Evaluation of the Tianjin explosion and comparisons to the West Fertilizer Explosion. A review of risk management yesterday, today and tomorrow.

Transcription

1 Evaluation of the Tianjin explosion and comparisons to the West Fertilizer Explosion A review of risk management yesterday, today and tomorrow. Dave Price - Gexcon

2 Port of Tianjin, China 2015

3 Port of Tianjin, China 2015 Epicentre of explosion

4 Image at epicentre 5 th July 2015

5 Image at epicentre 22 nd August 2015

6 Port of Tianjin, China 2015 The facts! Fire reported at a warehouse in the Binhai area around local time, 12 th August 2015 Fire fighters attended, initially being from the port authority (1000 firefighters in total) At the first explosion occurred recorded as 2.3 on Richter scale The second more violent explosion occurred approximately 30secs later Around a series of eight smaller explosions occurred as the original fire spread

7 Port of Tianjin, China 2015 The facts! The area consisted of a dense occupation of industrial use combined with residential properties Approximately 5,600 families were living within a 1.5km radius of the epicentre Closest residents only 600m away

8 Video courtesy of Dan van Duren /

9 Casualties 173 people died in total 95 firefighters 11 police officers 67 others 707 suffered injuries >300 homes destroyed

10 Rui Hai International Logistics Site layout Loading area Main Building Hazardous Materials Storage Transit Warehouse Image from

11 View looking North towards explosion site Rui Hai International Logistics site Image from

12 View looking South towards explosion site Apartments with broken windows Apartments with broken windows Light damage to rail station Site of explosion S11 Haibin Expressway Image from

13 Underneath of S11 Expressway Image from

14 Crater location superimposed onto image prior to explosion

15 Synopsis of disaster Report concludes that Nitrocellulose caught fire inside containers Theory that wetting agent (typically Ethanol) had flashed off due to high ambient temperatures at this time of the year Wetting agents properties Flash Point (FP) Ethanol 13 o C Lower Explosion Limit (LEL) 1.4% Upper Explosion Limit (UEL) 11.2% Auto Ignition Temperature (AIT) Minimum Ignition Energy (MIE) 365 o C < 1.0mj (Data from European Solvents Group) Fire rapidly spread to storage of other hazardous material including Ammonia Nitrate

16 Ammonia Nitrate Used widely as a nitrogen fertilizer (FGAN) and as an additive when manufacturing explosives Can be found naturally as a mineral Produced by reacting anhydrous ammonia with nitric acid and dried to form small beads / prills Image from

17 West Fertilizer, Texas, 17 th April 2013

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19 West Fertilizer, Texas 2013 The facts! Intense fire in the storage area reported at approx. 7.29pm, no employees on site. Emergency services in attendance at the scene when detonation occurred at approx. 7.50pm 15 people killed 250 injured Numerous buildings damaged and destroyed Large crater formed at blast site

20 West Fertilizer Texas, April 17th 2013 Video courtesey of WSJ Live - Youtube Video captured by father and daughter watching the fire unfold 300mtrs from the facility

21 Investigation Findings and Lessons Learned in the West Fertilizer Explosion Dr Scott Davies et al Heating AN beyond melting point causes exothermic reaction, possible runaway Energy releases temperatures 1800 o C to 2000 o C within the vicinity of the explosion Heating causes decomposition and generation of gases which require venting Detonation due to severe shock or heating with confinement Molten AN can cause explosive decomposition

22 Comparisons between Tianjin & West Tianjin, China West Texas Storage of AN 800 Tonnes (estimated) 30 Tonnes Initiating event Fire prior to explosions Fire prior to explosion Blast site Large crater approx. 90 M Dia. Large crater 28.5 M Dia. Near field Total destruction within several hundreds of metres Total destruction of facility and nearby buildings Far field Windows shattered up to 2km away Windows shattered up to 1km away Casualties 173 fatalities, 707 injuries 15 fatalities, 250 injuries

23 Craters 23.5M Approx. 90M Tainjin West

24 Size of crater in comparison to mass of AN T. J. Flanagan performed experiments at the Nevada test site Scaling analysis provided a correlation between volume of a crater V (m 3 ) and the mass of TNT W (kg) V = W ± Tianjin West Volume of crater 17,011m 3 (estimated) 324m 3 (calculated) Mass of equivalent TNT 294 Tonnes 9.17 Tonnes Mass of equivalent AN 700 Tonnes 21.8 Tonnes AN as a % TNT equivalency ranges from 0.42 to 1 (0.42 used here for conservatism)

25 Predicted mass of TNT According to the China Earthquake Networks Centre, the second, more powerful explosion only had a power equivalent to 21 tonnes of TNT detonating (source: BBC). Although Chinese scientists estimated that the second explosion involved the detonation of about 800 tonnes of ammonium nitrate, based on crater size and lethality radius (source: Huang, Ping; Zhang, Jingyuan (2015). "Facts related to August 12, 2015 explosion accident in Tianjin, China". Process Safety Progress. 34 (4): Retrieved 20 December 2015). Conflicting reports!!!

