Explosion at the off-Gas of a Nuclear Power Plant
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 Date
September 17, 1999
Record Quality Indicator
Region / Country
Event Initiating System
Classification of the Physical Effects
Nature of the Consequences
Causes
Cause Comments
Immediate and root causes are unknown. The site operations review of the plant performed an investigation, but its report is not publicly available.
Facility Information
Application Type
Application
Specific Application Supply Chain Stage
Components Involved
off gas system, secondary containment, nuclear power plant
Storage/Process Medium
Location Type
Location description
Countryside, Near Inhabited Area
Operational Condition
Pre-event Summary
The power plant was of the boiling water reactor type. At the moment of the incident it was operating for 271 consecutive days.
Consequences
Number of Injured Persons
2
Currency
Lessons Learned
Lessons Learned
In absence of he root cause investigation it is impossible to deduce specific and generic lessons.
Event Nature
Emergency Action
The plant was shut down and placed in MODE 4 to comply with technical specifications of the plant.
Detonation
No
Deflagration
No
High Pressure Explosion
No
High Voltage Explosion
No
Source Category
References
References
U.S. Nuclear Regulatory Commission, Weekly Information Report - Week Ending September 24, 1999, SECY-99-239,
http://www.nrc.gov/reading-rm/doc-collections/commission/secys/1999/
(accessed December 2020)