Dokument-ID Dokumenttyp Autoren/innen Persönliche Herausgeber/innen Haupttitel Abstract Auflage Verlagsort Verlag Herausgeber (Institution) Erscheinungsjahr Titel des übergeordneten Werkes Jahrgang/Band ISBN Veranstaltung Veranstaltungsort Beginndatum der Veranstaltung Enddatum der Veranstaltung Ausgabe/Heft Erste Seite Letzte Seite URN DOI Lizenz Datum der Freischaltung OPUS4-49263 Zeitschriftenartikel Qiao, Linan; Keller, Christian; Zencker, Uwe; Völzke, Holger Three-dimensional finite element analysis of O-ring metal seals considering varying material properties and different seal diameters Metal seals of O-ring form are often used in lid-systems of transport and storage casks for radioactive waste in Germany. To investigate their mechanical behaviour, three dimensional (3D) finite element (FE) models were created using solid elements for all of the seal components. The material behaviour of each component is described with a unified static elastic-plastic material model. The total strain is defined as the sum of linear elastic strain and plastic strain with power-law hardening. The model was carefully validated by comparison of Simulation results with experimental results. The influence of material fluctuation of each seal component due to varying properties and the sensitivity of different seal diameters on the seal force are analysed and discussed. The results show that the material properties of helical spring have major influence on seal force and that the influence of seal diameters is negligible small in the studied range. This is very important to use the test results from seals with small diameter for the assessment of seal behaviour with larger diameter as used in transport and storage cask. Amsterdam Elsevier Ltd. 2019 International Journal of Pressure Vessels and Piping 176 102953 10.1016/j.ijpvp.2019.103953 2019-10-14 OPUS4-48914 Beitrag zu einem Tagungsband Zencker, Uwe; Qiao, Linan; Völzke, Holger Fracture mechanical analysis of a cylindrical cast iron cask The safety evaluation of cask components made of ductile cast iron includes investigations to prevent brittle fracture. Generally, ductile cast iron is endangered by brittle fracture especially at low temperatures (down to -40°C) and in combination with existing crack-like material defects. An applicable method is the assessment of fracture resistance using fracture mechanics according to the IAEA guidelines. The approach is based on the prevention of fracture initiation. For application of these principles for drop loads, account must be taken both of dynamic stresses within the component and dynamic material behavior. Basically, the dynamic stress intensity factor of postulated pre-existing crack-like defects is compared with the dynamic fracture toughness of the material. Applicable numerical and experimental methods for the safety assessment of cask components are demonstrated for the case of an artificially pre-cracked cylindrical cast iron cask which undergoes dynamic loading conditions as result of the hard impact between the cask and a concrete target. The proposed evaluation procedure is a combination of numerical and experimental steps. Exemplarily, the calculated stress intensity factor is compared with measured fracture toughness values from single edge notched bending specimens. 2019 Proceedings of the 19th International Symposium on the Packaging and Transportation of Radioactive Materials (PATRAM 2019) 19th International Symposium on the Packaging and Transportation of Radioactive Materials (PATRAM 2019) New Orleans, LA, USA 04.08.2019 09.08.2019 Paper 1209, 1 7 2019-09-11 OPUS4-48869 Beitrag zu einem Tagungsband Zencker, Uwe; Simbruner, Kai; Völzke, Holger Brittle failure of spent fuel claddings under long-term dry interim storage conditions - Preliminary analysis The evaluation of cladding integrity is a major issue to be demonstrated in Germany for extended interim storage periods up to 100 years and subsequent transportation considering operational and accidental conditions with respect to reactor operation, cask drying and dry interim storage. The chemical reaction between the zirconium fuel cladding and the cooling water in water-cooled reactors produces hydrogen and zirconium oxide. Hydrogen diffuses into the cladding and precipitates as zirconium hydrides when the solubility limit is reached, preferably oriented in hoop direction. At high temperatures during vacuum drying procedures, the hydrides can dissolve. Over a succeeding period of slow cooling with existing hoop stress the hydrides precipitate again, but partly reoriented along the radial direction of the cladding. This change of microstructure in combination with a decreasing temperature (0.5...2 K/year) during (extended) interim storage and additional mechanical load by handling procedures or under accident conditions could lead to a potential cladding embrittlement and consequently increased failure probability. The current research project BRUZL (Fracture mechanical analysis of spent fuel claddings under long-term dry interim storage conditions) has been launched by BAM to investigate potential sudden brittle failure of spent fuel claddings at small deformation under long-term dry interim storage conditions and is presented. 