Maximum Credible Loss Scenario (MCLS)

In the process industry, incidents like fires and explosions can be devastating, posing a significant threat to People, Environment, Assets, and Reputation (PEAR). To mitigate such risks, numerous countries have invested considerable effort into researching and developing safety management and risk assessment techniques.

Identifying accident scenarios greatly influences plant layout, safety design, and the calculation of safety protection distances. It is a crucial aspect of risk assessment that determines the accuracy of the assessment results.

Maximum Credible Loss Scenario (MCLS):

The Maximum Credible Loss Scenario (MCLS) is a widely used concept in the risk assessment of chemical process industries. Central to this concept is the credibility of envisaged accident scenarios, which is often treated qualitatively based on the judgment of analysts. The MCLS method includes four steps: Hazard Identification, Consequence Analysis, and Assessment of Vulnerable Scenarios.

Conditions Considered in Accident Scenarios:

• Wind directions
• Leakage inventory
• Process parameters (e.g., temperature, pressure, and humidity)
• Sources of leakages

The findings are compiled into a table, accompanied by dispersion models that show the results contour on the layout.