Stand der Kenntnisse und Technik bezüglich Wasserstoffsicherheit

Die Einführung von Wasserstoff als sicherer Energieträger braucht eine robuste Wissensbasis, darauf aufgebaute Werkzeuge zur Auslegung und Sicherheitsbewertung von Wasserstofftechnologien und ein international harmonisiertes Regelwerk. Viele der innovativen Technologien implizieren Wasserstoff bei hohen Drücken und/oder kryogenen Temperaturen, mit denen in verteilten Anwendungen erstmalig private Nutzer in Kontakt kommen. Um überkonservative, teure Sicherheitslösungen zu vermeiden, gleichzeitig aber die Einsetzbarkeit und Sicherheit von Wasserstoffanwendungen zu demonstrieren und die Akzeptanz für die Technologie aufrecht zu halten, muss auch die Sicherheitsforschung mit den Trends der technologischen Entwicklung Schritt halten, oder sie besser noch antizipieren. So beschreibt dieser Überblicksartikel nicht nur den gegenwärtigen Stand der Kenntnisse und Technik bezüglich Wasserstoffsicherheit, sondern auch ihre Weiterentwicklung

Understanding of the Operation Behaviour of a Passive Autocatalytic Recombiner (PAR) for Hydrogen Mitigation in Realistic Containment Conditions During a Severe Light Water Nuclear Reactor (LWR) Accident

In the broader context of hydrogen risk mitigation in nuclear power plants (NPPs), experimental studies of a possible poisoning of Passive Autocatalytic Recombiners (PARs) by fission products (FPs) and aerosols released during a core meltdown accident were mainly conducted in the past with non-radioactive fission product surrogates (e.g., in the H2PAR facility at Cadarache, France). The decision was taken in 1997 to complement these studies by a test in the Phébus facility, a research nuclear reactor also at Cadarache: it was a rare opportunity to expose catalyst samples to an atmosphere as representative as possible of a real accident, containing gaseous fission products and aerosols released during the degradation of an actual irradiated nuclear fuel bundle. Before testing in Phébus during the FPT3 experiment, reference and qualification tests were performed in the H2PAR facility using the same samples — the so-called "coupons" — and coupon holder to check that the apparatus was functional and correctly designed for avoiding to tamper with the thermal-hydraulics and chemical conditions in the Phébus containment. The correct operation of catalysts was checked by measuring the surface temperature increase of the coupons due to the exothermic reaction between hydrogen and oxygen. After the Phébus FPT3 test (November 2004), REKO-1 tests were initiated at Jülich, Germany, to confirm the discrepancy in coupons temperature observed in Phébus FPT3 and H2PAR PHEB-03 tests, and to study the operation behaviour of PARs. Besides, before REKO-1 tests, a first interpretation of H2PAR and Phébus experiments was led to the conclusion that their difference during the operation was due to the different experimental conditions. Samples of catalysts (IRSN/IRCELYON coupon) similar to those used in Phébus and H2PAR facilities were exposed in REKO-1 facility to an atmosphere similar to that of the Phébus model containment. During the REKO-1 experiments, the temperatures of the coupon surface, together with the oxygen and hydrogen recombination kinetics, were measured as a function of the oxygen fraction in the feed. In these conditions, the inlet oxygen fraction was shown to be the main parameter affecting the recombination rate. The presence of steam was also taken into account during the IRSN/IRCELYON coupon operation in REKO-1. Finally, the PAR surface temperatures during the REKO-1 tests (both optical and thermocouple measurements) are compared with those obtained during the FPT3 and PHEB-03 tests. Then, the experimental observations (from the Phébus FPT3, H2PAR PHEB03 and REKO-1 tests) were corroborated by numerical calculations using the SPARK code developed at IRSN for catalytic reactors and recombiners applications. Despite the loss of performance experienced by the coupons in the FPT3 test, as compared with the PHEB-03 test, this study strengthens the qualification of PARs for risk mitigation in Pressurized Water Reactor (PWR) NPPs, and subsidiarily demonstrates that they could still be efficient in the rich burn conditions of partially inerted (oxygen depleted) Boiling Water Reactor (BWR) containments.JRC.F.5-Nuclear Reactor Safety Assessmen

