Journal of Safety and Environment

To scientifically evaluate the explosion risk associated with the powder compaction process of Roman Candle pyrotechnic compositions, this study integrated Fault Tree Analysis(FTA) with Dynamic Bayesian Network(DBN) methodologies. Initially, an FTA model was developed to identify and analyze the causal pathways leading to explosion accidents. This model was subsequently transformed into an equivalent Bayesian Network(BN) model. Next, eight experts were invited to assess the basic events using a five-point scale, and the reliability of their scores was verified through consistency checks utilizing a judgment matrix. Finally, the concept of time slices was introduced into the BN model to enhance its analytical capabilities. Basic events were categorized into static nodes and dynamic nodes based on the influence of time on their behavior. The prior probabilities for static nodes and the transition probabilities for dynamic nodes were calculated sequentially. A fuzzy analysis method was employed to convert expert scores into trapezoidal fuzzy numbers, allowing for the integration of expert opinions by assessing the similarity among their scores. This facilitated the computation of prior probabilities for the static nodes based on the consolidated expert assessments. Dynamic nodes were further classified into three categories—equipment failure, human error, and organizational factors—according to the types of accidents, enabling the calculation of their transition probabilities. GeNle software was utilized to simulate changes in accident probability over the next three years, using a 90-day time slice interval, under the assumption of neglecting the repair rate. The results indicated that the initial accident probability was 0.052 8, which increased to 0.268 after three years. Additionally, diagnostic reasoning was employed to calculate the posterior probabilities of basic events. By comparing the relative differences between posterior and prior probabilities, five key hazard sources were identified: low ignition energy of sulfur, improper material selection for mixing, failure of pressure relief devices, inadequate personnel training, and motor sparks resulting from line short circuits. Finally, targeted risk control measures were recommended across three dimensions: standardizing personnel operations, enhancing equipment and processes, and strengthening safety management systems. These measures aim to reduce the probability of fire and explosion incidents effectively.