TY - CONF A1 - Zencker, Uwe A1 - Weber, Mike A1 - Qiao, Linan A1 - Menzel, Martin A1 - Droste, Bernhard T1 - Beurteilungsmethoden für Transport- und Lagerbehälter mit erhöhten metallischen Reststoffanteilen - Behälterbruchsicherheitsuntersuchungen und Entwicklung eines KONRAD-Referenzprüfstandfundamentes T2 - 9. Internationales Symposium "Konditionierung radioaktiver Betriebs- und Stilllegungsabfälle" (KONTEC 2009) CY - Dresden DA - 2009-04-15 KW - Duktiles Gusseisen KW - Behälterdesign KW - Sicherheitstechnische Bewertung KW - Bruchmechanik KW - Dynamische Belastungsbedingungen KW - KONRAD KW - Referenzprüfstandfundament PY - 2009 SP - 646 EP - 652 PB - KONTEC CY - Hamburg AN - OPUS4-19396 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bletzer, Claus Wilhelm A1 - Zencker, Uwe A1 - Völzke, Holger A1 - Koch, Frank T1 - Asymmetrische Temperaturprofile in Transport- und Lagerbehältern für radioaktive Stoffe T2 - Jahrestagung Kerntechnik CY - Dresden, Deutschland DA - 2009-05-12 KW - Temperaturprofil KW - CFD-Berechnung KW - Transportbehälter KW - Radioaktive Stoffe PY - 2009 SP - 1 EP - 5(?) CY - Dresden AN - OPUS4-19431 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Magallanes, J.M. A1 - Martinez, R. A1 - Neser, A. A1 - Schreiber, D. A1 - Zencker, Uwe T1 - A comprehensive material testing program for characterizing concrete behaviors under dynamic loads T2 - 13th International symposium on interaction of the effects of munitions with structures, ISIEMS 13 CY - Brühl, Germany DA - 2009-05-11 KW - Concrete properties KW - Dynamic testing KW - Dynamic load KW - Triaxial compression test KW - Storage cask KW - Modified split-Hopkinson pressure bar (SHPB) KW - Moisture PY - 2009 IS - Paper # 46 SP - 1 EP - 13(?) CY - Brühl, Deutschland AN - OPUS4-19452 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe T1 - Safety analyses of cast iron containers hitting a KONRAD reference target T2 - Radioactive Materials Transport Conference CY - Manchester, England DA - 2009-05-13 PY - 2009 AN - OPUS4-19467 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zencker, Uwe A1 - Zeisler, Peter A1 - Droste, Bernhard T1 - Dynamic fracture mechanics assessments for cubic ductile cast iron containers PY - 2000 SN - 0957-476X VL - 11 IS - 1-2 SP - 113 EP - 118 PB - Nuclear Technology Publ. CY - Ashford, Kent AN - OPUS4-21857 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe T1 - Mechanical Safety Analyses of Cast Iron Containers for the KONRAD Repository T2 - 16th InternationalSymposium on the Packaging and Transport of Radioactive Materials CY - London, England DA - 2010-10-03 PY - 2010 AN - OPUS4-22217 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe T1 - Finite element mesh design of a cylindrical cask under puncture drop test conditions T2 - 16th International Symposium on the Packaging and Transport of Radioactive Materials CY - London, England DA - 2010-10-03 PY - 2010 AN - OPUS4-22218 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Protz, Christian A1 - Völzke, Holger A1 - Zencker, Uwe A1 - Hagenow, Peter A1 - Grünewald, Heike T1 - Entwicklung neuer Prüfmethoden zur numerischen Beanspruchungsanalyse für die Fallprüfung an Stahlblechcontainern für das Endlager Konrad N2 - Die Bundesanstalt für Materialforschung und -prüfung (BAM) führt im Rahmen einer Verwaltungsvereinbarung mit dem Bundesamt für Strahlenschutz (BfS) Bauartprüfungen für Behältertypen durch, die für die Endlagerung von nicht wärmeentwickelnden radioaktiven Abfällen in das Endlager Konrad vorgesehen sind. Zur Erlangung einer Eignungsbestätigung einer Behälterbauart für das Endlager Konrad müssen die Antragssteller die Einhaltung der vom BfS festgelegten behälterspezifischen Anforderungen nachweisen. Zentrale Bestandteile der Bauartprüfung sind die Sicherheitsnachweise zur Behälterauslegung gegen mechanische Betriebs- und Störfallbelastungen sowie gegen thermische Störfallszenarien. Die Prüfanforderungen umfassen hierbei Stapeldruckprüfung, Hebeprüfung, Fallprüfung, thermische Prüfung (Brand), ggf. einschließlich Dichtheitsprüfung zum Nachweis der Einhaltung von Dichtheitsanforderungen. Neben der Nachweisführung mittels sogenannter Baumusterprüfungen oder Obertragbarkeitsbetrachtungen können die Nachweise alternativ mittels numerischer Sicherheitsnachweise erbracht werden, sofern deren hinreichende Verifikation nachgewiesen wird, Dies kann u. a. durch den Vergleich mit hinreichend gesicherten experimentellen Ergebnissen geschehen, Die hier vorgestellten Untersuchungen sind Teil des internen Forschungsprojektes ConDrop der BAM, das zum Ziel hat, erweiterte Prüfmethoden zur Fallprüfung an Stahlblechcontainern