United States

Hydrogen sensors are recognized as a critical element in the safety design for any hydrogen system. In this role sensors can perform several important functions including indication of unintended hydrogen releases activation of mitigation strategies to preclude the development of dangerous situations activation of alarm systems and communication to first responders and to initiate system shutdown. The functionality of hydrogen sensors in this capacity is decoupled from the system being monitored thereby providing an independent safety component that is not affected by the system itself. The importance of hydrogen sensors has been recognized by DOE and by the Fuel Cell Technologies Office’s Safety and Codes Standards (SCS) program in particular which has for several years supported hydrogen safety sensor research and development. The SCS hydrogen sensor programs are currently led by the National Renewable Energy Laboratory Los Alamos National Laboratory and Lawrence Livermore National Laboratory. The current SCS sensor program encompasses the full range of issues related to safety sensors including development of advance sensor platforms with exemplary performance development of sensor-related code and standards outreach to stakeholders on the role sensors play in facilitating deployment technology evaluation and support on the proper selection and use of sensors.

The unconfined release of high-pressure hydrogen can create a large flammable jet with the potential to generate significant damage. To properly understand the separation distances necessary to protect the immediate surroundings it is important to accurately assess the potential consequences. In these events the possibility for a detonation cannot be excluded and would generally result in the worst case scenario from the standpoint of damaging overpressure. The strong concentration gradients created by a jet release however raises the question of what portion of the flammable cloud should be considered. Often all of the fuel within the limits of fast-flame acceleration or even all of the fuel within the flammability range is considered which typically comprises the majority of the flammable cloud. In this work prior detonation studies are reviewed to illustrate the inherently unstable nature of detonations with a focus on the critical dimensions and concentration gradients that can support a propagating detonation wave. These criteria are then applied to the flammable cloud concentration distributions generated by an unconfined jet release of hydrogen. By evaluating these limits it is found that the portion of the flammable cloud that is likely to participate is significantly reduced. These results are compared with existing experimental data on the ignition of unconfined hydrogen releases and the peak pressures that were measured are consistent with a detonation of a mass of fuel that is equivalent to the model prediction for the mass of fuel within the detonable limits. This work demonstrates how the critical conditions for detonation propagation can be used to estimate the portion of a hydrogen release that could participates in a detonation and how these criteria can be readily incorporated into existing dispersion modelling approaches.

A key challenge for future clean power or hydrogen projects via gasification is the need to reduce the overall cost while achieving significant levels of CO2 capture. The current state of the art technology for capturing CO2 from sour syngas uses a physical solvent absorption process (acid gas removal–AGR) such as Selexol™ or Rectisol® to selectively separate H2S and CO2 from the H2. These two processes are expensive and require significant utility consumption during operation which only escalates with increasing levels of CO2 capture. Importantly Air Products has developed an alternative option that can achieve a higher level of CO2 capture than the conventional technologies at significantly lower capital and operating costs. Overall the system is expected to reduce the cost of CO2 capture by over 25%.<br/>Air Products developed this novel technology by leveraging years of experience in the design and operation of H2 pressure swing adsorption (PSA) systems in its numerous steam methane reformers. Commercial PSAs typically operate on clean syngas and thus need an upstream AGR unit to operate in a gasification process. Air Products recognized that a H2 PSA technology adapted to handle sour feedgas (Sour PSA) would enable a new and enhanced improvement to a gasification system. The complete Air Products CO2 Capture technology (CCT) for sour syngas consists of a Sour PSA unit followed by a low-BTU sour oxycombustion unit and finally a CO2 purification / compression system.

The Hydrogen Safety Codes and Standards program element of the US Department of Energy's Fuel Cell Technologies Office provides coordination and technical data for the development of domestic and international codes and standards related to hydrogen technologies. The materials compatibility program task at Sandia National Laboratories (Livermore CA) is focused on developing the technical basis for qualifying materials for hydrogen service i.e. accommodating hydrogen embrittlement. This presentation summarizes code development activities for qualifying materials for hydrogen service with emphasis on the scientific basis for the testing methodologies including fracture mechanics based measurements (fracture threshold and fatigue crack growth) total fatigue life measurements and full- scale pressure vessel testing.

