions, are difficult to depict on a P&ID, and it makes the P&ID very crowded. Regarding the second issue, you may ask: “in the top example, how do we know that the left switching valve should be closed and the right switching valve should be opened when the level reaches high‐high?” This can be interpreted in the opposite way, i.e. “the left switching valve should be opened and the right switching valve should be closed when the level reaches high‐high!” This example was very obvious, but sometimes it is not so easy to work out what effect the SIS action will have. The solution to these two issues is to remove all the lines connecting different elements of SIS functions (decrease crowdedness) and to refer to another table for the inter - pretation of the SIS function (clarity of interpretation). FC IFC I/P FVXVFV XV?IAI/P Y Control va lueS witching value Control/Switching va lueIAIA IAYS SVent VentI Figure 16.11 Mer ging switching and control valves. LEI Close Open Figure 16.13 Example of a SIS.I PS Figure 16.14 Example of a SIS.PM I E542 S/SM Figure 16.12 Electr ic motor as SIS final element.

248 PROCESS SAFETY FOR ENGINEERS: AN INTRODUCTION Table 12.3. What-If analysis overview Typically Used During Resource Requirements Type of Results Advantages and Disadvantages Research and development Conceptual design Pilot plant operation Detailed engineering Construction / startup Routine operation Decommissioning Expansion or modification During HAZOP studies to address issues such as loss of utilities. Material, physical, and chemical data Basic process chemistry Process flow diagram Piping and Instrumentation Diagrams Scenario-based documentation of What-If questions, consequences, safeguards, risk ranking, and recommendations, if any. Allows an experienced facilitator to efficiently address issues of concern Inexperienced facilitators may miss potential process deviations if they don’t brainstorm all potential What-If questions. Hazard and Operability Analysis The Hazard and Operability (HAZOP technique sy stematically reviews a process or operation to determine whether deviations from the design or operation intent can lead to undesirable consequences. A HAZOP typically focuses on hazards and major operability issues. This technique can be used for continuous or batc h processes and can be adapted to evaluate written procedures. A HAZOP is typically conducte d by a multidisciplinary team consisting of the following. Leader Scribe Process design engineer Operator Instrument and control engineer Process safety engineer Other specialists as appropriate for the equipment under review The HAZOP is dependent on detailed engineer ing design data. Documents typically used in a HAZOP analysis include the following. PFD P&ID Equipment datasheets Cause and effect charts Management of Change records Incident reports

80 | 6 Implementing the REAL Model 6.3 Understand While reading incident reports, you should flag the text that pertains directly to corporate learning priorities. Also flag other items of interest that might merit later follow-up. These might include observations that trigger obvious to-do items, or that address lower or potential future priorities. Try to imagine yourself in the plant before the incident. What was happening in the weeks, days, and hours before the incident? How were decisions being made? What would you have heard or seen if you were there? How might that information have influenced the way you think about the incident? Ultimately, you need to become intimately familiar with the details of the incident, essentially making a mental model of how the incident occurred and how it might have been prevented. Not all incident reports contain the same amount of detail. If you find that an incident report might have left out a critical piece of information, note what’s missing for consideration in the next step. Take note of commonalities between the incidents and think of how the conditions in those plants compare to your own. It would not be unusual to look at an external incident report and find your mind beginning to dismiss what happened as something your company would never do. If you find your thoughts turning in this direction, remember that personnel at the company that had the incident were probably having similar thoughts right before the incident happened. 6.4 Drilldown In this step, the evaluator intentionally goes beyond the boundaries of the incident report to discover any deeper learnings that might not be explicitly stated in the investigation reports. This is important because the investigator may have had different learning objectives than those driving the evaluator’s study.

328 Table 13.2: Some inherent safety advantages and disadvantages of alternative process solvents Solvent Inherent Safety Advantages Inherent Safety Disadvantages Non-toxic, volatile Solvent is non-toxic, reducing hazards resulting from normal handling, and hazards resulting from a discharge due to a runaway reaction. The volatile solvent limits temperature rise in case of a runaway reaction due to the “tempering” effect when the solvent boils. High vapor pressure of solvent results in potential for high pressure in the reactor in case of a runaway exothermic reaction. Toxic, non-volatile Runaway reaction exotherm may not be sufficient to raise the reaction mixture temperature to its boiling point, so there is no risk of overpressurizing the reactor. Potential exposure of personnel to toxic solvent; environmental damage in case of a spill. 13.2.3 Reduced inventory vs. dynamic stability If the strategy of minimization is employed in a chemical process, there could be a tendency to reduce the sl ack inventory to a minimum in order to reduce the total potential re lease volume in the event of a containment breach. One inherent safety conflict with that concept is that a process may then actually be less tolerant of operational upsets. For example, assume there is a proces s that ordinarily has a surge drum with an inventory that allows for comp ensation of a loss of an upstream process by providing continued feed to the downstream process until the system is restored. In the interest of IS, the surge drum is minimized or eliminated, making the process less stable. If the results of a process

xxiii Figures Figure 2.1: Hierarchy of Controls Figure 2.2: Application of Inherent Safety Throughout the Process Life Cycle Figure 2.3: Inherent Safety Consider ations in Hierarchy of Controls Figure 2.4: Layers of Protection Figure 3.1: A Loop Reactor Production System Figure 3.2: Conventional process for methyl acetate Figure 3.3: Reactive distillation methyl acetate process Figure 4.1: Framework for Assessin g Safer Chemical Alternatives Figure 5.1: A refrigerated chlorine storage system with collection sump with vapor containment Figure 5.2: A liquefied gas storage facility Figure 5.3: A diking design for a flammable liquid Figure 5.4: A chemical process tota lly contained in a large pressure vessel Figure 6.1: A traditional methyl acet ate process using separate reaction and distillation steps Figure 6.2: The Eastman Chemical reactive distillation process for methyl acetate Figure 6.3: Old (a) and new (b) designs for a two-batch reaction system Figure 6.4: Fluidic pump system Figure 6.5: A complex batch re actor for a multistep process Figure 6.6: The same process as Fi gure 6.5 in a series of simpler reactors Figure 8.1: Stages in the Life Cycle of a Chemical Process

EQUIPMENT FAILURE 225 intersections and where it crosses overhead ma y be appropriate to prevent pipe damage and loss of containment. Processes handling saturated gases (the carbon atoms are fully saturated with hydrogen), are subject to auto refrigeration as experience d in the Esso Longford explosion described in Chapter 12. Auto-refrigeration can occur on adiabatic expansion of gasses. The resulting low temperature can bring metals like carbon steel below their ductile-brittle transition temperature resulting in metal embrittlement. This has resulted in complete rupture of vessels and pipelines with loss of containment and gas ex plosions. In addition to LPGs, gases such as ammonia, chlorine, and hydrogen chloride can cause auto-refrigeration. Failure of process equipment, including pumps and control valves, can lead to overpressure of process piping resulting in failu re. This can lead to large flammable releases. Pressure relief valves routed to flare systems are typically installed to prevent overpressure. An additional source of overpressure is bl ocked in piping segmen ts exposed to thermal radiation. Thermal relief should be provided in such situations. Corrosion of piping and equipment is a co mmon problem and can cause of loss of containment. This makes asset integrity and reliability a key PSM element for operations handling hazardous materials. NACE lists over 40 types of corrosion. (NACE b) A couple are highlighted as follows. Sulfidation corrosion is due to the reaction between sulfur compounds, especially H 2S, and iron at temperatures of 230 – 430 °C (450 – 800°F). This causes the thinning of materials such as steel, leading to failure of piping if not moni tored and controlled. This can occur in processes handling materials that contain sulfur, such as cr ude oil. The hazard can be reduced by the use of steel with higher chromium content. Such steels are inherently safer than carbon steel with respect to sulfidation corrosion. A good asset in tegrity program is still required to manage the corrosion hazards. API RP 939-C “Guidelines fo r Avoiding Sulfidation (Sulfidic) Corrosion Failures in Oil Refineries” is a good reference (API RP 939 C). In processes using hydrogen at high temper ature, High Temperature Hydrogen Attack (HTHA) can occur. In HTHA, hydrogen diffuses into the steel walls of equipment at high temperatures and reacts with carbon in the steel , producing methane. This causes a local high pressure in the steel grains. The methane causes fissures to form on the steel, weakening it. HTHA is difficult to identify in its early stages, as the fissures are very small. By the time it can be detected, the equipment already has a higher likelihood of failure. High chromium steel is more resistant to HTHA and is, therefore, a safer material of construction. API RP 941, “Steels for Hydrogen Service at Elevated Temperatures and Pressures in Petroleum Refineries and Petrochemical Plants” provides a curve (called Nelson curve) that shows the temperatures and pressures at which HTHA can occur for various metals. Corrosion can also occur on the outside of the pipe wall. A common problem is Corrosion Under Insulation (CUI). This occurs when pipi ng is insulated with fireproofing or thermal insulation. If a crack occurs in the insulation and water seeps into the space between the piping and the insulation, corrosion may occur undet ected for some time. API RP 571, “Damage Mechanisms Affecting Fixed Equipment in the Refining Industry”, address CUI.

EVIDEN CE ANALYSIS & CAUSAL FACTOR DETERM IN ATION 187 Other analyses specific to the components, materials, operating conditions, and potential modes of failure 9.3.3.5 Make a Failure Mechanism Determination - Step 5 This step is always performed. Th e combined information gathered from the above analyses, testing, and simulati ons are used to determine the failure mechanism. The mode of failure of a component can provide valuable insight into understan ding what occurred du ring the incident. 9.3.4 Advanced Data Systems Technology advances in electronics such as process control systems, safety instrumented systems, programmable logic controllers, the use of independent personal comp uters at field locations, and other computer capabilities present new challenges to incident investigation. Some of the advances are so rapid that the team ma y not have the internal expertise to determine failure hypotheses, sequen ces, and modes. The suppliers and manufacturers of these high-tech devices or other specialists are sometimes the only sources of credible inform ation on failure modes and related analysis techniques for these devices. Reliance on outside expertise may be the most feasible option for some of these issues at some locations. Th e incident investigation team may act as facilitators and advisors. The outside expert would supply information on which failures are credible, suggested ap plicable physical examinations and field performance tests, orchestrate su ch testing, etc. If available, an independent outside expert not associated with the su pplier or manufacturer of the equipment under examination can reduce percep tion of bias. 9.4 HYPOTHESIS FORM ULATION Hypothesis formulation is the process of using inductive reasoning based on observations, measurements, empirica l data, and other information to develop a hypothesis to describe wh at happened and how it happened. Multiple hypotheses are po stulated as described in Se ction 9.1. The section below describes techniques to summarize the incident development, identify pertinent facts, document informatio n, and organize the information and hypotheses. The suggested techniques are often used in conjunction with other tools such as sequence diagrams , fault/event trees, cause and effect diagrams, etc.

