Domino Risk Assessment Methods For Chemical Plants Based On Fishbone Analysis

With the rapid economy development of China,the number of risk sources sharply rose and severe chemical accidents frequently occurred.Therefore,China faced great challenges in safety control and environmental protection.In many serious accidents,domino effect played an important role in big casualties,huge financial loss and environmental pollution.In the process of chemical plants,without consideration of domino effect,staff couldn't comprehensively identified main causes of domino accidents in both safety control and environmental management,which was also the significant reason for interactive influence between process equipment and environmental devices and for the occurrence of chain accidents.Based on the above background,the essay introduced fishbone analysis which was used to identify cause-and-effect relationship on one problem.The fishbone analysis was employed in qualitatively identifying root causes and potential risk parts of domino accidents in chemical plants.The main causes of domino effect in chemical plants were concluded as follows:process and equipment,materials,staff,safety management,environmental management and emergency aid system.On the basis of fishbone diagram for identifying sources of domino effect,Domino Risk Index was proposed to assess the level of domino risk in chemical plants.After paper collection and field survey,the qualitative results of fishbone diagram were quantified and the structure of assessment methods was established with 6 sub-indices and 15 parameters.6 sub-indices are as follows-process and equipment(p1),materials(p2),staff(p3),safety management(p4),environmental management(P5)and emergency aid system(p6).In addition,15 parameters for 6 sub-indices of the DRI were determined,and the corresponding calculation methods were made.This essay took Koppers company in Pizhou Industrial Park as an example to compare this new method and traditional risk assessment method.On one hand,the score of Domino Effect Index of Koppers was 6.57,which indicated high domino risk in the chemical plant.The results implied that the most possible reason for occurrence of domino accidents in Koppers was problems in safety management,along with emergency aid system,materials,environmental management,process and equipment and staff.In terms of safety management,safety distances between risk sources would cause the largest risk.In the emergency aid system,the imperfection of emergency plans might bring high potential of domino risk.As for environmental management and process and equipment,insufficient examination for equipment might increase the level of domino risk.On the other hand,the traditional assessment method showed the risk level of the case company was medium.A comparison with the new method in the case study revealed that the current assessment method underestimated the risk level and needed adjustment.In conclusion,assessment system of Domino Risk Index provided another thinking way of risk assessment for domino effect and a kind of cause identification technique for chain accidents in chemical plants,totally different from traditional ones.Moreover,with the new evaluation method,the chemical plant could identify and improve the vulnerable parts and decrease the possibility of the domino effect.