Failure of a Heat Exchanger at a Nuclear Power Plant
Piping breakage at atomic power plant- Steam piping (inside diameter: 15 cm; thickness: 1.1 cm) of a heat exchanger for removing residual heat from a reactor was broken during the test of a high pressure core injection system for cooling water provided for an emergency core cooling system at a boiling-water light water reactor with an output of 0.54 million kW, thus resulting in leakage of radioactivity-containing gases. The part of the piping that was located on the 2nd floor of the building as broken but there were no workers there. However, there were 36 workers in the radioactivity control area inside the building. A heat insulating material was wrapped round the piping and was not covered by periodical inspections. Nuclear safety and security workers reported that the part of the piping was turned up from inside and completely broken. From the broken surface, a hydrogen gas tapped remaining in the piping apparently got ignited spontaneously by the catalyst action of platinum particles in the system, thus resulting in an explosion.
Event Date
November 7, 2001
Record Quality Indicator
Region / Country
Event Initiating System
Classification of the Physical Effects
Nature of the Consequences
Facility Information
Application Type
Application
Specific Application Supply Chain Stage
Components Involved
steam piping, heat exchanger
Location Type
Location description
Industrial Area
Pre-event Summary
.
Consequences
Number of Injured Persons
4
Lessons Learned
Lessons Learned
Unknown
Event Nature
Emergency Action
Unknown
Detonation
No
Deflagration
No
High Pressure Explosion
No
High Voltage Explosion
No
Source Category