Termination of emergency and Restoration of normalcy

Testing and critiquing the plan

Hazard: A physical situation with potential for an accident (injury, property damage, environmental damage).
Risk: Probability of a given undesirable event with specific consequences in a specified time period. $Risk_{consequences/yr} = Frequency_{events/yr} \times Magnitude_{consequences/event}$.
Risk Analysis: Hazard Identification, Consequence Assessment, Accident Frequency Assessment, Risk Estimation.

Purpose: Quick identification of hazards. Applicable in all plant lifecycle stages.
Limitations: Qualitative, quality depends on author's knowledge/experience.

Purpose: Early identification of hazards during design phase. Cost-effective for early design changes.

Purpose: Ensure procedure matches design intent. Methodical in-depth examination of operating system for safety.
Components: Audit Team, Pre-audit Questionnaire/Interviews, Plant Visit, Document Verification, Meeting with management, Safety audit report.

Assigns penalties for hazardous process materials/conditions and credits for safety features.
Combines these to derive an index for relative plant risk ranking (e.g., Dow Index, Mond Index). Qualitative method.

Examines deviations from design/operation intent (e.g., "What if the wrong material is delivered?").
Effective with experienced staff; results may be incomplete otherwise. Common for proposed plant changes.

Fundamental, qualitative hazard identification technique.
Examines each major hardware item ("study node") for causes/consequences of deviations from normal operating conditions using "Guide Words" and "Parameters".
Guide Words: NO, MORE OF, LESS OF, AS WELL AS, PART OF, REVERSE, OTHER THAN.
Teamwork approach with diverse expertise.
Assumptions: Plant operates as intended without deviations; operators are trained (human error not considered).
Timing: Conducted when design is almost finalized but equipment/control not firmed up, or for plant modifications.
HAZOP Team: Instrument, Project, Design, Maintenance, Operations, Safety Engineer, Plant Foreman.
Example: HAZOP table for "NO COOLING" deviation, listing causes, consequences, and actions.