Comparative study of risk analysis methods from a fire safety perspective - Case study of new underground facilities at CERN

Abstract: This report has investigated which type of risk analysis methods that can be used in an early design phase in a unique facility from a time and quality perspective. Two planned underground facilities for the HL-LHC at CERN have been used as a case study. The methodology is an action research study with information gathered from a literature study and survey. Six different risk analysis methods have been chosen to represent different types of methods. The chosen methods are event tree analysis, preliminary hazard analysis, What-if, Gretener method, ROGA and NFPA 101. The results from the comparison of the methods were that the more complex risk analysis method needed detailed information of the final design of the facility and equipment. In an early design phase, this was hard to find which lead to a result with many uncertainties and assumptions. One conclusion of this report is that a more simple methodology is to prefer in an early design phase when comparing different design options. Another conclusion is that there is a need to develop a tool to create design fires for electrical cabinets and to develop a specific risk analysis method for this type of facility that can be used in an early phase.