TY - GEN A1 - Goral, Milan A1 - Kömmling, Anja A1 - Probst, Ulrich A1 - Wossidlo, Peter A1 - Jaunich, Matthias A1 - Wolff, Dietmar A1 - Völzke, Holger T1 - Langzeitversuche über 10 Jahre an Federkern-Metalldichtungen mit Aluminium- bzw. Silberummantelungen N2 - Federunterstützte Metalldichtungen mit Aluminium(Al)- oder Silber(Ag)-Ummantelung werden u.a. in Behältern für Wärme entwickelnde radioaktive Abfälle eingesetzt, da diese Dichtungen eine sehr gute Dichtheit gewährleisten sowie Langlebigkeit und Beständigkeit gegenüber erhöhten Temperaturen und radioaktiver Strahlung aufweisen. Auch wenn die Sicherheit solcher Behälter und der verwendeten Dichtungen vielfach belegt wurde, sind sie Gegenstand andauernder Forschung, etwa im Hinblick auf eine absehbar benötigte verlängerte Zwischenlagerdauer. Aus diesem Grund werden an der Bundesanstalt für Materialforschung und -prüfung (BAM) im Fachbereich 3.4 „Sicherheit von Lagerbehältern“ seit über 20 Jahren Versuche an solchen Metalldichtungen durchgeführt. Dabei sollen zusätzliche Erkenntnisse hinsichtlich der Sicherheitsreserven der Dichtungen in unterstellten Störfallszenarien (axiale Bewegung des Deckelsystems bzw. Aufweitung der Nutgeometrie) und insbesondere detailliertere Erkenntnisse zum Langzeitverhalten gewonnen werden. KW - Federunterstützte Metalldichtungen KW - Transport- und Lagerbehälter für radioaktive Stoffe KW - Langzeitversuche KW - Alterung KW - Dichtheit KW - Leckagerate KW - Helium-Dichtheitsprüfung PY - 2023 VL - 2023 SP - 43 EP - 63 PB - ISGATEC GmbH CY - Mannheim AN - OPUS4-56399 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Grelle, Tobias A1 - Probst, Ulrich A1 - Jaunich, Matthias A1 - Skrotzki, Birgit A1 - Wolff, Dietmar T1 - Creep investigations on aluminum seals for application in radioactive waste containers N2 - In Germany spent nuclear fuel and high level radioactive waste is stored in interim storage containers with double lid systems. Those lids are equipped with metal seals (e.g. Helicoflex®) that ensure the safe enclosure of the inventory. The used metal seals consist of three components as can be seen in the cross-sectional view in Figure 1. The innermost part is a helical spring that is surrounded by an inner jacket made of stainless steel. The outer jacket that is made of a softer material which in case of assembly in the aforementioned storage containers is silver or aluminum (i.e. Al 99.5). During application the seal is compressed and due to the restoring force of the helical spring, the outer jacket is plastically deformed and adapts to the sealing surface. Hence, leakage paths are closed and the sealing function is generated. In Germany the above-mentioned containers are licensed for up to 40 years of interim storage, which in case extended storage becomes necessary before a final repository is available will have to be extended to even longer periods. Therefore, the evaluation of the long-term behavior of the seals is necessary, taking into account storage conditions, decay heat and possible mechanical loads as well. At Bundesanstalt für Materialforschung und –prüfung (BAM) long-term investigations are being conducted in which seals are assembled in test flanges and aged at temperatures ranging from room temperature to 150°C for accelerated aging. The aged seals are tested semi-annually (after the first 6 months in which the seals are tested more frequently) regarding the sealing performance, the remaining seal force, and the useable resilience upon decompression. Results of these investigations have been published over the past years (e.g. Grelle, Wolff, Probst, Jaunich, & Völzke, 2017; Völzke, Wolff, Probst, Nagelschmidt, & Schulz, 2014). It was found that the seal force and the useable resilience decrease with time and temperature, which is in agreement with the result of other studies (Sassoulas et al., 2006; Wataru et al., 2016) as well. Geometry change of the outer jacket has been identified as the main reason for this seal behavior. At the prevailing operating temperatures and stresses the aluminum is subjected to creep deformation leading to a thinning of the outer jacket. Since the seal groove depth remains unchanged the helical spring expands, which in turn leads to a decrease of the generated spring and seal force. Although the main reason for the change of seal parameters over time and temperature is known, a detailed characterization of the seal behavior and a reliable prediction of the parameter development for aging times that exceed the experimental time frame have not been possible, yet. For deeper understanding of the aging processes, an Investigation program, which is covered in this contribution, is conducted