EVIDEN CE ANALYSIS & CAUSAL FACTOR DETERM IN ATION 181 9.2 CONFIRM ATION BIAS It is human nature to quickly (and au tomatically) form a hypothesis and then begin to seek confirming evidence. This tendency is called “confirmation bias.” Investigators do not inherently place emphasis on seeking evidence that might disprove what he/she belie ves. Investigators can become fixated on (and vigorously defend) their favori te hypothesis even when faced with conflicting evidence that might dispro ve it. Investigator s therefore should make a strong and conscien tious effort to investigate with an open, unbiased approach, especially during the early ph ases of an investigation when data may be lacking and testing has not been performed. The investigation team should also make a conscientious effort to disprove every hypothesis. In the fiel d of critical and logical thinking, there is a concept of falsifiability where a sp ecific effort is made to disprove a hypothesis. This approach can be used to overcome “confirmation bias.” A hypothesis that withstands the attempts to disprove it is demonstrated to be true. 9.3 EVIDENCE AN ALYSIS Evidence analysis is a distinctly separa te activity from evidence gathering. The relevance of collected data to incident origin and causes can be determined by analysis. The evidence an alysis phase is an iterative activity that overlaps with evi dence gathering and can often lead to additional evidence collection. Evidence analysis is conducted over a typically longer timeframe and, on a major investigatio n, can last for several months as additional tests and data generation are done. Evidence analysis activities often identify the need for additional, specific information, and the evidence gathering cycle begins again. During evidence analysis, evidence ca n be compared to determine if one piece of evidence corroborates anot her piece of evidence or not. Corroboration of evidence adds confidence to the findings. Conversely, if no corroboration can be found for an item of evidence, it may not be given the same weight by the investigation as a well-corroborated item. Evidence analysis is performed using a systematic and thorough approach. Specific techniques for evi dence analysis are beyond the scope of this guidebook. This section is intended to provide an overview and general understanding of some of the common concepts an d issues associated with

218 PROCESS SAFETY FOR ENGINEERS: AN INTRODUCTION whole roof area. An internal floating roof tank is le ss susceptible because the vapor space is not flammable. Addition of incompatible materials can cause re actions, see Example 4 in this section. The first step in prevention is identification of potentially incompatible materials that could be unloaded in the storage tank. The SDS of the material is the first place to look. Other sources include the following. Bretherick’s Handbook of Reactive Chemical Hazards (Urban) Chemical Reactivity Worksheet, described in Chapter 5 (CCPS CRW) If incompatible materials that could be un loaded are identified, design measures can include: positive identification of materials by sampling before unloading, locating storage tanks of incompatible materials in separate di kes, use of dedicated unloading stations with special fittings, clear labeling of unloading lines and storage tank, and clear operating procedures with written checks for material identification. If storage tanks unload into manifolds where other materials can be, precauti ons against backflow into the tank include check valves, or block valves interlocked to close if backflow is detected. Self-reacting materials, such as monomers, or water reactive materials are special cases. Temperature control, for example, cooling, may be necessary for some self-reactive materials in warm climates. Monomers are shipped with inhi bitors and have a shelf life, so the tanks can be sized for rapid turnover. Monomers can also plug normal and emergency vents, so the frequency of inspection and cleaning may need to be increased. Water reactive materials can have inert gas padded atmosphere s to prevent water ingress. Design considerations for process safety. Options available to the designer when designing a storage tank include placement, roof type , and pressure design. Tanks can be located underground or aboveground. Aboveground tanks ca n be fixed roof or floating roof. Storage tanks can be atmospheric or pressurized and equipped with pressure/vacuum protection devices. The advantage of Underground Storage Tanks (U ST) is that they cannot be exposed to an external fire from, for example, loss of containment of a flammable material from a tank in the same dike. USTs are also sheltered from swings in external temperatures. Underground tanks, however, have an increased risk of soil and/ or groundwater contamination from leaks. Most underground tanks are now required to be doub le walled tanks or in a vault, with leak detection in the space between the tank walls or in the vault (Figure 11.32). Because of the risk of soil and groundwater contamination, the U.S. EPA and many states have strict regulations covering them. The U.S. EPA has a website with information about underground storage tanks at http://www.epa.gov/oust/index.htm. A variant of the underground tank is the mound ed tank design (Figure 11.33). This is an earth covered aboveground tank. The earth cove r makes the tank almost immune to BLEVE. Earth covered tanks are frequently used for an LPG bullet tank. Mounded tanks have no groundwater contamination issue as they are above ground level and an impervious membrane or cathodic protection systems similar to those used for pipelines to address corrosion issues can be inst alled during construction.

40 PROCESS SAFETY IN UPSTREAM OIL & GAS Example Topic: Standards Some standards apply to both upstream and downstream (e.g., ASME VIII, API 520), but there are also important di fferences. API has issued 50 to 100 recommended practices for up stream onshore and offshore, and these differ from most downstream standards. In the US, co mpanies must define the standards they intend to use (OSHA RAGAGEP regulation – Recognized and Generally Accepted Good Engineering Pr actice), and they are account able against these. In the goal-based approach, companies n eed to develop a safety case, which includes amongst other matters the stan dards used, and the safety case and specific national regulations become th e requirements for the company. RBPS Application Compliance with Standards sets out suggested means to comply with the range of relevant standards, codes and regulations. Internal specialists may be required to interpret the application of these to specific upstream activities. Finally, participation in standards committees and providing regulation feedback is an essential activity to ensure that these documents are up to date and cover engineering issues properly. As several investigations have shown, excellent performance in occupational safety does not guarantee similar performance in process safety. Personnel may have a good understanding of the precursors to occupational incidents and the barriers and behaviors that prevent these, but not necessarily the same level of understanding/knowledge for more complex and rarer process safety events. Companies need to assure themselves that personnel at all levels understand how to apply process safety principles. Th is competency requirement applies across the life cycle (exploration, well construction, design, production, and abandonment), including tasks that are rarely executed. A system for verification of this competency is necessary. RBPS Element 4: Work force Involvement This element addresses the need for broad involvement of operating and maintenance personnel in process safety activities to make sure that lessons learned by the people closest to the process are considered and addressed. Workforce involvement in process safe ty reviews (e.g., risk assessments, management of change, etc.) ensures their knowledge of potential problems and operation of key safety systems is included and considered in potential risk reduction enhancements. Their involvement also helps build an understanding in personnel of major hazards and how barriers are deploye d to make these safe. Most offshore regulators require workforce involvement for process safety.

Evaluating the Prior PHA 51 • Key questions that were not asked (e.g., no questions about cross- contamination of heat exchange r fluids; no questions about freezing in a cold climate) • Questions about failures of safeguards instead of the underlying loss scenario (e.g., questions about failure of the sprinkler system rather than questions about potential fire scenarios) • Responses that implicitly took credit for safeguards in the stated consequences (See example in the following text box.) If many such deficiencies are found in the core analysis, it is possible that analysis with a different methodology (e.g., HAZOP or FMEA) would provide a more systematic and comprehensive review. When using the What-If method, teams often use larger nodes or process sections, and in so doing, they may co mpletely overlook various process equip- ment or process operations (unless specif ically using a structured variation of this methodology). Therefore, it is important to review both the questions/answers and structure of the Wh at-If Analysis. If the questions asked were too general, or the nodes were too large, hazards may have been over- looked. Consider applying the Redo approach as necessary, breaking the existing process into multiple, easier to analyze, nodes and asking questions that are more specific, perhaps on a line-by-line or vessel-by-vessel basis, similar to the HAZOP approach. When checklists are used for supplemen tal analyses, they may be organized so the team can summarize the responses fo r each section of the checklist. This strategy is often used in cases wher e checklist questions are grouped under headings such as the Human Factors Checklists shown in Appendix F. Summarized/grouped checklist responses do not always mean a Checklist Analysis is lacking in detail, but it may be a reason to look further into the quality Example – What-If with Insuffici ent Detail and Accuracy What-if there was high level in the tank? If the documented consequence is “ process shutdown ,” the answer is likely taking credit for a high-level shutdown interlock. If the answer is “ overflow to bund ,” the answer is taking cred it for secondary containment. Either way, the responses to the What-If question do not provide a detailed list of safeguards, nor do they accu rately describe the consequences assuming failure of the engineering and administrative controls.

xxiv PROCESS SAFETY FOR ENGINEERS: AN INTRODUCTION Table 15.1. Typical risk reduction measures ................................................................................ 34 9 Table 15.2. Safety integrity levels ........................................................................................... ....... 350 Table 17.1. Typical construction, pre-commis sioning, and commissioning tasks ................... 380 Table 18.1. Types of changes and examples ................................................................................ 388 Table 19.1. Example Safe Work Practices ..................................................................................... 3 99 Table 21.1. Example process safety tr aining course list ............................................................. 437 Table 23.1. CCPS Vision 20/20 industry tenets and societal themes ........................................ 461 Table A.1. HAZOP Log Sheet .................................................................................................... ...... 468 Table A.2. Ethylene Chemical Properties ...................................................................................... 470 Table A.3. Node 1 – T-1 Intention, Boundary, Design Conditions and Parameters ................. 473 Table A.4. HAZOP Worksheet Node 1 – T-1 WWT Equalization Tank ........................................ 474 Table A.5 Risk Matrix Severity ................................................................................................ ........ 475 Table A.6 Risk Matrix Likelihood .............................................................................................. ...... 475 Table B.1. Typical engineering course rela tionship with book contents .................................. 477 Table C.1. Example RAGAGEP list ............................................................................................... ... 479 Table E.1. Tier 1 Level and Tier 2 Level Consequences ............................................................... 488 Table E.2. Threshold quantity relationship .................................................................................. 4 90 Table E.3. Material Release Threshold Quantities ....................................................................... 491 Table E.4. Examples for material categories ................................................................................ 49 5 Table G.1. CSB videos (as of January 2021) .................................................................................. 5 03

