If your existing and approved QRA was conducted in accordance with the previous QRA guidelines, it may not have the harm footprints listed.
In this case, you could conduct a simplified QRA to understand the risk and harm footprints better.
Alternatively, you could use the following estimations for the footprints:
- 20kW/m2 – 0.8 X distance of the 4kW/m2 footprint
- 2psi – 0.6 X distance of the 1psi footprint
For tank overfilling scenarios, use 400 metres as the consequence distance, as stipulated in the revised QRA guidelines.
You will need to revise the 20kW/m2 and 2psi harm footprints using actual consequence modelling on your next QRA revision i.e. when there is plant expansion or major modifications.