TY - CONF A1 - Zencker, Uwe T1 - Dynamic finite element analyses of a HLW transport cask with polyrethane impact limiters in 9m drop test T2 - PATRAM 2007, The 15th International Symposium on the Packaging and Transportation of Radioactive Material CY - Miami, FL, USA DA - 2007-10-21 PY - 2007 AN - OPUS4-16190 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe T1 - Application limits of low-ductile cast iron for radioactive waste containers T2 - PATRAM 2007, The 15th International Symposium on the Packaging and Transportation of Radioactive Material CY - Miami, FL, USA DA - 2007-10-21 PY - 2007 AN - OPUS4-16191 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe T1 - Numerische Analyse eines ungedämpften Behälterabsturzes aus 0,3 m Höhe T2 - Jahrestagung Kerntechnik 2008 CY - Hamburg, Germany DA - 2008-05-27 PY - 2008 AN - OPUS4-16329 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Neser, A. A1 - Schreiber, D. A1 - Magallanes, J. A1 - Martinez, R. A1 - Zencker, Uwe A1 - Weber, Mike T1 - A material testing program to characterize the concrete behavior under static and dynamic loads N2 - In this paper a comprehensive material testing program is described to characterize a German final repository concrete material (BERB1) subjected to static and dynamic loads. The BERB1 material was developed und specified by the German Bundesanstalt für Materialforschung und -prüfung (BAM) for targets used for drop tests according to the KONRAD requirements. The testing consists of three concurrent laboratory experimental programs performed in the USA. An extensive preliminary testing program in Germany was performed to assure the required concrete specifications during fabrication and curing. The first set of data is the static basic material test program consisting of structural tests to quantify macroscopic concrete properties under quasi-static loads. Cubic and cylindrical specimens are investigated under this effort. The second set of test data is from the static complete material test program, where cylindrical concrete specimens are subjected to a variety of quasi-static axial and radial stress and strain paths using a high-pressure hydraulic tri-axial chamber. The material is characterized for confining pressures up to 400 MPa. The third set of data is from the dynamic complete material test program, which uses a modified Split-Hopkinson Pressure Bar to induce dynamic compression and tension waves into cylindrical concrete specimens that generate strain-rates up to 400 s-1. The ensemble of data generated in these experiments provides a complete set of data that effectively describes the behavior of this concrete and can be used to develop a constitutive calculation model. In addition, the results of the tests show a significant effect of moisture on the strength and rheology of this concrete for quasi-static pressures greater than 50 MPa. Numerical drop test simulations with the developed constitutive model in the Lagrangian finite element code, LS-DYNA, show good agreement with the experimental results from a BAM research project. T2 - PATRAM 2010 - 16th International symposium on the packaging and transport of radioactive materials CY - London, UK DA - 2010-10-03 KW - Testing program KW - Concrete behavior KW - Static loads KW - Dynamic loads KW - KONRAD acceptance criteria KW - Ductile cast iron cask PY - 2010 SP - 1 EP - 8 (Session T40 / Paper 123) AN - OPUS4-23845 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zencker, Uwe A1 - Weber, Mike A1 - Wille, Frank T1 - Finite element mesh design of a cylindrical cask under puncture drop test conditions N2 - Transport casks for radioactive materials have to withstand the 9 m drop test, 1 m puncture drop test and dynamic crush test with regard to the mechanical requirements according to the IAEA regulations. The safety assessment of the package can be carried out on the basis of experimental investigations with prototypes or models of appropriate scale, calculations, by reference to previous satisfactory safety demonstrations of a sufficiently similar nature or a combination of these methods. Computational methods are increasingly used for the assessment of mechanical test scenarios. However, it must be guaranteed that the calculation methods provide reliable results. Important quality assurance measures at the Federal Institute for Materials Research and Testing are given concerning the preparation, run and evaluation of a numerical analysis with reference to the appropriate guidelines. Hence, a successful application of the finite element (FE) method requires a suitable mesh. An analysis of the 1 m puncture drop test using successively refined FE meshes was performed to find an acceptable mesh size and to study the mesh convergence using explicit dynamic FE codes. The FE model of the cask structure and the puncture bar is described. At the beginning a coarse mesh was created. Then this mesh was refined in two steps. In each step the size of the elements was bisected. The deformation of the mesh and the stresses were evaluated dependent on the mesh size. Finally, the