3152 Guidance on assigning ignition probabilities in onshore and offshore quantitative risk assessments

Overview:

The probability of ignition of flammable releases from onshore and offshore installations is a key factor in determining the risks such installations present to people, assets and the environment, yet data and practical models available to enable assessors to assign suitable ignition probability distributions in QRA have been lacking.

This publication presents the findings of a project to improve the modelling of ignition probabilities in onshore and offshore installation QRAs. Specifically, the project reviewed current data and models, developed an ignition probability model (made available as a functional workbook) for assigning ignition probabilities in QRA, and developed a simple basis and guidance to assist practitioners in assigning ignition probabilities to generic scenarios.

This guidance should be drawn to the attention of safety practitioners, risk analysts and designers who need to determine or evaluate ignition probabilities in QRA, such as where required for safety cases or safety reports.

This publication comprises the following:

• The published report: Guidance on assigning ignition probabilities in onshore and offshore quantitative risk assessments.
• Ignition model spreadsheets (Version D1) in single scenario and multirun formats (provided as Microsoft Excel ® spreadsheets).
• Look-up correlations workbook (Version D2) (provided as Microsoft Excel ® spreadsheet) including the updated guidance on their application.

The ignition model spreadsheets, which include the look-up correlations workbook, must be downloaded separately from this page and you must be logged in to do so.