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.

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…

1. Test safety system components even if they are new.
2. Do not rely on listening for valve movement as confirmation that a valve is closing; measure downstream pressure to determine if the valve is really sealing properly.
3. …

Recommended Actions:

• The recommended safe storage time for AHF is two years. Contact the vendor for pick up and disposal for cylinders more than two years old. (Unused gas should also be returned, even if it has been less than two…

In any event, the lesson that should be derived from this incident is the fact that the explosion could have been avoided either by using an inert gas instead of air across the diaphragm, or by monitoring the hydrogen concentration in the upper…

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,…

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…

Proper installation of check valves and other equipment should be visually inspected prior to pressurization.

Maintenance on the low-pressure venting system was not occurring at regular intervals. Ventilation integrity is now checked before starting an experiment.

1. Increased structural protection is needed at the back of a hydrogen tube trailer to protect the vulnerable hydrogen systems components in this location (valves, pressure-indicating devices, manifolds, piping) in case of an accident. Side…