The regime difference comes first
This document is an item of the Turkish regime and has no exact counterpart in the EU obligation list. An establishment that copies one country's list to the other either never prepares it, or produces it needlessly for a country that does not ask for it.
What it does
The document answers three questions together:
- Which major accident scenarios could occur at this establishment?
- Through what chain of events does each develop — initiating event, loss of control, consequence?
- At each link in the chain, which barrier stands, and how is that barrier tested?
Thinking in barriers
The point of writing scenarios is not to generate alarm but to show what has been put in between. Barriers are of two kinds: preventive ones that stop the event happening, and mitigating ones that limit the consequence once it has. Every barrier needs an owner, a test method and a record; a barrier with no owner disappears quietly at the first maintenance shutdown.
Where the scenarios come from
Three sources: the plant's own process hazard analysis, real events in the sector, and the establishment's own near-miss records. The third is usually the most valuable, because it is specific to this site — and usually the least used.
Relation to the other documents
The scenarios are the input to the internal emergency plan, which says what will be done if they occur. If the two carry different scenario lists, the plan is preparing for an accident that does not exist.