Evaluating the Prior PHA 55 involving a loss of containment, that result in consequences of interest even if some of the safeguards work properly. Those scenarios should be listed and ranked separately from the scenario assuming failure of all the safeguards. • Is the set of safeguards reason ably specific, relevant, and complete? If the prior PHA team listed only vague safeguards such as procedures, training, or main tenance, then it is virtually impossible to revalidate the accuracy of their risk judgments. If the issue is widespread, it is usually more efficient for the team to Redo the PHA than guess at the previous logic and edit all the entries as needed to add necessary details . Conversely, a more specific safeguard, such as “High level interlock” can be revised, if needed, to be more specific, such as “High level interlock LSH-406 with action to close feed valve XV-101.” Sometimes the listed safeguards do not appear to be relevant to the particular deviation, so at least the Update approach will be required to ensure safeguards are appropriate and documented as such. Finally, the listed safeguards should be compared against those shown on the P&IDs. If there were no recommendations to restore the functionality of the unlisted safeguards, then it is likely that the prior team overlooked them or made a simple typographic error. However, if the prior team judged the risk tolerable without them, those oversights can be corrected with an Update approach. • Do the recommendations seem reasonable? Are there cases where the risk appears to be quite high or RAGAGEP does not appear to have been followed, and there is no corresponding recommendation? • Does every deviation have recommendations? W h e n m o s t o r a l l deviations have recommendations, it is a very strong signal that the HAZOP was documented “by exception.” This is a common style of documentation for design hazard reviews. The reviewers do not expend resources documenting where the designers have achieved tolerable risk. They are trying to direct the designers’ attention to those areas that need further risk reduction. Hence, their sole focus is on recommendations, and the documentation supports their rationale for the recommendations . This style of documentation may be appropriate for an engineering design review, but it never meets regulatory requirements (and rarely meets corporate requirements) for a PHA. If the pr ior PHA was only documented “by exception,” the Redo approach is almost certainly required. FMEA. All the issues identified in the preceding discussion of the HAZOP method in Section 3.2.2 also apply to the FMEA method (ignoring minor terminology

7 • Unscheduled Shutdowns 137 anticipating for an extreme weather event can help reduce the damage associated with the impact of a storm. C7.6.4.2 -2 Arkema Crosby Flooding [78] Incident Year : 2017 Cause of the facility shut -down : Hurricane Harvey, a Category 4 storm, made landfall and produced “unprecedented amounts of rainfall, causing significant flooding.” Incident impact : The extensive flooding caused by the rainfall exceeded the equipment design elevations, causing loss of power, the back -up power, and the critical refrigeration systems. Eventually, all plant personnel and residents in a 2.4 km (1.5 mile)- radius area surrounding the facility were evacuated before the organic peroxides decomposed and burned. Twenty -one people sought medical attention from exposure to the fumes; more than 200 residents could not return to their homes for a week. Risk management system weaknesses: LL1) Although Arkema had a detailed hurricane preparedness plant protecting workers and property before, during, and after a hurricane, none of the Crosby employees anticipated the amount of rain or flooding level. All of the protection layers identified during the Process Hazard Analysis (PHA) failed during the flooding, a common mode of failure which was not recognized or addressed duri ng t he stu dy. Th e C rosby faci li ty p erso n ne l at t he t im e of th e flooding were unaware of their insurer’s floodplain designations, as well, and industrial guidance, at this point, did not specify recommended heights for locating critical equipment in floodplains. Relevant RBPS Elements : Process Knowledge Management Hazard Identification and Risk Analysis LL2) A major highway that bisected the evacuation zone remained open after the evacuation order was given so that emergency

Piping and Instrumentation Diagram Development 362 small diameter header. However, in a low pressure utility fluid networks keeping a small ratio (large diameter) is important. While in high pressure utility fluid networks a large diameter header is not neces - sary. To summarize, the lower the fluid pressure, the larger the header diameter. 6) The old r ule of thumb of “oversize the header by a fac - tor of 2” is not only because during the design phase the utility users “expand. ” It is also because a larger header diameter helps to hinder design inaccuracies caused by dictated parameters of the plot plan. It is very common to put tees and blinds in different points of a utility network. This practice helps the plant managers to add new utility users to the utility network with minimum downtime and a limited impacted area in future. A utility network can be arbitrarily divided into head- ers, sub‐headers and branches. It is a good idea to put manual isolation valves (e.g. gate valves) at the begin-ning of sub‐headers and/or branches. This help to keep a utility network functional even when there is a prob-lem in a portion of the branch or sub‐header. Such manual isolation valves in utility networks are known as “root valves” and are used to isolate a portion of a utility network from the rest of the network for repair and or inspection. 17.2.4 Placing P riority on Utility Users In this stage we need to identify the very important util- ity users (if they exist) and arrange their network accordingly. The “critical user” can be defined as a user that should never be left starving for the utility. There are very common cases where all utility users have the same level of criticality. In such cases there is no need for specific arrangements. However, there are some other cases where a user or a group of users have priority over other users of the same utility for consumption. In such cases a specific arrangement should be imple-mented for this preference (Figure 17.5).Figure  17.5(a) shows a simple utility distribution net - work where all the users have the same level of criticality. Figure  17.5(b) shows a case that a group of users is more important than others. In this case we can imple-ment a control system (or interlock system) to discon-nect the access on non‐critical users from the utility when there is not enough utility for all users. This arrangement is very common in a plant where they have one generation system for both instrument air and plant air. As instrument air is more important than plant air, this control arrangement can guarantee the availability of instrument air by scarifying plant air users. Figure 17.5(c) shows another design for more critical users. In this design the utility comes from a separate “utility surge container” (discussed in Chapter  5). For example when an area is a big air user or is a critical air user, a local plant air receiver may be used. These local plant airs are in addition to the main air receiver inside of an air generation package. The criticality level of users is not always carved in stone. For example it is common that we put down the criticality of a utility user to lower levels when it starts to consume a utility stream wildly. As mentioned in Chapter  14, an override control can take care of such situations.PSL More critical usersSame criticality of users Very critical users(a) (b) (c) Figure 17.5 Dealing with high impor tant users in pipe network design. User 1Make-up wate r Drain water Loop returnLoop supply Ultra pure water treatmentUser 2 User 3 User 6 User 5 User 4 Figure 17.4 Using loop distr ibution for ultra‐pure water.

DETERM INING ROOT CAUSES 241 approaches. The inve stigator needs to understand the functi onal objectives that provide the fo undation of the multiple cause determination. Without this understanding, a “shotgun approach” is often used, without rigor or a search for completeness. The first i dentified potential cause often becomes adopted by the investigation team as the cause, and the investigation terminates. This is one reason that failures recur although remedial action was taken after an earlier failu re. There is also a tendency to stop the investigation process at the intermediate causes level. In the case study, the general cause of bearing wiping was lubrication failure. Suggested cures were proposed for bearing redesign, ne w materials, vibration monitoring, etc. Even modified bearings would be prone to continued failure following winter outages until low temperature wa s identified as a cause and corrected. For example, the underlying cause of the low temperature could be related to inadequate design practices, an erro r in installation, inadequate training, etc. The investigation team should also consider why previous investigations did not identify root causes. 10.6.3 Logic Tree Summary Logic trees can be an effective means of identifying root causes. However, the technique requires skill, especially for complex, high risk incidents. One of the strengths of the logic tree method is that it creates a graphical aid for system analysis and management. Mana gers like the pictorial representation of system behavior and possible intera ctions, and for a complex system, it provides focus on the critical issues . Conversely, some background items might not fit easily in the tree, especial ly if they impact many branches. For example, human factors and cultural issues may be difficult to account for accurately. Table 10.2 illustrates some of the strengths and weaknesses of logic trees.

292 Industry has recognized that fatigu e is an important issue, and API RP-755 (Ref 11.3 API 755) has been published to provide guidance for facilities to detect and counter fati gue in those parts of the workforce working night shifts, rotating shifts, extended shifts/days, or call-outs and where their job requires proces s safety actions. This reference establishes a fatigue risk management system so that the process of managing fatigue among those positi ons may be sensitive to it is a continuous and sustainable process. However, if there are underlying pressure being brought to bear on personnel to work excessive overtime, then there is a safety/pro cess safety culture issue that must be solved first. Fitness for duty . Fitness-for-duty refers to a range of possible influences o n w o r k e r p e r f o r m a n c e , s u c h a s i mpairment due to drug or alcohol, fatigue (addressed above), illness, di straction due to personal issues, and mental condition (Ref 11.8 CCPS COO). No external influences on performance should be allowed for fa cility personnel. This includes the use of alcohol or drugs while on du ty, horseplay, harassment, and other aberrant behaviors. No tolerance for these behaviors goes beyond simply forbidding them in written policies and stating these prohibitions during training/orientation sessions. It means living them at each level of the organization, including self-pol icing within peer groups and during off shifts. Minimizing the external negative influenc es on personnel behavior and performance and establ ishing the minimum requirements for fitness for duty expectatio ns is an important activity. Shift differences and turnover . The culture of different operating shifts within a given facility sometimes va ries widely. What would never be tolerated on one shift might be to lerated on another. This often represents the difference between staf fing levels during normal working hours (i.e., day/weekday and off-ho urs (i.e., night/weekend/holiday shifts), and the presence and attention of technical staff and management during the day shift of n o r m a l w e e k d a y s . M o s t o f t h i s difference can be attributed to the a ttitudes and beliefs of supervisors, foremen, and other mid-level management assigned to off shifts. Having to accomplish the same level of production with less resources sometimes fosters the attitude that shortcuts and other deviations from approved procedures are acceptable in order to achieve those goals.

TOOLS AND METHODS FOR MANAGING ABNORMAL SITUATIONS 117 Table 5.3 Process Control Systems (cont.) Common Tools and Methods Strengths Weaknesses Big Data Can be used to analyze large sets of data where the relationships between process variables, equipment, and operating modes are difficult to derive May require additional capacity for data processing and expertise in configuring data to analyze. 5.3.1 Process Trend Monitoring The design of the control system shou ld provide an interface so that the panel operator can readily observe patterns and trends of multiple variables simultaneously. This desi gn exercise should be conducted based on consultation with the oper ating team and critical parameters that have been highlighted in previo us studies (such as HAZOP/ LOPA). Procedures and training must include instructions on the correct use of such displays including those that should be checked periodically and others that can provide helpful in formation under certain abnormal conditions. Displays that provide an overview of the key operating trends, key parameters, and “big pi cture” of the entire process are especially important features of a we ll-designed control panel. For batch processes that frequently start up and shut down, trending can be designed to notify the control pane l operator that the process may be beginning to experience an abno rmal situation. Problems have occurred, particularly during non-ro utine or transient operations, where an instrument has gone out of range ma king it very difficult for operators to correctly diagnose the situation. The design of the system should enable instruments to stay in rang e under all expected circumstances. Most modern control systems provid e additional features, such as a rate of change alarm, which can be helpful in certain circumstances, although these must be set with care to avoid becoming nuisance alarms. The benefits of adding a well- designed rate of change alarm are shown in Example Incident 5.1.

