IGN-ENSG-L.Dalençon Apprehend Industrial Risks from past accidents : 5 World-Known Major Accidents Evaluation Feyzin, France, 1966 Flixhborough, UK, 1974 Mexico City, Mexique 1984 Bhopal, Inde 1984 SEVESO, Italie, 1976 Enseignements Evaluation Glossaire

IGN-ENSG-L.Dalençon Understand the FEYZIN Accident (France) Course of the accident Home Page Context : Refinery with in particular: - 4 propane spheres of m3 - 4 butane spheres of m3 - two horizontal tanks (butane and propane) Storage of LPG are located at 450 m of the refinery and 300 m from the first houses (dwellings) Date of the accident : January 4, 1966 Lessons learnt from FEYZIN

IGN-ENSG-L.Dalençon 1. The Operator opens the A valve 2. The operator opens the B valve and tries to control the flow 6. Valve A freezes in open position (effect of the expansion of gas), preventing its closing and the mitigation of the leakage 3. A stopper of ice prevents the liquid from leaving 4. The stopper moves under the pressure 5. The stopper exits and the LPG is rejected into the atmosphere Next

IGN-ENSG-L.Dalençon 6. Dispersion of a propane cloud (h=1m) 8. Fire goes up to the sphere 7 A vehicle ignites the mixture of propane/air at 160 m from the leakage point The sphere at the origin of the leak is engulfed in flames Whereas the firemen try to cool the nearby tanks, the sphere explodes (BLEVE) A few moments later, a second sphere explodes causing the rupture of pipes connected to a third sphere in a draining process. Three other tanks open without explosion Home Page Understand the BLEVE Penomena Lessons learnt from FEYZIN

IGN-ENSG-L.Dalençon Understand the BLEVE Phenomena Boiling Liquid Vapour Explosion A BLEVE corresponds to the complete ruin of a pressurized tank containing a liquid stored at a higher temperature than its boiling point at the atmospheric pressure Home Page Pint GPL R Ball of fire Projectiles

IGN-ENSG-L.Dalençon Lessons learnt from FEYZIN 18 persons died and 84 were wounded primarily at the time of the first BLEVE On the whole, 11 tanks were destroyed Projectiles were found within more than 800 m away from the initial location of the vessels THERE IS NO EASY OPERATIONS Home Page

IGN-ENSG-L.Dalençon Understand the FLIXBOROUGH Accident (UK) Company NYPRO specialized in the synthesis of caprolactam, a component of Nylon In the process, the caprolactam is synthesized from cyclohexane circulating in reactors at a temperature of 155°C NYPRO only owns this site. Size relatively limited with a particularly hazardous process NYPRO faces economic difficulties and has a sharp productivity approach Home Page Course of the accident Lessons s learnts from FLIXBOROUGH

IGN-ENSG-L.Dalençon A leak starts on reactor 5 (27/03/1974) 2. Decision to by-pass n°5 and link reactors 4 & 6 by a bended pipe Home Page On 1/06/1974, the link gives away, under great mecanical stresss and is detached from the bellows, releasing large quantities of cyclohexane Lessons learnt from FLIXBOROUGH

IGN-ENSG-L.Dalençon Lessons learnt from Flixborough Home Page An explosion followed suit, causing broad damage and killing 28 people including 18 in the control room No calculation concerning the resistance of the pipe was carried out No diagram of the by-pass was carried out No test of the system was carried out

IGN-ENSG-L.Dalençon Understand the SEVESO Accident Constraints related to the TCDD Home Page Context : Company Icmesa Chemical Company specialized in particular in the production of 2,4,5-trichlorophenol (TCP) used in the manufacture of weedkillers and disinfectants The TCP is synthesized in a reactor in 2 stages: - Hydrolysis of tetrachlorobenzene (TCB) with sodium hydroxide in presence of glycol ethylene (solvents) at a temperature of 180°C. - Acidification of the TCB by hydrochloric acid At the end of the first stage, 50 % of the glycol ethylene is distilled and the temperature in the reactor is lowered with 50-60°C by addition of water Lessons learnt from SEVESO Course of the accident

IGN-ENSG-L.Dalençon Constraints related to the use of TCDD In the process, it is impossible to avoid the formation of TCDD (tetrachlorodibenzo-p-dioxin) TCDD: one of the most toxic substances Exposure by ingestion, inhalation, or cutaneous contact Effects: chloracnea, burns, damage to the kidneys, liver, nervous system... Substance very stable, insoluble in water and resistant to high temperatures In a normal operating system, the formation of TCDD is negligible (if T <180 °C) and the great majority is collected and incinerated on site If T goes up, the production of TCDD can strongly increase Home Page Course of the accident SEVESO Assessment

