A hydrogen cylinder was initially located in an adjacent laboratory, with tubing going through the wall into the laboratory in use. When the cylinder was moved to the laboratory in use, a required leak check was not performed. Unfortunately, a leak had developed that was sufficient to cause an accumulation of hydrogen to a level above the Lower Flammability Limit. The hydrogen ignited when a computer power plug was pulled from an outlet. The exact configuration of the leak location and the outlet plug is unknown.

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.

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.

An employee noticed an unusual smell in a fuel cell laboratory. A shunt inside experimental equipment overheated and caused insulation on conductors to burn. Flames were approximately one inch high and very localized. The employee de-energized equipment and blew out the flames. No combustible material was in the vicinity of the experiment. The fire was contained within the fuel cell and resulted in no damage to equipment.

An apprentice mechanic lacerated his right forearm while quickly sliding out from under a hydrogen prototype bus when the bus slipped off a hydraulic jack. The apprentice and another mechanic had raised the bus about 1 foot from the ground to position it on jack stands when the hydraulic jack tipped over. The apprentice went to the site medical facility, where he needed five stitches to close the wound in his forearm.

A brazing retort in a shop malfunctioned and resulted in an explosion that propelled the retort shell to the roof of the brazing area and then back to the floor. There were no injuries but damage was sustained by the furnace housing and the retort shell.

Administrative personnel were soon on the scene to make a preliminary assessment of the situation. An expert safety team was retained to assist in the investigation of the explosion. The safety team conducted their initial field investigation on the afternoon of the explosion and again on the following day.

A process area alarm activated. The alarm was caused by an instrument channel located above a reaction vessel off-gas system final HEPA filter canister, which indicated 25% of the lower explosive limit (LEL) for hydrogen. Since the only source of hydrogen is from the reaction vessel during the reaction of sodium with concentrated sodium hydroxide, the immediate actions were to shutdown the reaction process and place the facility in a safe condition.

An unplanned shutdown of the hydrogen supply system occurred, affecting the hydrogen furnaces in the plant. The apparent cause was an inadvertent valve closing, which was contrary to the written procedure.

A small hydrogen fire occurred in a chemical process hood. A chemist was performing an experiment reacting manganese dioxide with hydrogen to produce manganese oxide and water. The chemist had left the process, which would take approximately one hour to complete, and was working in a nearby lab. While the chemist was gone, a second worker heard a pop, saw the hydrogen fire in the hood, and requested the activation of a fire alarm. A third employee in the area activated a manual fire alarm.

Facility management confirmed that a hydrogen gas cylinder did not comply with the limiting condition for operation (LCO) for flammable gas control systems in the lab's safety requirements. Earlier erroneous calculations had shown that a release of the entire contents of the cylinder into the hood could not reach the lower flammability limit (LFL).