Event
- Event ID
- 509
- Quality
- Description
- An hydrogen explosion occurred within the off-gas system, causing the stop of the sump pump; subsequently both trains of the standby gas treatment system were declared inoperable.
The sump is part of the off-gas system and the secondary containment.
The hydrogen explosion was contained within the system, but the sump pump sustained some damage. - Event Initiating system
- Classification of the physical effects
- Hydrogen Release and Ignition
- Nature of the consequences
- Macro-region
- North America
- Country
- United States
- Date
- Root causes
- Unknown (No additional details provided)
- Root CAUSE analysis
- INITIATING and ROOT CAUSE are unknown.
The site operations review of the plant performed an investigation, but its report is not publicly available.
Facility
- Application
- Power Plant
- Sub-application
- Nuclear power plant
- Hydrogen supply chain stage
- All components affected
- offgas system, secondary containment, nuclear power plant
- Location type
- Unknown
- Operational condition
- Pre-event occurrences
- At the moment of the incident it was operating for 271 consecutive days.
- Description of the facility/unit/process/substances
- The power plant was of the boiling water reactor type.
Emergency & Consequences
- Number of injured persons
- 0
- Number of fatalities
- 0
- Post-event summary
- The sump sustained some damage but could be repaired.
Lesson Learnt
- Lesson Learnt
In absence of he root cause investigation it is impossible to deduce specific and generic lessons.
Event Nature
- Release type
- gas
- Involved substances (% vol)
- H2 100%
- Presumed ignition source
- Not reported
References
- Reference & weblink
U.S. Nuclear Regulatory Commission, Weekly Information Report - Week Ending September 24, 1999, SECY-99-239, <br />
http://www.nrc.gov/reading-rm/doc-collections/commission/secys/1999/ <br />
(accessed December 2020)
JRC assessment
- Sources categories
- NRC
