Severity
Non-Event
Leak
No
Ignition
No

Facility management confirmed that a hydrogen gas cylinder did not comply with the limiting condition for operation (LCO) for flammable gas control systems in the lab's safety requirements. Earlier erroneous calculations had shown that a release of the entire contents of the cylinder into the hood could not reach the lower flammability limit (LFL).

The facility manager determined that the LCO was applicable and immediately entered the action statement in the safety system, which required immediate termination of normal operations in the affected wing of the building. Because normal operations had already been terminated in the wing for HVAC maintenance, further efforts to terminate normal operations were not necessary. The hydrogen cylinder was removed from the hood, thus removing the out-of-specification condition and rendering the LCO not applicable. Removal of out-of-specification conditions is a valid action, regardless of whether it is specifically stated in the LCO. Following removal of the hydrogen cylinder, the facility exited the LCO.

The hydrogen cylinder was only a hazard inside the limited volume of the hood. The cylinder was removed from the hood and secured in the laboratory. All laboratory spaces in the facility were walked down to verify that there were no other flammable gas cylinders that had been improperly excluded from the requirements for a flammable gas control system. No other problems were found.

In the future, a policy will require verification of calculations performed for the hazard control plans by an independent engineer and will be included with the hazard control plan when it is submitted for approval. In order to clear up interpretation issues surrounding the safety policies and the use of a gas detection/shut off control system, the LCO will be simplified to require that any flammable gas source that could exceed the LFL in its respective volume be removed or replaced within an hour of discovery.

Incident Date
Aug 30, 2000
Setting
Equipment
  • Hydrogen Storage Equipment
  • Gas cylinder
Damage and Injuries
When Incident Discovered
Lessons Learned

A flammable gas explosion is an analyzed hazard and gas detection/shut off is a safety significant control system that requires a limiting condition for operation (LCO). The rigor of the evaluation of flammable gas systems was inadequate. There was no independent calculation for the hydrogen cylinder and there was no report to document the findings of the evaluation. As a result, incorrect assumptions were made about the acceptability of the hydrogen cylinder. Calculations, independently verified by an engineer, must be included for processes involving a flammable gas and must accompany the hazard control plan for approval.

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