Installation of a 9000-gallon liquid hydrogen storage tank by a lessee at a building has not been evaluated for effect on the Safety Authorization Basis (SAB) of nearby facilities.

During review of an Emergency Management Hazard Assessment document, a reviewer questioned whether the SAB of nearby facilities had been reviewed for the effect of the installed 9000-gallon liquid hydrogen tank. Reviews by the facility management and facility safety personnel confirmed the evaluations have not been performed.

The direct cause was determined to be a management problem, with policy not adequately defined, disseminated, or enforced to integrate potential lessee hazards into the facility safety program documentation on the 9000-gallon hydrogen tank and delivery. The existing policy view more

A hydrogen gas detector on the ground floor of a building registered the release of a small amount of hydrogen gas and actuated automatic alarms both at the fire department and in one of its buildings. Additionally, interlocks connected to the gas detector completely shut down the experiment. Upon hearing the alarm, all occupants (about 6) promptly left the building. Fire department personnel are housed in the trailer next to a building and responded within one minute. They tested the atmosphere within the building, reset the gas detector, and secured the alarm at 9:15. The alarm was actuated when an experimenter assigned to the experiment was evacuating lines using a vacuum pump.

The speed of evacuation was controlled by a commercially manufactured flow meter. It is believed view more

While refilling the hydrogen system after an outage caused by a power failure, the excess flow valve located at the hydrogen tank tripped, but did not go fully shut.

The large valve is equipped with a small bypass valve so that the valve can be pressurized on both sides as is required before the valve can be reset. The O-ring which makes this small valve gas tight was deformed and improperly seated, thus allowing gas to flow to each side of the large valve. This permitted the valve to trip normally, but not to seat properly. The following is the manufacturer's evaluation after disassembly and inspection of the valve.

This valve was recently installed to provide excess flow protection to the underground portion of the hydrogen system piping and to provide redundant view more

While attempting to light the hydrogen flare inside a Metalorganic Chemical Vapor Deposition (MOCVD) system burn box, a small explosion occurred, blowing the back section of the burn box off. Hydrogen flow was shut down immediately, and this MOCVD operation was suspended. Researchers made the determination that this was a minor incident and there were no injuries.

The follow-up investigation determined that the MOCVD HEPA filter had become sufficiently loaded to the point where performance of the burn box exhaust ventilation system was significantly degraded. The static pressure created across the "loaded" HEPA filter equaled the operating static pressure of the exhaust ventilation system servicing the burn box. This resulted in a region of "dead air" in the view more

While filling a sample cylinder with compressed hydrogen gas, a quick-disconnect coupler fitting came loose within a stainless steel laboratory hood, allowing a small purge of the hydrogen gas to escape directly into the hood through ~1/4-inch Tygon tubing. The stainless steel quick-disconnect fitting struck the stainless steel bottom of the laboratory hood and the hydrogen gas caught fire. It is not known what caused the hydrogen gas to catch fire. The most likely sources of a spark was from metal-to-metal contact of the quick-disconnect fitting with the laboratory hood floor, or the discharge of static electrical charge generated by flow of hydrogen gas through Tygon tubing. The resultant narrow jet of fire, directed toward the left side of the laboratory hood, extinguished itself view more

An individual inadvertently connected a pure hydrogen gas bottle to a chamber/glove box as opposed to a 10% hydrogen (in nitrogen) bottle that should have been used. [The wrong bottle had mistakenly been delivered, and the inexperienced individual did not know the difference.] The hydrogen concentration increased within the chamber to about 9%. Since there was insufficient oxygen in the chamber to support combustion, the hydrogen did not burn, and was quickly diluted with nitrogen.

A laboratory had an incident with an ammonia tank. When the valve was opened, the packing in the valve apparently "moved," and a faint ammonia smell was noticed. The tank was returned to the supplier.

An employee of an incubator company that was working in a university-owned laboratory facility was checking the hydrogen pressure through the main valve on a hydrogen cylinder. The regulator on this cylinder had not been properly closed. Hydrogen escaped through the regulator and was ignited. The fire was contained in the laboratory and extinguished by the building's fire sprinkler system before fire crews arrived. There were no injuries, and damage estimates were not available.

A facility uses small crucibles to heat precious metals within a fume hood, with natural gas as the fuel source for the Bunsen burner. Hydrogen is fed into the crucible at low pressure (<20 psi) to control the atmosphere within the vessel in order to prevent oxidation. The hydrogen is routed through a manifold with flexible tubing, which is connected to a ceramic tip and fitted into the crucible through a small opening in the crucible's lid. The hydrogen is consumed in the process. The facility believes that the hydrogen tubing developed a leak which eventually ignited. The plastic interior of the fume hood ignited and started to spread. The person working in the area shut off the natural gas and hydrogen (they had valves at the hood) and used a halon extinguisher in the view more

A liquid hydrogen tank’s rupture disc failed prematurely, which caused the tank to vent its entire gas contents through the tank’s vent stack. Venting was very loud and formed a condensed moisture cloud visible from the top of the stack. Liquid air was also visible coming off the stack. Venting ceased after approximately 5 minutes. On-site staff called the fire department, which arrived promptly and evacuated the area. Normal operations resumed after the Fire Department was able to determine there were no unsafe conditions.