Event
- Event ID
- 537
- Quality
- Description
- During the startup of the reactor with a new off-gas system, a spark from a closing valve initiated an explosion, caused by the presence of a flammable oxygen-hydrogen mixture.
[Zalosh and Short, 1978] - Event Initiating system
- Classification of the physical effects
- Hydrogen Release and Ignition
- Nature of the consequences
- Macro-region
- North America
- Country
- United States
- Date
- Main component involved?
- Off-Gas System (Pipe)
- How was it involved?
- Internal Explosion (H2-O2 Mixture)
- Initiating cause
- Inadequate Off-Gases Management
- Root causes
- Root CAUSE analysis
- The INITIATING CAUSE was the ignition of a flammable hydrogen-oxygen mixture in the off-gas system.
The use of a non-explosion proof valve provided the energy required for the ignition. However, the most effective preventive measure to avoid this type of mishaps would be to avoid the presence of both radiolitic gases in concentration exceeding the lower or higher flammability limits of the mixture.
Therefore, the ROOT CAUSE may be probably related to a shortcoming of the design. Considering that the affected system was a new off-gas system, inadequate procedures in the execution some operative step cannot be excluded.
Facility
- Application
- Power Plant
- Sub-application
- Nuclear power plant - BWR
- Hydrogen supply chain stage
- Location type
- Confined
- Location description
- Unknown
- Operational condition
Emergency & Consequences
- Number of injured persons
- 0
- Number of fatalities
- 0
- Currency
- US$
- Property loss (onsite)
- 0
Event Nature
- Release type
- gas mixture
- Involved substances (% vol)
- H2,
O2 - Ignition delay
- Mechanical sparks
References
- Reference & weblink
Table II - Industrial Incidetns 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