at Bundesanstalt für Materialforschung und –prüfung (BAM) that focusses on the behavior of the aluminum jacket and its influence on the long-term sealing performance. The program investigates properties of material samples as well as the behavior of the seal as a component. Original sheet material of the same aluminum that is used for manufacturing of the seals is investigated in compression creep tests. For this, a DMA (dynamic mechanical analysis) machine is employed (here used for static tests) that allows for a measurement of the specimens deformation under forces of up to 500 N. The advantage of this method is that the original material can be tested in the same shape as used for the seals which is 0.5 mm thick sheet material. For investigation of tensile creep standard specimens are used, that were machined from surrogate material of the same composition and annealing condition. Furthermore, aluminum seals that are cut into smaller segments are assembled in flanges and placed in heating chambers at temperatures ranging from 23°C to 150°C. After different periods of time from 3 days to 300 days the segments are taken out of the flanges and are investigated, thus giving information on different states of aging. Measurements of the development of the seal contact width and the aluminum jacket thickness are done with an optical microscope. Further investigations on the segments will include metallography and hardness measurements. From the detailed material and component behavior including the results of the long-term seal force and useable resilience investigations a better understanding of the overall seal behavior can be gained. The aim is to contribute to the development of material models and analytical approaches for the prediction of the sealing behavior in dependence of time and temperature. T2 - International Conference on Aluminum Alloys CY - Montreal, Canada DA - 17.06.2018 KW - Metal seal KW - Creep KW - Long-term behavior PY - 2018 SN - 978-1-926872-41-4 SP - 1 EP - 2 AN - OPUS4-45844 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Grelle, Tobias A1 - Probst, Ulrich A1 - Wolff, Dietmar A1 - Jaunich, Matthias A1 - Völzke, Holger T1 - Investigations on the long-term behavior of metal seals for dual purpose casks N2 - 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. T2 - 19th International Symposium on the Packaging and Transportation of Radioactive Materials PATRAM 2019 CY - New Orleans, LA, USA DA - 04.08.2019 KW - Metal seal KW - Radioactive waste containers KW - Creep KW - Long-term behaviour PY - 2019 SP - 1 EP - 6 AN - OPUS4-49019 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Grelle, Tobias A1 - Wolff, Dietmar A1 - Probst, Ulrich A1 - Jaunich, Matthias A1 - Völzke, Holger T1 - Investigation of the time and temperature dependent behavior of metal seals in radioactive waste containers N2 - The Bundesanstalt für Materialforschung und –Prüfung (BAM) runs an investigation program on the long-term behavior of multi-component metal seals. Such seals are used in a wide area of applications including transport and storage casks for spent nuclear fuel and high level radioactive waste. The seal function is mainly based on the compression of the inner helical spring, which generates the necessary seal force to keep the sealing surfaces in close contact. This in turn leads to a plastic deformation of the outer jacket of the seal, comprised of highly ductile aluminum or silver that adapts to the sealing surfaces of cask body and bolted lid, thus providing high Level leak tightness. In Germany, those casks are licensed for Interim storage periods of up to 40 years or more if extended Interim storage would become necessary before a final repository is available. Thus, the sealing performance has to be evaluated, including factors like elevated temperature due to decay heat or mechanical loads due to transport under normal as well as accident conditions. Long-term investigations at BAM have been running over the last nine years to identify and evaluate the seal performance by measuring the remaining seal force, the useable resilience and the leakage rate after various time intervals at temperatures ranging from room temperature up to 150 °C. It was found that the seal force and useable resilience decrease with time and temperature, caused by creep deformation of the outer jacket. In order to obtain an analytical description for the seal behavior and to achieve more information on the material behavior under application conditions a comprehensive investigation program with Focus on aluminum as outer jacket material was launched. The program includes material investigations such as compression and tension