The Department of Energy (DOE) Hydrogen Program Plan (the Program Plan or Plan) outlines the strategic high-level focus areas of DOE’s Hydrogen Program (the Program). The term Hydrogen Program refers not to any single office within DOE but rather to the cohesive and coordinated effort of multiple offices that conduct research development and demonstration (RD&D) activities on hydrogen technologies. This terminology and the coordinated efforts on hydrogen among relevant DOE offices have been in place since 2004 and provide an inclusive and strategic view of how the Department coordinates activities on hydrogen across applications and sectors. This version of the Plan updates and expands upon previous versions including the Hydrogen Posture Plan and the DOE Hydrogen and Fuel Cells Program Plan and provides a coordinated high-level summary of hydrogen related activities across DOE.



The 2006 Hydrogen Posture Plan fulfilled the requirement in the Energy Policy Act of 2005 (EPACT 2005) that the Energy Secretary transmit to Congress a coordinated plan for DOE’s hydrogen and fuel cell activities. For historical context the original Posture Plan issued in 2004 outlined a coordinated plan for DOE and the U.S. Department of Transportation to meet the goals of the Hydrogen Fuel Initiative (HFI) and implement the 2002 National Hydrogen Energy Technology Roadmap. The HFI was launched in 2004 to accelerate research development and demonstration (RD&D) of hydrogen and fuel cell technologies for use in transportation electricity generation and portable power applications. The Roadmap provided a blueprint for the public and private efforts required to fulfill a long-term national vision for hydrogen energy as outlined in A National Vision of America’s Transition to a Hydrogen Economy—to 2030 and Beyond. Both the Roadmap and the Vision were developed out of meetings involving DOE industry academia non-profit organizations and other stakeholders. The Roadmap the Vision the Posture Plans the 2011 Program Plan and the results of key stakeholder workshops continue to form the underlying basis for this current edition of the Program Plan.



This edition of the Program Plan reflects the Department’s focus on conducting coordinated RD&D activities to enable the adoption of hydrogen technologies across multiple applications and sectors. It includes content from the various plans and documents developed by individual offices within DOE working on hydrogen-related activities including: the Office of Fossil Energy's Hydrogen Strategy: Enabling a Low Carbon Economy the Office of Energy Efficiency and Renewable Energy’s Hydrogen and Fuel Cell Technologies Office Multi-year RD&D Plan the Office of Nuclear Energy’s Integrated Energy Systems 2020 Roadmap and the Office of Science’s Basic Research Needs for the Hydrogen Economy. Many of these documents are also in the process of updates and revisions and will be posted online.



Through this overarching document the reader will gain information on the key RD&D needs to enable the largescale use of hydrogen and related technologies—such as fuel cells and turbines—in the economy and how the Department’s various offices are addressing those needs. The Program will continue to periodically revise the Plan along with all program office RD&D plans to reflect technological progress programmatic changes policy decisions and updates based on stakeholder input and reviews.

Hydrogen Infrastructures are currently being built up to support the initial commercialization of the fuel cell vehicle by multiple automakers. Three primary markets are presently coordinating a large build up of hydrogen stations: Japan; USA; and Europe to support this. Hydrogen Fuelling Station General Safety and Performance Considerations are important to establish before a wide scale infrastructure is established.

This document introduces the ISO Technical Report 19880-1 and summarizes main elements of the proposed standard. Note: this ICHS paper is based on the draft TR 19880 and is subject to change when the document is published in 2015. International Standards Organisation (ISO) Technical Committee (TC) 197 Working Group (WG) 24 has been tasked with the preparation of the ISO standard 19880-1 to define the minimum requirements considered applicable worldwide for the hydrogen and electrical safety of hydrogen stations. This report includes safety considerations for hydrogen station equipment and components control systems and operation. The following systems are covered specifically in the document as shown in Figure 1:

• H2 production / supply delivery system
• Compression
• Gaseous hydrogen buffer storage;
• Pre-cooling device;
• Gaseous hydrogen dispensers.
• Hydrogen Fuelling Vehicle Interface

The draft TR 19880-1 (and current plan for the standard) also gives guidance for the fueling validation with safety considerations relevant to the interaction between the hydrogen station and hydrogen road vehicles (during fuelling).. Through a cross-industry risk assessment carried out between OEMs Hydrogen Suppliers and existing vehicle fuelling station providers & operators (e.g. oil and industrial gas companies) the hydrogen fueling protocol SAE J2601 and associated dispenser hardware was evaluated."

