Hydrogen release from a hydrogen pipeline

Alarm received by firefighters around midnight by a resident who heard abnormal noise under the Beaumont Bridge while walking his dog.
Perimeter of security set up very quickly with isolation of the section.
Pipeline was depressurised within the hour. The pipeline was completely emptied and purged with nitrogen.

A security perimeter was established in the night from Sunday to Monday, around 1 am and raised around 5 o'clock. The police banned access to several main arteries of the old town all night, and the inhabitants were confined to their homes.
Reparation was done during the next day and were validated in the night.
No significant impact on customers.

The INITIATING CAUSE was the loss of confinement of the pipeline.

This is usually related to local corrosion, which could start from the inside wall of the pipe (for example tiggered by hydrogen-steel interaction) or could be induced from outside, for example by chemical process in the ground around the pipe, or by external solicitations such as mechanical vibrations from traffic. The statistics related to gas leaks shows that this second type of damage is the most frequently causing gas releases.

For the ROOT CAUSE two alternative factors could be identified: a materials defect already existing in the as-manufactured pipe component, and/or a lack of maintenance allowing the corrosion to progress beyond an allowed degree of damage

pipeline

No impact on person, no material loss.
The police banned access to several main arteries of the old commune all night, and the inhabitants were confined to their homes.
Reparation is done, improve maintenance frequency