In recent years, high pressure gaseous hydrogen has become increasingly popular as a vehicle fuel. The National Fire Protection Association (NFPA) is one of several organizations developing codes and standards to ensure the safety of the vehicular hydrogen infrastructure. As part of code development activities, NFPA is exploring the use of Quantitative Risk Assessment (QRA) to help provide a technical basis for specific requirements in the Hydrogen Technologies Code (NFPA 2). The authors conducted the QRA activity to 1) provide screening-level insights into the fatality risk from code-compliant, indoor hydrogen fueling systems for NFPA 2 Chapter 10 (Gaseous Hydrogen Vehicle Fueling Facilities) and 2) identify gaps in QRA that must be resolved to enable more detailed, robust QRA analyses. This paper documents the results of this early-stage QRA activity and suggests several QRA improvements that would enable more widespread use of QRA for vehicular hydrogen applications.

In order to improve the safety of hydrogen-oxygen combustion in gas generator of liquid rocket engines, based upon simulation results of hydrogen-oxygen combustion and breakage of structure, we analyze the typical accidents in gas generator, and put forward methods for solution.

Hydrogen may appear to be an attractive alternative fuel due to its obvious environmental and potentials of significant technical and economic advantages, the design and manufacture a safe and reliable hydrogen tank is the number one priority for development and deployment of hydrogen technology. Compared with aluminum-lined hydrogen tanks, composite tanks offer advantages of lightweight and conformability. Real life tank testing is very expensive and time consuming. In this study, a finite element analysis (FEA) tool has been developed to provide a more economical alternative for composite hydrogen tank analysis at operating pressures of 35 MPa, 45 MPa, and 70 MPa. It was found that the carbon-fiber/epoxy shell acts as the primary structural member, unlike an aluminum-lined tank where the liner acts performs this function. Critical portions of the tanks were found to be the top and bottom domes as well as the interaction between the liner and boss. Some slight plastic deformation was found to occur in the liner at 70 MPa, though under the 35 MPa and 45 MPa loads, the liner exhibited only elastic behavior. The shell elastically deformed in all loading cases, which results in very low residual stress and strain values following the load release. The results may help manufacturers improve tank safety in the design and manufacture of composite hydrogen.

Hydrogen is an effective energy carrier whose properties include efficient energy density, biological benignity, renewability, and gee-independent sources of supply. The U.S. Department of Energy (DOE) supports a technologically advanced hydrogen program based on an industry-led, cost-share approach. Although the technical challenges are being addressed adequately by this approach there are nontechnical barriers which must be overcome in order to implement a hydrogen energy future. Upcoming demonstrations of hydrogen systems, as well as near-term commercial products, must be demonstrated as safe for the public to accept hydrogen as an energy carrier. The hydrogen community cannot afford even the slightest setback with regard to public perception of hydrogen safety. Industry currently uses many successful proprietary methods for handling large amounts of hydrogen safely. There are efforts underway to standardize the manufacture of hydrogen system components to ensure hydrogen safety in a variety of potential commercial hydrogen market applications. The NHA, with DOE and industry support, is working on many of these efforts, including participation in related international Standards Organization (ISO) hydrogen safety work items. In addition, the NHA provides a forum for gaining expert consensus on hydrogen codes and standards and disseminating it through participation in NHA Codes and Standards Workshops, publication of articles in the NHA Advocate newsletter, and technical presentations at the,Annual U.S. Hydrogen Meeting. As the commercialization of hydrogen systems progresses, the hydrogen community has recognized a need for readily available. empirically based information on prevailing practices, applicable standards. and regulatory codes, in addition. availability of existing hydrogen safety manuals, reports, technical papers, and safety assessments could be used to facilitate regulatory approvals for installing new hydrogen systems or operating demonstrations. The National Hydrogen Association (NHA) is making available a unique hydrogen sourcebook on CD ROM (with hard copy) under cooperative development with DOE, the National Renewable Energy Laboratory, Natural Resources Canada. and TekTrend international. This sourcebook includes case studies, reference material, and a checklist for safe hydrogen use. It is designed to facilitate understanding of hydrogen safety issues and provides a basis for code officials and developers to identify and resolve safety. concerns. The NHA encourages participation from industry in all hydrogen codes and standards activities. Only with industry consensus, both at a national and an international level, can the hydrogen community overcome the nontechnical barriers to implementing a hydrogen energy future.

