TY - CONF A1 - Völzke, Holger A1 - Droste, Bernhard A1 - Wieser, Günter A1 - Gogolin, Bernd T1 - Extended brittle fracture safety demonstrations of cubic ductile cast iron containers T2 - PATRAM ´95 - 11th International Conference on the packaging and transportation of radioactive materials CY - Las Vegas, Nevada, USA DA - 1995-12-03 KW - Container KW - Sprödbruch PY - 1995 VL - 3 SP - 1356 EP - 1363 AN - OPUS4-614 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Eisenacher, Germar A1 - Scheidemann, Robert A1 - Neumann, Martin A1 - Sterthaus, Jens A1 - Kasparek, Eva Maria A1 - Völzke, Holger T1 - Stauchversuche mit querdehnungsbehinderten Fichtenholzproben verschiedener Faserorientierungen bei veränderlicher Dehnrate T1 - Compression tests with laterally constrained spruce specimens with varying fiber orientations and loading rates N2 - Im Zuge des Forschungsvorhabens ENREA (Entwicklung rechnerischer Analysemethoden für stoßdämpfende Strukturen beim Anprall oder Absturz von Abfallgebinden) führt die BAM systematische Untersuchungen an stoßdämpfenden Werkstoffen, unter anderem an Fichtenholz, durch. Zweck der mit diesen Untersuchungen erzeugten Datenbasis ist die Erstellung und Parametrierung eines Finite-Elemente- (FE-) Materialmodells, das die Modellierung holzgefüllter stoßdämpfender Bauteile von Transportbehältern für radioaktive Stoffe in der FE-Simulation ermöglichen soll. Anhand von Ergebnissen aus der ersten Versuchsphase werden der Einfluss der Dehnrate und der Faserorientierung auf das Kraft-Verformungs-Verhalten von Fichtenholz diskutiert. Anschließend wird die rechnerische Modellierung von Fichtenholz diskutiert und die Anforderungen an ein Materialmodell werden erläutert. N2 - In the course of research project ENREA (development of numerical methods for analyzing impact limiters subjected to impact or drop scenarios), BAM is systematically investigating impact limiting materials, e. g. spruce wood. Goal of these investigations is to establish and parameterize a finite element (FE) material model which enables the modeling of wood filled impact limiting devices of transport casks for radioactive materials. Using results of the first test stage, the effect of loading rate and fiber orientation on the force-deflection characteristics of spruce wood will be presented. Following, computational modeling of spruce wood including requirements for a material model will be discussed. T2 - KONTEC 2011 - 10. Internationales Symposium "Konditionierung radioaktiver Betriebs- und Stilllegungsabfälle" CY - Dresden, Germany DA - 06.04.2011 PY - 2011 N1 - Sprachen: Deutsch/Englisch - Languages: German/English SP - 465 EP - 478 AN - OPUS4-23684 LA - mul AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Qiao, Linan A1 - Zencker, Uwe A1 - Völzke, Holger A1 - Wille, Frank A1 - Musolff, André ED - Topping, B.H.V. T1 - Validation of numerical simulation models for transport and storage casks using drop test results N2 - The safety assessment of new designs for transport and storage casks for radioactive materials is a challenging task accomplished using different methods such as prototype tests, model tests, calculations and analogy reflections. At BAM (Federal Institute for Materials Research and Testing), the test procedures for the mechanical IAEA (International Atomic Energy Agency) test conditions often start with preliminary finite element (FE) calculations mostly with a small-scale cask model for verification of the proposed test cask instrumentation and test plan. On that basis the extensive test cask instrumentation is applied and checked. After that, a series of drop tests consisting of different test sequences is performed. Following the drop tests, numerical post-analyses are carried out. These analyses offer the possibility of a detailed calculation and assessment of stresses and strains in the entire test cask construction. The calculation results have to be carefully compared with the measurement data over the impact history to find out all relevant parameters for a realistic simulation of the impact scenario. The desired ideal boundary test conditions often cannot be met exactly during the drop tests. Therefore, the numerical post-analyses are carried out by using the real boundary conditions of the drop tests. The objective is to find a validated model, where the results of the numerical simulations satisfactorily meet the experimental results. Under test conditions according to the IAEA transport regulations, casks are usually equipped with impact limiters and dropped onto a so-called unyielding target. In general, it