results were extrapolated to an infinite fine mesh or the continuous body, respectively. The uncertainty of the numerical solution due to the discretisation of the continuous problem is given. A safety factor is discussed to account for the uncertainty. KW - IAEA puncture drop test KW - Cylindrical cask KW - FE mesh refinement KW - Explicit dynamics KW - Numerical analysis PY - 2011 DO - https://doi.org/10.1179/1746510911Y.0000000008 SN - 1746-5095 SN - 1746-5109 SN - 0957-476X VL - 22 IS - 2 SP - 112 EP - 116 PB - Ramtrans Publ. CY - Ashford AN - OPUS4-24016 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe T1 - Finite Element Mesh Refinement Study for IAEA Pucture Drop Test T2 - 2012 Pressure Vessels & Piping conference CY - Toronto, Canada DA - 2012-07-15 PY - 2012 AN - OPUS4-26818 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe T1 - Modeling Strategies for Dynamic Finite element Cask Analyses T2 - 17th International Symposium on the Packaging and Transportation of Radioactive Materials (PATRAM 2013) CY - San Francisco, CA, USA DA - 2013-08-18 PY - 2013 AN - OPUS4-29171 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Qiao, Linan A1 - Kasparek, Eva Maria A1 - Völzke, Holger A1 - Zencker, Uwe A1 - Scheidemann, Robert T1 - Development of a finite element model for damping concrete under severe impact loads N2 - Finite element analysis (FEA) has been carried out for investigation of damping concrete under different impact loading conditions with a built-in material model and damage criteria available in FEA code ABAQUS. At first, all parameters for the selected material model had been derived from compression Tests of cubic specimens. After that, a validation was carried out with different static and dynamic penetration tests. Finally, a 5 meter real drop test with a 23 Mg cylindrical cask could successfully be simulated. 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 - Session D, Paper 127, 1 EP - 10 PB - Omnipress AN - OPUS4-29110 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe A1 - Qiao, Linan A1 - Kasparek, Eva Maria A1 - Völzke, Holger T1 - Modeling of cylindrical casks under horizontal drop test conditions N2 - Cylindrical casks made of ductile cast iron are used for transport, interim storage and final disposal of radioactive waste in Germany. A basic design criterion is the ability to withstand a horizontal drop without impact Binders onto a foundation representative for the real ground of a storage facility. The increasing use of more cost-effective material compositions requires optimized cask geometries to reduce stresses and strains in the cask structure. For example, a non-uniform wall thickness was introduced to reduce maximum wall bending stresses. As a result, the load characteristics changed from line load to point load at bottom and lid side under horizontal drop fest conditions. Hereby, the position of highest stress inside the structure has shifted significantly. This was the reason for a systematic investigation of effects caused by small design changes or small variations of fest conditions. It led to a better understanding of the positions of high local stresses, their time history and maximum value for cylindrical casks under horizontal drop test conditions. Hence, the paper presents the lessons learnt from modeling and simulating such scenarios considering an impact without limiters onto a realistic target. T2 - 14th International high-level radioactive waste management conference CY - Albuquerque, New Mexico, USA DA - 28.04.2013 KW - Cylindrical cask KW - Ductile cast iron KW - Numerical simulation KW - Horizontal drop test KW - Storage facility KW - Concrete foundation PY - 2013 SN - 978-1-62748-644-6 SP - 1114 EP - 1119 (Paper # 6862) PB - Omnipress AN - OPUS4-28529 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe T1 - Modeling of cylindrical casks under horizontal drop test conditions T2 - International High-Level Radioactive Waste Management Conference 2013 (IHLRWM 2013) CY - Albuquerque, NM, USA DA - 2013-04-28 PY - 2013 AN - OPUS4-28472 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Gründer, Klaus-Peter A1 - Kadoke, Daniel A1 - Protz, Christian A1 - Zencker, Uwe T1 - Optical 3D methods in steel sheet container drop test analysis N2 - In the context of a research project at BAM various drop tests and material as well as component investigations have to be performed with respect to steel sheet container drop test analysis. Both, experimental and computational methods (Finite Element Analysis) are involved. Among electrical sensor techniques optical measurement methods capable of dynamic and static 3D deformation analysis are applied. On the one hand this includes the Projected Fringes Method which provides a virtual digital round-about model of the actual package surface shape. On the other hand there is the Stereo Photogrammetry used for high speed imaging of points rich in contrast and permanently fixed to the container while dropping. Technical features of both methods are discussed. Diverse measurement results are compared with those