Event
- Event ID
- 434
- Quality
- Description
After a test of a LH2 vessel, during the warm up phase, the plan was to dispose of the hydrogen through the vent system. However, a leak to atmosphere occurred. This was due to a blind flange having been removed and an incorrect valve was opened allowing an open line from the vent system.
- Event Initiating system
- Classification of the physical effects
- Unignited Hydrogen Release
- Nature of the consequences
- leak no ignition
- Macro-region
- North America
- Country
- United States
- Date
- -
- Component involved
- valve (generic)
- Failure mode
- leak, no ignition
- Initiating cause
- wrong operation
- Root CAUSE analysis
The erroneous release of the LH2 was due to an operation which did not take into account temporary modifications of the piping system.
- Root causes
- Date entry in HIAD
- 01/11/2025
Facility
- Application
- Non-road vehicles
- Sub-application
- Aerospace
- Hydrogen supply chain stage
- All components affected
valve, tank
- Process temperature range [C]
- cryogenic temperature (below -50°C)
- Location type
- Unknown
- Location
- industrial area
- Operational condition
Emergency & Consequences
- Number of fatalities
- 0
- Number of injured persons
- 0
- Property loss (onsite)
- 0
In-depth data
- Release type
- liquid
- Involved substances (% vol)
- H2 100%
- Probable IGNITION SOURCE
References
- Sources categories
- ORDIN
- Reference & weblink
Mishap no 75 in
P. L. Ordin, Review of hydrogen accidents and incidents in NASA operations, 1974, NASA TM X-71565
https://ntrs.nasa.gov/citations/19740020344Hankinson and Lowesmith, Qualitative Risk Assessment of Hydrogen Liquefaction, Storage and Transportation, FCH JU project IDEALHY, Deliverable 3.10 (2013)
confidential
(accessed October 2025)Lowesmith et al., Safety issues of the liquefaction, storage and transportation of liquid hydrogen: An analysis of incidents and HAZIDS, Int. J. Hydrogen energy (2014) https://doi.org/10.1016/j.ijhydene.2014.08.002