8.8 Fukushima Daiichi, Japan | 117 8.8 Fukushima Daiichi, Japan, 2011 According to the report issued by the Fukushima Nuclear Accident Independent Investigation Commission, the 2011 Fukushima nuclear incident was a “Disaster Made in Japan” (NDOJ 2012). The chair of the commission, Kiyashi Kurokawa, did not mince words when he stated in the report that the cause of the accident stemmed from: …collective mindset of Japanese bureaucracy, by which the first duty of any individual bureaucrat is to defend the interests of his organization. Carried to an extreme, this led bureaucrats to put organizational interests ahead of their paramount duty to protect public safety. In March 2011, the Great East Japan Earthquake triggered a severe nuclear incident at the Fukushima Daiichi Nuclear Power Plant. The earthquake damaged electricity transmission facilities supplying the plant, resulting in the need to use emergency diesel generators. Although the plant survived the initial earthquake intact, the tsunamis that followed breached its walls and destroyed both the emergency diesel generators and the seawater pumps that were critical in cooling the nuclear reactors. The tsunami also destroyed buildings and tossed around heavy machinery, making access for repairs difficult once the water receded. The plant was built in 1967 in an area that was considered to have minimal seismic activity at the time. Its tsunami-resistant design was based on experience from the 1960 Chile tsunami. Over the next few decades, however, research had revealed an increased probability of a higher water level and velocity than observed in Chile, meaning the risk of an over-topping incident was higher than previously calculated. Engineers recommended that the floodwall be elevated and strengthened along with other countermeasures (for example, moving the backup generators up the hill, sealing the lower part of the buildings, and having some back-up for seawater pumps). However, the operating company didn’t take this research seriously and postponed updating its tsunami countermeasures. Japan’s regulating agency, the Nuclear & Industrial Safety Agency (NISA), continued discussing with the plant the need to update the tsunami countermeasures but did little to enforce this. A lax safety culture could also be found in the central government, which did not have clear emergency response and evacuation plans for radiation releases. After the total loss of power occurred Fukushima Daiichi, there was concern about radiation releases. Unfortunately, communications from the central government to municipalities were slow and lacked critical

18. Capturing, challenging and correcting operational error 231 Table 18-6: Types of task verification Tool Application Risk Level Self- checking The individual thinks about the intended action, understands the expected outcomes before acting, and checks the intended results after the action. Low Peer- checking This involves the individual self-checking and a peer checking for the individual at the same time, and together agreeing what the correct action is. Medium Independent verification One individual separated by distance and time from the action confirms the conditions. High Concurrent verification Two individuals working together at the same time and same place separately confirm the conditions. Independence of team member is important here. High Successful task verification requires: • Clear understanding of roles and responsibilities. • The checker understanding the potent ial errors and their consequences. • Utilization of checklists to support reliable performance of check. • A physical environment that is free fr om distractions, especially for high- risk tasks. • Learning from errors identified during checks. 18.7 Key learning points from this Chapter Key learning points include: • Common Human Factors reasons for fail ures in spotting, correcting, and challenging errors include cognitive bias , positional authority, task focus, time pressure, stress, and limited self-scrutiny. • Educating and training people about factors contributing to errors makes them more alert to error and consequently more likely to: o Detect error in themselves or others. o Challenge error. o Learn from errors and use this information to prevent future incidents and accidents.

330 Human Factors Handbook supervisor and/or manager may also implicitly show respect to the worker and may also convey that his work is important. Also, for some workers, they are less likely to escalate concerns in a large gr oup, however, task sa fety observations afford a more natural environment in whic h to escalate concerns since the worker can directly show the supervisor and/or manager the challenges he faces in the field. 25.4.7 Signs of individual operational mindfulness A lack of operational mindfulness can have severe consequences in a high-risk environment. A lack of mindfulness, when the mind wanders, is associated with failure to perform, failure to monitor pr ocedural steps, deficiencies in recalling information, inability to interpret al arms, and overall reduction in task performance. These performance failures can also be due to other systematic causes, and the reasons behind these failures should be determined, such as poor job design. If individual mindfulness is found to be the underlying cause of impaired performance, then it should be incorporated into performance indicators. Signs of mindfulness are shown in Figure 25-4. Mindful individuals exhibit alert and perceptive behavior towards hazard and risk identification (chronic unease) and they respond calmly in emergency situations, regularly engage in self- reflection, exhibit natural curiosity by asking open questions, and perceive error as a learning opportunity. Mindfulness is "the quality or state of being conscious or aware of something.” When a person is being mindful, they are focusing on the task in hand and aim to eliminate potential distractions (e.g., newspaper in the control room, or chatter on the radio). Mindfulness is not only influenced by an individual’s physical and psychologi cal state, but also by organizational (e.g., organizational change such as restructuring and staff reduction / de- manning) and environmental (e.g., ni ght shift, noise/alarms) factors.

A Human error concepts A.1 Human Error categoriza tion and terminology A.1.1 Intended and unintended errors A classic publication by A. D. Swain and H. E. Guttmann (1983) “Handbook of Human Reliability Analysis with Emphasis on Nuclear Power Plant Applications: Final Report” [118] classifies error into two general categories: unintentional and intentional. • Unintentional errors: The action was not intended, for example, pressing button A when the intention was to press button B. • Intentional errors: “The operator intends to perform some ac t that is incorrect but believes it to be correct or to represent a superior method of performance. In everyday language, he has good intentions, but the effect on the system of his performance may be undesirable.” (page 2-7) A.1.2 Errors of commission an d errors of omission. A. D. Swain and H. E. Guttmann (1983, page 2-16 [118]) also used the following categories of error: • Errors of commission: doing somethin g that is wrong. This includes: o Selection errors such as select wrong control; o Error of sequence (do things in the wrong sequence); o Time error (do something too early or too late); o Qualitative error (do something too much or too little). o Errors of omission: omitting to perform a task or a task step. A.1.3 Active and latent failures Professor Reason authored in 1990 an acci dent causation model termed the “Swiss cheese” model [19]. According to the mo del, hazards are prevented from causing loss by a sequence of barriers, such as training, supervision and engineered protection. Each barrier may have unint ended weaknesses. These weaknesses are represented as holes, such as with Swiss cheese. Human Factors Handbook For Process Plant Operations: Improving Process Safety and System Performance CCPS. © 2022 CCPS. Published 2022 The American Institute of Chemical Engineers.

102 Human Factors Handbook Figure 9-4: Control and instrumentation panel [40]

368 PROCESS SAFETY FOR ENGINEERS: AN INTRODUCTION Several critical task analysis methods are available. (NOPSEMA 2020, HSE 2000) A simplified approach called Task Improvement Proc ess, TIP, follows the steps shown in Figure 16.9 which are similar to many critical task analysis approaches. (Miller 2019) Figure 16.9. Task Improvement Plan steps (Miller 2019) Human reliability analysis. Several analysis me thods are used; two of the more commonly used methods are THERP and HEART. Human Reliability Analysis - A method used to evaluate whether system-required human-actions, tasks, or jobs will be completed successfully within a required time period. Also used to determine the probability that no extraneous human actions detrimental to the system will be performed. (CCPS Glossary) The Technique for Human Error Rate Prediction (THERP). THERP addresses task analyses, error identification, and quantified human error probabilities (HEP). The THERP includes tables of HEPs and uses event trees to determine ov erall failure probabilities. THERP was developed in the nuclear industry and has been applied to the process industries. (HSE 2009) The THERP Handbook is publicly available via the U.S. Nuclear Regulatory Commission website. (NUREG) Human Error Assessment and Reduction Tec hnique (HEART). HEART is a simpler error prediction method that can be applied by non- specialists. Nine Generic Task Types (GTTs) are described in HEART, each with an associated nominal human error potential (HEP), and 38 Error Producing Conditions (EPCs) that may a ffect task reliability, each with a maximum

207 Chemical Engineering, July 14-18, 1996, San Diego, CA (Paper 52d). New York: American Institute of Chemical Engineers, 1996. 8.35 Englund, S., (1990) Opportunities in the design of inherently safer chemical plants, Adva nces in Chemical Engineering, 15, 69-135, 1990. 8.36 Englund, S. (1991a), Design and operate plants for inherent safety - Part 1, Chemical Engineering Progress, 87 (3), 85-91, 1991. 8.37 Englund, S. (1991b), Design and operate plants for inherent safety - Part 2, Chemical Engineering Progress, 87 (3), 85-91, 1991. 8.38 European Union, Regulation (EC) No 1907/2006, Registration, Evaluation, Authorisat ion and Restriction of Chemicals (REACH), 2007. 8.39 Fauske, H., Managing Chemical Reactivity–Minimum Best Practice, Process Safety Progress 25 (2 ), 120-129, American Institute of Chemical Engineers, 2006. 8.40 Federal Emergency Management Agency (FEMA), U. S. Department of Transportation (D OT), and U. S. Environmental Protection Agency (EPA), Handbook of Chemical Hazard Analysis Procedures. FEMA Pub lications Office, 1989. 8.41 Gay, D., Leggett, D., Enha ncing thermal hazard analysis awareness with compatibility charts, Journal of Testing and Evaluation 21 (6), 477-80, 1993. 8.42 Gentile, M., Development of a hierarchical fuzzy logic model for the evaluation of inherent safety, PhD Thesis. Texas A&M University, College Station, TX, 2004. 8.43 Gupta, J., Edwards D., A simple graphical method for measuring inherent safety, Journal of Hazardous Materials, 104, 15-30, 2003. 8.44 Heikkilä, A., Inherent safe ty in process plant design. VTT Publications 384, Technical Research Centre of Finland, Espoo, D Tech Thesis for the Helsinki University of Technology, 1999.

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&OHJOFFST 26 3 AN OVERVIEW OF INVESTIGATION M ETHODOLOGIES Best practices in incident investigation have evolved substantially, particularly since the 1970s when structured methodologies for process safety incidents were virtually non-existent. Investigators now recognize that, for every incident, there are likely mult iple root causes. To identify and understand thes e root causes and how they interacted to result in that incident, an investigator collects eviden ce and conducts an analysis of that evidence. Today, organizations use a variety of methodologies to investigate incidents, using combinations of various investigation tools. This chapter provides a brief overview of investigation tools in simple, generic terms and demon strates the benefits of using a structured approach. A number of public and proprietary methodologies employ generic tools that are readily available to users. The following terminology is used throughout this chapter: Tool —A device or means used at a discrete stage of the incident investigation to facilitate understanding of event chronology, causal factors, and/or root causes. Technique —The manner in which an incident investigation tool is applied. Methodology —The use of incident investigation tools to analyze the evidence, develop and test hypotheses, identify causal factors, and determine the root causes of an incident. When choosing the tools and analysis methodologies to be used in an incident investigation, it is important to recognize that no single tool does everything. Good methodologies use c ombinations of tools to counteract their individual weaknesses. The ch oice of methodologies depends on the existing culture within the organization, the specific investigation leaders, level of training resources available, and complexity of the incident. It is important to under stand that the various t ools use different types of logic to arrive at the re sult. These types of logic are intuitive, inductive, deductive, or a combination. Most of the tools described in this guideline are intuitive or deductive.