creep tests with representative basic materials. An additional test setup allows for the continuous measurement of the remaining seal force at temperatures of up to 150 °C. Furthermore, seal segments are compressed and stored in heating chambers, thus producing segments at different stages of the aging process. The segments are investigated regarding the development of the contact area width, jacket thickness and microstructural changes. This data will be used to develop material models and an analytical description of the time and temperature dependent long-term sealing behavior. This paper explains the current status of gained test results and modelling approaches and closes with an outlook to the future Project plans. T2 - ASME 2018 Pressure Vessels and Piping Conference CY - Prague, Czech Republic DA - 15.07.2018 KW - Metal seal KW - Creep KW - Long-term behavior PY - 2018 SP - PVP2018-84584, 1 EP - 6 AN - OPUS4-46110 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Grelle, Tobias A1 - Wolff, Dietmar A1 - Probst, Ulrich A1 - Jaunich, Matthias A1 - Völzke, Holger T1 - Investigation programme for evaluation and prediction of the long-term behaviour of Helicoflex® metal seals N2 - In Germany, for the transport and storage of spent nuclear fuel, casks with double closure lid systems are used, which are equipped with Helicoflex® metal seals. The original interim storage period for these casks was planned to be 40 years. However, recent political developments indicate that a storage time of more than 80 years might be necessary. Therefore, the current storage licenses have to be renewed in due course, which requires extended knowledge of the long-term behaviour of all cask components. At the Bundesanstalt für Materialforschung und -prüfung (BAM), metal seals have been investigated after ageing at temperatures between room temperature and 150 °C for up to 7 years. At regular intervals the seals have been tested for leakage rate as well as for their mechanical behaviour. From these tests pronounced influence of ageing could be shown which results in the decrease of the seal force and the useable resilience. The main reason attributed to these performance changes is the increasing permanent deformation of the outer layer of the seal due to creep. So far, an explicit analytical description of the long-term behaviour that could be used for predictions exceeding the tested ageing times and temperatures was not suitable. In addition to the component tests that were already conducted, a comprehensive investigation programme has been started to describe the mechanical behaviour of the individual seal components. The individual seal components are tested regarding different material characteristics including creep, deformation and microstructural properties. The comparability of the material characterization is ensured by comparing the basic raw material of the specimen with the actual component material. Furthermore, detailed investigations of the time and temperature dependent deformation behaviour are realized by ageing seal segments at multiple temperatures for different periods of time and employing standardized tests. By analysing the acquired data in combination with the ongoing long-term component tests a dataset for analytical prediction of the long-term behaviour of the seals is intended for an extended period of time under a certain temperature regime. T2 - 48th Annual Meeting on Nuclear Technology (AMNT 2017) CY - Berlin, Germany DA - 16.05.2017 KW - Metal seal KW - Creep KW - Long-term behavior PY - 2017 SP - 1 EP - 7 AN - OPUS4-43418 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Grelle, Tobias A1 - Wolff, Dietmar A1 - Probst, Ulrich A1 - Jaunich, Matthias A1 - Völzke, Holger T1 - Component and material investigations on metal seals for high level radioactive waste containers N2 - Long-term investigations performed at BAM look to extend the state of knowledge on safety-related components of interim storage containers. Metal seals act as the primary sealing barrier in the bolted double lid closure system of the containers. The behaviour of metal seals has been investigated for ageing times up to 8.5 years and for various temperatures. The main cause for reduction in useable resilience overtime was due to creep deformation of the outer jacket of the seal. KW - Metal seal KW - Radioactive waste containers KW - Creep KW - Long-term behaviour PY - 2018 SN - 1745-2058 SP - 32 EP - 34 PB - Nuclear Institute CY - London AN - OPUS4-48206 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Grelle, Tobias A1 - Wolff, Dietmar A1 - Probst, Ulrich A1 - Jaunich, Matthias A1 - Völzke, Holger T1 - Component and material