Guidelines for Initiating Events and Independent Protection Layers in Layer of Protection Analysis E-Book

• Herausgeber: John Wiley & Sons
• Kategorie: Fachliteratur
• Sprache: Englisch

Seitenzahl: 532

Veröffentlichungsjahr: 2015

Beschreibung

The book is a guide for Layers of Protection Analysis (LOPA) practitioners. It explains the onion skin model and in particular, how it relates to the use of LOPA and the need for non-safety instrumented independent protection layers. It provides specific guidance on Independent Protection Layers (IPLs) that are not Safety Instrumented Systems (SIS). Using the LOPA methodology, companies typically take credit for risk reductions accomplished through non-SIS alternatives; i.e. administrative procedures, equipment design, etc. It addresses issues such as how to ensure the effectiveness and maintain reliability for administrative controls or "inherently safer, passive" concepts. This book will address how the fields of Human Reliability Analysis, Fault Tree Analysis, Inherent Safety, Audits and Assessments, Maintenance, and Emergency Response relate to LOPA and SIS. The book will separate IPL's into categories such as the following: * Inherent Safety * eliminates a scenario or fundamentally reduces a hazard * Preventive/Proactive * prevents initiating event from occurring such as enhanced maintenance * Preventive/Active * stops chain of events after initiating event occurs but before an incident has occurred such as high level in a tank shutting off the pump. * Mitigation (active or passive) * minimizes impact once an incident has occurred such as closing block valves once LEL is detected in the dike (active) or the dike preventing contamination of groundwater (passive).

Leseprobe

Contents

Cover

Half Title page

Title page

Copyright page

List of Data Tables

Acronyms and Abbreviations

Glossary

Acknowledgements

Preface

Chapter 1: Introduction

1.1 Audience

1.2 Scope

1.3 Key Changes Since the Initial LOPA Concept Book

1.4 Recap of LOPA

1.5 Disclaimer

1.6 Linkage to Other CCPS Publications

1.7 Annotated Description of Chapters

References

Chapter 2: Overview: Initiating Events and Independent Protection Layers

2.1 LOPA Elements: An Overview

2.2 Management Systems to Support LOPA

2.3 Scenario Selection

2.4 Overview of Scenario Frequency

2.5 Overview of Consequences

2.6 Risk Considerations

2.7 Conclusions

References

Chapter 3: Core Attributes

3.1 Introduction to Core Attributes

3.2 Independence

3.3 Functionality

3.4 Integrity

3.5 Reliability

3.6 Auditability

3.7 Access Security

3.8 Management of Change

3.9 Use of Data Tables

References

Chapter 4: Example Initiating Events and IE Frequencies

4.1 Overview of Initiating Events

4.2 Inherently Safer Design and Initiating Event Frequency

4.3 Specific Initiating Events for Use in LOPA

4.4 External Events

4.5 What If Your Candidate Initiating Event is Not Shown in a Data Table?

References

Chapter 5: Example IPLS and PFD Values

5.1 Overview of Independent Protection Layers (IPLs)

5.2 Specific Independent Protection Layers for Use in LOPA

5.3 What if Your Candidate IPL is Not Shown in a Data Table?

References

Chapter 6: Advanced LOPA Topics

6.1 Purpose

6.2 Use of QRA Methods Relative to LOPA

6.3 Evaluation of Complex Mitigative IPLs

6.4 Conclusions

References

Appendices

Appendix A. Human Factors Considerations

Introduction

What is Human Error?

Categorization of Human Errors

Performance Shaping Factors

Impact of Performance Shaping Factors on Human Error Probabilities

Dependence

Summary: Performance Shaping Factors

Human Error Rate and Initiating Event Frequency

Humans As IPLs

The Timeline of an IPL Response

Key Points

References

Appendix B. Site-Specific Human Performance Validation

Initiating Event Frequency Data Collection

Example of Site-Specific Data for Human Error Initiating Events

Example of Site-Specific Data Collection for Human IPLs

Example Use of Site-Specific Test/Drill Data to Validate Human Response IPLs

Approach to Using a Test/Drill Plan for Validation of Human IPLs

Approach to Using a Statistical Sample Plan for Validation of Human IPLs

Key Points

References

Appendix C. Site-Specific Equipment Validation

Considerations for Site-Specific Data Collection

Estimating Failure Rates and Probabilities Using Generic Data

Estimating Failure Rates and Probabilities Using Predicted Data

Estimating Company-Specific Failure Rates and Probabilities Using Plant-Specific Data

