System Resilience of a Liquid Hydrogen Terminal During Loading and Unloading Operations

Hydrogen technologies are playing an increasing role in transportation and industry. Key for taking maximum advantage out of the great gravimetric energy density of hydrogen are feasible and safe storage and transfer concepts. For the successful implementation of a hydrogen-based society with several green industrial initiatives, it is indispensable to develop an infrastructure of liquid hydrogen (LH2) terminals and tanker ships with the capability to bunker LH2. Liquid hydrogen might be used to store and transport large quantities of hydrogen. LH2 is a cryogenic fluid, so double-walled vacuum insulated tanks are required to keep it cold for long periods of time until further distribution or use. Whether transportation sector or industry, to date there is little knowledge on safety related issues available. Main concern when handling hydrogen are accidental releases that can lead to integrity damage on materials and structures, fires, and explosions. Assuming that LH₂ infrastructures will be widely deployed and in use all over the globe, accidents are possible to occur during loading and unloading of LH2 bunkering facilities. Therefore, it is necessary to conduct a detailed risk assessment that focuses on system resilience to improve the capabilities of the facility to keep its functionality up when errors occur. This study refers to the LH2 storage tank installed in the LH2 terminal in Kobe, Japan. This stationary storage tank is an essential element of the terminal that was constructed by the Hydrogen Energy Supply Chain Technology Research Association (HySTRA). HySTRA aims at the distribution of hydrogen in liquified form by ship from Australia to Japan. To date, there is only little data available regarding the facility in Kobe. Nevertheless, due to the novelty of the technology the risk for accidents to occur might be higher than in conventional fuel distribution terminals. Accidents might happen due to technical failures, human errors, or external causes such as natural events. The consequences could be catastrophic. Some of these may expose structures and personnel to extreme low temperatures, fires, and explosions which may hinder bunkering operations of the facility in Kobe. This study gives an overview on possible scenarios that lead to loss of containment and provides an insight in the process of evaluating system resilience during such a scenario. This work details with a framework for assessing system resilience applied to LH2 storage facilities. The system resilience calculation involves the examination of a critical hydrogen accident database and provides suitable preventive and mitigative safety barriers.