No ignitions sources (smoking, open fire, mobile phones forbidden)
Roof above dispenser should be avoided or designed so that released gas can not accumulate
Grounding of car and refuelling hose, person refuelling at same electrical potential
Layout – Safety distances – Area limitations – Fire walls/protection
The high pressure is a significant challenge related to localisation in densely populated areas, where large safety distances may be impossible to achieve. Location in such areas should therefore imply strict requirements to quality, inspection and protection of refuelling stations against impact that may lead to leaks. Also sabotage should be taken into consideration.
Walls/fences around the units may lead to reduced safety distances requirements if they are designed so that flammable concentrations will not reach outside these fences. In design of such fences the following should be considered:
Flow pattern, wake effects, increased probability of gas accumulation
Larger probability of explosion or larger explosion pressure in case of ignition due to increased confinement
Probability of flying debris in case of explosion Splint proof window panes
For all filling station concepts scenarios representing significant hazards and significant risk were identified. These scenarios need to be analysed in more detail to obtain a more accurate estimate of the actual risks. Common for all concepts are releases of hydrogen from high pressures leading to large hazard distances, and hydrogen releases in confined areas leading to risk of explosions. This is a challenge, especially in densely populated and crowded areas. Risk reducing measures are suggested and should be taken into consideration in the development of standards. Due to lack of experience and specific data, there is clearly a need for further research related to hydrogen hazards and development of safe systems.
The European Integrated Hydrogen Project, Phase 2, web site: www.eihp.org Contract: ENK6-CT2000-00442
Methodology for Rapid Risk Ranking for Hydrogen Refuelling Station Concepts rev.0, Norsk Hydro ASA and DNV for WP5.2 European Integrated Hydrogen Project
[EIHP2] Contract: ENK6-CT2000-00442.
G.P. Haugom, H. Rikheim, S. Nilsen: “Hydrogen applications – Risk acceptance criteria and risk assessment methodology”, to be presented at 1 European Hydrogen Energy Conference 2003.
ECTOS project: http://www.islensk-nyorka.is/