During an inspection, three potential safety problems were identified concerning the location of a hydrogen storage facility. The hydrogen storage facility is located on a building's roof, which is made of 30-inch-thick reinforced concrete. The following potential safety problems were identified during the inspection:

Leakage of hydrogen gas from the storage facility in proximity to the air intakes of the building's ventilation system may introduce a flammable or explosive gas mixture into the enclosure. Because the hydrogen storage facility, containing four 8,000-scf hydrogen tanks at up to 2,450 psig, is Seismic Category II, a seismic event may result in a hydrogen leak. Furthermore, the pressure relief valves in the hydrogen facility exhaust downward to within 6 inches of the roof in the vicinity of the ventilation system air intakes. It was also noted that six 8,000-scf nitrogen tanks were located in the vicinity of the building's air intakes. Nitrogen leakage and dispersion into the air intakes may lead to incapacitation of the occupants.
A detonation of a hydrogen storage tank may structurally damage and affect performance of safety-related equipment on the building's roof, such as the ventilation system intake and exhaust structure, the emergency pressurization system, and equipment in the building itself.
An explosion of the hydrogen delivery truck that provides hydrogen to the facility through a fill line located at ground level on the wall of the auxiliary building may structurally damage safety-related component cooling water pumps located inside the auxiliary building and in the vicinity of the hydrogen fill line.