Maximum Credible Accident Assessment (MCAA)
MCA means maximum credible accident i.e. an accident with a maximum reasonable damage distance possibility.
MCAA means maximum credible accident analysis or assessment.
Here probability of accident occurrence is not calculated but the probability of maximum damaging effect (potential and distance) is calculated to asses injury to people or/and properties in the surrounding area.
Consider Hazard potentiality by
- Type of material stored/processed (toxicity, flammability etc).
- Quantity of the material (it affects distance).
- Process or storage conditions (temperature, pressure, flow etc).
- Location of the unit or activity with respect to adjacent population.
Following steps are of MCAA:
- Chemical Inventory Analysis.
- Identification of hazardous processes in individual units.
- Identification of chemical release and accident scenarios.
- Data acquisition for MCAA.
- Effect and damage calculations for the primary events.
- Analysis of past accidents of similar nature.
- Short listing of maximum credible accident scenarios.
Identification of the chemical inventory is by MSIHC Rules or Rule 68 J of the Gujarat Factories Rules, short listed and prioritized on the basis of hazard potential.
The chemicals are generally classified as non-boiling and boiling liquids, gases / vapors and solids.
Identify Hazardous processes by above statutory provisions. Runaway reactions need due consideration during preliminary MCAA.