Severity
Incident
Was Hydrogen Released?
Yes
Was There Ignition?
No
Incident Date
Sep 30, 2009
Setting
Power Plant
Equipment
  • Cooling Equipment
  • Main Generator Stator Cooling Water System
Damage and Injuries
Plant shutdown for maintenance
Probable Cause
Inadequate System Monitoring/Oversight
Incomplete Operating and Maintenance Procedures
Contributing Factors
Operation Induced Damage
When Incident Was Discovered
During Operations
Lessons Learned

Incorporate external operating experience lessons learned into site program controls. Other nuclear plants had similar strand failures and back-of-core issues that were not evaluated for impact on procedures or system/component health plans.
Be more sensitive to precursor indications of declining system/component health; in this case the main generator. Insensitivity resulted in material condition deficiencies and elevated risks to generation that are undesirable given the economic importance of this high-value asset.
Follow OEM and industry recommendations for component (stator) preparation for testing and lay-up.
Have a detailed component (generator) Life-Cycle Management Plan.

Additional details regarding probable causes and lessons learned can be found in Attachment 2.

Post date
September, 2017

Key:

  • = No Ignition
  • = Explosion
  • = Fire
Hydrogen Incident Summaries by Equipment and Primary Cause/Issue
Equipment / Cause Equipment Design or Selection Component Failure Operational Error Installation or Maintenance Inadequate Gas or Flame Detection Emergency Shutdown Response Other or Unknown
Hydrogen Gas Metal Cylinder or Regulator   3/31/2012
4/30/1995
2/6/2013		 4/26/2010 12/31/1969     3/17/1999
11/1/2001
12/23/2003
Piping/Valves 4/4/2002
2/2/2008
5/11/1999		 4/20/1987
11/4/1997
12/31/1969
8/19/1986
7/27/1991
12/19/2004
2/6/2008
10/3/2008
4/5/2006
5/1/2007
9/19/2007
10/31/1980		 2/7/2009 1/24/1999
2/24/2006
6/8/1998
12/31/1969
2/7/2009

9/1/1992
10/31/1980

 10/3/2008  
Tubing/Fittings/Hose   9/23/1999
8/2/2004
8/6/2008
9/19/2007		 1/1/1982 9/30/2004
10/7/2005		   10/7/2005  
Compressor   10/5/2009
6/10/2007
8/21/2008
1/15/2019		     10/5/2009 8/21/2008  
Liquid Hydrogen Tank or Delivery Truck 4/27/1989 12/19/2004
1/19/2009		 8/6/2004 12/31/1969   1/1/1974 12/17/2004
Pressure Relief Device 7/25/2013
5/4/2012		 1/15/2002
1/08/2007		 12/31/1969        
Instrument 1/15/2019 3/17/1999
12/31/1969
2/6/2013		     11/13/73    
Hydrogen Generation Equipment 7/27/1999     10/23/2001      
Vehicle or Lift Truck   7/21/2011         2/8/2011
12/9/2010
Fuel Dispenser   8/2/2004
5/1/2007
6/11/2007
9/19/2007		   2/24/2006
1/22/2009		      
Fuel Cell Stack            

5/3/2004
12/9/2010
2/8/2011
Hydrogen Cooled Generator       12/31/1969
2/7/2009		      
Other (floor drain, lab
anaerobic chamber,
heated glassware,
test chamber,
gaseous hydrogen
composite cylinder,
delivery truck)		   11/14/1994
7/21/2011		 7/27/1999
6/28/2010
8/21/2008		 12/31/1969
3/22/2018		     6/10/2019
  • = No Ignition
  • = Explosion
  • = Fire