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 step was added to the laboratory procedure in which all catalyst waste is thoroughly dampened with water and sealed in a plastic bag before being placed into a waste container.

Safe work procedures will be prepared and followed. Hydrogen will be vented out of the system to create an inert atmosphere before working on system tubing and joints. The importance of purging hydrogen piping and equipment is discussed in the…

1. All samples with potential for hydrogen buildup should be limited to ground shipment only. (This shipment was by ground and air. If this incident were to have happened in an airplane, the consequences may have been worse.)

2. All…

1. Maintenance work scopes must be adhered to. If added work is approved, it must be tracked and reviewed to ensure that the equipment is inspected by operations personnel. Scheduled work and extra work should be listed and checked off for…

The following recommended actions were identified:

1. Reemphasize the current lab management policies and practices on how process changes are evaluated for direct/indirect impacts on the process.
2. Reinforce with lab workers…

1. Defects in equipment, such as welds, may not be evident during initial proof testing and operation.
2. When an equipment defect is found, check equipment for possible similar defects in other areas of the equipment.

Manuals showing the correct connecting and disconnecting procedures were established for each fueling dispenser. Separate manuals were needed since the shape of the grip differs from dispenser to dispenser.

The packing in the flow control valve should be replaced periodically. A planned investigation will determine the optimum time period for packing replacement.

1. Ensure that equipment and materials exposed to hydrogen are compatible with a hydrogen environment (even hydrogen-service-rated equipment).

2. Equipment designs in a hydrogen environment that use the fracture toughness for 17-4…

Mechanical pressure gauges tend to be imprecise if only used in a narrow portion of the full scale. Digital transducers, although slightly more expensive, offer much more precision. The event happened because the set pressure was only 10% of full…

Corrective actions included replacing the breakaway with a new one, which restored normal operation of the dispenser.

Verify and periodically inspect the pull/separation force adjustment if the breakaway is so equipped.

Additional…

A gas detector was added in close proximity to the compressor shaft and a vibration switch is under consideration. Additional predictive measures are being considered to predict bearing failure. In addition, the manufacturer has been contacted…

Included inspection on monthly preventive maintenance plan and evaluated alternate materials for better cold-weather performance.

The fitting was an SAE straight thread and was likely loosened by torque applied to the fueling hose. After the incident, these fittings had additional means applied to restrict loosening, a cover installed to deflect any leakage, and means taken…

The following corrective actions have been taken:

• The non-return valve was dismantled, cleaned, and tested. Following positive testing, the system was restarted and pressurized without any further malfunctioning.
• The…

The possible outcomes from new maintenance scenarios can be predicted by using an accurate simulation. The proposed filter change-out maintenance was studied to identify conditions to which the catalyst might be exposed and a mock-up of the…

1. Hydrogen safety training should be provided to local emergency responders.
2. Liquid hydrogen installations should be inspected by facility personnel on a frequent basis, consistent with NFPA 55, to verify proper operation and…