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.
Utilize a Six Sigma Black Belt to statistically evaluate LFL monitor reliability and determine the failure rate based on the existing technology.
Revise the tank uncertainty calculation and surveillance to include a wider "Required…
Frequently inspect and maintain all elements of hydrogen-related systems.
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…
The hydrogen facility does not meet industrial guidelines for facilities of this type, from the standpoint of (1) the separation distance needed between a hydrogen pipe break and the building ventilation intake to prevent buildup of a flammable…
The lessons of this event fall into five categories: (1) proper in-plant communications during events, (2) proper valve application for use with hydrogen, (3) excess flow check valve set point, (4) heating and ventilation and air conditioning (…
Standard procedures must be followed at all times. The importance of doing so should be frequently reinforced through safety communications to all staff.
Proper bolt identification can prevent similar occurrences in the future. This can be achieved by simply painting the critical bolt heads a certain color (or by purchasing bolts with painted bolt heads). An explanation form should then be clearly…
Lessons Learned
Construction errors are difficult to detect once construction is complete. It is important to develop and use a systematic oversight process for minimizing construction errors during the construction process.
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Investigation determined that internal galling has caused the failure rendering the needle valve unusable. The galling was caused by a stainless steel stem acting against a stainless steel seat. This failure mode had been observed before and the…
For the use of mechanical fittings in hydrogen service, administrative controls should be in place, as in this case, to ensure that leak testing is conducted on a regular basis. It should never be assumed that every fitting is tight. Additional…
The combination of the cold water temperature (reducing the fatigue strength of the bolt), and the abnormally high number of cyclical stresses imposed by the imbalance from the hydraulic system check valve failure resulted in the failure of the…
Maintenance on the low-pressure venting system was not occurring at regular intervals. Ventilation integrity is now checked before starting an experiment.
Excessive venting of hydrogen from the tank due to lower facility consumption, in combination with extreme temperature conditions, placed thermal stress on the gland nut, causing a leak. The low consumption of hydrogen resulted from the shutdown…
Disable the fueling process if the operator does not follow the proper sequence of steps in the fueling procedure. Improve the fueling procedure to make it inherently impossible for the sequence to be done improperly with the same result.
A tool is provided for removing the cylinder cap that cannot contact the valve.
Several best practices resulted from this incident and will be implemented if similar circumstances present themselves in the future.
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.
Process changes have been implemented for development and review of safety basis documents that focus on a collaborative effort between the preparer and reviewers in order to provide a more in-depth review. This change is anticipated to provide…
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