Risk Assessment
How QRA Works for Refinery Major Accident Hazard Units
Vinit Pandey · Published 4 August 2026
In short: QRA for a refinery must cover a large set of credible major accident scenarios across crude and product storage, process units, and pipeline interconnections, integrated into facility-wide individual and societal risk figures for safety report and land-use planning submissions.
Key takeaways
- Refinery MAH status under MSIHC Rules makes QRA a recurring, not one-time, requirement
- Scenario scope spans storage tanks, process units, and pipeline/loading-arm releases
- Domino effect and escalation scenarios must be explicitly modelled given unit interconnection
- QRA outputs directly support land-use planning and ALARP demonstration around the site boundary
Refineries typically carry Major Accident Hazard status under India's MSIHC Rules due to large hydrocarbon inventories, making QRA a recurring requirement for safety report submission rather than a one-time exercise.
Scenario selection for a refinery QRA must cover storage tank failures, process unit loss-of-containment events, and pipeline or loading-arm releases, each requiring different consequence modelling approaches — pool fires for stored liquids, jet fires and vapour cloud explosions for pressurised process streams.
Domino effect potential is a distinctive concern in refinery QRA: a fire or explosion at one unit can escalate to affect neighbouring equipment via thermal radiation or blast overpressure, requiring escalation scenarios to be explicitly modelled rather than treating each unit's risk in isolation.
QRA outputs — individual risk contours and societal risk F-N curves — directly support land-use planning decisions around the refinery boundary and inform where additional risk reduction is required to demonstrate ALARP.