Overview: A hydrogen leak and explosion occurred due to the installation of an incorrectly sized gasket at the suction line of a hydrogen compressor in a refinery hydrodesulfurization plant. The incorrectly sized gasket was mounted during the startup of the plant in 2001 and had never being inspected nor replaced.
Incident synopsis: The operating conditions were stable when the operator received an alarm indicating pressure loss in the circuit. He immediately instructed his field personnel to inspect the area. The hydrogen leak was confined inside the compressor room because the walls and roof were not provided with ventilation devices. An explosion occurred, causing two fatalities and the destruction of the compressor room and some of the surrounding area.
- Carefully revise the risk assessment process to evaluate any confined areas where hydrogen is handled.
- Separate the fire and gas detection alarm system from the process information to provide easy and clear identification.
- Refresh and re-enforce personnel training on fire and gas identification and interpretation.
- Retrain personnel on emergency procedures and enhance their understanding and awareness of risky, flammable, explosive, and/or toxic substances. Avoid underestimation of the hazards and complacency.
- Re-enforce training and review training courses for recently hired personnel.