Event
- Event ID
- 330
- Quality
- Description
During a cryo-irradiation testing, a Dewar failed or leaked hydrogen into the atmosphere, causing a fire. The Dewar's contained liquid hydrogen for testing metal samples at cryogenic temperature. The internal vessel containin gLH2 was surrounded with vacuum, liquid nitrogen and an external vacuum space. The hydrogen fire developed in vicinity of the upper part of Dewar.
- Event Initiating system
- Classification of the physical effects
- Hydrogen Release and Ignition
- Nature of the consequences
- fire
- Macro-region
- North America
- Country
- United States
- Date
- -
- Component involved
- cryogenic vessel
- Failure mode
- rupture & ignition
- Initiating cause
- over-pressurisation (thermal insulation degradation)
- Root CAUSE analysis
The hydrogen compartment of the Dewar failed and leak the LH2 into the vacuum space between the liquid hydrogen and the liquid nitrogen. Cooling of the nitrogen compartment which was open to the atmosphere could have resulted in cryo-pumping of air into the vent. The wall between the nitrogen compartment and vacuum space (now filled with liquid hydrogen) failed, allowing air to mix with hydrogen.
There were no ignition sources evident.
ROOT CAUSE is unknown- Root causes
- Unknown
- Date entry in HIAD
- 30/10/2025
Facility
- Application
- Laboratory / R&D
- Sub-application
- Aerospace
- Hydrogen supply chain stage
- All components affected
dewar
- Process temperature range [C]
- cryogenic temperature (below -50°C)
- Location type
- Unknown
- Location
- countryside or desert
- Operational condition
Emergency & Consequences
- Number of fatalities
- 0
- Number of injured persons
- 0
In-depth data
- Release type
- gas
- Involved substances (% vol)
- H2 100%
- Probable IGNITION SOURCE
References
- Sources categories
- ORDIN
- Reference & weblink
Mishap no 38 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
