A Study for Development of Regional Risk Assessment for Technological Disaster

1. GRF DAVOS, 2010A Study for Development of Regional Risk Assessment for Technological Disaster Won K.Kim, PE, MNFPA, MSFPE, MAIChE, MSRA President of Risk Management Support

2. Background The numbers of victims from technological disasters have increased continuously since 1900. The types of technological disaster include chemical spill, gas leak, collapse, explosion, fire and transportation accidents. Urban population has also increased continuously in many countries. Many places in big city have hazards for technological disaster. Need to assess the risk of them to manage the risk efficiently. 2 Risk Management Support

3. Goals of Study To develop a quantitative risk assessment method for technological risk in urban area. To provide decision making tool in preparing urban development plan To prepare a emergency response plan To provide tools for risk communication with public 3 Risk Management Support

4. Regional Risk Assessment Model Classify Risk Investigate Population Density Model Frequency Model Severity Model Mitigation Factor Model Mitigation Factor Calculate Risk Index Present the Risk 4 Risk Management Support

5. Risk Classification Technological disaster is represented as men-maid disaster and it is classified in local regulation as; fire, explosion, collapse, transportation accidents, toxic gas release and environmental pollution. In this study collapse, transportation accidents and environmental pollutions are excluded as their risk management approach is different from fire, explosion and toxic gas release. Selected Risk Classification Structural Fire; subway station, railroad station, underground shopping mall Fire & Explosion from Hazardous Materials; city gas pipelines and valve station, LPG station, gas station, tank lorry Toxic Material Release; refrigeration warehouse, water cleaning plant 5 Risk Management Support

6. Population Density Population density has to be investigated to estimate the numbers of victims. Based on minimum unit of administrative district. Separately prepared by day time and night time. 6 Risk Management Support

7. Frequency Modeling Adjusted mitigation index is calculated by subtracting prevention index from frequency index. Frequency of 1x10-6/yr has an index of 0, which means the chance of occurring is very remote. The average frequency of technological disaster is 5x10-4/yr, and frequency index 500 was given to it. Index 1000 was given to frequency 1x10-1/yr (frequently occurring), 800 to 1x10-2/yr, 600 to 1x10-3/yr 400 to 1x10-4/yr, 200 to 1x10-5/yr accordingly. 7 Risk Management Support

8. Example of Frequency Estimation for LPG Station Frequency Index = Initiating Event Index – Mitigating Index Initiating Event Index Estimation = 500 + Classification Factor + Exposure Factor + Unloading Frequency Factor (If the summation is over 1000, then take 1000) Mitigating Index Protection Measure Collision Protection Measure for Tank Lorry Inspection and Test Frequency Exposure to Ignition Sources 8 Risk Management Support

9. Example of Frequency Estimation for LPG StationBasic Index Value Median value 500 was taken at 5x10-4/yr. 9 Risk Management Support

10. Example of Severity Estimation for LPG Station Severity Index = Index of Casualties (directly calculated numbers of casualties from BLEVE & UVCE) – Mitigating Index Severity of an accident is divided in five categories; Category I ; 1 to 5 injuries (Index of 200) Category II ; 1 to 5 casualties (Index of 400) Category III ; 5 to 50 casualties (Index of 600) Category IV ; 50 to 500 casualties (Index of 800) Category V ; 500 to 1000 casualties (Index of 1000) 10 Risk Management Support

11. Example of Severity Estimation for LPG Station Mitigating Index Category I Local Emergency Response Plan Effective Alarm System Training and Drills Category II Valve Closing Protection Measures Fire Department Arrival Time Category III Safety Distance 11 Risk Management Support

12. Risk Ranking X-axis represents severity of accident and Y-axis represents frequency of accident. Then, risk is re-categorized into 5 different categories. 12 Risk Management Support

13. Example of Regional Risk Presentation 13 Risk Management Support

14. Presentation of Regional Risk K-District of Seoul City was selected to assess the risk by a method developed by this study. Disasters from railroad, CNG station, and water cleaning plant were assumed, because there were no such a places and facilities in the selected district. Whole region was divided by 100m grid and the risk was presented based on the grid. Category I represent very low risk, and Category V represent very high risk. Hazardous objects in this district are shown in the table 1. 14 Risk Management Support

15. Hazardous Objects and Types of Accident 15 Risk Management Support

16. CNG Truck Fire 16 Risk Management Support

17. Hazardous Material Train Fire 17 Risk Management Support

18. Hazardous Material Train Explosion 18 Risk Management Support

19. City Gas Pipeline Fire 19 Risk Management Support

20. CNG Station Fire 20 Risk Management Support

21. City Gas Valve Station Explosion 21 Risk Management Support

22. Gas Station Fire 22 Risk Management Support

23. LPG Station Fire 23 Risk Management Support

24. Toxic Gas Release from Water Cleaning Plant 24 Risk Management Support

25. Toxic Gas Release from Refrigerated Warehouse 25 Risk Management Support

26. Conclusion It was convinced that a regional risk assessment can be performed quantitatively through a method developed by this study. The risk assessment result can be used in urban development planning, emergency response planning and execution effectively. To improve the quality of risk assessment and maintain the objectivity of the risk assessment, it is recommended to establish the data-base for input data. This can eventually enable to perform a national wide risk assessment. This data-base can be interfaced with other data-base such as population and building data-bases. It is also recommended to develop integrated software which can do the risk assessment work and make an access to data-base mentioned. Risk can be presented on a GIS map for its convenient usage. 26 Risk Management Support