An explosion at a coal-fired power plant killed one person and injured 10 others. The blast killed the delivery truck driver who was unloading compressed hydrogen gas, which is used to cool the plant's steam generators. Hydrogen deliveries are routine at the plant, occurring about once a week. Evidence pointed to the premature failure of a pressure-relief device (PRD) rupture disk, which had been repaired by the vendor six months prior to the explosion.

Incident Date
Jan 08, 2007
  • Pressure Relief Devices
  • Burst Disk
  • Vehicle & Fueling Systems
  • Gaseous Hydrogen Delivery Vehicle
Probable Cause
Contributing Factors
When Incident Discovered
Lessons Learned

Verify that all PRDs contain fuse-backed adapters.
Explore elimination of rupture disk PRDs and substitution of spring-style relief valves.
Develop new hydrogen unloading procedure using a written checklist. * Add instrumentation to monitor the high-pressure hydrogen system.
Confirm that temporary offices/facilities are not co-located with hazardous chemical storage sites.
A procedure is now in place that requires a Job Hazard Analysis (JHA) to be done on unloading hydrogen and shared enterprise-wide.
A competent plant employee must be present during all hydrogen unloading activities.