investigations on metal seals for high level radioactive waste containers N2 - In Germany casks for interim storage of spent nuclear fuel and high level radioactive waste are equipped with Helicoflex® metal seals as main sealing barrier of the double lid system. The long-term behaviour of those seals is investigated at Bundesanstalt für Materialforschung und –prüfung (BAM) in order to evaluate the safety function of the containment at different temperatures over storage periods of 40 years or more in case extended interim storage becomes necessary. Long-term investigations have been done for ageing times of up to 8.5 years at temperatures ranging from room temperature to 150 °C. It was found that the seal force and useable resilience decrease over time, which is mainly caused by creep deformation of the aluminium (or silver) outer jacket of the seals. This effect becomes stronger with increasing temperature. The ageing processes of the seal material and the overall seal behaviour is under investigation in order to derive analytical descriptions for the long-term seal performance. Thus, standardized tests on the basic seal materials, with focus on aluminium, and additional investigations on the seals as a component are conducted. The current investigations include compression and tension creep measurements as well as tensile testing. Furthermore, ageing of seal segments provides information on the development of the contact area width, jacket thickness and microstructural changes in dependence of time and temperature. The obtained data are used for the development of material models and an analytical approach to describe and predict the time and temperature dependent sealing behaviour in the long-term. T2 - 11th International Conference on the Transport, Storage and Disposal of Radioactive Materials CY - London, UK DA - 15.05.2018 KW - Metal seal KW - Creep KW - Long-term behavior PY - 2018 SP - 18535, 1 EP - 6 AN - OPUS4-45452 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Grelle, Tobias A1 - Wolff, Dietmar A1 - Probst, Ulrich A1 - Jaunich, Matthias A1 - Völzke, Holger T1 - Material investigation and long-term sealing behavior of Helicoflex® metal seals used in containers for spent nuclear fuel N2 - In Germany spent nuclear fuel is stored and transported in casks that possess bolted lid systems equipped with double jacket metal seals of Helicoflex® type in order to enable safe enclosure of the radioactive inventory. A dry interim storage period of 40 years was planned and the casks are licensed for that time span. However, due to political reasons and delayed disposal projects this time span is expected to increase significantly. It is therefore necessary to evaluate the long-term sealing behavior of the casks exceeding 40 years of operating time. In this paper, we discuss our approach to investigate the aging behavior of such metal seals, and to predict the long-term sealing behavior. Accelerated aging component tests with seals are performed at temperatures up to 150°C to investigate the course of seal force, useable resilience and leakage rate. Even though these tests have already shown a significant decrease in seal force and useable resilience after aging times of less than 1 year, for most seals the leakage rate stayed better than the specified value. However, observation of the leakage rate has to be continued to determine the aging effect on the seal properties. As a main influence on the seal long-term behavior the increasing permanent deformation of the outer jacket has been recognized. It is made of aluminum or silver which means that the temperatures that are relevant for the aforementioned application in casks lead to creep deformation. For further investigation of seal behavior a comprehensive research program concerning the material characteristics and aging behavior of the individual seal components, with an emphasis on the outer jacket material, has been launched. The aim is to get a better understanding of the time and temperature dependent creep mechanisms and deformation. The examinations are separated into tests on seal segments and tests on standardized specimen. In order to be able to study the aging process, seal segments are compressed in flanges and stored at temperatures ranging from room temperature to 150°C. After defined time intervals the segments are analyzed by using standardized tests including structure investigation and creep tests. The results are compared with the behavior of the specimen basic raw material. This is done to ensure comparability of the thin jacket material and additional sheet material used for standardized tests. Thus, the prediction of component changes after different aging times at different temperatures can be made. As a result forecasts on the long term seal behavior are intended. T2 - Waste Management Symposia CY - Phoenix, AZ, USA DA - 05.03.2017 KW - Metal seal KW - Creep KW - Long-term behavior PY - 2017 SN - 978-0-9828171-6-2 SP - Article 17135, 1 EP - 8 AN - OPUS4-40611 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Jaunich, Matthias A1 - Probst, Ulrich A1 - Schulz, Sebastian A1 - Wolff, Dietmar A1 - Stark, Wolfgang ED - Berger, K.