This study proposes a fire dynamics simulation method for combustion modeling using heat release and toxic gas emission experimental data. The feasibility of the proposed method is verified through simulations of a cable spreading room of a nuclear power plant where a high level of safety is required. In addition to CO and CO2, nine other toxic gases are detected in the simulations, and the toxic effect is assessed considering two aspects. First, the order of toxic gases reaching the toxicity criteria, which is identical to the order of the hazardousness, is assessed. The arrival times to the lowest allowable exposure limits are ranked as CO < NO2 < SO2 < HCl < HCN < HBr < HF < CH2CHCN < HCHO < CO2 < H2S. The arrival time is inversely proportional to the degree of risk. Second, the comprehensive toxicity index (TI) and its time-weighted average are proposed to assess the combined effects of all emissions. The comprehensive TI of combined emissions is substantially larger than that of only CO. This implies that the conventional performance-based design method, typically used to assess the toxic and suffocation effects of only CO, CO2, and O2, may cause considerable error during risk assessment, because it ignores toxic effects of minor gases such as NO2, SO2, HCl, HCN, HBr, HF, CH2CHCN, HCHO, and H2S. The proposed experimental-data-based simulation method enables more advanced fire dynamics simulations for accurately assessing the hazardousness of toxic gases to humans, and thus, it can be used practically for establishing suitable fire emergency response plans and countermeasure strategies.
