The Use of Probabilistic Risk Assessment in the Design of High-Hazard Facilities

Publication Date Oct 09, 2014 by Garrick B.J.

To be published in the PE (Professional Engineer) Magazine in the November issue, Volume 36, Number 9.

The design of facilities involving large inventories of hazardous and toxic materials requires rigorous analyses to assure the health and safety of the workers, the public, and the protection of the environment. If properly applied, the risk sciences provide the methods for such assurance. Answering the question of what is the risk, implies answering three questions: what can go wrong, how likely is it, and what are the consequences. The first and third questions are answered by a set of scenarios with the consequences being the endpoints of the scenarios. Answering the second question is a matter of quantifying probabilities, where probability is a number between zero and one representing the credibility of a hypothesis based on the totality of the supporting evidence. Risk-based rigorous analysis should be the cornerstone of the design criteria for facilities involving large inventories of dangerous materials.