-F. ED - Kiefer, S. T1 - Elastomere - Untersuchung des Tieftemperaturverhaltens im Dichtungseinsatz N2 - Aufgrund ihrer einfachen und zuverlässigen Anwendung werden Elastomere für viele Dichtungsaufgaben eingesetzt. In vielen Anwendungsbereichen, wie z.B. Verkehr, Luftfahrt und Verfahrenstechnik, können während des Einsatzes tiefe Temperaturen auftreten, bei denen die Funktionsfähigkeit der Dichtung erhalten bleiben muss. Daher ist die Untersuchung des Verhaltens von Elastomerdichtungen bei tiefen Temperaturen wichtig, um ihren Temperatureinsatzbereich nach unten abzugrenzen und dadurch einen verlässlichen Betrieb zu sichern. Ziel dieser Arbeit ist es, den sicheren Einschluss von gefährlichen Gütern unter verschiedenen Umgebungsbedingungen und über lange Zeiten zu ermöglichen bzw. die Materialauswahl entsprechend zu steuern. KW - Dichtung KW - Druckverformungsrest KW - Elastomer KW - Glasübergang PY - 2013 SN - 978-3-9811509-7-1 SP - 82 EP - 91 CY - Mannheim AN - OPUS4-29661 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Probst, Ulrich A1 - Schulz, Sebastian A1 - Jaunich, Matthias A1 - Wolff, Dietmar A1 - Völzke, Holger ED - Berger, K.-F. ED - Kiefer, S. T1 - Langzeituntersuchungen an Metalldichtungen mit innen liegendem Federkern und doppelter Ummantelung N2 - In Deutschland werden in Transport- und Lagerbehältern (TLB) wärmeentwickelnde radioaktive Abfälle gegenwärtig über einen Zeitraum von bis zu 40 Jahren zwischengelagert. Aufgrund der Situation der noch nicht abgeschlossenen Endlagersuche werden hier möglicherweise Verlängerungen in Betracht zu ziehen sein. Im Deckeldichtsystem der TLB werden in der Regel Metalldichtungen vom Typ Helicoflex® eines französischen Herstellers verwendet, die aus einem innen liegenden Spiralfederkern und zwei Ummantelungen bestehen. Die Ermittlung der Fliess- und Relaxationseigenschaften der Dichtungskomponenten über den vorgesehenen langen Betriebseitraum sind vor dem Hintergrund des Erhalte eines geforderten hohen Dichtniveaus ein wichtiger Untersuchungsgegenstand. KW - Metalldichtung KW - Langzeiteignung KW - Dichtsysteme KW - Transport- und Lagerbehälter für radioaktive Stoffe PY - 2013 SN - 978-3-9811509-7-1 SP - 1 EP - 11 CY - Mannheim AN - OPUS4-28912 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Shirai, K. A1 - Namba, K. A1 - Wataru, M. A1 - Völzke, Holger A1 - Wolff, Dietmar A1 - Probst, Ulrich A1 - Jaunich, Matthias A1 - Schulz, Sebastian T1 - Numerical evaluation of the long-term sealing performance of the silver gasket for dual purpose metal cask under high temperature N2 - It is important to evaluate the effect of thermal ageing on the sealing performance of metal gaskets under high temperature for long-term usage. Therefore, in order to gain representative data for this kind of metal-sealed lid System, BAM is currently performing laboratory tests of different gasket types with aluminum and silver jackets at three different temperatures under static conditions up to four years so far, using test flanges for gaskets with full scale cross section diameter but much smaller outer diameter. On the other hand, in order to investigate the applicability of the numerical methodology to evaluate the long-term behavior of the metal gaskets, such as a correlation between seal pressure force and holding time, CRIEPI is developing a modeling method including material tests (tensile and creep tests) at high temperature. In this paper, the applicability of the finite element method (ABAQUS) to predict the recovery displacement and residual seal pressure force of the gasket complex was verified by comparing the calculated values with BAM’s laboratory test results under the joint research agreement between BAM and CRIEPI. T2 - PATRAM 2013 - 17th International symposium on the packaging and transportation of radioactive materials CY - San Francisco, CA, USA DA - 18.08.2013 KW - Metal seals KW - Extended storage KW - Long-term storage KW - Dual purpose cask PY - 2013 SP - 1 EP - 8 PB - Omnipress AN - OPUS4-31947 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weber, Mike A1 - Kömmling, Anja A1 - Jaunich, Matthias A1 - Wolff, Dietmar A1 - Zencker, Uwe A1 - Völzke, Holger A1 - Schulze, Dietmar