is difficult to verify a complex FE model by using results from only one drop test because of the complex impact process and the complex structure of such packages. After each drop test, numerical post-analyses should be carried out. Only if all drop tests were simulated successfully by using the same FE model under different test conditions, it is possible to obtain a validated numerical model for further investigations. In this case the results of the numerical simulations meet satisfactorily the experimental results. In this paper a study is presented, where the influence of different components on the cask loading is investigated systematically. T2 - 11th International conference on computational structures technology CY - Dubrovnik, Croatia DA - 04.09.2012 KW - Impact KW - Simulation KW - Cask KW - Dop test KW - Finite element model KW - Validation KW - Dynamics KW - Transport and storage cask PY - 2012 DO - https://doi.org/10.4203/ccp.99.273 SN - 1759-3433 IS - Paper 273 SP - 1 EP - 12 PB - Civil Comp Press AN - OPUS4-26537 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Protz, Christian A1 - Völzke, Holger A1 - Ellouz, Manel A1 - Kasparek, Eva Maria A1 - Zencker, Uwe A1 - Grünewald, Heike A1 - Gründer, Klaus-Peter T1 - ConDrop - Development of numerical simulation approaches for drop test analyses of steel sheet containers N2 - According to disposal requirements, containers for radioactive waste have to withstand drop tests at defined conditions corresponding to the considered package category. Alternatively to prototype drop tests, numerical methods can be applied, if they are suitable and sufficiently verified. In this context BAM (Federal Institute for Materials Research and Testing) started the research project ConDrop to develop a reliable Finite Element (FE) model describing the mechanical behavior of a box shaped steel container during a drop test and to determine unfavorable scenarios within future safety assessment procedures of comparable steel sheet containers. In a first step, a FE model of a representative steel sheet container was developed. Flat bottom-side drop tests with the unloaded container from different heights onto an IAEA target were simulated. In order to verify the numerical calculations, two drop tests with an unloaded KONRAD Type V steel sheet container were carried out at the BAM drop test facility. Both drop tests (flat drop from heights 0.4 m and 5 m onto the unyielding IAEA target) had been documented by various extensive measurements: strain and deceleration measurement by means of strain gauges and accelerometers, high-speed video as well as optical 3D-measurements using the method of projected fringes in combination with close range photogrammetry. The measured strain and deceleration values are presented and compared with the calculated results. T2 - 53rd INMM Annual meeting CY - Orlando, FL, USA DA - 15.07.2012 KW - INMM 53rd annual meeeting PY - 2012 SP - 1 EP - 7 AN - OPUS4-26417 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Völzke, Holger T1 - Stand bei den Behälterbauartprüfungen für das Endlager Konrad N2 - Die Verfügbarkeit von Behältern für die Entsorgung nicht Wärme entwickelnder radioaktiver Abfälle im Endlager Konrad stellt ein wesentliches Element des nationalen Entsorgungskonzeptes für diese Abfallart dar. Grundlage für die Verfügbarkeit geeigneter Behälter sind typspezifische Bauartprüfungen, auf deren Grundlage eine Eignungs-feststellung in Form eines Prüfzeugnisses durch die Bundesgesellschaft für Endlagerung mbH (BGE), vormals Bundesamt für Strahlenschutz (BfS), erfolgt. Die Prüfgrundlagen sind in den durch das BfS (heute BGE) veröffent-lichten „Anforderungen an endzulagernde radioaktive Abfälle“ (Endlagerungsbedingungen) sowie der zugehörigen „Produktkontrolle radioaktiver Abfälle, radiologische Aspekte“ (PK) verankert. Die Eignungsfeststellung für eine Be-hälterbauart ist gleichzeitig die Grundlage für eine Behälterserienfertigung entsprechend den im Prüfzeugnis veran-kerten Spezifikationen und Randbedingungen. Mit den Gesetzen zur Neuordnung der Organisationsstruktur im Bereich der Endlagerung (Mitte 2016) und zur Neuordnung der Verantwortung in der kerntechnischen Entsorgung (Mitte 2017) mit der Finanzierung des Kern-energieausstiegs wurden wesentliche Weichenstellungen im Hinblick auf den anstehenden Rückbau der bereits stillgelegten und in den kommenden Jahren noch stillzulegenden deutschen Kernkraftwerke vorgenommen. Bezüg-lich der nicht Wärme entwickelnden radioaktiven Abfälle führt dies zu einer spürbaren Intensivierung der Anstren-gungen zur Bereitstellung