468 PROCESS SAFETY FOR ENGINEERS: AN INTRODUCTION Note that at the 90 °C normal operating temper ature, the vapor pressure of the styrene-ethyl benzene mixture is 0.22 bar absolute with the balance of the normal operating pressure from the nitrogen pad. 4. Beyond chemical hazards, what other hazards might warrant consideration? 5. Have there been any accidents in industry that you can learn from? 6. Make a plan for what process safety studies and activities you will do, or have done, at what stage of the project. 7. A HAZOP is to be conducted. Usin g the jacketed reactor as a node, Develop a design intent statement. Include as appropriate intended volumes, flow rates, composition, temperature, pre ssure, and other process information. Add to the HAZOP Log Sheet other paramete r/deviations and causes as you can think of. Complete the remaining columns for each scenario added. Refer to the P&ID for existing safeguards. Document any recommendations you think would help eliminate the scenario or significantly re duce the severity of the consequence. Using a scale of high/medium/low, rank the severity and likelihood for each scenario. Table A.1. HAZOP Log Sheet Scenario Parameter/ Deviation Cause Consequences Existing Safeguards Severity Likelihood Recommend- ations 1 Level- High Level Control Loop Failure Overflow of styrene-ethyl benzene mixture onto floor of the enclosed process area. Evaporation of spill with ignition leading to a Building Explosion. High Level Alarm with a procedure to stop all feeds. High Level Alarm with a procedure to stop all feeds. Route the pressure relief device to a “safe” location outdoors.

E.19 Knowing What You Don’t Know |305 Understand and Act Upon Hazards/Risks, Provide Strong Leadership, Ensure Open and Frank Communications. E.19 Knowing What You Don’t Know A new Facility M anager came from a business background. She had no experience or training in engineering or operations, and little working knowledge of process safety technology or management system s. Her facility had a procedure that required the Facility M anager to sign perm its approving bypass of critical safeguards, including SISs and relief devices. The Facility Manager was also required to approve extension of ITPM tasks for the same types of equipment. Shortly after taking the job, she received several requests to extend the proof testing of a SIS by 6 months and to bypass a relief device by shutting the inlet and discharge block valves. She did not know what a SIS was, only vaguely understood pressure relief, and was unfam iliar with the process safety ram ifications The requests were presented at the start of a long operations m eeting with a very full agenda. It was clear that they represented critical m aintenance tasks that were delayed pending her approval. With a full agenda ahead, she signed the permits, even though she did not understand the risks involved. She justified signing to herself thinking that the requesters would not ask if they did not think it was safe. Non-technical m anagers do get assigned to senior operations roles. What preparation should they have before assuming those roles? What are some questions the new operations manager could have asked to be m ore informed when signing the perm its? Regardless of background, a new facility manager cannot be expected to know everything about the facility. How can facility m anagers and their team s bridge this knowledge gap? Understand and Act Upon Hazards/Risks, Defer to Expertise, Provide Strong Leadership. B ased on Real Situations

Evaluating the Prior PHA 43 before becoming process engineer would understand the process from a broader perspective. Finally, experience need not be limited to years in a particular job. Consider the extreme case of a team that conduc ts an initial PHA of a completely new process. Since the process has not yet st arted up, no one on the team has any actual operating experience with the specific process at the proposed production scale. While staffing of init ial PHA teams for new processes is not a PHA revalidation issue (the initial PHA orga nizers needed to address that issue), the team that first revalidates the PHA often has significantly more knowledge of and experience with the actual process and its operations than the initial PHA team. Therefore, for the first revalidat ion, “lessons learned” and operating experience gained since initial startup should be considered along with other factors in deciding whether to Update or Redo the PHA. This is further discussed in Chapter 4. The quality of the prior PHA is likely to be as dependent on the experience of the PHA team leader in applying the core methodology as it is on the technical and operational knowledge of anyone else on the team. Some companies have programs to ensure PHA team leaders ar e qualified and remain so, but that is outside the scope of this book. If a company has rules on the qualifications of the PHA team leader, but an exception wa s granted for the prior PHA leader or the prior PHA leader did not follow the company PHA guidelines (See the discussion of company standards in Chapte r 2.), it would justify scrutiny of the quality of the PHA as described in Section 3.2. 3.1.3 Prior PHA Scope The scope of a PHA includes the physical scope (i.e., equipment items), operational scope (i.e., modes of operation for each equipment item), and analytical scope (i.e., consequences of interest). If the prior PHA scope was constrained by any assumptions (e.g., that the hazards associated with raw material and product piping are included in the tank farm PHA), the evaluation should determine whether those same as sumptions are valid and applicable to the revalidation. Physical Scope. It is usually straightforward to verify the physical scope of a PHA by comparing P&IDs or process flow diagrams with the nodes or process sections shown in different colors that correspond to each analysis node or with a separate document that denotes proces s boundaries. If a company chooses to conduct PHAs on anything less than “all” its process assets, then the physical scope must include all the equipment cover ed by policy or regulation. In many

Appendix 210 It is important to recognize that there are several start-up-related steps that should be addressed de pending on the type of preceding shut-down that occurred. Incid ents have occurred when the operations group has attempted their restart without understanding why the process was shut-down in the first place or what “final” condition the equipment was in after the shut-down. The different shut-downs and the different resp onses and subsequent start-ups corresponding the them are summarize d in Table A.2-1. Safe, incident- free restarts require the Operational Discipline (OD) of everyone to understand and address any issues , no matter whether it was an unexpected, unscheduled, or emergency shut-down. The effect of weak OD was discussed in Chapter 10 , showing with the simplified risk equation that by increasing OD acro ss all levels in an organization helps reduce its process safety risks (Equation 10.1). As noted earlier in this guideline, process and faci lity shutdowns have had start-up- related issues when equipment-rela ted issues arose when preparing for the commissioning step, as well. Further analysis of the incident results has been drafted at the time of publication of this book [108]. The paper addresses process safety culture and leadership and its impact on the facility’s operational discipline to manage its start-ups and shut-downs effectively and safely. The conclu sion (similar to the higher-level assessment in this guideline) is that the process safety risk for incidents is higher during start-ups and shut-downs when the engineering controls have not been maintained and the administrative controls are not effective.

F.2 Culture Assessment Protocol |357 114. Does the organization only seek inform ation to confirm its superiority? 115. Does the organization believe that its process safety program has precluded process safety risk because it com plies with regulations and standards? 116. Does the organization discount inform ation that identifies a need to im prove its process safety program ? 117. Is there no interest in learning from other organizations or industries? Is the organization overly insular? 118. Are those who raise process safety concerns viewed negatively? 119. Does the response to process safety concerns focus on explaining away the concern rather than understanding it? 120. Are the investigations of process safety incidents superficial with a focus on the actions of individuals? 121. Are failures viewed as being caused by bad people rather than system inadequacy? 122. Is shift turnover a formal process? Is there a procedure or checklist for shift turnover? Is it logged? 123. Are operating procedures left to “gather dust on a shelf” because they are out of date, too cumbersome to use in day- by-day activities, or poorly written? 124. Have different M OC procedures/pathways been devised for different types of changes? This custom izes the MOC requirements so that they are stream lined for particular purposes rather than relying one a single, com prehensive, and administratively burdensom e “one-size-fits-all” MOC procedure. 125. Does the MOC process require proactive activities in advance of making a change, rather than the change occurring first and the MOC paperwork following merely as a form of documentation? This type of MOC process m ay leave behind a set of records that described what happened, but it obviates the entire purpose of MOC, which is to ensure that a proposed change receives a thorough and careful review and approval

72 4.2 GREEN CHEMISTRY A United States Environmental Protec tion Agency (EPA) report (Ref 4.18 Lin) contains an extensive review of inherently safer process chemistry options that have been discussed in the literature. This report includes chemistry options that have been investigated in the laboratory, as well as some that have advanced to pilot pl ant and even to production scale. In the 1990’s, the US EPA established the Green Chemistry Program with the goal of pr omoting innovative chemical technologies that reduce or elim inate the use or generation of hazardous substances in the design, manufacture, and use of chemical products. Green chem istry is a highly effective approach to pollution prevention because it applies innovative scientific solutions to real-world environmental situations. For these reasons, the Green Chemis try Program covered activities that are broader in scope than the IS concepts described in this book. Hendershot (Ref 4.11 Hendershot 2006) provides a clear description of the relationsh ip between inherently safer technologies and green chemistry. However, among the twelve principles of Green Chemistry, as published by EPA, are: oto design chemical products to be fully effective, yet have little or no toxicity, and oto design syntheses to use and generate substances with little or no toxicity to humans and the environment. These principles, as well as the others that define the Green Chemistry Program are compatible with the goals and objectives of IS. An example of an award given to co mpanies that have redesigned their processes under the Green Chemistry Program include: The use of transition metals for ca talyzing reactions is of growing importance in modern organic chemistry. These catalysts are widely used in the synthesis of pharmaceuticals, fine chemicals, petrochemicals, agricultural chem icals, polymers, and plastics. Of particular importance is the formation of C–C, C–O, C–N, and C–H bonds. Traditionally, the use of an inert gas atmosphere and the exclusion of moisture ha ve been essential in both organometallic chemistry and tr ansition-metal catalysis. The

OVERVIEW OF IN CIDEN T CAUSATION 17 In reality, the holes or weaknesses are not static; they are dynamic and continually open and close. For example, one personnel shift may be more experienced and diligent than another, so that some barriers begin to degrade further at shift change. Each barrier may not work when needed, and is fully dependent on management system implementation to ensure a reasonable probability of working on demand. If a weakness occurs in one barrier, there may be one or more other barriers that can provide sufficient prot ection and, while the weakness may have an undesirable outcome, it is unlikely that a significant incident will occur. However, most process safety incidents involve a combination of multiple active and latent failures. Therefore, investigators should understand that no layer of protection is perfect , and look for weaknesses in all barriers. 2.1.4 Importance of Latent Failures The Swiss Cheese model introduced th e concept of latent failures (also known as latent conditions). Historic incident data show that latent failures have played an important role in inci dent causation (Reason, 1990). The term latent failure implies the condition is dormant or hidden. Normally the latent failure can be revealed before an incide nt occurs, through testing or auditing during typical operations within th e process, as shown in Figure 2.3 . Figure 2.3 Latent (hidden) Failure

PROCESS SAFETY INCIDENT CLASSIFICATION 153 Table 9.2. Typical Tier 3 and Tier 4 process safety metrics (derived from CCPS 2019) Tier 3 Challenges to Safety Systems Opening of a rupture disc, a pressure control valve to flare or atmospheric release, or a pressure safety valve when a pre- determined trigger point is reached Activation of a safety instrume nted system when an “out of acceptable range” process variable is detected, e.g. activation of high-pressure interlock Process Deviations or Excursions Excursion of parameters such as pressure, temperature, flow outside of the standard oper ating limits (the operating “window” for quality control) but remaining within the process safety limits Inspection, Testing and Preventive Maintenance (ITPM) Primary containment inspection or testing results outside acceptable limits Discovery of a failed safety system upon testing, e.g. relief devices that fail bench tests at set points LOPC not classified as Tier 1 or 2 LOPC events that do not meet the Tier 1 or 2 criterion considered Tier 3 incidents Other Dropping loads / falling objects within range of process equipment Failure to remove line blanks in critical piping