für das Endlager Konrad mittels numerischer Beanspruchungsanalyse zu entwickeln. Dazu soll ein Finite-Elemente-(FE)-Modell entwickelt und mit experimentellen Daten, die in Fallversuchen ermittelt werden, verifiziert werden. T2 - Jahrestagung Kerntechnik 2011 CY - Berlin, Deutschland DA - 17.05.2011 KW - Falltest KW - Stahlblechcontainer KW - Endlager Konrad KW - Numerische Beanspruchungsanalyse PY - 2011 IS - Session TS-19 / Paper 161 SP - 1 EP - 3 AN - OPUS4-23755 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kasparek, Eva Maria A1 - Scheidemann, Robert A1 - Wolff, Dietmar A1 - Zencker, Uwe A1 - Völzke, Holger T1 - Untersuchungen zum Verhalten von Dämpferbeton unter Stossbelastung N2 - Während des Transportes sind Behälter für hoch radioaktive Abfälle durch stoßdämpfende Bauteile vor Einwirkungen, die aus Unfallszenarien gemäß den IAEA Regularien resultieren können, weitestgehend geschützt. Nach dem Entfernen dieser Komponenten im Rahmen der Einlagerung ins Zwischenlager müssen Vorkehrungen getroffen sein, um Beanspruchungen der Behälter aus möglichen Handhabungsunfällen im Empfangsbereich zu reduzieren. Die Maßnahmen müssen vor allem darauf abzielen, die stoßdämpfenden Eigenschaften der potentiellen Aufprallflächen zu optimieren. Da Standardmaterialien für Fundamente nur ein geringes Energieabsorptionsvermögen aufweisen, wurde durch die Firma HOCHTIEF eine neuartige Betonmixtur entwickelt, bei der ein spezieller Leichtzuschlag zum Einsatz kommen. Zur Charakterisierung dieses sogenannten Dämpferbetons liegen Standardkennwerte vor sowie Messwerte aus Eindringversuchen, die zur Qualitätssicherung für jede Produktcharge durchgeführt werden. Das stoßdämpfende Potential des neuen Werkstoffs kann jedoch nur dann vollkommen ausgeschöpft werden, wenn die Energieabsorption in numerischen Simulationen der Behälterabstürze über die gesamte Belastungsdauer zuverlässig wiedergegeben wird. Für die Implementierung und Anpassung eines entsprechenden Materialmodelis in einem Finite Elemente (FE) Programm sind Daten aus systematischen Druckversuchen mit Variation der relevanten Einflussgrößen erforderlich. An der BAM werden daher im Rahmen eines werkstoffübergreifenden Forschungsvorhabens zur Untersuchung von stoßdämpfenden Strukturen auch die Eigenschaften von Dämpferbeton experimentell untersucht und zugehörige numerische Methoden entwickelt. Der aktuelle Beitrag behandelt die Ergebnisse der ersten Projektphase, in der kubische Probekörper mit der Kantenlänge 100mm bei unterschiedlichen Lagerungsbedingungen statisch und dynamisch gestaucht wurden. In nachfolgenden Versuchen wird der Einfluß der Probengröße ermittelt sowie die Eignung der verwendeten Materialmodelle anhand realistischer Belastungssituationen validiert. Versuchsprogramm. T2 - Jahrestagung Kerntechnik 2011 CY - Berlin, Germany DA - 17.05.2011 KW - Stoßdämpfende Werkstoffe KW - Materialmodellierung KW - Versuchsprogramm KW - Stoßbelastung KW - Dehnratenabhängigkeit KW - Temperaturabhängigkeit KW - Polyurethan Schaum KW - Dämpferbeton PY - 2011 IS - Session TS-17 / Paper 171 SP - 1 EP - 5 AN - OPUS4-23836 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF 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 BAM 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 method requires a suitable mesh. An analysis of the 1 m puncture drop test using successively refined finite element meshes was performed to find an acceptable mesh size and to study the mesh convergence using explicit dynamic finite element codes. The finite element 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 discretization of the continuous problem is given. A safety factor is discussed to account for the uncertainty. The calculation results are compared with experimental data from a puncture drop test with a half-scale model of a cylindrical cask. This paper supports the convergence studies of the Task Group on Computational Modeling for Explicit Dynamics reporting to the ASME BPV Code Working Group on Design Methodology. T2 - PATRAM 2010 - 16th International symposium on the packaging and transport of radioactive materials CY - London, UK DA - 2010-10-03 KW - IAEA puncture drop test KW - Numerical analysis KW - Verification KW - Explicit dynamics PY - 2010 SP - 1 EP - 8 (Session T45 / Paper 219) AN - OPUS4-23843 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe A1 - Weber, Mike A1 - Qiao, Linan A1 - Droste, Bernhard A1 - Völzke, Holger T1 - Mechanical safety analyses of cast iron containers for the KONRAD repository N2 - Within the last years BAM has carried out numerous drop tests with prototype casks made of ductile cast iron onto targets