One of the main benefits sought by including hydrogen in the alternative fuels mix is emissions reduction – eventually by 100%. However in the near term there is a very significant cost differential between fossil fuels and hydrogen. Hythane (a blend of hydrogen and natural gas) can act as a viable next step on the path to an ultimate hydrogen economy as a fuel blend consisting of 8−30 % hydrogen in methane can reduce emissions while not requiring significant changes in existing infrastructure. This work seeks to evaluate whether hythane may be safer than both hydrogen and methane under certain conditions. This is due to the fact hythane combines the positive safety properties of hydrogen (strong buoyancy high diffusivity) and methane (much lower flame speeds and narrower flammability limits as compared to hydrogen). For this purpose several different mixture compositions (e.g. 8 % 20 % and 30 % hydrogen) are considered. The evaluation of (a) dispersion characteristics (which are more positive than for methane) (b) combustion characteristics (which are closer to methane than hydrogen) and (c) Combined dispersion + explosion risk is performed. This risk is expected to be comparable to that of pure methane possibly lower in some situations and definitely lower than for pure hydrogen. The work is performed using the CFD software FLACS that has been well-validated for safety studies of both natural gas/methane and hydrogen systems. The first part of the work will involve validating the flame speeds and flammability limits predicted by FLACS against values available in literature. The next part of the work involves validating the overpressures predicted by the CFD tool for combustion of premixed mixtures of methane and hydrogen with air against available experimental data. In the end practical systems such as vehicular tunnels garages etc. is used to demonstrate positive safety benefits of hythane with comparisons to similar simulations for both hydrogen and methane.

Contrary to several reports in the recent literature the use of oxygen sensors for indirectly monitoring ambient hydrogen concentration has serious drawbacks. This method is based on the assumption that a hydrogen release will displace oxygen which is quantified using oxygen sensors. Despite its shortcomings the draft Hydrogen Vehicle Global Technical Regulation lists this method as a means to monitor hydrogen leaks to verify vehicle fuel system integrity. Experimental evaluations that were designed to impartially compare the ability of commercial oxygen and hydrogen sensors to reliably measure and report hydrogen concentration changes are presented. Numerous drawbacks are identified and discussed.

This paper introduces the 3D risk management (3DRM) concept with particular emphasis on hydrogen installations (Hy3DRM). The 3DRM framework entails an integrated solution for risk management that combines a detailed site-specific 3D geometry model a computational fluid dynamics (CFD) tool for simulating flow-related accident scenarios methodology for frequency analysis and quantitative risk assessment (QRA) and state-of-the-art visualization techniques for risk communication and decision support. In order to reduce calculation time and to cover escalating accident scenarios involving structural collapse and projectiles the CFD-based consequence analysis can be complemented with empirical engineering models reduced order models or finite element analysis (FEA). The paper outlines the background for 3DRM and presents a proof-of-concept risk assessment for a hypothetical hydrogen filling station. The prototype focuses on dispersion fire and explosion scenarios resulting from loss of containment of gaseous hydrogen. The approach adopted here combines consequence assessments obtained with the CFD tool FLACS-Hydrogen from Gexcon and event frequencies estimated with the Hydrogen Risk Assessment Models (HyRAM) tool from Sandia to generate 3D risk contours for explosion pressure and radiation loads. For a given population density and set of harm criteria it is straightforward to extend the analysis to include personnel risk as well as risk-based design such as detector optimization. The discussion outlines main challenges and inherent limitations of the 3DRM concept as well as prospects for further development towards a fully integrated framework for risk management in organizations.

