Kayan:
You're right. Hydrogen, like any other fuel, should be a safety concern. However, I don't know what "mitigation" measure you are talking about putting in place and I also don't know what state of Hydrogen you are working with. Liquid Hydrogen is a common, ordinary bulk commodity supplied all across the USA by such companies as Air Liquide, Air Products, Praxair, etc. This liquified product is normally vaporized at the use site employing ambient vaporizers. Smaller consumption capacities are delivered as high pressure gas in tube trailers and cascaded down from a conventional pressure of 3,500 psig to consumption pressures. Which system are you talking about?
I also don't understand your classification of the safety issue as hinging on the size of the storage facility. Gaseous H2 will burn with the same temperature and flame size depending only on the type & size of excape that it finds from the storage system - regardless of the size of the storage system itself. Could you please specifically explain what you conceive to be your safety problem?
Are you concerned with an explosion, rather than a fire involving hydrogen?