according to the requirements for final disposal of non-heat generating waste in the German KONRAD repository. The results have shown that the target specifications in the acceptance criteria have to be defined more accurately to get reproducible test results with high precision. Hence, a suitable test stand foundation was developed with much effort. The integrity of the upper concrete layer of this target must be preserved during a test. Recently the geometrical properties of a tested cubic cast iron container led to a concentration of the impact forces beneath the container walls. The target was damaged strongly with the consequence of inadmissible reduction of cask stresses. For that reason the target construction was modified. However, the basic design was not changed. A prefabricated concrete slab was still joined by a mortar layer to the IAEA target of the BAM drop test facility. In the course of the optimization of the test stand foundation the concrete slab dimensions and the reinforcement were enlarged. During the drop test repetition the target kept intact. Additionally, the mechanical behavior of the cast iron container and the target was analyzed by finite element calculations. This improved target construction is suggested as a reference target for drop tests with casks whose mass and base area are covered by the container types VI or VII respectively according to the KONRAD repository acceptance criteria. The measurements during the drop tests with cast iron casks have provided the strains on the cask surface at selected positions. This allows the verification of finite element simulations of drop tests which show the stress distribution also inside the component. In September 2008 a drop test was carried out with a cylindrical cast iron cask containing an artificial material defect which was designed under consideration of critical stress states in the cask body. This drop test could demonstrate the safety against failure by fracture of a cask made of a special cast iron with reduced fracture toughness. T2 - PATRAM 2010 - 16th International symposium on the packaging and transport of radioactive materials CY - London, UK DA - 2010-10-03 KW - Ductile iron KW - Container design KW - Safety assessment KW - Fracture mechanics KW - Dynamic loading conditions PY - 2010 SP - 1 EP - 8 (Session T28 / Paper 220) AN - OPUS4-23844 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe 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 AN - OPUS4-3336 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe T1 - Experimentelle und rechnerische Untersuchungen an Endlagerbehältern für radioaktive Stoffe T2 - BAM-Kolloquium CY - Berlin, Germany DA - 2004-10-20 PY - 2004 AN - OPUS4-4568 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe T1 - The Application of Fracture Mechanics to the Safety Assessment of Transport Casks for Radioactive Materials T2 - 14th International Symposium on the Packaging and Transportation of Radioactive Materials (PATRAM 2004) CY - Berlin, Germany DA - 2004-09-20 PY - 2004 AN - OPUS4-4569 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe T1 - Development of Assessment Methods for Transport and Storage Containers with Higher Content of Metallic Recycling Material T2 - 14th International Symposium on the Packaging and Transportation of Radioactive Materials (PATRAM 2004) CY - Berlin, Germany DA - 2004-09-20 PY - 2004 AN - OPUS4-4562 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe T1 - Dynamic Fracture Mechanics Safety Assessment of Cask Designs T2 - 6th International Conference on Radioactive Materials Transport - 2002 CY - Edinburgh, Scotland DA - 2002-11-05 PY - 2002 AN - OPUS4-5747 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe T1 - Entwicklung von Beurteilungsmethoden für Transport- und Lagerbehälter mit erhöhten metallischen Reststoffanteilen - Ein zusammenfassender Überblick T2 - Tagungsband KONTEC 2005 7. Internationales Symposium "Konditionierung radioaktiver Betriebs- und Stilllegungsabfälle" einschließlich 7. Statusbericht des BMBF "Stilllegung und Rückbau kerntechnischer Anlagen" CY - Berlin, Germany DA - 2005-04-20 PY - 2005 AN - OPUS4-7371 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe A1 - Müller, Karsten T1 - Modern Safety Assessment of Cubic Cast Iron Containers Under Mechanical Impact N2 - In the present study, ductile cast iron from an original DCI container with a wide variety of microstructure was investigated in order to determine the materials fracture toughness under impact loading conditions. Three-point bending specimens with thickness of 140 mm from a cubic DCI container were investigated at elevated