Estimating Failure Rate When the Failure has not Yet Occurred

Selected Example for Calculating Reliability Data for Use in LOPA from Plant-Specific Data

Sources of Data

References

Appendix D. Example Reliability Data Conversion for Check Valves

Data Discussion

Data Conversion to Failure Rate

Fault Tree Analysis Summary Results

Guidance for LOPA and QRA

References

Appendix E. Pressure Vessels and Piping Overpressure Considerations

Defining Overpressure

Factors that Limit Pressure Rise

Options for Treatment of Overpressure

References

References

Index

GUIDELINES FOR INITIATING EVENTS AND INDEPENDENT PROTECTION LAYERS IN LAYER OF PROTECTION ANALYSIS

Copyright © 2015 by the American Institute of Chemical Engineers, Inc. All rights reserved.

Published by John Wiley & Sons, Inc., Hoboken, New Jersey. Published simultaneously in Canada.

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Library of Congress Cataloging-in-Publication Data:

Guidelines for initiating events and independent protection layers in layer of protection analysis / Center for Chemical Process Safety of the American Institute of Chemical Engineers.       pages cm    Includes index.     Summary: “Presents a brief overview of Layer of Protection Analysis (LOPA)and its variations, and summarizes terminology used for evaluating scenarios in the context of a typical incident sequence"—Provided by publisher.    ISBN 978-0-470-34385-2 (hardback)   1. Chemical process control—Safety measures. 2. Chemical processes—Safety measures. 3. Chemical plants—Risk assessment. I. American Institute of Chemical Engineers. Center for Chemical Process Safety.    TP155.75.G854 2014    660’.2815—dc23

2014012633

This book is one in a series of process safety guidelines and concept books published by the Center for Chemical Process Safety (CCPS). Refer to www.wiley.com/go/ccps for a full list of titles in this series.

It is sincerely hoped that the information presented in this document will lead to an even more impressive safety record for the entire industry. However, the American Institute of Chemical Engineers, its consultants, the CCPS Technical Steering Committee and Subcommittee members, their employers, their employers’ officers and directors, and Process Improvement Institute, Inc., and its employees do not warrant or represent, expressly or by implication, the correctness or accuracy of the content of the information presented in this document. As between (1) American Institute of Chemical Engineers, its consultants, CCPS Technical Steering Committee and Subcommittee members, their employers, their employers’ officers and directors, and Process Improvement Institute, Inc., and its employees, and (2) the user of this document, the user accepts any legal liability or responsibility whatsoever for the consequences of its use or misuse.

LIST OF DATA TABLES

Initiating Events and Initiating Event Frequencies

Data Table 4.1.

BPCS control loop failure

Data Table 4.2.

Spurious operation of SCAI9

Data Table 4.3.

Human error during a routine task that is performed ≥ once per week

Data Table 4.4.

Human error during a task that is performed between once per month and once per week

Data Table 4.5.

Human error during a nonroutine task that is performed < once per month

Data Table 4.6.

Pressure regulator failure

Data Table 4.7.

Screw conveyor failure

Data Table 4.8.

Screw conveyor overheating of materials

Data Table 4.9.

Pump, compressor, fan, or blower failure

Data Table 4.10.

Localized loss of power

Data Table 4.11.

Single check valve failure

Data Table 4.12.

Failure of double check valves in series

Data Table 4.13.

Pump seal leak

Data Table 4.14.

Complete primary pump seal failure

Data Table 4.15.

Hose failure, leak and rupture

Data Table 4.16.

Premature opening of spring-loaded relief valve

Data Table 4.17.

Atmospheric tank: catastrophic failure

Data Table 4.18.

Atmospheric tank: continuous 10 mm diameter leak

Data Table 4.19.

Pressure vessel: catastrophic failure

Data Table 4.20.

Aboveground piping: full breach failure (pipe size ≤ 150 mm, 6 in)

Data Table 4.21.