Integration of Experimental Facilities - a Joint Effort for Establishing a Common Knowledge Base in Experimental Work on Hydrogen Safety

With regard to the goals of the European HySafe Network, research facilities are essential for the experimental investigation of relevant phenomena, for testing devices and safety concepts as well as for the generation of validation data for the various numerical codes and models. The integrating activity "Integration of Experimental Facilities (IEF)" has provided basic support for jointly performed experimental work within HySafe. Even beyond the funding period of the NoE HySafe in the 6th Framework Programme, IEF represents a long lasting effort for reaching sustainable integration of the experimental research capacities and expertise of the partners from different research fields. In order to achieve a high standard in the quality of experimental data provided by the partners, emphasis was put on the know-how transfer between the partners. The strategy for reaching the objectives consisted of two parts. On the one hand, a documentation of the experimental capacities has been prepared and analysed. On the other hand, a communication base has been established by means of biannual workshops on experimental issues. A total of 8 well received workshops has been organised covering topics from measurement technologies to safety issues. Based on the information presented by the partners, a working document on best practice including the joint experimental knowledge of all partners with regard to experiments and instrumentation was created. Preserving the character of a working document, it was implemented in the IEF wiki page, which was set up in order to provide a central communication platform. The paper gives an overview of the IEF network activities over the last 5 years.JRC.F.2-Cleaner energ

On the Use of Hydrogen in Confined Spaces - Results from the Internal Project InsHyde

The paper presents an overview of the main achievements of the internal project InsHyde of the HySafe NoE. The scope of InsHyde was to investigate realistic small-medium indoor hydrogen leaks and provide recommendations for the safe use/storage of indoor hydrogen systems. Additionally, InsHyde served to integrate proposals from HySafe work packages and existing external research projects towards a common effort. Following a state of the art review, InsHyde activities expanded into experimental and simulation work. Dispersion experiments were performed using hydrogen and helium at the INERIS gallery facility to evaluate short and long term dispersion patterns in garage like settings. A new facility (GARAGE) was built at CEA and dispersion experiments were performed there using helium to evaluate hydrogen dispersion under highly controlled conditions. In parallel, combustion experiments were performed by FZK to evaluate the maximum amount of hydrogen that could be safely ignited indoors. The combustion experiments were extended later on by KI at their test site, by considering the ignition of larger amounts of hydrogen in obstructed environments outdoors. An evaluation of the performance of commercial hydrogen detectors as well as inter-lab calibration work was jointly performed by JRC, INERIS and BAM. Simulation work was as intensive as the experimental work with participation from most of the partners. It included pre-test simulations, validation of the available CFD codes against previously performed experiments with significant CFD code inter-comparisons, as well as CFD application to investigate specific realistic scenarios. Additionally an evaluation of permeation issues was performed by VOLVO, CEA, NCSRD and UU, by combining theoretical, computational and experimental approaches with the results being presented to key automotive regulations and standards groups. Finally, the InsHyde project concluded with a public document providing initial guidance on the use of hydrogen in confined spaces.JRC.DDG.F.2-Cleaner energ

Achievements of the EC network of excellence Hysafe

International audienceIn many areas European research has been largely fragmented. To support the required integration and to focus and coordinate related research efforts the European Commission created a new instrument, the Networks of Excellences (NoEs). The goal of the NoE HySafe has been to provide the basis to facilitate the safe introduction of hydrogen as an energy carrier by removing the safety related obstacles. The prioritisation of the HySafe internal project activities was based on a phenomena identification and ranking exercise (PIRT) and expert interviews. The identified research headlines were "Releases in (partially) confined areas", "Mitigation" and "Quantitative Risk Assessment". Along these headlines existing or planned research work was re-orientated and slightly modified, to build up three large internal research projects "InsHyde", "HyTunnel", and "HyQRA". In InsHyde realistic indoor hydrogen leaks and associated hazards have been investigated to provide recommendations for the safe use of indoor hydrogen systems including mitigation and detection means. The appropriateness of available regulations, codes and standards (RCS) has been assessed. Experimental and numerical work was conducted to benchmark simulation tools and to evaluate the related recommendations. HyTunnel contributed to the understanding of the nature of the hazards posed by hydrogen vehicles inside tunnels and its relative severity compared to other fuels. In HyQRA quantitative risk assessment strategies were applied to relevant scenarios in a hydrogen refuelling station and the performance was compared to derive also recommendations. The integration process was supported by common activities like a series of workshops and benchmarks related to experimental and numerical work. The networks research tools were categorised and published in online catalogues. Important integration success was provided by commonly setting up the International Conference on Hydrogen Safety, the first academic education related to hydrogen safety and the Hydrogen Safety Handbook. Finally, the network founded the International Association for Hydrogen Safety, which opens the future networking to all interested parties on an international level

