• When truck drivers are carrying new trailers, with new load distribution characteristics, they need to exercise caution, especially on hazardous roadways such as the one described in this occurrence. If the trailer stack would have been…

• All tank trailers should have a safely accessible auxiliary shut off valve in case of spills.
• Emergency personnel need to have access to all of the appropriate protective clothing, including shoes. Liquid hydrogen is stored at 20…

Standard procedure must be followed in all cases. Assumptions are made at great risk. Risk also increases with complacency.

Standard procedures must be followed at all times. The importance of doing so should be frequently reinforced through safety communications to all staff.

The use of inerting gas or other means of separation should be employed when conducting mechanical work where hydrogen gas could be present. More importantly, per CGA S1.3, the vessel should be equipped with a dual relief system that can isolate…

Extra caution should be taken working around elevated pressure or low-temperature fluids and storage. Values should be checked and then verified by a second party, if possible.

• Facilities housing battery charging systems need to ensure the ventilation systems are operational, and delivering enough outdoor air to properly ventilate the enclosure.
• Operators need to be aware of safe practices and proper…

Normally hydrogen fires are not extinguished until the supply of hydrogen has been shut off due to the danger of re-ignition and explosion. During a gas leak/fire, it is important to shut off the source of the hydrogen if it is safe to do so. If…

Lessons Learned The site initiated the establishment of a field patrol and strengthened their onsite monitoring of mechanical equipment during a plant-wide temperature rise.

• Quantitative control of tightening torque on bolts…

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.

…

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…

Work pre-planning is essential whenever maintenance or work activities may have an adverse impact on everyday operations. When there are changes to the operational status of any critical system, especially a safety critical system, those changes…