F.2 Culture Assessment Protocol |345 8. Does the organization believe that M OC is important, and that changes cannot occur, however convenient they may be, or however sim ple and obvious they may seem without the appropriate review and authorization using the MOC process? 9. Is there a “shoot the messenger” mentality with respect to dissenting views, or raising process safety problems? 10. Are the decision m akers technically qualified to m ake judgments on com plex process system designs and operations? Are they able to credibly defend their judgments in the face of knowledgeable questioning? Do process safety personnel find it intim idating to contradict the m anager’s/leader’s strategy? 11. Do production and protection com pete on an equal footing when differences of opinion occur as to the process safety/safety of operations? 12. Has the staffing of key process safety positions been shifted, over the years, from senior levels to positions further down the organization? Are there key positions currently vacant? 13. Does m anagement encourage the developm ent of safety and risk assessments? Are recommendations for safety improvements welcomed? Are costly recommendations, or those im pacting schedule, seen as “career threatening” if the person making the recommendations chooses to advocate them ? 14. Is auditing regarded as a negative or punitive activity? Are audits conducted by technically com petent people? How frequently do audits return only a few m inor findings? Is it generally anticipated that there will be “pushback” during the audit closeout m eetings? 15. Is safety and process safety a core value? Are the core process safety values are written down and stressed in training and other forums? Is there a com pany or facility document that describes process safety as a core value? Is there evidence, e.g., m inutes of m eetings and agendas for safety meetings or

CONTINUOUS IMPROVEMENT 161 Example Incident 6.2 – The Dike That Wasn’t During a field review of safety sy stems in a tank farm, the auditor noted that the diked area around on e tank had a drain valve that was open. He was told that the valve was provided to allow rainwater to be drained from the diked area follo wing heavy rains. If the valve is not reclosed after draining the rainwa ter, the dike will not be able to contain a large spill from the tank – which, given the topography of the facility, would have resulted in a st ream of fuel oil running downhill into the nearby process areas, crea ting both safety and environmental problems. Lessons learned in relation to abnormal situation management: Understanding abnormal situations: Diking of tanks for containment with installed dike drains is a standard design. The potential consequences of leaving the drain valve open should be explained and understood. Procedures: A written policy or checklist procedure should be in place for managing drain valves in dikes. Previous chapters have highlighted the importance of other RBPS elements with respect to abnormal situations. The intent is not to duplicate that text, but auditing should prioritize: Operating procedures – readily accessible troubleshooting guidance to correct abnormal situations Training & performance assurance – competency of workforce to recognize and intervene to correct abnormal situations Asset integrity & reliability – abse nce of overdue in spection, testing and preventive maintenance (ITPM) tasks on safety-critical equipment/elements to enhance reliability to work on demand Management of change – projects should identify conditions that could lead to abnormal situations, as a result of change

Containers 155 9.9.4 The Size, Number, and Rating of Nozzles No zzles sizes and pressure ratings are important, too. Nozzle sizes can be seen on P&IDs if they are not connected to a pipe or are different from the connected pipe size. Nozzle numbers are decided based on the required functionality. Nozzle pressure ratings are only shown on the P&IDs IF the pressure rating is different from that of the pipe that is the connecting pipe to the nozzle. The pressure rating of nozzles should match the design pressure of the container they are attached to. However we generally don’t choose a 150# pressure rating for small nozzles (say less than 3″ ) even though they are connected to atmospheric tanks. To provide enough integrity in small nozzles the minimum pressure rating for them is chosen to be 300#. Typical sizes of different nozzles are shown in Table 9.9. 9.9.5 Mer ging Nozzles The number of nozzles on containers should be kept to a minimum. One reason is nozzles are expensive parts and the other reason is that nozzles are heavy, and installation of more than needed nozzles on con-tainers may force us to use thicker and more expensive shells for container fabrication. There are different ways to decrease the number of nozzles on containers. For example, if there are several incoming fluids to a container, instead of a locating one nozzle for each stream we may merge the streams together and then direct the mixed flow to the container through one nozzle (Figure 9.18).Figure 9.17 Pr eference of elevated inlet nozzle for two phase liquid-gas flow pipes. Table 9.9 Size of no zzles. Nozzle name Size Number Process nozzles Minimum 2″ (to avoid plugging) Per connecting pipes’ number Instrument nozzles 2″–3″ Per required instruments Manway 24″–30″– 36″ Per client request or one manway per every 10 m of diameter of container for shell manways, and for roof manways one manway per every 15 m of diameter Overflow nozzle Needs sizingAs a rule of thumb: maximum inflow sizeOne Thief hatch The same as manway size One (or occasionally two) Pressure protection nozzle Needs sizing Needs sizing Vacuum protection nozzle Needs sizing Needs sizing Free vent nozzle Needs sizing Generally one Clean‐out doors 8″ × 16″, 24″ × 24″, 34″ × 48″, 48″ × 48″ (Limited application)One Drain nozzles Up to 2″ Multiple Truck‐out nozzles 3″–4″ Multiple Hand hole 8″ Number to provide full reachability Drain and vent size Discussed in Chapter 8 Multiple Sting nozzle 2″–4″ Multiple Steam‐out nozzle 1½″ or the same as vent size Multiple Purge nozzle The same as vent size or one size largerOne or two View or inspection port 6″–8″ One Media adding/removal 4″ One Cathodic protection 4″–6″ Needs sizing

156 INVESTIGATING PROCESS SAFETY INCIDENTS or discoloration was created relative to the time of the incident and the subsequent emergency response, re covery, and clean-up activity. The team should record the accumulation of soot or airborne fallout debris and the overall deposit pattern. The investigators should also note irregularities, breaks/gaps in the pattern, or the absence of soot or fallout, especially when there is an anomaly in the pattern. Any differences in depth, color, pattern, or appearance, should be noted, examined, analyzed, and photographed. Maps and diagrams should be us ed to document the locations of items such as people, equipment, materials, and structures. Measurements to reference points can be written on the drawings. The movement of key personnel can be traced on a map or plot plan. Using color-coding and recording the times the individuals we re at each location can help to understand the testim ony of witnesses. Certain incidents, such as explosio ns, may require special mapping of fragments and selected debris. By carefu l documentation, established at the onset of the investigation, it is po ssible to create an accurate diagram of the relative position of the various pieces of a vessel after an explosion. By using the data from this missile mapping, kn owing the weight of each fragment, and having an indication of the trajectory of fragments, it may be possible to estimate of the energy releas e of the explosion. The energy release value can sometimes be used to confirm or rule out certain proposed scenarios. The Pietersen (Pietersen, 1985) report on the Mexico City LPG terminal disaster is an excellent example of such a study. Comprehensive treatment of analysis techniques can be found in Baker and CCPS (Baker, 1983; CCPS, 2010). 8.3 EVIDENCE GATHERING The following sections describe the init ial site visit, evidence management, team tools and supplies, and advice on photography. Some activities may proceed simultaneously, in cluding the witness inte rviews discussed in Chapter 7. As a result, it may be necessary for the investigation team to split up assignments. The team leader should ensure that everyone understands their respective roles and responsibilities. An “Action Reminders” list is included in Appendix E.

RISK ASSESSMENT 317 an equal basis. Guidance can include software used, failure rate data, consequence modeling approaches, structural response to explosio ns, human impact criteria, and qualification requirements for risk analysts. Frequency Analysis In order to estimate the risk, the frequency of a scenario is needed along with the consequence of the scenario. A few definitions important to the topic of frequency analysis are listed. Frequency - Number of occurrences of an event per unit time (e.g., 1 event in 1000 yr = 1 x 10-3 events/yr). (CCPS Glossary) Probability - The expression for the likelihood of occurrence of an event or an event sequence during an inte rval of time, or the likelihood of success or failure of an event on test or on demand. Probability is expressed as a dimensionless numbe r ranging from 0 to 1. (CCPS Glossary) Likelihood - A measure of the expected probability or frequency of occurrence of an event. This may be expressed as an event frequency (e.g., events per year), a probability of occurrence during a time interval (e.g., annual probability) or a conditional probability (e.g., probability of occurrence, given that a precursor event has occurred). (CCPS Glossary) Common frequency assessment te chniques include the following: Review of historical records of similar events Fault tree analysis (Refer to Section 12.3.6) Event tree analysis (Refer to Section 12.3.7) Layer of Protection analysis (Refer to Section 14.7) The first step of frequency analysis is clearly describing the incident scenario. This can be thought of as telling a story. Scenario - A detailed description of an unplanned event or incident sequence that results in a loss event and its associated impacts, including the success or failure of safeguards involved in the incident sequence. (CCPS Glossary) For example, the scenario story could be: the hazardous materials leaks from a pipe, and then, the materials form a vapor cloud that disperses downwind, and then, the vapor cloud may or may not be ignited, and if it is, it may flash back, or it may create a vapor cloud explosion, and finally, people may or may not be in the vicinity and be harmed.

246 PROCESS SAFETY FOR ENGINEERS: AN INTRODUCTION Table 12.1. Preliminary hazard identification study overview Typically Used During Resource Requirements Type of Results Advantages and Disadvantages Research and development Conceptual design Pilot plant operation Material, physical, and chemical data Basic process chemistry Process flow diagram Rough screening of general hazards Ranking of hazardous areas or processes Provides a quick focus on big issues Potential to miss something due to limited design details Checklist Analysis A Checklist Analysis uses a written list of items or procedural steps to verify the status of a system. They can be simple or very detailed. Checklists are frequently used to evaluate compliance with standards and practices. In some cases, analysts use a more general checklist in combination with another hazard evaluation method to discover common hazards that the checklist alone might miss. While developing a good checklist may be challenging, using the checklist is easy and can be applied at any stage of the process life cycle. A checklist used in hazard identification can be focused on a single process. For example, a checklist for distillation units can be develo ped with input from distillation experts and process safety engineers and can include learning s from industry distillation unit incidents. A checklist could also be focused on a specific topic that is then applied to all hazard identification studies. For example, a human factors checklist can be applied to every hazard identification study conducted to ensure that human factors considerations are addressed. Checklists may be available from va rious sources including the following. Chemical Process Safety, Fundamentals wi th Applications, 4th edition, Chapter 11 (Crowl 2019) Guidelines for Revalidating Process hazard analysis, 1st edition (CCPS 2001) Guidelines for Hazard Evaluation Procedures, 3rd Edition, (CCPS 2008 b) A danger with checklist analysis is that it can constrain the thinking of the hazard identification team to the items on the checklis t. This might fail to identify novel hazards. However, good leadership and team brainstorming can avoid this pitfall. An advantage of the checklist approach is that it guarantees that the team will address potentially obscure sequences that have occurred in the past and thus are included in the checklist. Table 12.2 provides an overview of Checklist Analysis requirements and results. Checklist Analysis is well suited for determining if regulatory requirements or industry/corpora te guidance is being followed.