Aboveground piping: full breach failure (pipe size > 150 mm, 6 in)

Data Table 4.22.

Aboveground piping: leak (pipe size ≤ 150 mm, 6 in)

Data Table 4.23.

Aboveground piping: leak (pipe size > 150 mm, 6 in)

Independent Protection Layers and Probabilities of Failure on Demand

Data Table 5.1.

End-of-line deflagration arrester

Data Table 5.2.

In-line deflagration arrester

Data Table 5.3.

In-line stable detonation arrester

Data Table 5.4.

Unstable (overdriven) detonation arrester

Data Table 5.5.

Overflow line with no impediment to flow

Data Table 5.6.

Overflow line containing a passive fluid or with a rupture disk

Data Table 5.7.

Line containing a fluid with the potential to freeze

Data Table 5.8.

Dikes, berms, and bunds

Data Table 5.9.

Drainage to dikes, berms, and bunds with remote impoundment

Data Table 5.10.

Permanent mechanical stop that limits travel

Data Table 5.11.

Fire-resistant insulation and cladding on vessel

Data Table 5.12.

Safety control loop

Data Table 5.13.

Safety interlock

Data Table 5.14.

SIS loop

Data Table 5.15.

Spring-operated pressure relief valve

Data Table 5.16.

Dual spring-operated pressure relief valves

Data Table 5.17.

Pilot-operated pressure relief valve

Data Table 5.18.

Gas balance/adjustable set pressure surge relief valve

Data Table 5.19.

Buckling pin relief valve

Data Table 5.20.

Buckling pin isolation valve

Data Table 5.21.

Rupture disk

Data Table 5.22.

Spring-operated pressure relief valve with rupture disk

Data Table 5.22.

Continued

Data Table 5.23.

Conservation vacuum and/or pressure relief vent

Data Table 5.24.

Vacuum breaker

Data Table 5.25.

Frangible roof on flat-bottom tank

Data Table 5.26.

Explosion isolation valve

Data Table 5.27.

Explosion panels on process equipment

Data Table 5.28.

Vent panels on enclosures

Data Table 5.29.

Excess flow valve

Data Table 5.30.

Restrictive flow orifice

Data Table 5.31.

Pipeline surge dampening vessel

Data Table 5.32.

Check valve

Data Table 5.33.

Pressure reducing regulator

Data Table 5.34.

Continuous pilot

Data Table 5.35.

Captive key/lock system

Data Table 5.36.

Multiple mechanical pump seal system with seal failure detection and response

Data Table 5.37.

Continuous ventilation

without

automated performance monitoring

Data Table 5.38.

Continuous ventilation

with

automated performance monitoring

Data Table 5.39.

Emergency ventilation initiated by safety controls, alarms, and interlocks (SCAI)

Data Table 5.40.

Mechanically activated emergency shutdown/isolation device

Data Table 5.41.

Mechanical overspeed trip on a turbine

Data Table 5.42.

Automatic fire suppression system (within process equipment)

Data Table 5.43.

Automatic fire suppression system for local application

Data Table 5.44.

Automatic fire suppression system for a room

Data Table 5.45.

Automatic explosion suppression system for process equipment

Data Table 5.46.

Human response to an abnormal condition

Data Table 5.47.

Human response to an abnormal condition with multiple indicators and/or sensors, and the operator has > 24 hours to accomplish the required response action

Data Table 5.48.

Adjustable movement-limiting device

Data Table 5.49.

Personal protective equipment (PPE)

ACRONYMS AND ABBREVIATIONS

ACGIH – American Conference of Governmental Industrial Hygienists

AIChE – American Institute of Chemical Engineers

AIHA – American Industrial Hygiene Association

ALARP – As Low As Reasonably Practicable

ALOHA – Areal Locations of Hazardous Atmospheres

ANSI – American National Standards Institute

API – American Petroleum Institute

APJ – Absolute Probability Judgment

ASME – American Society of Mechanical Engineers

ASSE – American Society of Safety Engineers

ATEX – Atmospheres Explosibles (Europe)