RCS for hydrogen technologies were first developed approximately sixty years ago when hydrogen was being sold as an industrial commodity. The advent of new hydrogen technologies such as Fuel Cell Electric Vehicles (FCEVs) created a need for new RCS. These RCS have been developed with extensive support from the US DOE. These new hydrogen technologies are approaching commercial deployment and this process will produce information on RCS field performance that will create more robust RCS.

Safety is of paramount importance in all facets of the research development demonstration and deployment work of the U.S. Department of Energy’s (DOE) Fuel Cell Technologies Program. The Safety Codes and Standards sub-program (SC&S) facilitates deployment and commercialization of fuel cell and hydrogen technologies by developing and disseminating information and knowledge resources for their safe use. A comprehensive safety management program utilizing the Hydrogen Safety Panel to raise safety consciousness at the project level and developing/disseminating a suite of safety knowledge resources is playing an integral role in DOE and SC&S efforts. This paper provides examples of accomplishments achieved while reaching a growing and diverse set of stakeholders involved in research development and demonstration; design and manufacturing; deployment and operations. The work of the Hydrogen Safety Panel highlights new knowledge and the insights gained through interaction with project teams. Various means of collaboration to enhance the value of the program’s safety knowledge tools and training resources are illustrated and the direction of future initiatives to reinforce the commitment to safety is discussed.

As of 2014 the majority of the Codes and Standards required to initially deploy hydrogen technologies infrastructure in the US have been promulgated1. These codes and standards will be field tested through their application to actual hydrogen technologies projects. CCSI is process of identifying code issues that arise during project deployment and then develop codes solutions to these issues. These solutions would typically be proposed amendments to codes and standards. The process is continuous because of technology and the state of safety knowledge develops there will be a need for monitoring the application of codes and standards and improving them based on information gathered during their application. This paper will discuss code issues that have surfaced through hydrogen technologies infrastructure project deployment and potential code changes that would address these issues. The issues that this paper will address include:

• Setback distances for bulk hydrogen storage
• Code mandated hazard analyses
• Sensor placement and communication
• The use of approved equipment
• System monitoring and maintenance requirements

There exists an international commitment to increase the utilization of hydrogen as a clean and renewable alternative to carbon-based fuels. The availability of hydrogen safety sensors is critical to assure the safe deployment of hydrogen systems. Already the use of hydrogen safety sensors is required for the indoor fueling of fuel cell powered forklifts (e.g. NFPA 52 Vehicular Fuel Systems Code [1]). Additional Codes and Standards specific to hydrogen detectors are being developed [2 3] which when adopted will impose mandatory analytical performance metrics. There are a large number of commercially available hydrogen safety sensors. Because end-users have a broad range of sensor options for their specific applications the final selection of an appropriate sensor technology can be complicated. Facility engineers and other end-users are expected to select the optimal sensor technology choice. However some sensor technologies may not be a good fit for a given application. Informed decisions require an understanding of the general analytical performance specifications that can be expected by a given sensor technology. Although there are a large number of commercial sensors most can be classified into relatively few specific sensor types (e.g. electrochemical metal oxide catalytic bead and others). Performance metrics of commercial sensors produced on a specific platform may vary between manufacturers but to a significant degree a specific platform has characteristic analytical trends advantages and limitations. Knowledge of these trends facilitates the selection of the optimal technology for a specific application (i.e. indoor vs. outdoor environments). An understanding of the various sensor options and their general analytical performance specifications would be invaluable in guiding the selection of the most appropriate technology for the designated application.

The development of a set of safety codes and standards for hydrogen facilities is necessary to ensure they are designed and operated safely. To help ensure that a hydrogen facility meets an acceptable level of risk code and standard development organizations (SDOs) are utilizing risk-informed concepts in developing hydrogen codes and standards. Two SDOs the National Fire Protection Association (NFPA) and the International Organization for Standardization (ISO) through its Technical Committee (TC) 197 on hydrogen technologies have been developing standards for gaseous hydrogen facilities that specify the facilities have certain safety features use equipment made of material suitable for a hydrogen environment and have specified separation distances. Under Department of Energy funding Sandia National Laboratories (SNL) has been supporting efforts by both of these SDOs to develop the separation distances included in their respective standards. Important goals in these efforts are to use a defensible science-based approach to establish these requirements and to the extent possible harmonize the requirements. International harmonization of regulations codes and standards is critical for enabling global market penetration of hydrogen and fuel cell technologies.

