CHECK OUT OUR MOST RELEVANT INCIDENT LISTINGS!
Disclaimer: The Lessons Learned Database includes the incidents that were voluntarily submitted. The database is not a comprehensive source for all incidents that have occurred.
Several procedural and design changes should be considered for the future:
Replace the use of pure hydrogen with a 95:5 mixture of nitrogen and hydrogen to reduce the possibility of an explosive atmosphere occurring. Laboratory personnel…
The turbine components that caused the vibrations were a retrofit design which had been in service for about two years and were under warranty from the vendor. The root cause analysis of the event determined that the damage was caused by a defect…
All installed and certified safety and emergency systems functioned as designed.1. The fuel cell turned off immediately after fire detection.2. The fire suppression system was immediately initiated thereafter.3. The physical separation of the…
Place signs on all liquid hydrogen tanks indicating that no water is to be put on the vent stack.
An additional secondary backup vent stack was added to liquid hydrogen tanks. This secondary stack is designed to be used only if needed in…
A new best practice resulted resulted from this incident. It states that before any work is started, a third party should verify with a visual inspection that the actual equipment to be used matches the planned equipment list/protocol.
Several best practices resulted from this incident and will be implemented if similar circumstances present themselves in the future.
Close bay door.
Keep within proximity of bay.
Be aware of other bays operating with open…
A tool is provided for removing the cylinder cap that cannot contact the valve.
Many accidents reported from paper mills have much in common with this incident. Microorganisms in the process water with pulp produce hydrogen gas that mixes with air to form an explosive atmosphere. The ignition source is typically sparks…
Mounting hardware incorporated polymeric braces not suitable for long-term exposure to sunlight and temperature extremes. With time, the polymeric materials had disintegrated, allowing the mounting brackets to become loose. In addition, the…
To prevent a similar flashback, the following measures have been taken:
The valve is opened slowly to avoid a major leading shock into the venting line.
A special nozzle (Laval or similar) is mounted directly after the opening…
1. The trailer involved in the incident used a frangible burst disk based upon the proprietary metal compound designated as Inconel #600. Random sampling of similar pressure relief devices from the same trailer showed that all of them failed at…
LESSONS LEARNED:
Compressed gas cylinder caps can be very difficult to open as rust often occurs in the threads.
There are wrenches specifically designed to remove compressed gas cylinder caps. The lab had such a wrench and it was…
1. Increase physical protection, shielding, and securing of transported hydrogen tube valves, piping, and fittings from multi-directional forces that are likely to occur during accidents, including rollovers. Reference: 49 Code of Federal…
Upgrade the liquid hydrogen pump control system to shut down operation of the pump and protect the system when malfunctions like leaks, pump cavitation, or loss of purge gas occur.
Verify that maintenance procedures used for liquid…
It is important to understand the requirements and standards associated with safe equipment design (especially electrical equipment containing an internal ignition source with flammable gas) in potentially explosive atmosphere environments.…
1. Management must ensure that operating decisions are not based primarily on cost and production. Performance goals and operating risks must be effectively communicated to all employees. Facility management must set safe, achievable operating…
Redundant safety systems prevented this event from becoming an incident. The 1%-hydrogen-concentration-level-triggered fan was backed up by a 2%-hydrogen-concentration alarm. The alarm is continuously monitored (24/7) by a remote Network…
The SS 24-inch pipe that failed was replaced with 1-1/4 Cr 1/2 Mo alloy pipe that is corrosion-resistant to SCC. A revised HTS bypass piping layout was installed to prevent the hazardous conditions that lead to the failure. A detailed hazard…
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.…
Key:
- = No Ignition
- = Explosion
- = Fire
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 |
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 | |||||||
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