BEP – Best Efficiency Point

BLEVE – Boiling Liquid Expanding Vapor Explosion

BMS – Burner Management System

BPCS – Basic Process Control System

BPVC – Boiler and Pressure Vessel Code (ASME)

BS – British Standards (UK)

CCPS – Center for Chemical Process Safety (of AIChE)

CFR – Code of Federal Regulations (USA)

CPR – Committee for the Prevention of Disasters (The Netherlands)

CPQRA – Chemical Process Quantitative Risk Analysis

CPU – Central Processing Unit (Logic Solving Integrated Circuit)

CR – Contractor Technical Report (by the Nuclear Regulatory Commission, USA)

CSB – Chemical Safety Board (USA)

DCS – Distributed Control System

DDT – Deflagration-to-Detonation Transition

DIN – Deutsches Institut für Normung (Germany)

EGIG – European Gas Pipeline Incident Data Group

EPA – Environmental Protection Agency (USA)

ESD – Emergency Shutdown Device

ETA – Event Tree Analysis

FMEA – Failure Mode and Effects Analysis

FMECA – Failure Modes, Effects, and Criticality Analysis

FRP – Fiber-Reinforced Plastic

FTA – Fault Tree Analysis

GCPS – Global Congress on Process Safety (of AIChE)

HAZMAT – Hazardous Material

HAZOP – Hazard and Operability; as in HAZOP Analysis or HAZOP Study

HEART – Human Error Assessment and Reduction Technique

HEP – Human Error Probability

HERA – Human Event Repository and Analysis

HRA – Human Reliability Analysis

HCR – Human Cognitive Reliability

HMI – Human-Machine Interface

I/O – Input/Output

IE – Initiating Event

IEF – Initiating Event Frequency

IEC – International Electrotechnical Commission

IEEE – The Institute of Electrical and Electronics Engineers

IEF – Initiating Event Frequency

IPL – Independent Protection Layer

IPS – Instrumented Protective System

IRT – Independent Protection Layer (IPL) Response Time

ISA – International Society of Automation

ISO – International Organization for Standardization

ITPM – Inspection, Testing, and Preventive Maintenance

LOC – Loss of Containment

LOPA – Layer of Protection Analysis

LPG – Liquified Petroleum Gas

MAWP – Maximum Allowable Working Pressure

MOC – Management of Change

MPS – Machine Protection System

MSP – Maximum Setpoint

MSS – Manufacturers Standardization Society

NOAA – National Oceanic and Atmospheric Administration (USA)

NFPA – National Fire Protection Association

NPRD – Nonelectric Parts Reliability Data

NRC – Nuclear Regulatory Commission (USA)

NRCC – National Research Council Canada

NTSB – National Transportation Safety Board (USA)

NUREG – U.S. Nuclear Regulatory Commission Document

OREDA – Offshore Reliability Data

OSHA – Occupational Safety and Health Administration (USA)

PERD – Process Equipment Reliability Database

PES – Programmable Electronic System

PFD – Probability of Failure on Demand

PFDavg – Average Probability of Failure on Demand

PHA – Process Hazard Analysis

P&ID – Piping & Instrumentation Diagram

PID – Proportional–Integral–Derivative

PLT – Process Lag Time

PMI – Positive Material Identification

PPE – Personal Protective Equipment

PRV – Pressure Relief Valve

PSF – Performance Shaping Factor

PSM – Process Safety Management

PST – Process Safety Time

QRA – Quantitative Risk Assessment

RAGAGEP – Recognized and Generally Accepted Good Engineering Practice

RBPS – Risk Based Process Safety

RD – Rupture Disk

RFO – Restrictive Flow Orifice

RRF – Risk Reduction Factor

SCAI – Safety Controls, Alarms, and Interlocks

SIF – Safety Instrumented Function

SIL – Safety Integrity Level

SIS – Safety Instrumented System

SLIM – Success Likelihood Index Method

SME – Subject Matter Expert

SPAR–H – Standardized Plant Analysis Risk Model – Human Reliability Analysis

SPIDR™ – System and Part Integrated Data Resource

THERP – Technique for Human Error Rate Prediction

TR – Technical Report (by ISA)

UL – Underwriters Laboratory

USCG – United States Coast Guard

VRV – Vacuum Relief Valve

VPRV – Vacuum Pressure Relief Valve

VSV – Vacuum Safety Valve

GLOSSARY

Administrative Control

Procedural mechanism for controlling, monitoring, or auditing human performance, such as lockout/tagout procedures, bypass approval processes, car seals, and permit systems.

