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Control of Industrial Major Accident Hazards (CIMAH) Report Page 36
Ranhill SAJ Sdn. Bhd. Revision 01
Part D: Information on the Potential Major Accident Date Aug 2019

D.6.0 CONSEQUENCE ANALYSIS & QUANTITATIVE RISK

ASSESSMENT

D.6.1 Consequence Analysis

A consequence modeling was carried out to assess the consequence or harm
footprint of accident scenarios deemed to pose the risk of major accident hazards.
For each of the identified accident, the detailed consequence analysis was carried
out to determine the maximum extent of its effect.

Consequence analysis comprises of the following:
• Source term modeling;
• Physical effects modeling, which involves estimating the effects zone of the
various hazardous outcomes; and
• Assessment of the impact of hazardous outcomes on the exposed population
or surrounding.

D.6.1.1 Source Term Modelling

A source term is the information required for gas dispersion, fireball, jet fire or other
consequence models to describe the discharge rate and quantity of hazardous
substance to be considered. Standard orifice type calculations are used to determine
the rate of discharge, based on conditions of pressure, temperature and phase of
material. Duration of discharge is determined from inventory and release rate.

D.6.1.2 Assumptions Register

The following are the assumption for developing the consequence modelling.
0
• Ambient temperature and relative humidity selection are at 29 C and 80%
respectively;

• Wind speed and weather condition selection are at (i) 1F and (ii) 5D;
• Potential of multiple failure of Chlorine cylinder or drum simultaneously
assumed to be remote thus, all scenarios modelled were based on one single
cylinder failure at a time;
• Chlorine stored in the drum is assumed to be 100% Chlorine; and
• All scenarios modelled did not take into account measures to mitigate or
minimize the impact of the accident (e.g. gas detectors to initiate alarm and
activate the emergency scrubber system).