In the bitumen storage and loading/unloading unit at a refinery, a 12-m high tank installed on the site for 30 years featuring a floating roof, a capacity of 1,200 m3 and a heating coil, suddenly ruptured at the level of the shell-foundation joint. The casing was projected a distance of 15 m, breaking in its path the piping braces placed 5 m aboveground; it then fell onto another bitumen tank. Some 550 tons of bitumen and 120 tons of hot-oil at 170°C used in the heating coil, spilled over a zone of about 13,000 m2.Fire subsequently broke out in the tank basin and spread by domino effect to nearby installations, other storage areas and the tanker trucks being loaded. Internal and external emergency plans were immediately activated. The fire is estinguished after about 3 hours of internal fire team’s intervention and external fire brigades.

It was determined that this tank failed due to internal overpressure caused by the presence of light flammable hydrocarbons overheated by the heating coil and wrongly introduced into the tank during unloading from tank-trucks to the tank of bitumen in excess present in the trucks.

This accident killed 1 and injured 3 truck drivers due to the ensuing fire. The smoke plume was seen by the near city population, but its effects were juged at low impact by the regional environmental protection agency. Bitumen also spilled into the adjacent sea through wastewater discharge pipes and polluted the seaside beach for 8 km far away. The explosion and fire damaged a number of facilities and structures on site. The coasts were estimated at 25 M€ for production losses and 3 M€ for the property damage and environmental restoration/cleanup.

The investigation bring out deficiencies in management factor and human factor (SMS) and the operator decided to remove the loading platform from the storage area and modify operative procedures to load tank-trucks.

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