Risk assessment and accident analysis at hazardous production facilities
Scope
This domain tests structured risk assessment and accident analysis at HPFs. The exam expects you to choose a method, show the logic and link findings to safeguards. It also tests the difference between a technical investigation of an accident and a disciplinary or criminal investigation.
Core rules
- Common methods: HAZID, HAZOP, fault tree, event tree, consequence modelling and risk matrices.
- Risk combines likelihood and severity; a matrix without defined criteria is weak.
- Accident analysis looks for direct, contributing and root causes, not only the immediate act.
- Recommendations must be specific, assigned and tracked to closure.
- Risk assessment is repeated after changes and before major operations.
Worked example
A pressure vessel develops a leak at a flange. Reasoning: use a fault tree to test possible causes: gasket failure, wrong bolt torque, corrosion, thermal cycling, or procedure error. A HAZOP-style review of the node asks what happens if pressure rises or the gasket degrades. Rank the risk by likelihood and consequence. Recommend a specific safeguard, such as controlled torque procedure and periodic inspection, then assign an owner and date. Saying 'retrain operators' without linking it to the cause is not a root-cause fix.
Traps
- Rating risk by severity only and ignoring likelihood.
- Writing generic recommendations that cannot be verified.
- Confusing accident investigation with blame allocation.