LESSONS LEARNED:

1. Compressed gas cylinder caps can be very difficult to open as rust often occurs in the threads.
2. There are wrenches specifically designed to remove…

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…

To prevent a similar flashback, the following measures have been taken:

1. The valve is opened slowly to avoid a major leading shock into the venting line.
2. A special nozzle (Laval or similar) is mounted directly after the…

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…

A tool is provided for removing the cylinder cap that cannot contact the valve.

Consider design review of all adapter fittings.

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…

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.

1. Place signs on all liquid hydrogen tanks indicating that no water is to be put on the vent stack.
2. An additional secondary backup vent stack was added to liquid hydrogen tanks. This secondary stack is designed to be used only if…

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…

Several procedural and design changes should be considered for the future:

1. 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…

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…

Recommendations:

1. The using organization should define necessary activities in order to place hydrogen systems in long-term periods of inactivity. The defined activities should address requirements for rendering inert, isolation (i.…

Although the preparation-for-transport procedures were done the same way they were done for previous outreach programs, this time it proved to be a different situation. It is not clear what caused the ignition of the first balloon, which then set…

Safe storage and transportation of balloons filled with a hydrogen-oxygen mixture is a very risky undertaking. There are few scenarios that do not involve enclosed spaces (e.g., a car) and the potential for static discharge. Perhaps a mesh bag…

• Active GH2 sensors should be installed and continuously monitored in all enclosed buildings near GH2 sources. All buildings near areas where hydrogen is used should be designed to preclude GH2 entrapment (e.g., sloping roof with…

The incident resulted from an inadequate design for the storage location of the copper gas supply tubing (too close to an electrical outlet). The gas supply tubing was too long for its intended purpose and posed a hazard in its coiled state near…

The direct cause of the over-pressurization of the two drums was the repackaging of the phosphoric acid into metal UN1A1 drums and the resultant hydrogen gas generation within the sealed drums. At the time of this incident (1997), 49 CFR and…

The lessons learned from this incident are:

1. Verify the gas that you are using.
2. Avoid using "quick-disconnect" fittings in this type of situation. If they are absolutely needed, there are sets available that ensure that…

• Carefully revise the risk assessment process to evaluate any confined areas where hydrogen is handled.
• Separate the fire and gas detection alarm system from the process information to provide easy and clear identification.…