2019 Proceedings of the IAEA International Conference on the Management of Spent Fuel from Nuclear Power Reactors IAEA International Conference on the Management of Spent Fuel from Nuclear Power Reactors Vienna, Austria 24.06.2019 28.06.2019 Paper IAEA-CN-272/49, 1 8 2019-09-06 OPUS4-49019 Beitrag zu einem Tagungsband Grelle, Tobias; Probst, Ulrich; Wolff, Dietmar; Jaunich, Matthias; Völzke, Holger Investigations on the long-term behavior of metal seals for dual purpose casks In Germany, spent nuclear fuel and high active waste from reprocessing is stored in transport and storage containers with double lid systems that are equipped with metal seals completing the primary sealing barrier. The tasks of the Bundesanstalt für Materialforschung und -prüfung (BAM) within the interim storage licensing procedures ruled by the German Atomic Energy Act include the long-term safety evaluation of the container design regarding the permanently safe enclosure of the inventory. In order to generate a knowledge base for the safety evaluation, research regarding the long-term behavior of the critical components is performed. So far, the containers are licensed for an interim storage period of 40 years. However, due to significant delays in establishing a final repository, the required time span for interim storage is expected to increase significantly. Thus, a widespread investigation program is run to gain systematic data on the long-term behavior of the seals and to develop prediction models. Long-term seal investigations consider the development of their restoring seal force, their useable resilience and their achievable leakage rate caused by aging at temperatures ranging from room temperature up to 150 °C. This year, the total time span of the tests reaches 10 years. Furthermore, seal segments are aged at the selected temperatures for up to 300 days. From these segments additional information on the sealing behavior, changes of the seal contact and the material behavior is gained. This contribution deals with the current results of the long-term seal investigations at BAM. Furthermore, insights of the more in-depth component and material investigations of the metal seals with focus on the seal contact development are discussed and the ongoing work aiming for an analytical description of the thermo-mechanical aging effects on metal seals are presented. 2019 Proceedings of the 19th International Symposium on the Packaging and Transportation of Radioactive Materials PATRAM 2019 19th International Symposium on the Packaging and Transportation of Radioactive Materials PATRAM 2019 New Orleans, LA, USA 04.08.2019 1 6 2019-09-20 OPUS4-48519 Buchkapitel Wolff, Dietmar; Völzke, Holger; Bevilacqua, A.; Alejano, C.; Conde, J.M.; Einziger, R.E.; Fukuda, S.-I.; González Espartero, A.; Gouzy-Portaix, S.; Haddad Andalaf, R.E.; Hambley, D.; Issard, H.; Kessler, J.; Kurpaska, L.; Legat, A.; Qureshi, A.H.; Ruiz, J.; Shirai, K.; Šmaižys, A.; Verrastro, C.A. González Espartero, A. Demonstrating performance of spent fuel and related storage system components during very long term storage - Final report of a coordinated research project This publication summarizes the work carried out during an IAEA coordinated research project (CRP) on safe and reliabe management of spent nuclear fuel. This work contributes to the overall goal of demonstrating the performance of spent nuclear fuel and related storage systems components over long durations, and facilitates the transfer of this knowledge to Member States. The technical areas addressed by the CRP participants were related to potential degradation mechanisms in metal casks and concrete overpacks, such as stress corrosion cracking; long term integrity and performance of the fuel cladding; thermo-mechanical behaviour of the metal seals; and long term gamma and neutron shielding capability. The participants also considered past and ongoing demonstration programmes. For each technical topic addressed the main conclusions have been drawn, including information on the development of specific monitoring and inspection techniques as well as future opportunities for closing relevant data gaps. A major achievement is also the establishment of a worldwide network of experts working on current research projects to demonstrate the long term performance of spent fuel in dry storage systems. Vienna, Austria IAEA Publishing Section International Atomic Energy Agency 2019 IAEA TecDoc Series 1878 978–92–0–103319–2 1 198 2019-07-22 OPUS4-51833 Zeitschriftenartikel Jaunich, Matthias; Goral, Milan; Wolff, Dietmar; Völzke, Holger Krüssenberg, A. Overview of metal seal tests performed at BAM and implications for extended interim storage The investigation of the long-term performance