Release from a pipeline in a refinery

A hydrogen feed line ruptured without igniting at an oil refinery.

Initiating cause: Hydrogen feed line ruptured

hydrogen feed line

8:50 Explosion, accompanied by abundant black smoke. The seven-men operation team on the site activates the emergency stop and evacuates the unit because of the risk of toxic leak, moving to the fall-back zone (reinforced control room). Some employees of neighbouring units ran to hide in their vehicles while others attend calmly to the subsequent fire.

9:15 The plant operator triggers the emergency plan around, alerts the public rescue service and the crisis unit of the prefecture, which was already operational, thanks to an ongoing emergency drill.
The Firefighters mobilise 70 men, 25 vehicles and a mobile chemical intervention cell (CMIC).). They take over from the in-house firefighters who water the accident unit with 3 spears to prevent the spread of the fire.
In the control room, the production team flushes the synthesis gas circuit with nitrogen in order to remove the H2 and stops the machines in the workshop while a lower secondary explosion is heard.
The plant operator closes the water networks of the site to avoid pollution of the river Seine by the extinction water.

9:55 the fire dies out due to lack of fuel

9:50 The gendarmerie and the inspection of IC arrived on the site.
Toxicity measurements are performed in the unit and around the site by fixed and mobile sensors. Measurements carried downwind (10 km/h) around the site did not reveal a dangerous concentration; however, 200 ppm was measured at 10:07 to the machine room of the accident unit (toxicity threshold of 345 ppm for a 1 hour exposure). Characteristic NH3 odours were perceptible off site.

10:40 A press release from the prefecture announcing the smells, the absence of toxic effects and the control of the accident is sent, while an automatic telephone message informed the mayors of local communities.

10:55 the emergency plan is called off.

11:25, the NH3 concentrations are zero at the level of the accident unit, which has been put in cold stop. The operator holds a press conference with the prefecture for the benefit of the numerous local and national media who visited the site; information and photos of the accident taken by local residents were circulating on the Internet since 10 am. The management of the site apologized to the residents for the inconvenience caused by the accident.

11:50.Firefighters leave the site