Insights from an Integrated Deterministic Probabilistic Safety Analysis (IDPSA) of a Fire Scenario

For assessing the performance of fire fighting means with emphasis on human actions, an integrated deterministic probabilistic safety analysis (IDPSA) was performed. This analysis allows for a quite realistic modelling and simulation of the interaction of the fire dynamics with relevant stochastic influences which refer, in the presented application, to the timing and outcome of human actions as well as to the operability of technical systems. For the analysis, the MCDET (Monte Carlo Dynamic Event Tree) tool was combined with the FDS (Fire Dynamics Simulator) code. The combination provided a sample of dynamic event trees comprising many different time series of quantities of the fire evolution associated with corresponding conditional occurrence probabilities. These results were used to derive exemplary probabilistic fire safety assessments from criteria such as the temperatures of cable targets or the time periods with target temperatures exceeding critical values. The paper outlines the analysis steps and presents a selection of results which also includes a quantification of the influence of epistemic uncertainties. Insights and lessons learned from the analysis are discussed.