Experience makes a superior teacher. Sharing the details surrounding safety events is one of the best ways to help prevent their recurrence elsewhere. This approach requires an open non-punitive environment to achieve broad benefits. The Hydrogen Incident Reporting Tool (www.h2incidents.org) is intended to facilitate the sharing of lessons learned and other relevant information gained from actual experiences using and working with hydrogen and hydrogen systems. Its intended audience includes those involved in virtually any aspect of hydrogen technology systems and use with an emphasis towards energy and transportation applications. The database contains records of safety events both publicly available and/or voluntarily submitted. Typical records contain a general description of the occurrence contributing factors equipment involved and some detailing of consequences and changes that have been subsequently implemented to prevent recurrence of similar events in the future. The voluntary and confidential nature and other characteristics surrounding the database mean that any analysis of apparent trends in its contents cannot be considered statistically valid for a universal population. A large portion of reported incidents have occurred in a laboratory setting due to the typical background of the reporting projects for example. Yet some interesting trends are becoming apparent even at this early stage of the database’s existence and general lessons can already be taken away from these experiences. This paper discusses the database and a few trends that have already become apparent for the reported incidents. Anticipated future uses of this information are also described. This paper is intended to encourage wider participation and usage of the incidents reporting database and to promote the safety benefits offered by its contents.

As hydrogen fuel cell vehicles become more widely adopted by consumers the demand for refuelling stations increases. Most vehicles require high-pressure (either 350 or 700 bar) hydrogen and therefore the refuelling infrastructure must support these pressures. Fast running reduced order physical models of releases from high-pressure sources are needed so that quantitative risk assessment can guide the safety certification of these stations. A release from a high pressure source is choked at the release point forming the complex shock structures of an under-expanded jet before achieving a characteristic Gaussian pro le for velocity density mass fraction etc. downstream. Rather than using significant computational resources to resolve the shock structure an equivalent source model can be used to quickly and accurately describe the ow in terms of velocity diameter and thermodynamic state after the shock structure. In this work we present correlations for the equivalent boundary conditions of a subsonic jet as a high-pressure jet downstream of the shock structure. Schlieren images of under-expanded jets are used to show that the geometrical structure of under-expanded jets scale with the square root of the static to ambient pressure ratio. Correlations for an equivalent source model are given and these parameters are also found to scale with square root of the pressure ratio. We present our model as well as planar laser Rayleigh scattering validation data for static pressures up to 60 bar.

In this paper we present a detailed design study of a novel apparatus for safely generating hydrogen (H2) on demand according to a novel method using a controlled chemical reaction between water (H2O) and sodium (Na) metal that yields hydrogen gas of sufficient purity for direct use in fuel cells without risk of contaminating sensitive catalysts. The apparatus consists of a first pressure vessel filled with liquid H2O with an overpressure of nitrogen (N2) gas above the H2O reactant and a second pressure vessel that stores solid Na reactant. Hydrogen gas is generated above the solid Na when H2O reactant is introduced using a regulator that senses when the downstream pressure of H2 gas above the solid Na reactant has dropped below a threshold value. The sodium hydroxide (NaOH) byproduct of the hydrogen producing reaction is collected within the apparatus for later reprocessing by electrolysis to recover the Na reactant.

Envisioned below is an energy system named Thermal Hydrogen developed to enable economy-wide decarbonization. Thermal Hydrogen is an energy system where electric and/or heat energy is used to split water (or CO₂) for the utilization of both by-products: hydrogen as energy storage and pure oxygen as carbon abatement. Important advantages of chemical energy carriers are long term energy storage and extended range for electric vehicles. These minimize the need for the most capital intensive assets of a fully decarbonized energy economy: low carbon power plants and batteries. The pure oxygen pre-empts the gas separation process of “Carbon Capture and Sequestration” (CCS) and enables hydrocarbons to use simpler more efficient thermodynamic cycles. Thus the “externality” of water splitting pure oxygen is increasingly competitive hydrocarbons which happen to be emissions free. Methods for engineering economy-wide decarbonization are described below as well as the energy supply carrier and distribution options offered by the system.