Asset Integrity

A risk-based process safety element involving work activities that help ensure that equipment is properly designed, installed in accordance with specifications, and remains fit for purpose over its life cycle. (Previously referred to as “mechanical integrity.”)

Average Probability of Failure on Demand (PFDavg)

Average PFD over the proof test interval of an equipment item.

Basic Process Control System (BPCS)

System that responds to input signals from the process, its associated equipment, other programmable systems and/or operator and generates output signals causing the process and its associated equipment to operate in the desired manner but that does not perform any safety instrumented functions with a claimed SIL ≥ 1 (IEC 61511 2003).

Bathtub Curve

Typical plot of equipment failure rate as a function of time. It is used to characterize the equipment lifecycle, such as early or premature failure, steady-state or normal operation failure, and wear out or end of useful life failure.

Beta Factor

A mathematical term applied in the PFDAVG to account for the fraction of the probability of failure that is due to dependent, or common cause, failure within the system.

Car Seal

A metal or plastic cable used to fix a valve in the open position (car sealed open) or closed position (car sealed closed). Proper authorization, controlled via administrative procedures, is obtained before operating the valve.

Chain Lock

A chain that is wrapped through or over a valve handle and locked to a support to prevent inadvertent repositioning of a valve once it is in its correct position. Removal is intended to occur only after approval is received from someone with authority and after checking that all prerequisites are met. The chain and lock provides an easy inspection aid to visually verify that the valve is in the intended position.

Clean Service

The process fluids and/or conditions do not result in fouling, corrosion, erosion, or deposition that negatively impacts the performance of a layer of protection, such as polymer formation under, in, or downstream of a relief valve.

Compensating Measures

Planned and documented methods for managing risks. They are implemented temporarily during any period of maintenance or of process operation with known faults or failures in an IPL, where there is an increased risk.

Common Cause Failure

Failure of more than one device, function, or system due to the same cause.

Common Mode Failure

A specific type of common cause failure in which the failure of more than one device, function, or system occurs due to the same cause, and failure of the devices occurs in the same manner.

Conditional Modifier

One of several possible probabilities included in scenario risk calculations, generally when the risk criteria are expressed in impact terms (e.g., fatalities) instead of loss event terms (e.g., release, loss-of-containment, vessel rupture).

Consequence

The undesirable result of an incident, usually measured in health and safety effects, environmental impacts, loss of property, and business interruption costs.

Dangerous Failure Rate

The rate (normally expressed in expected number of failures per year) that a component fails to an unsafe state/mode. (Other failure states or modes may lead to spurious trips of a system, but they do not lead to the unsafe condition of interest.)

Demand Mode

Dormant or standby operation where the IPL takes action only when a process demand occurs and is otherwise inactive. Low demand mode occurs when the process demand frequency is less than once per year. High demand mode occurs when the process demands happen more than once per year.

Dormant

A state of inactivity until a specific parametric level is reached.

Enabling Condition

Operating conditions necessary for an initiating cause to propagate into a hazardous event. Enabling conditions do not independently cause the incident, but must be present or active for it to proceed.

Event

An occurrence involving the process caused by equipment performance, human action, or external influence.

Frequency

Number of occurrences of an event per unit time (typically per year).

Human Error Probability (HEP)

The ratio between the number of human errors of a specific type and the number of opportunities for human errors on a particular task or within a defined time period. Synonyms: human failure probability and task failure probability.

Independent Protection Layer (IPL)

A device, system, or action that is capable of preventing a scenario from proceeding to the undesired consequence without being adversely affected by the initiating event or by the action of any other protection layer associated with the scenario.

Independent Protection Layer Response Time (IRT)

The IPL Response Time is the time necessary for the IPL to detect the out-of-limit condition and complete the actions necessary to stop progression of the process away from the safe state.

Incident Scenario

A hypothetical sequence of events that includes an initiating event and failure of any safeguards that ultimately results in a consequence of concern.

