Layer of Protection Analysis: Simplified Process Risk Assessment

Acknowledgments.

Acronyms and Abbreviations.

1. Introduction.

1.1 Audience.

1.2 History of LOPA.

1.3 Use of LOPA in the Process Life Cycle.

1.4 Linkage to Other CCPS Publications.

1.5 Annotated Outline of the LOPA book.

2. Overview of LOPA.

2.1 Purpose.

2.2 What is LOPA?

2.3 What LOPA Does.

2.4 When to Use LOPA.

2.5 How LOPA Works.

2.6 How to Implement LOPA.

2.7 Limitations of LOPA.

2.8 Benefits of LOPA.

2.9 Introduction of Continuing Examples.

3. Estimating Consequences and Severity.

3.1 Purpose.

3.2 Consequences of Interest.

3.3 Consequences Evaluation Approaches for LOPA.

3.4 Continuing Examples.

3.5 Link Forward.

4. Developing Scenarios.

4.1 Purpose.

4.2 LOPA Scenarios and Components.

4.3 Identifying and Developing Candidate Scenarios.

4.4 Continuing Examples.

4.5 Link Forward.

5. Identifying Initiating Event Frequency.

5.1 Purpose.

5.2 Initiating Events.

5.3 Frequency Estimation.

5.4 Expression of Failure Rates.

5.5 Continuing Examples.

5.6 Limitations (Cautions).

5.7 Link Forward.

6. Identifying Independent Protection Layers.

6.1 Purpose.

6.2 Definition and Purpose of an IPL.

6.3 IPL Rules.

6.4 LOPA IPL Assessment.

6.5 Example of IPLs.

6.6 Preventive IPLs versus Mitigation IPLs.

6.7 Continuing Examples.

6.8 Link Forward.

7. Determining the Frequency of Scenarios.

7.1 Purpose.

7.2 Quantitative Calculation of Risk and Frequency.

7.3 Look-up Table Determination of Risk of Frequency.

7.4 Calculation of Risk of Frequency with Integer Logarithms.

7.5 Continuing Examples.

7.6 Link Forward.

8. Using LOPA to Make Risk Decisions.

8.1 Purpose.

8.2 Introduction.

8.3 Comparing Calculated Risk to Scenario Risk Tolerance Criteria.

8.4 Expert Judgment.

8.5 Using Cost-Benefit to Compare Alternatives.

8.6 Comparison of Approaches, Pros and Cons.

8.7 Cumulative Risk Criteria versus Scenario Criteria.

8.8 Continuing Examples.

8.9 Cautions.

8.10 Link Forward.

9. Implementing LOPA.

9.1 Purpose.

9.2 Is the Company ready for LOPA?

9.3 What Is the Current Foundation for Risk Assessment?

9.4 What Dare Are Required?

9.5 Will the IPLs Remain in Place?

9.6 How Are the Risk Tolerance Criteria Established?

9.7 When IS LOPA Used?

9.8 Typical Implementation Tasks.

10. Using LOPA for Other Applications.

10.1 Purpose.

10.2 Using LOPA in Capital Improvement Planning.

10.3 Using LOPA in Management of Change.

10.4 Using LOPA in Mechanical Integrity Programs or Risk-Based Inspection/Risk-Based Maintenance Programs.

10.5 Using LOPA in Risk-Based Operator Training.

10.6 Using LOPA in emergency Response Planning.

10.7 Using LOPA to Determine a Credible Design Basis for Overpressure Protection.

10.8 Using LOPA in Evaluating Facility Siting Risks.

10.9 Using LOPA to Evaluate the Need for Emergency Isolation Valves.

10.10 Using LOPA to Evaluate Taking a Safety System Out of Service.

10.11 Using LOPA during Incident Investigations.

10.12 Using LOPA in the Determination of SIL for SIF.

11. Advanced LOPA Topics.

11.1 Purpose.

11.2 Counting Multiple Functions in One BPCS as IPLs in the Same Scenario.

11.3 Summation of Risk for Multiple Scenarios.

11.4 Using LOPA to Develop F/N Curves.

11.5 Operator Response Issues.

11.6 Normal Plant Operations as “Tests: of IPL Components.

11.7 Focused Fault Tree/Event Tree Analysis of IPL Components.

Appendix A. LOPA Summary Sheets for the Continuing Examples.

Appendix B. Worked Examples from CCPS’s Safe Automation Book.

Appendix C. Documentation for a LOPA Study.

Appendix D. Linkage with Other Publications.

Appendix E. Industry Risk Tolerance Criteria Data.

Appendix F. High Initiating Event Frequency Scenarios.

Appendix G. Additional Reading.

References.

Glossary of Terms.

Index.