In close cooperation with their Canadian counterparts United States public safety authorities are taking the first steps towards creating a proper infrastructure to ensure the safe use of the new hydrogen fuel cells now being introduced commercially. Currently public safety officials are being asked to permit hydrogen fuel cells for stationary power and as emergency power backups for the telecommunications towers that exist everywhere. Consistent application of the safety codes is difficult – in part because it is new – yet it is far more complex to train emergency responders to deal safely with the inevitable hydrogen incidents. The US and Canadian building and fire codes and standards are similar but not identical. The US and Canadian rules are unlikely to be useful to other nations without modification to suit different regulatory systems. However emergency responder safety training is potentially more universal. The risks strategies and tactics are unlikely to differ much by region. The Hydrogen Executive Leadership Panel (HELP) made emergency responder safety training its first priority because the transition to hydrogen depends on keeping incidents small and inoffensive and the public and responders safe from harm. One might think that advising 1.2 million firefighters and 800000 law enforcement officers about hydrogen risks is no more complicated than adding guidance to a website. One would be wrong. The term “training” has specific legal implications which may vary by state. For hazardous materials federal requirements apply. Insurance companies place training requirements on the policies they sell to fire departments including the thousands of small all-volunteer departments which may operate as private corporations. Union contracts may define training and promotions may be based on satisfactorily completed certain levels of training. Emergency responders could no sooner learn how to extinguish a<br/>hydrogen fire by reading a webpage than a person could learn to ride a bicycle by reading a book. Procedures must be learned by listening reading and then doing. Regular practice is necessary. As new hydrogen applications are commercialized additional responder training may be necessary. This highlights another obstacle emergency responders’ ability to travel distances and take the time to undergo training. Historically fire academies established adjunct instructor programs and satellite academies to bring the training to firefighters. The large well-equipped academies are typically used for specialized training. States rarely have enough instructors and instructors often must take the time to create a course outline research each point and produce a program that is informative useful and holds the attention of responders. The challenge of training emergency responders seems next to impossible but public safety authorities are asked to tackle the impossible every day and a model exists to move forward in the U.S. Over the past few years the National Association of State Fire Marshals and U.S. Department of Transportation enlisted the help of emergency responders and industry to create a standardized approach to train emergency responders to deal with pipeline incidents. A curriculum and training materials were created and more than 26000 sets have been distributed for free to public safety agencies nationwide. More than 8000 instructors have been trained to use these materials that are now part of the regular training in 23 states. Using this model HELP intends to ensure that all emergency responders are trained to address hydrogen risks. The model and the rigorous scenario analysis and review used to developing the operational and technical training is addressed in this paper.

The University of Missouri-Rolla (UMR) through a hydrogen internal combustion engine vehicle evaluation participation agreement with the Ford Motor Company will establish a commuter bus service and hydrogen refueling at a station in rural Missouri near Ft. Leonard Wood (FLW). Initiated by a request from the U.S. Army Maneuver Support Center at FLW UMR is leading the effort to launch the commuter service between FLW and the neighboring towns of Rolla and Lebanon Missouri each of which are located approximately 40 km from the military base on Interstate-44 highway. The broad research training and education agenda for the rural hydrogen transportation test bed is to develop demonstrate evaluate and promote safe hydrogen-based technologies in a real world environment. With funds provided by the Defense Logistics Agency through the Air Force Research Laboratory this hydrogen initiative will build and operate a hydrogen fueling facility that includes on-site generation of hydrogen through electrolysis as well as selling a range of other traditional and alternative fuels.

In any application involving the production storage or use of hydrogen sensors are important devices for alerting to the presence of leaked hydrogen. Hydrogen sensors should be accurate sensitive and specific as well as resistant to long term drift and varying environmental conditions. Furthermore as an integral element in a safety system sensor performance should not be compromised by operational parameters. For example safety sensors may be required to operate at reduced oxygen levels relative to air. In this work we evaluate and compare a number of sensor technologies in terms of their ability to detect hydrogen under conditions of varying oxygen concentration.

