At around 11:15 a.m., a fire broke out at a disused refinery that was being demolished. A puddle of hydrocarbons in the bund of a storage tank that was being dismantled ignited on contact with a blowtorch. The demolition workers tried, unsuccessfully, to put out the fire with extinguishers. They left the site and called the firefighters, who fought the fire using foam. Metal sheets that had piled up in the tank were removed by a mechanical excavator fitted with a claw. The fire was brought under control at 1:40 p.m.

The leak was cause by a ruptured drain valve

The hydrocarbons in the bund came from the pipe supplying the tank that was being dismantled. Three days before the fire, oxy-cutting equipment had been used to cut the tank’s panels into 15 m sections. The pre-cut sections were then knocked out using a hydraulic excavator. One panel struck the supply line as it fell, breaking a drain valve. The 45 mm pipe, which contained crude oil, emptied its contents into the bund. The leak went undetected. Subcontractors who came to cut the panels 6 m away from the drain valve did not notice the puddle of hydrocarbons and they did not have the necessary hot-work permit.

Insufficient risk analyses

The operator knew that the pipe was not completely empty because the circuit had simply been purged. Nonetheless, he considered that the pipe’s angle made it unlikely that oil would be near the storage tank. After analysing the event, he proposed to the inspection authorities for classified facilities that burying the pipes supplying the other storage tanks under earthen mounds would protect them from impacts. The inspection services asked that the pipes be drained and inerted before commencing oxy-cutting operations. A hot-work permit would provide better protection against fire and explosion hazards.