The indisputable need by heat treaters to save energy, boost productivity, minimize distortion and improve metallurgical properties while reducing environmental impacts should lead furnace manufacturers to place an increased emphasis on enhancing gas quenching performance. The purpose of this study is to analyze the cooling performances of the various quench gases that are available to the vacuum heat treater. The benchmark gas for quenching, and the industry standard for many years has been nitrogen. Based on theoretical thermodynamics of gases, the hypothesis states that hydrogen should cool 50%2faster than nitrogen and hydrogen should cool 17%2faster than helium. [GRAPHICS] With the ever-increasing expense of helium and the world's reserves of helium being finite, Solar Atmospheres' engineers are working to understand high pressure cooling properties of hydrogen. Safety issues, of course, must be resolved when working with hydrogen. Solar engineers are working on this subject everyday while being guided by NFPA 86 Code.

The HTTR project aims at demonstrating inherent safety features of High temperature gas-cooled reactors (HTGRs) by safety demonstration tests, and establishing nuclear heat utilisation technology by a hydrogen production demonstration test. The safety demonstration tests are divided to the first phase and second phase tests. In the first phase tests, simulation tests of anticipated operational occurrences and anticipated transients without scram are conducted. The second phase tests will simulate accidents such as a depressurisation accident (loss of coolant accident). The first phase safety demonstration tests have been carried out during FY 2002-2005, and the second phase tests are planned to start in FY 2006. A hydrogen production facility will be connected to the HTTR for the hydrogen production demonstration test to establish the coupling technology such as well as the procedure on safety design and evaluation. The coupling technology consists of safety-related one such as countermeasures against explosion of combustible gas and tritium permeation from helium gas to process gas and so on, and control ones for preventing thermal mismatch between reactor and hydrogen production facility. This report describes the present status and the future plan of the HTTR project.

Among the different possible solutions for the reduction of greenhouse effect, hydrogen has been proposed as a clean and efficient energy carrier. However, high capacity storage is still to be developed. Many metals, alloys and intermetallic compounds are able to store hydrogen gas. Such possibility is of interest in terms of safety, global yield and long time storage. However, to be suitable for applications, such compounds must present high capacity, good reversibility, fast reactivity and sustainability. In this paper, we will review on the thermodynamic properties of metal hydrides. Their solid-gas hydrogenation behaviour and the related absorption-desorption isotherm curves are examined as a useful criterion for the selection of suitable materials for applications. The paper emphasizes the possibility to reach given properties by convenient chemical substitutions of the compounds.

The ongoing nuclear program in Korea is for large-scale electricity generation, which is mainly relying on PWR systems. KSNPP (Korean Standard Nuclear Power Plant) was developed as a standardization effort of existing 1,000 MWe-size PWR systems, and its improved concepts have been progressively adopted in each unit under present construction and in planning stage up to the year of 2006. This paper presents the program of adopting passive safety features in the advanced nuclear systems that will be introduced in Korea beyond the year of 2006. The advanced nuclear systems introduced in this presentation are KNGR (Korean Next Generation Reactor) which is a 1,300 MWe-size PWR of advanced concept, its follow-up units in post-KNGR era, and SMART (System-Integrated Modular Advanced Reactor) which is a 330 MWt-size multipurpose integral-type reactor. In designing these advanced nuclear systems, the safety objective is to keep the risk to the general public within the level of 10(-7) to 10(-6) per reactor-year, and the economic objective is to secure 20%2cost advantage over competing energy sources. The additional adoption of passive feature is decided based upon cost-benefit studies as long as the safety of a nuclear system is within the acceptable range. Fluidic device, passive secondary condensing system, fusible plugs, and catalytic hydrogen ignitors are the specific passive safety features which are decided to be adopted for KNGR design. R&D efforts are still in progress in the areas of passive shutdown decay heat removal, passive safety injection, and passive containment cooling Tor further improvement of safety in KNGR design; and innovative ideas are recommended in SMART design.

Hydrogen is a flammable and explosive gas that is given off from most aqueous batteries. For Outdoor Enclosures where equipment and batteries are co-located the batteries will then be located in a confined volume where there will be little and poorly characterized ventilation. Several unknown factors are involved, the actual rate of hydrogen given off from the battery is a very important factor, the other decisive unknown variable is the actual ventilation levels in enclosures where no forced ventilation is installed. Through the years we have worked out strategies to qualify and safe guard the enclosures for the hydrogen peril. The authors have the opinion that there is the need for international standardisation around the hydrogen management in particular and secondly around the safety for valve regulated lead acid batteries.