of sealing systems employed in containers of radioactive waste and spent nuclear fuel is one research focus area for division 3.4 \Safety of Storage Containers" at the Bundesanstalt für Materialforschung und -prüfung. The behaviour of metallic seals, which are employed in interim storage casks for spent nuclear fuel and high active waste, over time is of high importance for ensuring safe enclosure. Therefore, investigations on these systems were started at BAM to get a general understanding of the relevant processes. Our investigations comprise investigations on different parameters which influence the seal Performance and the main part is focussed on the time and temperature dependent behaviour. Our aim is to understand the longterm behaviour of the sealing systems for evaluation of their performance during possible extended interim storage and subsequent transportation. In this contribution an overview of the performed tests and their respective results is given. A focus lies on a comparison between seals with large torus diameter in comparison to small diameters. München Carl Hanser Verlag 2020 Kerntechnik 85 Safety of Extended Dry Storage of Spent Nuclear Fuel SEDS2020: International online-workshop Online meeting 03.06.2020 6 440 443 10.3139/124.200071 2020-12-16 OPUS4-51486 Beitrag zu einem Tagungsband Kömmling, Anja; Simbruner, Kai; Grelle, Tobias; Jaunich, Matthias; Zencker, Uwe; Wolff, Dietmar; Orellana Pérez, Teresa; Völzke, Holger Research at BAM for evaluating long term safety of container systems and components Safety of long term containment and storage of radioactive waste is an essential issue, which is increasingly gaining international attention. Extending interim storage beyond initial license periods is one of the major challenges worldwide. BAM has been involved in all kinds of radioactive waste container safety evaluation for storage and transportation including their long term performance from the very beginning. Today, all work related to the safe management of radioactive waste is linked by the activity field "Nuclear Waste Management" within the Focus Area "Energy" at BAM and in conjunction with a research strategy and agenda. Most recently, the working group "Long Term Safety of Container Systems and Components" was established to launch and perform research projects related to safety issues concerning the extended interim storage of radioactive waste. For example, within our project LaMEP, we investigate ageing effects of metal and elastomer seals as well as polymeric neutron shielding materials, which are container components that fulfil major safety functions. The results of the experiments help to understand the long term behaviour of these components. Likewise, our project BRUZL started at BAM in 2018 with the aim of developing a fracture mechanics approach to understand and describe a potential brittle failure mechanism of fuel cladding during long-term interim storage. BAM also contributes to the GRS project "Development of methods and models and international exchange for safety evaluation in the frame of interim storage of radioactive waste". Additionally, BAM is involved in several international research programmes dealing with extended interim storage, such as the European Joint Programme on Radioactive Waste Management (EURAD), the Extended Storage Collaboration Program (ESCP) and IAEA Coordinated Research Projects. The present contribution provides a comprehensive overview of BAM research activities contributing to national and international gap analyses and to filling knowledge gaps regarding the safe long term management of radioactive waste. 2019 Annual Meeting on Nuclear Technology 978-3-926956-95-8 Annual Meeting on Nuclear Technology 2019 Berlin, Germany 07.05.2019 08.05.2019 1 5 2020-12-07 OPUS4-51616 Vortrag Völzke, Holger Update on the German Spent Fuel Management Strategy The presentation provides an update on the German spent fuel Management strategy in the areas of transportation, dry interim storage and deep geological disposal. 2020 IAEA 18th TWG-NFCO Online meeting 07.09.2020 11.09.2020 2020-11-23 OPUS4-51615 Vortrag Völzke, Holger Research at BAM on Metal Seal Performance and Fuel Rod Integrity The presentation provides an update on preliminary results from research projects in the area of long term performance of metal seals and fuel rod integrity as safety relevant components of spent fuel transport and storage casks for spent nuclear fuel. 2020 Extended Storage Collaboration Program (ESCP) Winter Meeting 2020 Online meeting 09.11.2020 12.11.2020 2020-11-23 OPUS4-49619 Vortrag Völzke, Holger Internationale Forschung zur langfristigen trockenen Zwischenlagerung bestrahlter Brennelemente Der Vortrag adressiert die internationalen Forschungsprogramme und -schwerpunkte im Zusammenhang mit der Notwendigkeit einer deutlich verlängerten Zwischenlagerung Wärme entwickelnder radioaktiver Abfälle. 2019 BGZ - Workshop Zwischenlagerung Berlin, Germany 22.10.2019 23.10.2019 2019-11-20