Achievements of the EC network of excellence HYSAFE

International audienceIn many areas European research has been largely fragmented. To support the required integration and to focus and coordinate related research efforts the European Commission created a new instrument, the Networks of Excellences (NoEs). The goal of the NoE HySafe has been to provide the basis to facilitate the safe introduction of hydrogen as an energy carrier by removing the safety related obstacles. The prioritisation of the HySafe internal project activities was based on a phenomena identification and ranking exercise (PIRT) and expert interviews. The identified research headlines were "Releases in (partially) confined areas", "Mitigation" and "Quantitative Risk Assessment". Along these headlines existing or planned research work was re-orientated and slightly modified, to build up three large internal research projects "InsHyde", "HyTunnel", and "HyQRA". In InsHyde realistic indoor hydrogen leaks and associated hazards have been investigated to provide recommendations for the safe use of indoor hydrogen systems including mitigation and detection means. The appropriateness of available regulations, codes and standards (RCS) has been assessed. Experimental and numerical work was conducted to benchmark simulation tools and to evaluate the related recommendations. HyTunnel contributed to the understanding of the nature of the hazards posed by hydrogen vehicles inside tunnels and its relative severity compared to other fuels. In HyQRA quantitative risk assessment strategies were applied to relevant scenarios in a hydrogen refuelling station and the performance was compared to derive also recommendations. The integration process was supported by common activities like a series of workshops and benchmarks related to experimental and numerical work. The networks research tools were categorised and published in online catalogues. Important integration success was provided by commonly setting up the International Conference on Hydrogen Safety, the first academic education related to hydrogen safety and the Hydrogen Safety Handbook. Finally, the network founded the International Association for Hydrogen Safety, which opens the future networking to all interested parties on an international level

Achievements of the EC Network of Excellence HYSAFE

In many areas European research has been largely fragmented. To support the required integration and to focus and coordinate related research efforts the European Commission created a new instrument, the Networks of Excellences (NoEs). The goal of the NoE HySafe has been to provide the basis to facilitate the safe introduction of hydrogen as an energy carrier by removing the safety related obstacles. The prioritisation of the HySafe internal project activities was based on a phenomena identification and ranking exercise (PIRT) and expert interviews. The identified research headlines were "Releases in (partially) confined areas", "Mitigation" and "Quantitative Risk Assessment". Along these headlines existing or planned research work was re-orientated and slightly modified, to build up three large internal research projects "InsHyde", "HyTunnel", and "HyQRA". In InsHyde realistic indoor hydrogen leaks and associated hazards have been investigated to provide recommendations for the safe use of indoor hydrogen systems including mitigation and detection means. The appropriateness of available regulations, codes and standards (RCS) has been assessed. Experimental and numerical work was conducted to benchmark simulation tools and to evaluate the related recommendations. HyTunnel contributed to the understanding of the nature of the hazards posed by hydrogen vehicles inside tunnels and its relative severity compared to other fuels. In HyQRA quantitative risk assessment strategies were applied to relevant scenarios in a hydrogen refuelling station and the performance was compared to derive also recommendations. The integration process was supported by common activities like a series of workshops and benchmarks related to experimental and numerical work. The networks research tools were categorised and published in online catalogues. Important integration success was provided by commonly setting up the International Conference on Hydrogen Safety, the first academic education related to hydrogen safety and the Hydrogen Safety Handbook. Finally, the network founded the International Association for Hydrogen Safety, which opens the future networking to all interested parties on an international level.JRC.DDG.F.2-Cleaner energ