A properly trained first responder community is critical to the successful introduction of hydrogen fuel cell applications and their transformation in how we use energy. Providing resources with accurate information and current knowledge is essential to the delivery of effective hydrogen and fuel cell-related first responder training. The California Fuel Cell Partnership and the Pacific Northwest National Laboratory have over 15 years of experience in developing and delivering hydrogen safety-related first responder training materials and programs. A National Hydrogen and Fuel Cell Emergency Response Training Resource was recently released. This training resource serves the delivery of a variety of training regimens. Associated materials are adaptable for different training formats ranging from high-level overview presentations to more comprehensive classroom training. This paper presents what has been learned from the development and delivery of hydrogen safety-related first responder training programs (online classroom hands-on) by the respective organizations. The collaborative strategy being developed for enhancing training materials and methods for greater accessibility based on stakeholder input will be discussed.

Due to rapid growth in the use of hydrogen powered fuel cell forklifts within warehouse enclosures Sandia National Laboratories has worked to develop scientific methods that support the creation of new hydrogen safety codes and standards for indoor refuelling operations. Based on industry stakeholder input conducted experiments were devised to assess the utility of modelling approaches used to analyze potential consequences from ignited hydrogen leaks in facilities certified according to existing code language. Release dispersion and combustion characteristics were measured within a scaled test facility located at SRI International's Corral Hollow Test Site. Moreover the impact of mitigation measures such as active/passive ventilation and pressure relief panels was investigated. Since it is impractical to experimentally evaluate all possible facility configurations and accident scenarios careful characterization of the experimental boundary conditions has been performed so that collected datasets can be used to validate computational modelling approaches.

Sandia National Laboratories has worked with stakeholders and original equipment manufacturers (OEMs) to develop scientific data that can be used to create risk-informed hydrogen codes and standards for the safe operation of indoor hydrogen fuel-cell forklifts. An important issue is the possibility of an accident inside a warehouse or other enclosed space where a release of hydrogen from the high-pressure gaseous storage tank could occur. For such scenarios computational fluid dynamics (CFD) simulations have been used to model the release and dispersion of gaseous hydrogen from the vehicle and to study the behavior of the ignitable hydrogen cloud inside the warehouse or enclosure. The overpressure arising as a result of ignition and subsequent deflagration of the hydrogen cloud within the warehouse has been studied for different ignition delay times and ignition locations. Both ventilated and unventilated warehouses have been considered in the analysis. Experiments have been performed in a scaled warehouse test facility and compared with simulations to validate the results of the computational analysis.

Performing research in the interest of providing relevant safety requirements is a valuable and essential endeavor but translating research results into enforceable requirements adopted into codes and standards a process sometimes referred to as codification can be a separate and challenging task. This paper discusses the process utilized to successfully translate research results related to bulk gaseous hydrogen storage separation (or stand-off) distances into code requirements in NFPA 55:Storage Use and Handling of Compressed Gases and Cryogenic Fluids in Portable and StationaryContainers Cylinders and Tanks and NFPA 2: Hydrogen Technologies. The process utilized can besummarized as follows: First the technical committees for the documents to be revised were engaged to confirm that the codification process was endorsed by the committee. Then a sub-committee referred to as a task group was formed. A chair must be elected or appointed. The chair should be a generalist with code enforcement or application experience. The task group was populated with several voting members of each technical committee. By having voting members as part of the task group the group becomes empowered and uniquely different from any other code proposal generating body. The task group was also populated with technical experts as needed but primarily the experts needed are the researchers involved. Once properly populated and empowered the task group must actively engage its members. The researchers must educate the code makers on the methods and limitations of their work and the code makers must take the research results and fill the gaps as needed to build consensus and create enforceable code language and generate a code change proposal that will be accepted. While this process seems simple there are pitfalls along the way that can impede or nullify the desired end result – changes to codes and standards. A few of these pitfalls include: wrong task group membership task group not empowered task group not supported in-person meetings not possible consensus not achieved. This paper focuses on the process used and how pitfalls can be avoided for future efforts.