Pollution
Humain
Environnement
Economique

A liquid sulphur leak occurred on a 14,900-tonne capacity tank containing 11,000 tonnes of product kept hot at a temperature of 155°-160°C. The leak was flowing at a rate of 8.5 m³/hr (350 tonnes/day) through a hole between 1 and 2 cm in diameter at the base of the shell. The crack was caused by the rupture of internal anchorage points on the tank supply pipe originating inside the production units. Vibrations emitted during material transfer operations (600 m³/hr) gave rise to tensions acting on a weld of one of the reheating pipes, which broke allowing vapour to leak. This rupture induced erosion over a previously corroded zone, thus leading to perforation of the tank wall. Drainage required 6-8 days via transfer to various consumption units. The sulphur was channelled to a former parking lot for subsequent recovery by means of grinding after cooling. No external consequences were reported.