The control of hydrogen losses in a hydrogen production industrial plant is of crucial importance especially for its safety implications. The high temperatures and pressures required in hydrogen production processes as well as the corrosive process fluids can enhance drastically the intrinsic permeation characteristics of metals and alloys. To reduce hydrogen permeation and a subsequent mechanical degradation of structural materials, hydrogen permeation barriers can be applied. As shown by previous works performed in the frame of the European Fusion Technology Programme, satisfactory hydrogen permeation reductions were achieved using alumina-rich coatings. Several deposition techniques were investigated and coatings were obtained by chemical vapour deposition (CVD) and hot dipping, and these processes seem to have exhibited a better TPB efficiency with respect to the coatings obtained by spray techniques. This work contains a review of the deposition techniques and the efficiency of the different hydrogen permeation barriers developed in the frame of the EU Fusion Programme.

If it is tried that new hydrogen energy applications reach a high degree of acceptance in the public worldwide, accidents than would generate serious negative effects must be avoided or minimized In accordance with this point, the industrial experience can contribute in favor of the generalized knowledge in the field of safety, because hydrogen has been handled successfully for decades in the chemical process industries. All whatever is known from industrial experience and dedicated R&D activities is important to help in the construction of a hydrogen safety database. Additionally, the international standardization activities could bring us the opportunity for spreading, out that information as normative documents (ISO/TC 197 Technical Committee), The present work takes advantage of the rich experience obtained during the construction and operation of industrial installations, which use hydrogen, deuterium and hydrogen containing compounds. The referred experience is presented in such a way that it can be translated into safety recommendations applicable in the development of safer hydrogen energy facilities.

A program to modify a hydrogen hybrid electric bus is described. This is an electric bus that uses a hydrogen-fueled internal combustion engine to charge on-board batteries. The primary goal of the reported work is to extend the range of the bus in a cost-effective manner. Among the modifications being made are the development of a new engine, upgrading the power control system, rewiring critical elements, adapting a supercapacitor regenerative braking system, devising more effective changes to the safety hydrogen systems, and adding a high pressure gas storage system to supplement the existing hydride bed hydrogen storage. All of this work is being supplemented with the use of a dynamic simulation code to determine optimal operational strategies.

Due to the importance of hydrogen attack regarding the safety and competitivity of the European petrochemical industry, and to the lack of experimental data on hydrogen-creep interaction, a dedicated testing rig has been designed and built at JRC/IAM which allows high internal pressure tube testing with hydrogen at elevated temperatures. The tubes, being under multiaxial stress, simulate closely many industrial components such as hydrocracking pressure vessels and piping. An advanced capacitive method for strain measurements has been developed, and measurements of the hoop strain evolution during testing have provided full creep curves. Special attention to safety aspects, crucial for such experiments, was taken and is described here. Initial results on steel tubes are very promising. Hydrogen attack under multiaxial stress has been produced allowing more reliable information on the mechanisms of damage to be derived.

In December 2006 Enel promoted a project oriented towards Environment and Innovation including the development of zero emission plants. The hydrogen project foresees the construction of a I I MW,, hydrogen-fed gas turbine able to couple high efficiency (fuel utilization) with low nitrogen-oxide emissions. The project (partly funded by Regione Veneto, a local authority in the North-East of Italy), will be built at Enel's coal-fired Fusina Power Plant [1]. The aim of a first demonstrative phase is to verify the correct operation of the gas turbine supplied by pure hydrogen and to acquire know-how of hydrogen combustion, safety aspects and control technologies in gas turbine cycles. In the second phase, the goal will be to optimize the combustion technology, paying particular attention to NO(x) emissions. To make hydrogen suitable for the electricity generation in an environmentally compatible manner, Enel is developing the Fusina's experimental power plant project. Since currently no commercial hydrogen burners are suitable for gas turbine power plants, both Enel and Nuovo Pignone are investigating feasible solutions for a hydrogen-fuelled low-NO(x) diffusion burner design. In this context, this paper presents the results from a CFD analysis showing the NO(x) reduction based on steam injection and burner minor modifications. An initial model with a coarse mesh and simple aerodynamic treatment was used to evaluate the NO(x) emissions with varying amount of steam injected into the combustion chamber. In the view of the following experimental campaign, some solutions have been selected after an initial tuning of the CFD model. Furthermore, a second CFD model based on a finer mesh and a detailed geometry discretization will enable a more precise investigation of the fluidynamic field. Results of the numerical model, which simulates a GE10 gas turbine combustor fuelled with pure hydrogen, are presented and compared with experimental tests at full scale and full pressure conditions.