26 Predicted mass of TNT While there have been many explosion tests involving AN, the reported values for %TNT equivalent varies over a broad range from 0.42 to 1.0. We chose the lower end value of the range (0.42). It is therefore estimated that the 800 tonnes of AN assumed to have been involved in the second explosion is equivalent to 336 tonnes of TNT. Therefore, 2 blast simulations were undertaken using FLACS-Blast, one modelling the detonation of 21 tonnes of TNT and one modelling the detonation of 336 tonnes of TNT.

27 Predicted blast pressures Sadovsky formula, approximate pressure with distance from the detonation, given for mass of TNT.

28 Effects of blast pressures

29 Site overview Image from

30 Geometrical model for CFD (FLACS) Nearby apartment complex

31 Geometrical model for CFD (FLACS) Approximate blast location (centre of crater)

32 Flyover of CFD model Approximate blast location Apartment buildings Rows of cars Expressway

33 Simulation results 21 tonnes TNT Probable glass breakage at 650M from source

34 Simulation results 336 tonnes TNT Probable glass breakage at 1700M from source

35 2 km radius from centre 336 tonnes TNT 0.0 seconds

36 2 km radius from centre 336 tonnes TNT 0.25 seconds

37 2 km radius from centre 336 tonnes TNT 0.5 seconds

38 2 km radius from centre 336 tonnes TNT 0.75 seconds

39 2 km radius from centre 336 tonnes TNT 1.0 seconds

40 2 km radius from centre 336 tonnes TNT 1.25 seconds

41 2 km radius from centre 336 tonnes TNT 1.5 seconds

42 2 km radius from centre 336 tonnes TNT 1.75 seconds

43 2 km radius from centre 336 tonnes TNT 2.0 seconds

44 2 km radius from centre 336 tonnes TNT 2.25 seconds

45 2 km radius from centre 336 tonnes TNT 2.5 seconds

46 2 km radius from centre 336 tonnes TNT 2.75 seconds

47 2 km radius from centre 336 tonnes TNT 3.0 seconds

48 2 km radius from centre 336 tonnes TNT 3.25 seconds

49 2 km radius from centre 336 tonnes TNT 3.5 seconds

50 Conclusions The simulations modelling the detonation of 21 tonnes of TNT showed pressures likely to break glass reaching a radial distance of approximately 650 m from the blast location. The simulations modelling the detonation of 336 tonnes of TNT showed pressures likely to break glass reaching a radial distance of approximately 1,700 m from the blast location. The larger mass of TNT modelled showed results more consistent with the damage observed at the site.

51 Concerns raised by emergency responders Are fire crews and emergency responders properly trained and suitably equipped to deal with these incidents? Is sufficient evaluation of the potential consequence performed? How can we learn more and be better prepared?

52 Fire and explosion risk management. Yesterday, today and tomorrow!

53 Accidents Can Happen Extraction, conversion, transport, storage and use of energy in various forms play a fundamental role for the advancement of modern societies, and will continue to do so in the foreseeable future. Accumulation of energy represents a hazard! Piper Alpha, 6 July 1988 Major accidents cause severe losses a majority of the 100 largest property losses in the hydrocarbon industries from 1972 to 2011 involved fire and explosions. Oil companies have invested significant amounts in R&D, including fire and explosion safety Deepwater Horizon, 20 April 2010