of alternative experimental techniques as well as numerical simula-tions. T2 - OPTO 2013 - 11th International conference on optical technologies for sensing and measurement CY - Nürnberg, Germany DA - 14.05.2013 KW - Steel sheet container KW - Drop test KW - Numerical simulation KW - Optical digitization KW - High speed stereo photogrammetry PY - 2013 SN - 978-3-9813484-3-9 DO - https://doi.org/10.5162/opto2013/o4.2 N1 - Serientitel: AMA Conferences – Series title: AMA Conferences IS - 4.2 SP - 74 EP - 78 AN - OPUS4-28559 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Daum, Werner A1 - Gründer, Klaus-Peter A1 - Kadoke, Daniel A1 - Protz, Christian A1 - Zencker, Uwe T1 - Optical 3D dynamic deformation analysis of a ram container during a drop test N2 - Containers for interim storage and final disposalof radioactive material (RAM) have to meet certain requirements regarding mechanical stability and integrity. The assessment procedure applied by BAM is based on a series of full-scale drop tests with different drop heights and Container Orientations. In parallel dynamic FEM calculations are performed. The Container behaviour is monitored during the drop test by a large number of simultaneously triggered biaxial electrical strain gauges and uniaxial accelerometers in order to measure local strains at selected positions and to determine the kinematic behaviour and Orientation of the Container during the impact. Within a research project a dynamic Stereo photogrammetry approach was applied in a high-speed camera configuration to investigate the kinematic rigid body behaviour, relative local movements of the Container or its structural parts in 3D, respectively. In the following the results of this approach are presented. A comprehensive description how to use optica) methods in drop tests can be found in. T2 - 30th Danubia-Adria symposium on advances in experimental mechanics CY - Primosten, Croatia DA - 25.09.2013 KW - Steel sheet container KW - Drop test KW - Numerical simulation KW - Optical digitization KW - High speed stereo photogrammetry PY - 2013 SN - 978-953-7539-17-7 SP - 45 EP - 46 AN - OPUS4-29414 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe A1 - Qiao, Linan A1 - Droste, Bernhard T1 - Assessment of dynamically loaded surface cracks in cubic containers T2 - 13th International Conference on Packaging and Transportation of Radioactive Materials ; PATRAM 2001 CY - Chicago, IL, USA DA - 2001-09-03 PY - 2001 IS - CD-ROM PB - PATRAM CY - Chicago, Ill. AN - OPUS4-1889 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zencker, Uwe A1 - Clos, R. T1 - Limiting Conditions for Compression Testing of Flat Specimens in the Split Hopkinson Pressure Bar KW - Split Hopkinson pressure bar KW - High strain rate testing KW - Dispersion correction KW - Stress distribution KW - Triaxiality PY - 1999 SN - 0014-4851 SN - 1741-2765 VL - 39 IS - 4 SP - 343 EP - 348 PB - Springer CY - Norwell, Mass. AN - OPUS4-743 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Zencker, Uwe A1 - Völzke, Holger A1 - Droste, Bernhard T1 - Stilllegung und Rückbau kerntechnischer Einrichtungen: Entwicklung von Beurteilungsmethoden für Transport- und Lagerbehälter mit erhöhten metallischen Reststoffanteilen (EBER) N2 - Die sicherheitstechnische Auslegung von Behältern aus duktilem Gusseisen mit erhöhten Reststoffanteilen wird untersucht. Ausgehend von den zu gewährleistenden Anforderungen an Transport- und Lagerbehälter für radioaktive Abfälle werden Referenzbeanspruchungs- situationen definiert. Für einen ausgewählten Referenzfall (bestehend aus der Kombination der Behälterbauart Gusscontainer Typ VI, einem Absturz aus 5 m Höhe auf ein hartes Endlagergestein simulierendes Betonfundament als repräsentativer Störfall und vorgegebenen Werkstoffeigenschaften) wird eine numerische Spannungsanalyse durchgeführt. Die Berechnungen erfolgen mit der Methode der finiten Elemente an dreidimensionalen Modellen, deren numerische Stabilität und Genauigkeit überprüft wird. Zur Berechnung der Behälterbeanspruchungen in Abhängigkeit vom Reststoffanteil werden dynamische Fließkurven für definiert legierte Testabgüsse angegeben. T3 - BAM Forschungsberichtreihe - 240 PY - 2002 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-2109 SN - 978-3-89701-523-4 SN - 0938-5533 VL - 240 SP - 1 EP - 71 PB - Wirtschaftsverlag NW CY - Bremerhaven AN - OPUS4-210 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe A1 - Simbruner, Kai A1 - Völzke, Holger T1 - Analysis of Zirconium Hydride Structures in Spent Fuel Claddings Subjected to Storage Conditions N2 - Pre-storage drying and the early stage of storage can subject spent fuel claddings to higher temperatures and higher tensile hoop stresses than those associated with in-reactor operation. Under these conditions, existing circumferential hydrides in zirconium-based alloys can be partly reoriented into radial ones that may result in embrittlement of the cladding material. As a consequence, the failure limits may be reduced under mechanical loads caused by handling or during transport after storage. The potential