Hydrogen Safety Panel, Safety Knowledge Tools, and First Responder Training Resources 

The aim of the present work is to assess the risk of explosion in closed containments used for the transportation of nuclear materials or nuclear waste. Indeed, it is very well known that hydrogen can be produced due to (i) the radiolysis of different materials within the containment, (ii) the thermal decomposition of mainly the organic part in the containment. Since hydrogen has a very low ignition energy and a very wide flammability domain, it is important to determine the risk of ignition of the subsequent mixture produced by the aforementioned mechanisms.

This Technical Memorandum was originally prepared as an Annex on the topic of Hydrogen Embrittlement for the AIAA Guide to Safety of Hydrogen and Hydrogen Systems (G-095-2004), then in revision [1]. The Guide establishes a uniform NASA process for hydrogen system design, materials selection operation, storage and transportation, and represents a broad collection of aerospace acumen.

In collaboration with Parker Hannifin Corporation, the Fire Safety Branch of the FAA conducted testing to evaluate the effects of three potential failure conditions of hydrogen proton exchange (or polymer electrolyte) membrane fuel cell stacks supplied by Nuvera Fuel Cells. The three conditions examined were a loss of coolant to the stack, short circuit, and a crossflow condition.

VIII.6  Hydrogen Safety Panel, Safety Knowledge Tools and First Responder Training Resources

The Baker-Strehlow-Tang vapor cloud explosion (VCE) blast load prediction methodology utilizes flame speed as a measure of explosion severity. In previous publications, guidance has been presented for selecting flame speeds as a function of congestion, confinement, and fuel reactivity. These recommended values were based on empirical data available from the literature.