Fire in a chemicals plant

The event occurred at a sodium chlorate production plant. A flare-like flame of less than one metre in height was located on a hydrogen pipe. Very near the control room,
After an unsuccessful attempt to use fire extinguishers, they executed the emergency shutdown of all units.

The post-accident analysis of the components detected pulverised rust dust inside the removed pipe section. The metal of the corroded section had completely softened, and the connector piece could be removed by pulling by hand.

The INITIATING CAUSE was a leak from a hydrogen pipe, due to corrosion.

Hydrogen appeared to have leaked out from the leak site for an extended period, until an igniting factor was introduced. IGNITION could have happened due to electrostatically charged particles (snow).

ROOT CAUSE was an organisational cause: shortcomings in service and maintenance allowed advancement of the pipe corrosion till when it was not able to bear the internal pressure. An important fact was the absence of sensors which would have been able to detect soon the leaking hydrogen. This highlights a lack of a risk assessment based on worst scenarios and the failure to take measures to prevent them.

Hydrogen pipe in a sodium chlorate plant

3 production lines were shut down.