Incident Synopsis
While attempting to replace a rupture disk in a liquid H2 vessel, H2 gas was released and ignited. In fighting the fire, liquid N2 was sprayed onto a second liquid H2 vessel located nearby. This resulted in cracking of the outer mild steel vacuum jacket. The loss of the vacuum caused a rapid increase in pressure and rupture of the burst disk of the second vessel. H2 boiled off and was burned in the fire.

The rupture disk was being replaced with a load of liquid H2 in the vessel and no separating inerting gas. The H2-air mixture was probably ignited by static discharges. Rupture of the second vessel burst disk was caused by the low-temperature exposure of the mild steel vacuum jacket.

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