54 Accidents Can Happen Flixborough Explosion at chemical plant. Killed 28 people and injured 36 (out of 7 on site). Led to a more systematic approach to process safety in UK. Ekofisk Bravo A blowout occurred due to an incorrectly installed downhole safety valve. At 126,000 barrels, it was the first and largest blowout in the North Sea and highlighted significant deficiencies. Piper Alpha An explosion, and the resulting oil and gas fires killing 167. The accident was the worst offshore oil disaster. Led to the adoption of the Offshore Installations (Safety Case) Regulations. Imperial Sugar 14 people were killed when a dust explosion occurred at a sugar refinery. Led to OSHA proposing the Combustible Dust Explosion and Fire Prevention Act of Seveso Toxic release from chemical facility. Health impacts on 1000s of people. Gave rise to standardised industrial safety regulations. The EU industrial safety regulations are known as the Seveso II Directive. Bhopal A gas leak incident in India, considered the world's worst industrial disaster. Over 500,000 people were exposed, killing up to 16,000. Resulted in U.S. legislation regarding the accidental release of chemicals in the US. Buncefield Large explosion and fire at oil storage terminal. Hedgerows accelerated the flame front to such a degree its pressure wave caused remaining air fuel cloud to detonate. The HSE Process Safety Leadership Group formed to implement Recommendations. Macondo Explosion and fire resulted in the sinking of the Deepwater Horizon and the deaths of 11 workers. Considered the largest accidental marine oil spill in the world, and the largest environmental disaster in U.S. history.

55 Understanding Explosions Are Explosions of Concern? Test program: Safety on the Continental Shelf Driven by the Bravo blowout and Flixborough explosion Early experiments at Gexcon (CMI/CMR) to gain knowledge about explosion phenomena By varying obstructions and ignition, large range of explosion pressures: 20 mbar to 20 bar Need for more understanding!

56 The Past - Equations, look up tables and graphs

57 Understanding Explosions What is an Explosion? Offshore Explosion safety JIP at Gexcon (~10 mill USD) BP, Elf, Esso, Mobil, Norsk Hydro & Statoil Scaled explosion tests in modules Explosions are complicated! We need a predictive tool Start of CFD (FLACS) development

58 Understanding Explosions Post Piper-Alpha Test program: BFETS Large Scale Tests Explosion model benchmarking; models Moderate scale, congestion and confinement Much higher pressures than expected by industry 4-5 barg Explosion Phenomena too complex for simple models CFD is required

59 Today Probabilistic Studies Probability of Exceedance, Northern Firewall 1,00E-02 1,00E-03 Frequency [/year] 1,00E-04 1,00E-05 1,00E ,5 1 1,5 2 2,5 3 3,5 4 4,5 5 5,5 6 Pressure [Barg] Accumulated Explosion frequencies With Wall Without Wall Plated Grated 1.00E E-04 Freq [1/year] 1.00E E E Cloud size (m3)

60 Predicting Risk Today Integrated risk-based tools Traditional methods for reporting probabilistic studies: Static documents The results are simplified to a few simple numbers Full 3D risk picture not as apparent 1.00E E-04 Drag forces [kpa] Object 10-4 /year 10-5 /year Piping in Module M Frequency of exceeding explosion overpressure Local panels Global panels Frequency (per year) 1.00E E E Pressure (barg)

61 Predicting Risk Today Integrated risk-based tools Drive to take advantage of increased computing power and modern visualisation techniques

62 Predicting Risk Case Study: Hydrogen Refuelling Station Summary of isolatable inventory properties Process units and scenarios Pressure [barg] Max leak diameter [mm] Release rate [kg s -1 ] Container with compressor unit High pressure storage tanks Tube trailer Dispenser Summary of event frequencies for the risk analysis Process units and scenarios Releases [1/yr - ] Jet fires [1/yr] Explosion [1/yr] Container with compressor unit 2.3E E E-05 High pressure storage tanks 1.1E E E-05 Tube trailer 2.2E E E-05 Dispenser 7.1E E E-05

63 Predicting Risk Today Case Study: Hydrogen Refuelling Station

64 Predicting Risk Today Case Study: Hydrogen Refuelling Station

65 Virtual Reality VR Safety Project started in 2004 funded by Statoil and Norsk Hydro. A virtual reality application for the oil and gas industry for enhancing safety through risk communication, interactive learning and training. Specialized for gas leaks, fire, and explosion scenarios At the time VR was too expensive to be really effective

66 Communicating Risk Today VR Safety Modern technology (e.g. Oculus Rift) has made VR affordable

67 EPA Recommendations following the West incident

68 The Future! Intuitive computers developed on consequence modelling and artificial intelligence coupled to live telemetry using heads up displays providing augmented virtual reality for incident controllers and emergency responders! Can it be possible?

69 Could we soon have our own Iron Men?

70 Well to some extent we already have! Video Credit: Joeseph Juhnke NKE, INC.

71 Learning and innovation go hand in hand. The arrogance of success is to think that what you did yesterday will be sufficient tomorrow William Pollard

72 Thank you! Address Unit 831 Birchwood Boulevard Birchwood Warrington Cheshire WA3 7QZ