occurrence of brittle fracture strongly depends on the specific location, size, and orientation of the zirconium hydrides. The morphology of such hydride structures was experimentally investigated in unirradiated, hydrogen-loaded samples made of a zirconium-based alloy. The hydrogen was introduced into the cladding sample by means of a cathodic charging process. The loading process was followed by a thermal treatment to precipitate the hydrides in the circumferential direction and then a thermomechanical treatment to reorient the hydrides in the radial direction. Metallographic methods were used to describe and classify the hydride morphology. The resulting metallographic micrographs were evaluated using suitable radial hydride metrics. The determination of the maximum length of a hydride structure was carried out in two different ways, each with its own advantages and disadvantages. Both methods consider neighboring hydrides as continuous according to the definition of the Radial Hydride Continuity Factor (RHCF). The first option is to measure the Euclidean distance between the two most distant pixels of the hydride structure in the image analysis, whereby the actual maximum size of the hydride structure is determined. The second possibility is to measure the maximum size of a hydride or a hydride structure within a certain arc length in the radial direction of the cladding tube. This value is of particular interest because the ratio of the maximum radial size of a hydride structure to the wall thickness of the cladding tube is used for the safety assessment of spent fuel claddings with radial hydrides using the RHCF. T2 - 21st International Symposium on the Packaging and Transportation of Radioactive Materials - PATRAM 2025 CY - San Antonio, TX, USA DA - 27.07.2025 KW - Extended Interim Storage KW - Nuclear Fuel Cladding KW - Zirconium Hydride Structure KW - Ring Compression Test KW - Micrograph Analysis PY - 2025 SP - 1 EP - 8 CY - Indianapolis, IN, USA AN - OPUS4-63875 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe T1 - Analysis of Zirconium Hydride Structures in Spent Fuel Claddings Subjected to Storage Conditions N2 - Pre-storage drying and the early stage of storage can subject spent fuel claddings to higher temperatures and higher tensile hoop stresses than those associated with in-reactor operation. Under these conditions, existing circumferential hydrides in zirconium-based alloys can be partly reoriented into radial ones that may result in embrittlement of the cladding material. As a consequence, the failure limits may be reduced under mechanical loads caused by handling or during transport after storage. The potential occurrence of brittle fracture strongly depends on the specific location, size, and orientation of the zirconium hydrides. The morphology of such hydride structures was experimentally investigated in unirradiated, hydrogen-loaded samples made of a zirconium-based alloy. The hydrogen was introduced into the cladding sample by means of a cathodic charging process. The loading process was followed by a thermal treatment to precipitate the hydrides in the circumferential direction and then a thermomechanical treatment to reorient the hydrides in the radial direction. Metallographic methods were used to describe and classify the hydride morphology. The resulting metallographic micrographs were evaluated using suitable radial hydride metrics. The determination of the maximum length of a hydride structure was carried out in two different ways, each with its own advantages and disadvantages. Both methods consider neighboring hydrides as continuous according to the definition of the Radial Hydride Continuity Factor (RHCF). The first option is to measure the Euclidean distance between the two most distant pixels of the hydride structure in the image analysis, whereby the actual maximum size of the hydride structure is determined. The second possibility is to measure the maximum size of a hydride or a hydride structure within a certain arc length in the radial direction of the cladding tube. This value is of particular interest because the ratio of the maximum radial size of a hydride structure to the wall thickness of the cladding tube is used for the safety assessment of spent fuel claddings with radial hydrides using the RHCF. T2 - 21st International Symposium on the Packaging and Transportation of Radioactive Materials - PATRAM 2025 CY - San Antonio, TX, USA DA - 27.07.2025 KW - Extended Interim Storage KW - Nuclear Fuel Cladding KW - Zirconium Hydride Structure KW - Ring Compression Test KW - Micrograph Analysis PY - 2025 AN - OPUS4-63876 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe T1 - Failure Analysis on Spent Fuel Claddings Subjected to Long-Term Dry Interim Storage N2 - Long-term dry interim storage may adversely affect the mechanical properties of spent fuel claddings, possibly resulting in a reduced resilience during handling or transport after storage. Pre-storage drying and the early stage of interim storage can subject the cladding to higher temperatures and higher