11.4 Drilldown | 149 11.4 Drilldown After her meeting with Lucas, Charlotte continued to think about all the information she had found. It was troubling to her to find so many instances where poor process safety culture resulted in the loss of so many lives. The Texas City incident really hit home for her. The 12-hour shifts for 29 or more consecutive days sounded all too familiar. Were there other shift arrangements that would be less stressful yet not impact production? Were there studies she could share with management that would help them to see the risk they were taking by demanding such a rigorous schedule? At the minimum, at least they would be informed about the decisions they were making. She identified two other questions her incident reviews suggested: • One key driver of poor process safety culture is the lack of the sense of vulnerability. How could the company create this sense of vulnerability? • Communication was a key factor in all the incidents she studied. What could the company do to ensure that written procedures were followed? How could they ensure that communication from shift to shift was done effectively? 11.5 Internalize After thinking about the situation more deeply, Charlotte sat down with Lucas and Oliver to go over the findings and come up with a plan. Lucas invited Oliver to the meeting because he knew that an effective change in process safety culture needed to have complete leadership buy-in. If they could engage Oliver, they would have a stronger case when they presented it to Mason. Charlotte started the meeting with a question, “Did you know that there have been safety incidents on other rigs under circumstances that are not very different from our own?” “Sure, but that’s them,” Oliver grumbled. “We’re better than that. It won’t happen to us.” Lucas said, “I’m sure that’s exactly what they thought too, until it happened. Charlotte went on, “I reviewed the information on the Bass Strait incident where two men lost their lives. They didn’t follow the procedures for management of change, likely because it would cause delays. There’s no telling what would have happened that day, but the likelihood of this accident would have been reduced if they had just followed their own procedures.” “You have a point,” Oliver conceded. “We’ve been trying to avoid delays by finding workarounds, but we haven’t gotten to the point where we don’t follow our

Table A.4 IST Checklist Simplify Questions 4 SIMPLIFY Questions: 4.1 Can equipment be designed such that it is difficult or impossible to create a potential hazardous situation due to an operating or maintenance error? • Easy access and operability of valves to prevent inadvertent errors • Elimination of all unne cessary cross-connections • Use of dedicated hoses and comp atible couplings for reactants where hose connections are used • Designing temperature-limited heat transfer equipment to prevent exceeding maximum process or equipment design temperatures • Use of corrosion resistant materials for process equipment, piping and components • Operating at higher temperature to avoid cryogenic effects such as embrittlement failures • Using alternative agitation methods (e.g., external circulation using sealless pump which elimin ates potential releases due to agitator seal failures) • Use of mixing feed nozzle instead of agitator for vessel mixing • Using underground or shielded tanks • Specifying fail-safe operation on utility failure (e.g., air, power) • Allocating redundant inputs and outputs to separate modules of the programmable electronic system to minimize common cause failures • Provide continuous pilots (independent, reliable source) for burner management systems • Using refrigerated storage vs. pressurized storage • Using independent power buses for redundant equipment to minimize consequences of partial power failures • Minimizing equipment wall area to minimize corrosion/fire exposure • Minimizing connections, paths and number of flanges in hazardous processes • Avoiding use of threaded connections in hazardous service 450

2.5 Maintain a Sense of Vulner ability |43 decom pose the remaining cooling water into hydrogen and oxygen. This mixture subsequently exploded, causing a loss of nuclear containment. Engineers at the facility conducted the trial hoping to find a way to more safely shut down and restart. The trial required operating with the cooling water level below the safe operating level. The engineers with a lost Sense of Vulnerability never considered that their trial could place the reactor in an unsafe condition. Instead they accepted a Normalization of Deviance and did not consider the need to Understand/Act upon Hazards/Risks . Catastrophic incidents involving hazardous materials or activities happen all too often. However, they happen in relatively small num bers compared to the large num ber of hazardous facilities. For this reason, many facilities and indeed many com panies have not experienced very large incidents. This can create a false sense of security and complacency. The opposite of com placency – a sense of vulnerability – naturally follows a serious incident or near-m iss. This can readily be understood by considering a close call while driving a car. Immediately following the incident, the driver becomes m ore intensely focused on the surrounding environment, looking for the next threat. They will likely drive slower, provide greater spacing from the car in front, and change lanes less frequently. This will continue for a time. Sim ilarly, following the Texas City explosion, many leaders of refineries and sim ilar facilities felt a keen sense of vulnerability. They undertook many activities to improve process safety culture, m anagement system s, and engineering. However, people tend to forget the lessons learned from catastrophic incidents, lesser incidents, and near misses relatively quickly. A study by Throness (Ref 2.19) showed that unless people

192 that the design, installation, op eration, and maintenance of the modified equipment or practice i ncorporates the four inherently safer strategies, where appropriate. Plant modifications also provide an opportunity to incorporate inherently safer strategies that were overlooked or deferred during the initial design. For example, if a pressu re vessel must be replaced because it is at or near retirement thickness, this is an opportunity to specify a replacement vessel that has a higher pressure rating that cannot be reached or exceeded by the worst-case credible transient event, or to upgrade to a different material of cons truction that is more resistant to known corrosion or damage mech anisms. The MOC program should trigger review of such consideratio ns during the change review and approval process. A final check that inherent safe ty issues have been properly addressed on projects can also be added to pre-startup safety review (PSSR) procedures and checklists. 8.9 DECOMMISSIONING The application of inherently safer strategies during the decommissioning phase of the life cycle is just as important as its design or operations phases. This is beca use the equipment is not under the daily attention and care of personnel who are responsible for its safe continued operation. Decommi ssioned equipment may be “abandoned,” with respect to operat ing or maintenance personnel, for years before some action is taken to recommission or dismantle it. Inspection, testing, and preventive maintenance activities are likely to have been discontinued because the hazardous materials have presumably been completely removed from the equipment. Sometimes, the safe work practices and other ca refully applied rules for performing work on the equipment, including li ne breaking/equipment opening may have been abated as the equipment is no longer considered hazardous from a chemical release viewpoint. If the decommissioning phase has lasted years, there simply may be no one who can remember the state in which the equipment was left. In particular, the inherently safer strategies of Moderation and Substitution are important while in a decommissioned state. The key acti ons necessary to ensure that a

240 | 7 Sustaining Process Safety Culture 1. The ability to produce profitably today without com promising the ability of future generations to do so. 2. The ability to maintain or support an activity, process, or results over the long term. The first definition represents a m utual recognition by business and environmental advocates that society requires both profits and a clean environmental to thrive long-term . The second is used more generally in the business context and, points to strong m anagement and leadership. Process safety culture and PSMSs in general rely heavily on both definitions. Clearly, avoiding incidents also helps avoid environmental im pacts, along with injuries to workers and the public. Also, the results of a strong process safety effort can bring additional business benefits (Ref 7.2). Equally importantly, process safety needs to be m aintained and continually improved over the long term, just like other business objectives. Some indicators of a sustainable process safety culture and PSMS include: The PSM S is institutionalized. It can survive the loss of its original authors, im plementers, and leaders who, through their personal commitment and hard work, m ade it succeed initially. Everyone at every level is aware of their process safety roles and responsibilities, how they fit in the overall process safety effort, and how they benefit personally. Everyone at every level has an appropriate sense of vulnerability. Continual improvement of the culture and the PSMS is institutionalized and follows the Plan-Do-Check-Act model. Documentation is thorough enough and clear enough that any capable person can understand what has occurred in the past and plan future activities. Process safety culture is strong. • • • • • •

52 | 4 Examples of Failure to Learn 4.2 API Recommended Practice (RP) 752 (2009). Management of Hazards Associated with Location of Process Plant Permanent Buildings. Washington, DC: American Petroleum Institute. 4.3 API Recommended Practice (RP) 756 (2014). Management of Hazards Associated with Location of Process Plant Tents. Washington, DC: American Petroleum Institute. 4.4 ARIA (2013). Overflow of a gasoline tank inside a refinery. IMPEL - French Ministry for Sustainable Development, Report No. 41148. 4.5 ASF (2000). Explosion caused due to an overflow of aqueous hydrogen peroxide at a peracetic acid manufacturing plant. www.shippai.org/fkd/en/cfen/CC1000131.html (accessed April 2020). (See Appendix, index entry J85). 4.6 BASF (2020) Explosion in Oppau. www.basf.com/ global/en/ who-we- are/history/chronology/1902-1924/1921.html (accessed May 2020). 4.7 BBC (2013). Fukushima leaks: radioactive water overflows tank. www.bbc.com/news/world-asia-24377520 (accessed April 2020). 4.8 Johnson, R.W., Rudy, S.W., and Unwin, S.D. (2003). Essential Practices for Managing Chemical Reactivity Hazards. New York: CCPS. 4.9 CCPS (2014). Guidelines for Initiating Events and Independent Protection Layers in Layer of Protection Analysis. Hoboken, NJ: AIChE/Wiley. 4.10 CCPS (2018). Essential Practices for Creating, Strengthening, and Sustaining Process Safety Culture. Hoboken, NJ: AIChE/Wiley. 4.11 CCPS (2020). Chemical Reactivity Worksheet. www.aiche.org/ccps/ resources/chemical-reactivity-worksheet (accessed December 2019). 4.12 CSB (1999). Union Carbide Corp. Nitrogen Asphyxiation Incident. CSB Report No. 98-05-I-LA. 4.13 CSB (2002). Improving Reactive Hazard Management. CSB Report No. 2001-01-H. 4.14 CSB (2003). Hazards of Nitrogen Asphyxiation. CSB Report No. 2003-10-B. 4.15 CSB (2006). Valero Refinery Asphyxiation Incident. CSB Report No. 2006- 01-I-DE. 4.16 CSB (2007a). Formosa Plastics Vinyl Chloride Explosion. CSB Report No. 20014-10-I-IL. 4.17 CSB (2007b). Synthron Chemical Explosion. CSB Report No. 2006-04-I-NC. 4.18 CSB (2009a). INDSPEC Chemical Corporation Oleum Release. CSB Report No. 2009-01-I-PA. 4.19 CSB (2009b). T2 Laboratories Inc. Reactive Chemical Explosion. CSB Report No. 2008-3-I-FL.

