Explosion on hydrogen dryers at a nuclear power plant

Event

Event ID: 503
Quality: 3
Description: The incident occurred at the hydrogen coolant system of the power generator. The control panel door for the 32 hydrogen dryer blew off due to a small hydrogen explosion. No one was injured in the event, which occurred in the non-nuclear side of the plant in the main turbine building. Plant operations was not impacted by the explosion, and the licensee intends to replace both hydrogen dryer units.

Source: U.S. Nuclear Regulatory Commission, One White Flint North, Rockville, Maryland, Tuesday, June 25, 1996, http://www.nrc.gov/reading-rm/doc-collections/commission/tr/1996/
Event Initiating system: Hydrogen System Initiating Event
Classification of the physical effects: Hydrogen Release and Ignition
Nature of the consequences: Explosion
Macro-region: North America
Country: United States
Date: 06/06/1996
Main component involved?: Hydrogen Dryers
How was it involved?: Internal Explosion (H2-Air Mixture)
Initiating cause: Unknown
Root causes: Unknown (No additional details provided)

Application: Power Plant
Sub-application: Nuclear power plant
Hydrogen supply chain stage: Hydrogen Production
All components affected: hydrogen dryers, non-nuclear area
Location type: Unknown
Location description: Industrial Area
Operational condition: Normal
Description of the facility/unit/process/substances: DESCRIPTION OF THE COMPONENT
The hydrogen dryers are part of the hydrogen loop providing the coolant to the generator of the turbine-generator system. Their purpose is to maintain the purity and dryness of the hydrogen gas which serves as the cooling medium for the large turbine generators, not the reactor itself. They prevent moisture-related damage and improve the generator's efficiency and safety.

Reference & weblink: U.S. Nuclear Regulatory Commission, briefing on operating reactors, 25 <br />
http://www.nrc.gov/reading-rm/doc-collections/commission/tr/1996/<br />
(accessed aug 2023)