A hydrogen fire occurred in a nuclear power plant outside the controlled area. The leaking point was on a pipe system of the distribution circuit of the gas network (6 bar nominal working pressure). The specific location was a joint on the fire-protection cupboard containing the hydrogen cylinders. The fire started during a repairing intervention on a cupboard nearby, performed by a sub-contractor using a hot surface welding equipment. Internal emergency services isolated and depressurized the pipes, and extinguished the flame.

Explosion in a chemical manufacturing plant for the pharmaceutical and cosmetics industries, classified as Seveso high level, The explosion occurred in the hydrogenation reactor, when opening two buffer tanks to clean the reactor the after hydrogenation using a catalyst (ruthenium on coal). Following the explosion, the operator initiated the emergency plan, evacuated personnel and secured the area. Two operators were injured.

In a graphite purification workshop, the cooling circuit of an electric furnace leaks, the water decomposes in contact with materials heated to a temperature of 1,800C; the gas mixture (hydrogen, air...) explodes. The carbon contained in the furnace is dispersed and ignites.

The explosion occurred in a copper electroplating plant test furnace when starting the operation of copper plating. EVENT DETAILS A tinned copper pipe had been placed inside another copper pipe and lined with pellets. Inside the furnace, the pellets were intended to adhere to the outer surface of the smaller tinned copper pipe under hydrogen atmosphere. The test was the third in the series. A vacuum was created inside the furnace, and an indicator light showed that a vacuum had been successfully generated.

A fire occurred in a hydrogen and catalyst loading lines of heavy oil unit. The most likely cause was that a hydrogen purge pipeline failure allowing hydrogen to escape. This mixed with hot oil bringing the temperature to approximately 825 degrees F (441 degrees C), i.e. above the auto-ignition temperature.

The event started when a gasket in a water pump was blown out. The water pump was situated inside a 100 m long, 10 m wide, and 7 m high building. The pump was feeding water to a vessel containing hydrogen gas at pressure of 30 bars. The accident occurred when operators tried to change over from pump B to pump A. They did not realise that the inlet valve on the low-pressure side of pump A was closed. Following a series of attempt to solve the situation, a valve remained partially open and the gasket failed.

An explosion at a refinery Hydrotreater plant involving a furnace and hydrogen caused by faulty operation. Source of ignition was furnace.

An incident occurred on a compressor at a refinery Fluid Catalytic Cracker Unit (FCCU) plant involving hydrogen. Source of ignition was hot surface.

Ejection of rotor wedge material lead to vibration induced failure of components, including hydrogen seals. Serious fire resulted from hydrogen leakage, which subsequently lead to an oil fire. Ignition from metal to metal contact between fractured components.

Explosion in condenser area two hours after the unit tripped (due to a stator earth fault). The stator earth fault had damaged two hydrogen cooler tubes, which allowed hydrogen to pass from the stator casing into the condenser via the condensate system. Ignition source thought to be contact with the hot metal of the IP steam chests or due to an electrostatic spark.