Defining footprint scenarios

When defining footprint scenarios in RISKCURVES, understanding and correctly inputting data for different phenomena is crucial for accurate risk assessment. This article explains how to define footprint scenarios, with connections to the previous article on consequence and lethality footprints.

About footprint import

Types of footprints

Each footprint definition scenario includes one specific phenomenon, such as:

• BLEVE (Boiling Liquid Expanding Vapour Explosion)

• Local cloud fire

• Vapour Cloud Explosion

• Jet Fire

• Pool Fire

• Toxic Dispersion

Weather class specific footprints

Footprints can be specific to weather classes:

• Use the combo box at the top of the input panel to choose a weather class for the footprint.

• Enter "Default" to link values to all weather classes.

• Overwriting specific weather classes will unlink them from the default.

Input consistency check

Ensure the consistency of footprint data:

• Footprint dimensions should be row ascending.

• Lethality or consequence levels should be row descending.

• If not consistent, the definition will be labelled RED.

Data entry per footprint type

The data to be entered varies per type of footprint. Refer to specific guidelines in the article consequence vs lethality footprints. For example:

• Explosion footprint: Parameters include flammable cloud size, overpressure offset, and distance vs. overpressure data (as discussed in the "Explosion Consequence Definition" section of the previous article).

• Fireball Footprint: Parameters include radius, duration, and heat radiation vs. distance from the flame centre.

Units adjustments

Change the units by selecting a different unit in the column header.

Importing large numbers of footprints

To efficiently import a large number of footprints (scenarios), use an import spreadsheet for efficiency, consistency, and better organization compared to importing footprints individually.

Adding footprints step by step

• Right-click at the ‘‘Equipment’’ node to open a pop-up menu.

• Move your cursor at <Add scenario> → <Footprint definitions> → select the appropriate footprint.

• The created Scenario will consist of 2 nodes:

  • Upper node: Failure frequencies and associated probabilities represent the likelihood of different types of failures occurring.

  • Lower node: Consequence model calculates the potential effects and damage resulting from the failures.

• Fill in input parameters for failure frequencies and associated probabilities.

• Enter the consequence result in the form of a footprint. Follow instructions per a specific type of footprint (as detailed in the previous article).

• Press ‘‘Calculate’’.

By following these guidelines and understanding the different calculation approaches, you can effectively add models in RISKCURVES to perform thorough risk assessments.

Tip for importing footprints from EFFECTS

Copy/paste contour dimensions from reports in EFFECTS directly into these definitions, thanks to adjusted table layout in EFFECTS.