A1 - Probst, Ulrich T1 - Testing and Numerical Simulation of Elastomers - From Specimen Tests to Simulation of Seal Behavior under Assembly Conditions N2 - Due to delays in the siting procedure to establish a deep geological repository for spent nuclear fuel and high level radioactive waste as well as in construction of the already licensed Konrad repository for low and intermediate level radioactive waste, extended periods of interim storage become more relevant in Germany. BAM is involved in most of the cask licensing procedures and especially responsible for the evaluation of cask-related long-term safety issues. The long-term performance of elastomer seals for lid systems of transport and storage casks, whether used as auxiliary seals in spent fuel casks or as primary seals for low and intermediate level waste packages, is an important issue in this context. The polymeric structure of these seals causes a complex mechanical behavior with time-dependent sealing force reduction. The results of a comprehensive purpose-designed test program consisting of basic compression and tension tests as well as relaxation tests on unaged specimens of representative types of elastomers (fluorocarbon rubber (FKM) and ethylene propylene diene rubber (EPDM)) at different temperatures and strain rates are presented. They were used to identify the constitutive behavior and to obtain parameters for finite element material models provided by the computer code ABAQUS®. After estimating the influence of uncertainties such as Poisson’s ratio and friction coefficient by sensitivity analyses, the chosen parameters had to prove their suitability for the finite element simulation of the specimen tests themselves. Based on this preliminary work the simulation of a specific laboratory test configuration containing a typical elastomer seal with circular cross section is presented. The chosen finite element material model and the implemented parameters had to show that they are able to represent not only the specimen behavior under predominantly uniaxial load but also the more complex stress states in real components. Deviations between the measured and calculated results are pointed out and discussed. For the consideration of long-term effects in the simulation of elastomer behavior, test results of aged specimens are needed. First information about a new test program, started recently and planned to provide these data, are given. T2 - ASME 2017 Pressure Vessels & Piping Conference (PVP2017) CY - Waikoloa, Hawaii, USA DA - 16.07.2017 KW - Time dependent effects KW - Low temperature behavior KW - Elastomeric seals KW - Aging KW - Simulation KW - Testing PY - 2017 SN - 978-0-7918-5802-8 VL - 7 SP - Article UNSP V007T07A035, 1 EP - 8 AN - OPUS4-41841 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wolff, Dietmar A1 - Jaunich, Matthias A1 - Probst, Ulrich A1 - Nagelschmidt, Sven T1 - Understanding the long-term behavior of sealing systems and neutron shielding material for extended dry cask storage N2 - In Germany, the concept of dry interim storage in dual purpose metal casks before disposal is being pursued for spent nuclear fuel (SF) and high active waste (HAW) management. However, since there is no repository available today, the initially planned and established dry interim storage license duration of up to 40 years will be too short and its extension will become necessary. For such a storage license extension it is required to assess the long-term performance of SF and all safety related storage system components in order to confirm the viability of extended storage. The main safety relevant components are the thick-walled dual purpose metal casks. These casks consist of a monolithic cask body with integrated neutron shielding components (polymers, e.g. polyethylene) and a monitored double lid barrier system with metal and elastomeric seals. The metal seals of this bolted closure system guarantee the required leak-tightness whereas the elastomeric seals allow for leakage rate measurement of the metal seals. This paper presents an update on running long-term tests on metal seals at different temperatures under static conditions over longer periods of time. In addition, first results of our approach to understand the aging behavior of different elastomeric seals and neutron radiation shielding material polyethylene are discussed. T2 - PSAM 12 - Probabilistic safety assessment and management CY - Honolulu, Hawaii, USA DA - 22.06.2014 KW - Extended storage KW - Dual purpose casks KW - Metal seals KW - Elastomeric seals KW - Neutron shielding material PY - 2014 SP - 1 EP - 9 AN - OPUS4-32072 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -