The information in this document provides answers to the questions that were raised during the Center for Hydrogen Safety September 4, 2023 webinar.

The three-year HyTunnel CS project culminated in the report titled Deliverable D6.9, “Recommendations for inherently safer use of hydrogen vehicles in underground traffic systems.” The HyTunnel CS project aimed to perform pre-normative research for the safety of hydrogen-fueled vehicles traveling through tunnels or entering confined spaces. The main objective was to compare the relative risk of hydrogen vehicles entering underground traffic systems to existing fossil fuel-powered vehicles [1].

Sodium chloride and four or five other particulate materials have been used successfully as fire suppression agents for specific combustible metal fires. The certification testing and National Fire Protection Association recommendations for using these suppression agents are summarized here. The sodium chloride based agent and ordinary sand have also been used in some sodium hydride fires, and in a sodium hydride fire test series.

The information in this document provides answers to the questions that were raised during the Center for Hydrogen Safety February 7, 2023 webinar.

The information in this document provides answers to the questions that were raised during the Center for Hydrogen Safety April 27, 2023 webinar. The Q&As are sorted by topic with the question number for reference. The Q&As are sorted by topic with the question number for reference. Redundant questions were deleted from the original list.

This document and its companion document, Safety Standard for Oxygen and Oxygen Systems (NSS1740.151996),are identified as Tier 2 Standards and Technical Requirements in the NASA Safety and Documentation Tree (NHB 1700.1 1993). The information presented is intended as a reference to hydrogen design and practice and not as an authorizing document. The words "shall" and "must" are used in this document to indicate a mandatory requirement, and the authority for the requirement is given.

Several codes require excess flow valves in pipelines so that in the case of line rupture, the flow will be shut off.   In theory, this is a good idea, however, in practicality, it has many limitations.  The sizing and practical uses make the sizing difficult if sometimes impossible, depending on the design parameters.   

Summary report of the Clean Hydrogen Joint Undertaking Expert Workshop on the Environmental Impacts of Hydrogen

Owner/operators of chemical processing and petroleum refining sites often ask whether unconfined hydrogen vapor cloud explosions (VCEs) can actually occur. This question normally arises during the course of a consequence-based facility siting study (FSS) or a quantitative risk assessment (QRA). While it is generally recognized that a hydrogen release within a process enclosure could lead to an explosion, the potential for an external hydrogen release to cause a VCE is not as widely recognized and is often questioned.

Hydrogen is a key energy carrier for modern society. The breaking of the hydrogen bonds within traditional hydrocarbon molecules has been the primary mode of energy utilization since the industrial revolution. An increased focus on “net-zero” greenhouse gas emissions, specifically carbon dioxide and methane, has resulted in a global push for lower carbon energy vectors, including pure hydrogen.