Safety is a key issue whenever hydrogen is of concern, an issue that needs to be urgently and adequately addressed to ensure global dissemination of hydrogen and its technologies. International exchangeability of hydrogen technologies would be very difficult if there is no common language and understanding as to how tolerable risk could be achieved. Standardization, especially if international, is meant to provide such technical agreements. An overview of how the safety aspects are covered within the current projects of ISO/TC 197, the ISO technical committee dealing with Hydrogen technologies, will be provided as well as some insight as to how one could initiate a project and how it will proceed after its acceptance.

Computational fluid dynamics (CFD) calculations were performed simulating tunnel accidents with a hydrogen powered vehicle. The investigated scenarios assume damage of the LH2 system, release of gaseous H-2, mixing with air, ignition and finally combustion. Gaseous H-2 rises to the tunnel ceiling forming a strongly stratified mixture. Shape, size, inner structure and temperature of the evolving H-2-air clouds were calculated. Using new developed criteria, the time and space regions with potential for fast combustion modes were identified. For the given H-2 sources the combustion regime is governed by the ignition time. For late ignition a slow and incomplete combustion of the partly premixed H-2-air cloud along the tunnel ceiling is predicted. For early ignition a standing diffusion flame develops with dimensions and heat fluxes determined by the H-2 release rate. Temperature, oxygen and flow velocity fields during the combustion were computed. In both cases only minor pressures are generated. The highest damage potential appears to exist for intermediate ignition times. Design measures can be used to limit the risk of hydrogen driven vehicles to the level of gasoline cars.

It is planned to use hydrogen extensively as a source of clean energy in the next century. So we have been studied to establish a safety scheme to ensure that both existing hydrogen technologies and new technologies are implemented without endangering public safety. The studies are administrated through the New Energy and Industrial Technology Development Organization(NEDO) as a part of the International Clean Energy Network Using Hydrogen Conversion(WE-NET) Program with funding from the Agency of Industrial Science and Technology(AIST) in Ministry of International Trade and Industry(MITI) of Japan. First we must specify safety features and functions for each WE-NET system to meet the safety goal, and evaluate the consequence of the postulated accident of liquid-hydrogen. Since we have developed the multi-phase hydrodynamics analysis code, we applied the code to establish the safety standard for the total WE-NET system.

The WE-NET project started its phase 2 program from FY1999 and it will last for 5 years. Various R&D is carried out for future establishment of 'World Energy Network System" and for early introduction of dispersed use of hydrogen. The aim of the safety studies in Phase 2 is to provide evaluation tool for safety assessment and data for risk assessment of above systems. In order to clarify the key phenomena related to hydrogen explosion, the fbllowing experiments are planned. They are leakage experiment of liquid hydrogen and explosion experiment of hydrogen / air mixture. In the leakage experiment, extension of liquid surface, evaporation and atmospheric dispersion of leaked hydrogen will be obtained to clarify the behavior of hydrogen cloud. In this paper, we will show the R&D activities on safety for the WE-NET project and the small-scale leakage experiment carried out in 1999.

This report describes the progress made on the design of the liquid hydrogen absorber for the international Muon Ionization Cooling Experiment (MICE). The absorber consists of a 21-liter vessel that contains liquid hydrogen (1.5 kg) or liquid helium (2.63 kg). The cryogen vessel is within the warm bore of the superconducting focusing magnet for MICE. The purpose of the magnet is to provide a low beam beta region within the absorber. For safety reasons, the vacuum vessel for the hydrogen absorber is separated from the vacuum vessel for the superconducting magnet and the vacuum that surrounds the RF cavities or the detector. The absorber has two 300 mm-diameter thin aluminum windows. The vacuum vessel around the absorber has a pair of thin aluminum windows that separate the absorber vacuum space from adjacent vacuum spaces. The absorber will be cooled using a heat exchanger that is built into the absorber walls. Liquid nitrogen is used to cool the absorber to 80 K. Liquid helium completes the absorber cool down and condenses hydrogen in the absorber. The absorber may also be filled with liquid helium to measure muon cooling in helium.