IGN-ENSG-L.Dalençon Course of the SEVESO Accident On July the 9th, 1976: the operation of synthesis begins Following Stage 1, only 15 % of the glycol ethylene is distilled (instead of 50 %) No addition of water to cool the temperature in the reactor Operations are stopped for the weekend and the reactor is left without action to reduce the temperature of the mixture An exothermic reaction takes place in the reactor and heats the mixture more and more A few hours later, a rupture disc bursts, releasing a gas cloud containing a few kg of TCDD Home Page Constraints related to the TCDD SEVESO AssessmentEVESO

IGN-ENSG-L.Dalençon Lessons learnt from SEVESO Ten km² contaminated and several hundreds of people had to be evacuated No immediate deaths associated to the TCDD but - Death of animals in the following days - Diseases catching several people - miscarriages Extremely lasting and expensive decontamination plan Home Page

IGN-ENSG-L.Dalençon Understand the MEXICO CITY Accident (Mexico) Terminal PEMEX is used for the storage and distribution of LPG The LPG is conveyed by pipelines from three refineries The storage capacity is m3 with six spheres and 48 horizontal rolls There are many dwellings near the production site Home Page Course of the accident Mexico CityMexico City Assessment

IGN-ENSG-L.Dalençon Course of the MEXICO CITY Accident On the 19/11/1984, the installation is in the course of filling, a 200 mm pipe breaks down releasing the flammable gas The cloud : surface on the ground of approximately 200 X 150 m² and height 2 m It ignites on a flare. This ignition causes the destruction of several houses At 5:45, a first BLEVE occurs followed, one minute later, by the BLEVE of two spheres giving place to a 300 m diameter fireball BLEVEs occurred in series (nearly 15 explosions in 1hour 1/2) Home Page Mexico CityMexico City Assessment Understand the BLEVE Phenomena

IGN-ENSG-L.Dalençon Lessons learnt from MEXICO CITY In a radius of 300 m, all the people were killed or wounded More than 500 died, wounded, evacuated people and people implied in the first-aid organizations. Only 4 tanks over the 48 present remained intact Fragments were found at distances from of over several hundred meters. The most remote fragments was projected to m of its place of emission Home Page Many people were killed or injured due to the presence of crowded places in the vicinity of the plant

IGN-ENSG-L.Dalençon Understand the BHOPAL Accident (India) The company Union Carbide India Ltd is specialized in the manufacture of pesticides Located in a dense urban environment Following the strong competition of another company, the closing of the factory is considered by the American head office The activity is held thanks to drastic economies Qualification of the operators is lowered, the framing is reduced, work of maintenance reduced to bare essential. For its production, Union Carbide handles very dangerous products of which methyl isocyanate Methyl isocyanate = gas very toxic by inhalation: Effects : pulmonary oedemas. This gas can also set in the system to form cyanide Following the refitting, several accidents occurred causing nearly 50 people poisoned among the workmen over one period one year Home Page Course of accident BHOPAL Assessment

IGN-ENSG-L.Dalençon Course of the BHOPAL Accident Home Page 1. Water penetrates in a tank. An exothermic Reaction starts with the CMI 2. The pressure increases in the tank a leak is detected around the tank 4. Decision to send the gas to the flare Impossibility to light the flare 5. Opening of the valve ; discharge of gas to the atmosphere 3. Decision to start the soda treatment. The pump is faulty Soda BHOPAL Assessment

IGN-ENSG-L.Dalençon Lessons learnt from BHOPAL The leak happened in the early morning of the 3/12/1984 At 2 km of the site, in 4 minutes, 150 died, 200 paralysed people, 600 people lose conscience, people seriously affected. In the end, nearly died and people were poisoned. Home Page The safety level of a plant strongly relies on a efficient safety organization

IGN-ENSG-L.Dalençon Proximity of industrial activities and centres of population can be a real issue if it is not controlled First victims = often the operators of the plant at the origin of the accident Much can be learnt from industrial accidents and even the incidents. Need for managing the experience feedback to progress The major industrial accidents often led to revisions of the regulation. Case of the SEVESO directive Drawing lessons from Major Accidents Home Page

IGN-ENSG-L.Dalençon Evaluation Home Page

IGN-ENSG-L.Dalençon Glossaries Home Page INERIS Lexic : Insitut National de lenvironnement Industriel et de Risques