Event
- Event ID
- 327
- Quality
- Description
- This event occurred when dismantling the cryostat. While a hot air dryer was being used to free a coupling in a hydrogen cryostat, a flash fire occurred.
[Ordin, NASA (1974)] - Event Initiating system
- Classification of the physical effects
- Hydrogen Release and Ignition
- Nature of the consequences
- Fire (No additional details provided)
- Macro-region
- North America
- Country
- United States
- Date
- -
- Main component involved?
- Cryogenic Vessel
- How was it involved?
- Internal Explosion (H2-Air Mixture)
- Root causes
- Root CAUSE analysis
- The INITIATING CAUSE the formation of an air-hydrogen explosive mixture in the cryostat.
The temperature at the centre of the cryostat was sufficiently low to liquefy air. The ignition of the hydrogen-air mixture was probably due to a spark from an open filament of the dryer.
The prescribed requirements for purging and bringing cryostat to room temperature was circumvented.
The ROOT CAUSE a human error.
Facility
- Application
- Non-Road Vehicles
- Sub-application
- Aerospace
- Hydrogen supply chain stage
- All components affected
- cryostat
- Location type
- Unknown
- Operational condition
- Pre-event occurrences
- The cryostat was being heated up and emptied (probably at the end of an experiment)
Emergency & Consequences
- Number of injured persons
- 0
- Number of fatalities
- 0
- Environmental damage
- 0
Lesson Learnt
- Lesson Learnt
- In this event, the existing procedure for bringing back the cryostat to room temperature and to dismantle it were not followed. The report does not explain why , but it is easy to assume that the operators wished to accelerate the work and forced a quicker warming up of the coupling by using an heating equipment which clearly was not fitted for the purpose, because not being explosion proof. This suggests a lack of basic knowledge of hydrogen safety principles, and possibly also a lack of supervision or of communication.
Event Nature
- Release type
- gas
- Involved substances (% vol)
- H2 100%
- Presumed ignition source
- Electricity
References
- Reference & weblink
Mishap no 37 in <br />
P. L. Ordin, Review of hydrogen accidents and incidents in NASA operations, 1974, NASA TM X-71565<br />
https://ntrs.nasa.gov/citations/19740020344Lowesmith 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
Hankinson and Lowesmith, Qualitative Risk Assessment of Hydrogen Liquefaction, Storage and Transportation, FCH JU project IDEALHY, Deliverable 3.10 (2013)<br />
confidential<br />
(accessed October 2025)Hankinson and Lowesmith, HAZIDs for Hydrogen Liquefaction, Storage and Transportation , FCH JU project IDEALHY, Deliverable 3.11 (2013)<br />
https://www.idealhy.eu/uploads/documents/IDEALHY_D3-10%20HAZIDs_Liquefa… />
(Only summary publicly available, accessed October 2025)Also in H2TOOLS<br />
https://h2tools.org/lessons/hydrogen-cryostat-dismantling-incident<br />
(Accessed December 2025)
JRC assessment
- Sources categories
- ORDIN
