Release in chlorate production plant

In a plant manufacturing chlorate products, a hydrogen leak occurred via the water drainage outlet onto the factory floor. Pressure in the hydrogen line increased because the hydrogen pipes were filled with water. The situation was rectified by shutting down the process, draining the pipes and by redirecting the hydrogen flow.

Water entered into the hydrogen pipes because the selection switch on the hydrogen compressor had been turned to the 'fresh water' position, and as consequence more water was incorrectly fed into the process. As the intention was to run the compressor in the standard mode, water did not, within the time available, exit the system along the open route; instead, it rose to the hydrogen pipes.

INITATING CAUSE: a wrong manual operation
ROOT CAUSE: may be deemed to be the insufficient level of automation because a selection permitting human error had been left in the process.

hydrogen supply line

The root cause was an insufficient level of automation, which allowed human error. Risk assessment shall consider this scenario and safety design should provide effective preventing measures.

The switch, which had been manually turned into an incorrect position, was removed.
Another upper limit was set that locked the valve controlling the separator level and ensuring that the compressor is stopped.