Event
- Event ID
- 213
- Quality
- Description
- The tank of a liquid hydrogen tanker was manually vented prematurely on its empty return trip. 9,000 cu ft (22 kg) of hydrogen were released
[Zalosh and Short, 1978] - Event Initiating system
- Classification of the physical effects
- Unignited Hydrogen Release
- Nature of the consequences
- Macro-region
- North America
- Country
- United States
- Date
- Main component involved?
- Lh2 Tanker
- How was it involved?
- Manual Venting
- Initiating cause
- Unknown
- Root causes
- Root CAUSE analysis
- The INITIATING CAUSE was the over-pressurisation of the tank when returning empty of liquid hydrogen after delivery.
The ROOT CAUSE was probably a small shortcoming in the execution of the procedure for stabilisation of the tank pressure after delivery.
Facility
- Application
- Hydrogen Transport And Distribution
- Sub-application
- LH2 tanker
- Hydrogen supply chain stage
- Hydrogen Transport (No additional details provided)
- All components affected
- manual vent
- Location type
- Open
- Operational condition
Emergency & Consequences
- Number of injured persons
- 0
- Number of fatalities
- 0
- Currency
- US$
- Property loss (onsite)
- 0
- Property loss (offsite)
- 0
- Emergency action
- none
Lesson Learnt
- Lesson Learnt
- This event could be considered almost a near miss. The safety procedure (manual venting) preventing the pressure to increase beyond the allowed value functioned as planned, avoiding uncontrolled hydrogen release.
Zalosh et al (see references), concluded their analysis of hydrogen transportation accidents till 1978 with the following conclusions:
"Finally, an encouraging aspect of the transportation incident compilation is that 71% of the hydrogen releases did not lead to an ignition. ... The relatively few ignitions may be due to either to lack of ignition sources or to the rapid dispersal of hydrogen into the atmosphere. In any event, the accident data provide further incentive to transport , transfer and store hydrogen outdoors away from occupied areas."
Event Nature
- Release type
- gas
- Involved substances (% vol)
- H2 100%
- Released amount
- 21
- Presumed ignition source
- No ignition
References
- Reference & weblink
Extract from Table III of Appendix A of Zalosh and Short<br />
COMPARATIVE ANALYSIS OF HYDROGEN FIRE AND EXPLOSION INCIDENTS<br />
Quarterly Report No. 2 for Period December 1, 1977 - February 28, 1978<br />
https://www.osti.gov/biblio/6566131<br />
(accessed September 2020)
JRC assessment
- Sources categories
- Zalosh