Initiating Event (IE)

A device failure, system failure, external event, or wrong action (or inaction) that begins a sequence of events leading to a consequence of concern.

Initiating Event Frequency (IEF)

How often the IE is expected to occur; in LOPA, the IEF is typically expressed in terms of occurrences per year.

Inspection, Testing, and Preventive Maintenance (ITPM)

Scheduled proactive maintenance activities intended to (1) assess the current condition and/or rate of degradation of equipment, (2) test the operation/functionality of the equipment, and/or (3) prevent equipment failure by restoring equipment condition. ITPM is an element of asset integrity.

Maximum Setpoint (MSP)

The maximum setpoint for an IPL is the point of maximum process deviation from the normal condition that would still allow sufficient time for the IPL to detect the deviation, to take action, and for the process to respond, preventing the consequence of concern. For SIS, this is called Maximum SIS Setpoint (MSP) per ISA-TR84.00.04 (2011).

Must

This Guidelines subcommittee believes that the IEF, PFD, or other aspect of an IE or IPL is valid only if the listed criteria are met. “Must” can also be used in reference to basic definitions.

Passive Fluid

Nonreactive and nonhazardous fluid.

Performance Shaping Factors (PSF)

Factors that influence the likelihood of human error.

Probability of Failure on Demand (PFD)

The likelihood that a system will fail to perform a specified function when it is needed.

Process Lag Time (PLT)

The process lag time indicates how much time it will take for the process to respond and avoid the consequence of concern, once the IPL has completed its action.

Process Safety Time (PST)

The time period between a failure occurring in the process, or its control system, and the occurrence of the consequence of concern.

Risk

A measure of potential economic loss, human injury, or environmental impact in terms of the frequency of the loss or injury occurring and the magnitude of the loss or injury if it occurs.

Safeguard

Any device, system, or action that either interrupts the chain of events following an initiating event or that mitigates the consequences. Not all safeguards will meet the requirements of an IPL.

Safety Controls, Alarms, and Interlocks (SCAI)

Process safety safeguards implemented with instrumentation and controls, used to achieve or maintain a safe state for a process, and required to provide risk reduction with respect to a specific hazardous event (ANSI/ISA 84.91.01 2012). These are sometimes called safety critical devices or critical safety devices.

Safety Instrumented Function (SIF)

A safety function allocated to a Safety Instrumented System (SIS) with a Safety Integrity Level (SIL) necessary to achieve the required risk reduction for an identified scenario of concern.

Safety Integrity Level (SIL)

One of four discrete ranges used to benchmark the integrity of each SIF and the SIS, where SIL 4 is the highest and SIL 1 is the lowest.

Safety Instrumented System (SIS)

A separate and independent combination of sensors, logic solvers, final elements, and support systems that are designed and managed to achieve a specified Safety Integrity Level (SIL). A SIS may implement one or more Safety Instrumented Functions (SIFs).

Severity

A measure of the degree of impact of a particular consequence.

Should

This Guidelines subcommittee believes that an alternative protocol to achieve the same criteria/goal is acceptable.

Systematic Error

Also referred to as “systemic error.” ISA-TR84.00.02 (2002) defines systematic error as “an error that occurred during the specification, design, implementation, commissioning, or maintenance.”

Validation

Activity of demonstrating that the installed equipment and/or associated human actions achieve the core attributes and the requirements of the design basis. Testing is one approach to validation.

Verification

Activity of making sure the equipment is installed to specification. (In the case of a Safety Instrumented Function (SIF), SIL verification often refers to calculating the PFDavg of a SIS to ensure that it achieves the stipulated SIL.)

ACKNOWLEDGMENTS

The American Institute of Chemical Engineers (AIChE) and the Center for Chemical Process Safety (CCPS) express their appreciation and gratitude to the members of the Guidelines in Initiating Events and Independent Protection Layers in Layer of Protection Analysis subcommittee of the CCPS Technical Steering Committee for providing input, reviews, technical guidance, and encouragement to the project team throughout the preparation of this book. CCPS expresses gratitude to the team member companies for their generous support of this effort. CCPS also expresses appreciation to the members of the Technical Steering Committee for their advice and support in the writing of this book.