Publications

Risk associated with the use of barriers in hydrogen refueling stations

Houf, William G.; Phillips, Jesse P.

Separation distances are used in hydrogen refueling stations to protect people, structures, and equipment from the consequences of accidental hydrogen releases. Specifically, hydrogen jet flames resulting from ignition of unintended releases can be extensive in length and pose significant radiation and impingement hazards. Depending on the leak diameter and source pressure, the resulting separation distances can be unacceptably large. One possible mitigation strategy to reduce exposure to hydrogen flames is to incorporate barriers around hydrogen storage, process piping, and delivery equipment. The effectiveness of barrier walls to reduce hazards at hydrogen facilities has been previously evaluated using experimental and modeling information developed at Sandia National Laboratories. The effect of barriers on the risk from different types of hazards including direct flame contact, radiation heat fluxes, and overpressures associated with delayed hydrogen ignition has subsequently been evaluated and used to identify potential reductions in separation distances in hydrogen facilities. Both the frequency and consequences used in this risk assessment and the risk results are described. The results of the barrier risk analysis can also be used to help establish risk-informed barrier design requirements for use in hydrogen codes and standards.