qualifizierter Gebinde für das Endlager Konrad, das nach aktueller Planung bis 2027 sei-nen Einlagerungsbetrieb aufnehmen soll. Dies wiederum führt zu einer erheblichen Verdichtung der Verfahren zur Behälterbauartprüfung, die allen Seiten (Antragsteller, BGE, Gutachter) erhebliche Anstrengungen abfordert. Die Bundesanstalt für Materialprüfung und –forschung (BAM) ist auf Grundlage des Kap. 7 der o. g. „Produktkon-trolle …“ (PK) von der BGE mit den Behälterbauartprüfungen für das Endlager Konrad beauftragt. Hierbei ist eine Vielzahl von Anforderungen zu berücksichtigen, wozu neben den Anforderungen an Abfallbehälter gemäß Kap. 5 der Endlagerungsbedingungen weitere Anforderungen an die Verpackung (Kap. 3.2.2 PK), Kenngrößen (Kap. 3.5.1 PK) und schließlich die eigentliche Prüfung von Behältern/Verpackungen zählt (Kap. 7 PK). Letzteres beinhaltet die umfassende Behälterbeschreibung und –spezifikation, die Behälterauslegung, die thermischen und mechanischen Baumusterprüfungen (z.B. Brand- und Fallprüfungen), und schließlich die qualitätssichernden Maßnahmen für Her-stellung und Betrieb der Behälter. Neben der klassischen Bauartprüfung neuer Behältertypen spielt auch die Prü-fung bereits hergestellter Behälter, sog. Altbehälter, eine wesentliche Rolle, da sich etliche tausend Gebinde bereits in der Zwischenlagerung befinden und nach Möglichkeit für das Endlager Konrad qualifiziert werden sollen. Dieser Beitrag berichtet aktuell über den Umfang und Stand der laufenden Bauartprüfungen bei der BAM unter Be-rücksichtigung der besonderen Herausforderungen und der zuletzt erzielten Fortschritte. Dabei erfordert die paral-lele Bearbeitung der zahlreichen Verfahren einen verstärkten Koordinierungsbedarf hinsichtlich vergleichbarer fach-licher Aspekte sowie hinsichtlich Priorisierung und Ressourceneinsatz. Bei den experimentellen Nachweisen (Fall- und Brandversuche) betrifft das hinsichtlich der Nutzung der Versuchseinrichtungen bei der BAM die Koordination mit anderen Prüfaufträgen, wie z. B. verkehrsrechtliche Baumusterprüfungen. Schließlich erfordern diverse Fach-fragen zur Interpretation der Anforderungen aus Endlagerungsbedingungen und Produktkontrolle intensive Abstim-mungsprozesse zwischen BAM, BGE und Antragstellern. Wichtige Ergebnisse mit übergeordneter Bedeutung wer-den in Form erläuternder Fachnotizen durch die BGE veröffentlicht und können so bei zukünftigen Antragsverfahren berücksichtigt werden. T2 - KONTEC 2019 CY - Dresden, Germany DA - 27.03.2019 KW - Endlager KW - Container KW - Bauartprüfung KW - Konrad PY - 2019 SP - Paper 017, 205 EP - 212 PB - Kontec GmbH CY - Hamburg AN - OPUS4-47667 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe A1 - Simbruner, Kai A1 - Völzke, Holger T1 - Brittle failure of spent fuel claddings under long-term dry interim storage conditions – Preliminary analysis N2 - 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. T2 - IAEA International Conference on the Management of Spent Fuel from Nuclear Power Reactors CY - Vienna, Austria DA - 24.06.2019 KW - Ageing Management KW - Cladding Embrittlement KW - Extended Storage KW - Ring Compression Test KW - Spent Nuclear Fuel PY - 2019 SP - Paper IAEA-CN-272/49, 1 EP - 8 AN - OPUS4-48869 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe A1 - Qiao, Linan A1 - Völzke, Holger T1 - Fracture mechanical analysis of a cylindrical cast iron cask N2 - 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. T2 - 19th International Symposium on the Packaging and Transportation of Radioactive Materials (PATRAM 2019) CY - New Orleans, LA, USA DA - 04.08.2019 KW - Ductile Cast Iron KW - Brittle Fracture KW - Cylindrical Cask PY - 2019 SP - Paper 1209, 1 EP - 7 AN - OPUS4-48914 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jaunich, Matthias A1 - Grelle, Tobias A1 - Kömmling, Anja A1 - Wolff, Dietmar A1 - Völzke, Holger ED - Stuke, M. T1 - Long-term evaluation of sealing systems for radioactive waste packages N2 - The investigation of the long-term performance of sealing systems employed in containers for 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 (BAM). Our investigations comprise investigations on metallic and elastomeric seals and covers experimental investigations to get a database on the component/material behaviour, work on analytical descriptions and numerical analysis. Our aim is to understand the long-term behaviour of the sealing systems for evaluation of their performance during possible extended interim storage and subsequent transportation. T2 - 3rd Workshop on Safety of Extended Dry Storage of Spent Nuclear Fuel CY - Garching, Germany DA - 05.06.2019 KW - Seal performance KW - Rubber seal KW - Metallic seal KW - Ageing PY - 2019 SP - 57 EP - 62 AN - OPUS4-48225 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weber, Mike A1 - Zencker, Uwe A1 - Wolff, Dietmar A1 - Jaunich, Matthias A1 - Kömmling, Anja A1 - Völzke, Holger A1 - Schulze, Dietmar T1 - Numerical simulation of the behaviour of elastomer seals under consideration of time dependent effects N2 - Due to delays in the site-selection procedure to establish a deep geological repository for spent nuclear fuel and high level waste and in construction of the already licensed Konrad-repository for low and intermediate level waste without heat generation, 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 caslcs or as primary seals for low and intermediate level waste packages is an important issue in this context (Jaunich, 2013; Jaunich, 2014; Kömmling, 2015). The polymeric structure of these seals causes a complex mechanical behaviour with time-dependent elasticity reduction and loss of elastic recovery. The paper presents first results of a comprehensive test Programme consisting of several static and dynamic mechanical short- and long-term tests which have been carried out at BAM on specimens made of representative types of elastomers, fluorocarbon rubber (FKM) and ethylene propylene diene rubber (EPDM). The investigation of the test results used to identify material models and their Parameters as well as the development of two finite element models for the numerical Simulation of tension and compression tests using the finite element code ABAQUS® are described. The calculation results are presented in comparison to the test results. The influence of important material and test parameters was investigated and discussed in sensitivity analyses. T2 - RAMTRANSPORT 2015 - International conference on the radioactive materials transport and storage CY - Oxford, UK DA - 19.05.2015 KW - Numerical analysis KW - Extended interim storage KW - Elastomer seals PY - 2015 SP - Session 4, Paper 28, 1 EP - 9 AN - OPUS4-33832 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jaunich, Matthias A1 - Wolff, Dietmar A1 - Stark, Wolfgang A1 - Völzke, Holger T1 - Investigation of elastomer seal behavior for transport and storage packages N2 - Rubbers are widely used as main sealing materials for containers for low and intermediate level radioactive waste and as additional component to metal seals in spent fuel and high active waste containers. According to appropriate guidelines and regulations safe enclosure of the radioactive container contents has to be guaranteed for long storage periods as well as down to temperatures of -40 °C for transportation. Therefore the understanding of seal behavior is of high importance. In this paper we focus on the behavior of elastomer seals at low temperatures with regard to poten-tial decrease of leak-tightness. In addition, changes in material properties due to aging effects over long periods of time and their influence on the seal performance is investigated. It is known that material properties of rubbers are strongly temperature dependent. At low tempera-tures this is caused by the rubber-glass transition (abbr. glass transition). During continuous cool-ing, the material changes from rubber-like entropy-elastic to stiff energy-elastic behavior, that al-lows nearly no strain or retraction due to the glass transition. Hence rubbers are normally used above their glass transition but the minimum working temperature limit is not defined precisely. Aging of elastomer seals is important, as possible dynamic loads may have to be considered during the whole interim storage period (so far approved in Germany for up to 40 years) and for transporta-tion after storage. For the investigations, fluorocarbon (FKM) and ethylene-propylene-diene (EPDM) rubbers were selected as they are often used in radioactive waste containers. Some materials were purchased from a commercial seal producer and some materials were compounded and cured at BAM. The elastom-ers where studied by several thermo-analytical methods and compression set to characterize the material behavior at low temperatures. Additionally component tests were performed to determine the breakdown temperature of the sealing function of complete elastomer O-rings. T2 - PATRAM 2013 - 17th International symposium on the packaging and transportation of radioactive materials CY - San Francisco, CA, USA DA - 18.08.2013 PY - 2013 SP - Paper 227, 1 EP - 8 PB - Omnipress AN - OPUS4-30377 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -