In a chemical plant, the safety disk fitted on the 1st of the 2 reactors of an ethylene/methyl acrylate copolymer (EDA) production line in stable operation ruptured at around 2.10 am, releasing decomposition products from the reaction medium which ignited when coming out of the stocks despite an automatic injection of water. Finally, the injection of nitrogen extinguished the flames, but at around 2.20 am an ignited coolant leak was detected at the inter-reactor connection. The manuel and automatic isolation valves of the coolant system were then closed as close to the leak as possible, and internal equipment was used to extinguish the fire. The situation was under control 15 min later, but preventive spraying continued until 3 am.

The accident only had economic consequences: internal material damage assessed at 251,000 euros and operating losses at 600,000 euros.

Premature wear of the bottom bearing of the agitator fitted to the reactor caused heating which then resulted in decomposition of the reaction medium and the pressure buildup in the 1st reactor. As the inter-reactor connection was the seat of significant heating related to this decomposition, excessive expansion of the connecting tube and ring resulted in its plastic deformation which then, during cooling, less retracted than the tube, creating a tenth of a millimetre space causing the coolant leak (estimated at a few hundreds of litres).

The following improvements were made to the installation after this accident: modification of the design of the coolant circulation double jacket (shrink-fitting and packing assembly), installation of a temperature gauge on the inter-reactor connection, and increase in the frequency of agitator bearing inspections.