Personnel should be aware that items requiring special receiving inspections should still be verified/examined by the end user prior to use.

Given that the anaerobic chamber and associated nearby electrical equipment were not designed or…

1. Specific response drills/exercises need to be conducted yearly. In this case, all safety systems worked as they should and outside emergency responders were not needed.
2. Performing other tasks while filling hydrogen tube trailers,…

1. Include the tanks in a regular inspection program. Evaluate their condition and replace if necessary.
2. Fill the tanks only half full with leach material.
3. Keep the material completely submerged in solution.
4. Install a…

• Replace the existing copper and carbon steel hydrogen pipeline with ¾-inch schedule 40 stainless steel.
• Reroute the new hydrogen line in the preferred location.
• Locate new hydrogen shut-off valves in a more convenient…

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…

This incident led to several changes in procedure:

• The purity of any gas bottle connected is double-checked. The practice outlined in the SOP requires confirming the content of the cylinder via the cylinder label prior to…

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

The site needs to implement a good Operational and Readiness Inspection procedure. System inspection deficiencies need to be identified, and (if possible) reviewed by a second party before future tests are conducted. This inspection could include…

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
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.

…

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…

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…

• 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…

Mounting hardware incorporated polymeric braces not suitable for long-term exposure to sunlight and temperature extremes. With time, the polymeric materials had disintegrated, allowing the mounting brackets to become loose. In addition, the…

Consider design review of all adapter fittings.

A hydrogen release of this type is a significant event. The event highlighted a number of procedural contributing factors that will influence the manner in which these fuel cell systems will be serviced in the future. A complicating factor in…

1. Carbon steel Nelson curve methodology cannot be depended on to prevent HTHA equipment failures and cannot be reliably used to predict the occurrence of HTHA equipment damage. Revisions to recommended practices should be considered…

An investigative communication notes that "mechanical integrity programs at refineries repeatedly emphasize inspection strategies rather then the use of inherently safer design to control the damage mechanisms that ultimately cause major process…

Do not interconnect hydrogen drain trap lines with other drain lines

Thoroughly inspect equipment installation to manufacturer’s installation instructions

Warn against unauthorized field modifications

Consult the…