tensile hoop stresses than those associated with in-reactor operation and pool storage. Under these conditions, radial hydrides may precipitate in zirconium-based alloys (Zircaloy) during slow cooling, which result in embrittlement of the cladding material and eventually a possible sudden failure of cladding integrity under additional mechanical loads. Especially long, continuous radial hydride structures and low temperature can cause severe embrittlement of claddings and finally failure by fracture even at small deformations. Therefore, the study of hydride morphology plays an important role in describing the brittle failure behaviour of the claddings. The focus of the presented research is on the development of appropriate numerical methods for predicting the mechanical behaviour and identification of limiting conditions to prevent brittle fracture of Zircaloy claddings. An established experimental method for characterising cladding materials is the Ring Compression Test (RCT). Some test results on irradiated cladding tubes after operation in pressure water reactors are publicly available. However, it is helpful to carry out studies on unirradiated surrogate claddings with similar material properties to reduce the effort associated with irradiated samples in hot cells and to perform material tests with a wider range of parameters. On the basis of such experimental data, load-displacement curves have been numerically analysed for a selection of cladding materials. Radial hydrides can cause a sample to break suddenly. Noticeable load drops in the RCT are caused by unstable crack propagation through the radial hydride network. The failure mechanism is quasi-cleavage in the hydrides and micro-void nucleation, growth, and coalescence in the zirconium matrix, with ductile tearing patches connecting adjacent hydrides. The cohesive zone approach was used to simulate the failure process taking into account the radial hydride morphology. Experimental investigations, numerical analyses and evaluation methods for both the deformation and failure behaviour of irradiated as well as unirradiated claddings of zirconium-based alloys with radial hydrides are discussed. Limiting conditions can be expressed in terms of fracture energy and cohesive strength. T2 - IAEA Technical Meeting on the Behaviour of Spent Fuel and Cladding During Storage and the Performance of Spent Fuel Storage Systems CY - Seoul, South Korea DA - 23.06.2025 KW - Extended Interim Storage KW - Nuclear Fuel Cladding KW - Numerical Failure Analysis KW - Ring Compression Test KW - Spent Fuel Characterization PY - 2025 AN - OPUS4-63597 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe T1 - Embrittlement of spent fuel claddings during long-term dry interim storage - Current approach at BAM N2 - In this presentation, the actual situation of long-term dry interim storage of spent nuclear fuel in Germany is reported. An extension of the interim storage period between 40 and 100 years for at least a relevant number of casks is foreseeable. To demonstrate the integrity of fuel rods and cladding tubes throughout the extended dry interim storage, a potential cladding embrittlement should be investigated. The current approach at BAM is a research project on experimental and numerical investigations of sudden failure of unirradiated pre-hydrided cladding tubes after hydride reorientation at small deformation under Ring Compression Test conditions. A fracture mechanics based failure analysis and suggested failure criteria for a potential brittle failure of spent fuel claddings after long-term dry interim storage under mechanical loads are discussed. T2 - IAEA - Second Coordinate Research Meeting and Consultancy Meeting on Ageing Management Programmes for Spent Fuel Dry Storage Systems CY - Lemont, IL, USA DA - 29.04.2019 KW - Ageing Management KW - Extended Storage KW - Spent Nuclear Fuel KW - Cladding Embrittlement KW - Ring Compression Test PY - 2019 AN - OPUS4-48745 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe T1 - Brittle failure of spent fuel claddings during long-term dry interim storage N2 - The current research project BRUZL (Fracture mechanical analysis of spent fuel claddings during long-term dry interim storage) is presented. General aim of the project is the development of methods for risk assessment and identification of boundary conditions to prevent potential sudden brittle failure of spent fuel claddings at small deformation during long-term dry interim storage and subsequent transportation. The project is funded by the Federal Ministry for Economic Affairs and Energy (BMWi) under contract no. 1501561. T2 - 3rd GRS Workshop on Safety of Extended Dry Storage of Spent Nuclear Fuel CY - Garching, Germany DA - 05.06.2019 KW - Ageing Management KW - Cladding Embrittlement KW - Extended Storage KW - Ring Compression Test KW - Spent Nuclear Fuel PY - 2019 AN - OPUS4-48867 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe 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 AN - OPUS4-48868 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -