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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The uncontrolled release of hydrogen occurred as a result of the rupture of the No. 6 hydrogen storage tube’s burst disc. This disc failed in response to being overloaded by mechanical stresses developed as water expanded and formed ice while in…

Although a functional fire protection system would have helped to extinguish the fire, a properly installed hydrogen detection system, coupled with a properly designed ventilation system, could have prevented the incident altogether.

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Routine maintenance activities on pressurized hydrogen systems should be conducted per written design specifications. The procedures should provide detailed oversight regarding bolt, nut and fitting replacements or repairs. A formal review…

This incident emphasizes the need for proper gas detection and ventilation systems, as well as fire suppression systems, in laboratories using and storing hydrogen. This is especially true when open flame burners are in close proximity.…

Hazards should be eliminated to the extent possible rather than depending on workers to follow an operations manual.

Potassium carbonate draw-off operations should be improved, and the operations manual should be revised. The manual…

Fail-safe position of control valves in supply lines must be set correctly to prevent damage to pressure vessels.

Recommendation

Set all valves for fail safe operation (open or closed) according to needs before installation…

1. The dilution water for making a polythionic acid aqueous solution was changed from industrial water to pure water to lower the chlorine concentration in the piping.
2. Water that accumulated in the drain was removed before heating…

1. The plant tried to increase production and decrease workload, but failed to notice the potential negative outcomes of this change.
2. It is necessary to thoroughly simulate all potential negative outcomes of a change in procedures…

• Operation and management of the hydrodesulfurization unit should be strengthened to account for abnormal phenomena such as local corrosion.
• The safety review system for remodeling existing equipment and facilities should be…

• Verify that all PRDs contain fuse-backed adapters.
• Explore elimination of rupture disk PRDs and substitution of spring-style relief valves.
• Develop new hydrogen unloading procedure using a written checklist. * Add…

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…

Failure of a diaphragm is not infrequent, but the seizure of the main nut threads is very rare. The manufacturer claimed this had never occurred before with this type of unit. The broken plunger is likely the result of poor instructions/…

The visiting intern had several years of experience in research projects and tasks that were similar to those in progress at this laboratory. This led to the incorrect assumption that formal introductory training for this laboratory was…

After the aforementioned incident, a rigid cage was designed to protect the reactor from external conditions, and to protect the contents of the hood and any experimenter from the reactor, in the event of a pressure burst from the reactor cell.…

High-pressure fueling hoses should be examined daily for signs of external damage, including corrosion, abrasion, cuts, and kinking. High-use fueling hoses should be replaced every six months.

1. Revise fire protection operations surveillance tests to include a maximum of 110% of the agent net weight to prevent over-filled cylinders from being placed in service.
2. Identify cylinders currently in service that exceed the 110…

• The fuel cell vehicle that was involved in the accident has been retired. The fuel cell power plant from that vehicle has been removed and is being used in another fuel cell vehicle.
• The fuel cell vehicle accident reinforced the…

An investigation team was formed to determine the cause of this anomaly. The team performed a fault tree analysis which identified the following five main paths or gates: fault in the original weld, age, component not built per design intent,…