9.6 Prepare | 127 When the results came back, two of the four processes had self- accelerating decomposition temperatures (SADT) for the startup reactants in the presence of the new catalyst that were less than 50oC above the maximum temperature typically seen at start up. For these same processes, the SADTs were 75oC above the stable hold temperature with final product, but the time to maximum rate (TMR) for final product was less than 24 hours. The three were about to jump to an engineering solution, but Jason pulled them back to discuss the situation more strategically. He reminded his colleagues what they’d just learned: Several of their processes had potential chemical reactivity hazards that they had not recognized before. He recommended that they first develop a design standard addressing reactivity hazards, including when and how to test, and how to design and operate the process, depending on the test results. This standard would not only guide their current efforts but also inform future process designs and modifications. 9.6 Prepare Jason, Emma, and Phillip invited Chip, the chief engineer, to join their group to draft the chemical reactivity hazard management standard and plan the path forward. They also invited Maria, an instrument and controls engineer, who was assigned the task of developing the necessary interlocks and logic to meet the eventual standard. They drafted the standard with input from the testing lab and from CCPS literature (CCPS 1995), then circulated it to key stakeholders in engineering, production, and HSE. About half of the reviewers resisted the standard, citing the cost and claiming the proposed temperature and time limits were too conservative and rigid. Emma responded by providing time-temperature graphs for all the holds the site had experienced over the past three years. She overlaid the TMR test graph for the appropriate new catalyst. From this presentation, it was clear that the site had had five holds during that period where the plant was on the brink of thermal runaway. The critics then saw the wisdom of the recommended conditions. The team noted that they should have done the overlay analysis as a first step. With agreement from the stakeholders, Maria provided the draft standard to the technology licensor and began discussing with them the hardware and software that would be needed to control temperature within the range specified in the draft standard.

121 6.11.2 Equipment Layout, Accessibility, and Operability Process equipment should be designed in such a way that it is simple and intuitive as possible and be installed such that all equipment is easily accessible. Ground-level installati on of instrumentation and other equipment is preferable where po ssible. Ergonomics, which is one aspect of human factors, should be applied in the layout of equipment, valves, controls, and anything else that operating, and maintenance personnel need to access. Designs that provide good easy access to equipment, while ideally avoiding undo bending, climbing, and stretching, make it more likely that process equipment will be operated properly, and safety equipment will be properly operated in an emergency, particularly if additional highlighting aids are provided such as through signage, color-coding, clear labeling, and/or lighting. Designs should also avoid requiring an op erator to change locations when monitoring and controlling a process. For example, an operator should be able to see the temperature indicator for a process from the same location where the operation of the cooling water control valve is performed. Designs and systems sh ould minimize potential harmful exposures in both normal and emergency operations. This consideration affects the location of normal and emergency drains and vents. The chemistry of a process can be made inherently safer by selecting materials that can better tolerate hum an error in handling, mixing, and charging. For example, if a concentrated reagent is used in a titration, precision in reading the burette is important. However, if a dilute reagent is used, less precision is needed. 6.11.3 Maintainability A space station design that requires less “spacewalk” time is inherently safer than a design that requires more . If the astronauts do not need to go outside their space vehicle, they bear less risk. For chemical plants, designs or operating regimes that reduce or eliminate the need for vessel or other process equipment open ing, entries, or hazardous levels of maintenance are, in general, inhere ntly safer than those that do not. For example, in one chemical plant, rail cars, tank trucks, and some reactors and storage tanks were cleaned manually by personnel who entered the vessel; fatalities occu rred from unexpected or undetected

99 facilities, as today’s tec hnology more easily allows for remote monitoring and operation of equipment and proces ses. Nonetheless, it can also be considered at other points in the life cycle of a facility. For example, refineries and chemical plants have begun to relocate their control rooms and other occupied buildings ou tside of the blast radius and/or toxic footprint of the process release points, to reduce or eliminate the effects of a loss of containment or explosion on personnel. The 1999 Control of Major Accident Hazards (COMAH) regulation in the UK requires the consideration and documentation of inherently safer design alternatives du ring the initial design st age. In addition to the standard IS strategies, it includes plant layout as part of the overall approach, particularly to prevent the potential for domino effects by fire, explosion (pressure wave and missile s) or toxic gas cloud that could cause loss of operational control in another location. Plant layout, which is established during the design st age, is often a compromise between a number of factors such as: •The need to keep distances fo r materials transfer between plant/storage units to a minimu m to reduce costs and risks; •The geographical limitations of the site; •Interaction with existing or pla nned facilities on-site, such as existing roadways, drainage, and utilities routings; •Interaction with other plants on-site; •The need for plant operab ility and maintainability; •The need to locate hazardous materials facilities as far as possible from site boundaries and from people living in the local neighborhood; •The need to prevent confinemen t where release of flammable substances may occur; •The need to provide access for emergency services; •The need to provide emergency escape routes for on-site personnel; and, •The need to provide acceptab le working conditions for operators. For example, these issues are part ially dealt with in the US OSHA PSM and US EPA RMP regulations under facility siting, which involves the spatial relationship between process hazards and people but can also be applied to the spatial relationship between hazards and other buildings,

258 PROCESS SAFETY FOR ENGINEERS: AN INTRODUCTION Leading a good quality analysis requires good facilitation skills. Keeping the team on-task for hours, days, even weeks is no small challenge. Encourage all to participate and control those who tend to dominate the conversation. The details of the analysis should be captured in worksheets. It should be recognized that these worksheets may be picked up in months, maybe years, and someone will try to understand what the analysis covered and what was found. Avoid using shorthand and abbreviations that might only be meaningf ul to the team members who participated. Documentation should be a complete listing of the cause, consequence, safeguards, and recommendations, as appropriate. Where no feas ible cause can be determined or no adverse consequence found, this should be documented . Documenting only when a hazard is found will leave those trying to understand the an alysis or respond to its recommendations wondering what the complete scenario was or if it was even addressed. Useful guidance for recording hazard identification studies is provided in Guidelines for Hazard Evaluation Procedures . (CCPS 2008 b) What a New Engineer Might Do As a new engineer, or an engineer new to process safety, it is very likely that you will participate i n s o m e f o r m o f p r o c e s s h a z a r d a n a l y s i s i n your first few years in the process industries. Participation in a process hazard analysis such as a HAZOP is an excellent way to learn about a process and how it is actually operated and maintained. New processes and substantially modified processes require the involvement of many engineering disciplines in addition to the role of chemical engineers, and thus all of these engineering disciplines can help support process ha zard analysis either on a full time or part time basis. Mechanical engineers are often helpful in identifying vulnerabilities such as materials of construction, stress cracking, th ermal cycling, and stress analysis that may contribute to hazardous events. Civil engineers may be needed to identify concerns/solutions t o e x t e r n a l e v e n t s s u c h a s f l o o d i n g , e a r t h q u a k e s , a n d h i g h w i n d l o a d i n g . I n s t r u m e n t a n d Control engineers are often crucial to identify ing control reliability, control response, and control suitability for addressing consequences identified. Electrical engineers often provide insight into critical distribution system reliabilities, needs for redundancy, and issues involving electrical coordination. Nearly all process hazard analysis w ill require the involvement of a process safety engineer to either lead the analysis or support the critical thinking. Section 12.3.9 discussed non-technical skills th at new engineers must possess to support quality process hazard analysis including documenting process hazards analyses and participating in, scribing for, and leading analys is teams. These require writing skills, public speaking skills as well as human relation skills such as good listening, assertiveness, and respect for another person’s opinion. Process hazard analysis necessar ily requires identification of scenarios that can lead to impacts such as environmental releases, inju ries and fatalities, and property damage. Engineers should learn to state these in fact-b ased terms. For example, consider identifying that a large release of a flammable material inside a congested area can lead to an explosion if ignited. One should not write, “This will blow up the entire unit and kill everybody!” Instead, “if ignited, this can potentially lead to damage to the equipment or processing unit, and one or

77 | 6.1 Focus Table 6.1 Possible Triggers for Seeking Learning Trigger Type Learning Trigger Regular, ongoing learning • employee development • required regulatory training Events and conditions • high-profile incidents • acquisition and post-acquisition integration • new process development and design • new product or technology strategy • organizational changes or new initiatives Metrics and data • tier 4 leading metrics • audit findings and recommendations • tier 3 near-miss metrics • incident and near-miss investigations • gut feel and warning sign analysis In general, give the highest priority to learning opportunities that metrics and data indicate will have the largest positive impact on process safety performance. These generally come from Tier 4 and Tier 3 metrics. To help prioritize, think of the worst thing that could have happened if the Tier 3 or 4 event proceeded to the worst-case scenario. As learning opportunities triggered by events and conditions arise, leaders should fit them into the priority list as appropriate. Finally, ongoing learning related to organizational issues should always be included to help the company react nimbly to change without compromising process safety. Here’s a hypothetical example. During a management review meeting, the leadership team of a refining company discusses the points presented in Table 6.2 below. From this, they develop corresponding short-term improvement goals. Table 6.2 Example of Process Safety Goal Development Discussion point Possible Goal In the past year, seven facilities had audit findings related to operating procedures. Deploy a common operating procedure based on best practices and audit to ensure it is followed. In the past two years, the Tier 4 metrics for asset integrity ITPM have slipped from 99.5% completed on schedule to 97%. Evaluate gaps in the asset integrity program and recommend actions for improvement.

204 | Appendix: Index of Publicly Evaluated Incidents Section 2: Culture Core Principles (In Principle order) Establish the Imperative for Process Safety—Primary Findings A5, A7, A10 C15, C16, C17, C18, C22, C44, C57, C70 D7, D21, D25 J4, J5, J29, J30, J32, J35, J44, J58, J61, J68, J70, J85, J90, J91, J114, J116, J143, J144, J148, J157, J164, J165, J166, J167, J170, J173, J174, J175, J176, J177, J178, J179, J180, J181, J182, J183, J185, J186, J187, J188, J189, J190, J192, J193, J195, J196, J197, J199, J212, J237, J240, J262, J270, J271 S7, S14, S16, S17 Establish the Imperative for Process Safety—Secondary Findings A2 C5, C13, C14, C19, C37, C46, C51, C53, C54, C69 D33 HA3 J1, J2, J3, J7, J79, J86, J130, J132, J147, J158, J160, J161, J163, J171, J213, J239 S1, S5 Leadership See RBPS Elements Conduct of Operations and Management Review, and other Culture Core Principles Mutual Trust—Primary Findings D21 Mutual Trust—Secondary Findings D25 J164 Open/Frank Communications—Primary Findings C24, C35 D21 J59, J63, J189, J214, J216 S9 Open/Frank Communications—Secondary Findings A11 C30, C70 D25 J90, J164, J270 S10, S14, Sense of Vulnerability—Primary Findings A2, A4, A5, A6, A7, A10, A11 C11, C12, C13, C19, C22, C23, C24, C44, C45, C68, C69, C70, C71 D18