loading rates to provide reliable fracture toughness parameters for the assessment procedures. In contrast to static fracture behaviour, the fracture toughness values of thick-walled DCI at higher loading rates show a remarkable reduction with decreasing temperature up to –50 °C and a significant shift of the transition range. The lower bound fracture toughness value used in the BAM DCI safety concept was confirmed for impact loading conditions by these fracture mechanics tests using large specimens. These measurements are relevant to the licensing tests for storage containers without shock absorbers, especially to the assessment of the dynamic behaviour of crack-like defects inside a cask structure under drop test conditions. Using extensive dynamic numerical analyses it could be shown, that for special crack configurations the dynamic crack tip parameter (KI, or J) may be estimated by static formulae even under mechanical impact. These results of the safety assessment were verified according to the German Konrad repository acceptance criteria by a drop test with a cubic waste container with artificial crack-like defects from 5 m height onto a representative storage facility foundation. T2 - 17th International Conference on Structural Mechanics in Reactor Technology ; SMiRT 17 CY - Prague, Czech Republic DA - 2003-08-17 KW - Ductile cast iron KW - Mechanical impact KW - Dynamic fracture KW - Safety assessment KW - Storage containers PY - 2003 IS - G04-4 SP - 1(?) EP - 8(?) CY - Prague AN - OPUS4-2650 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - RPRT A1 - Zencker, Uwe A1 - Qiao, Linan A1 - Droste, Bernhard T1 - Entwicklung von Beurteilungsmethoden für Transport- und Lagerbehälter mit erhöhten metallischen Reststoffanteilen - Weiterführende Untersuchungen (EBER II) N2 - Der erhöhte Zusatz metallischer Reststoffe aus der Stilliegung und dem Rückbau kerntechnischer Einrichtungen bei der Herstellung von Behältern aus Gusseisen mit Kugelgraphit führt einerseits durch das Recycling zu einer Reduzierung der Menge des endzulagernden radioaktiven Metallschrottes, aber andererseits auch zu einer nachteiligen Beeinflussung sicherheitsrelevanter Werkstoffeigenschaften. Unter den hochdynamischen Beanspruchungsbedingungen der nicht mit Stoßdämpfern ausgerüsteten Behälter liegt die Bruchzähigkeit um mehr als die Hälfte unter dem Mindestwert für die bisher genehmigten Werkstoffqualitäten, was eine Anpassung der sicherheitstechnischen Bewertungsmethoden für Behälter aus Gusseisen mit Kugelgraphit an den neuen Werkstoff erfordert. Im ersten Teil des Projektes EBER wurden dazu die Grundlagen erarbeitet. In diesem zweiten Teil wird die Beanspruchungsanalyse der Behälter weiter vervollkommnet. Die Werkstoffdämpfung wird mittels einer Analyse der Ausbreitung von Spannungswellen im Gusseisen berechnet. Die Behälterstruktur wird genauer als bei den bisherigen Berechnungen in den Modellen abgebildet. Im Mittelpunkt steht die Weiterentwicklung des sicherheitstechnischen Bewertungskonzeptes. Zur Bewertung von rissartigen Werkstofffehlern in geometrisch komplexen Behälterpartien wurden statische und dynamische bruchmechanische nu- merische Berechnungen eines Risses in einer Hohlkehle und in der Mitte einer Behälterwand durchgeführt. Die Berechnungsergebnisse wurden für spezielle Anwendungsfälle verifiziert, für die bereits Lösungen bekannt sind. Die gewonnenen Erkenntnisse wurden in einfach zu handhabende Bewertungsdiagramme umgesetzt. Das sicherheitstechnische Bewertungskonzept wurde schließlich bei einem Fallversuch mit einem rissbehafteten Prototypbehälter definierter Werkstoffqualität überprüft. Eine Minderung der Beanspruchung infolge konstruktiver Verbesserungen (größere Hohlkehlen, Bodenleiste) durch den Behälterkonstrukteur konnte dabei bestätigt werden. KW - Duktiles Gusseisen KW - Transportbehälter KW - Lagerbehälter KW - Fallversuch KW - Spannungsanalyse KW - Sicherheitsbewertung KW - Dynamische Belastung PY - 2002 SP - 1 EP - 70 PB - Bundesanstalt für Materialprüfung CY - Berlin AN - OPUS4-3475 LA - deu 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 cracks in fillets N2 - Practical methods for the safety assessment of postulated crack-like material defects of cubic containers made of ductile cast iron are presented. A formula for the stress intensity factor of a crack in a fillet with a radius from 20 to 200 mm under static load conditions is given. From that, an assessment diagram is derived for the critical depth of a crack in a fillet. The formula may be used to estimate the stress intensity factor of a dynamically loaded crack for special cases. As an application the results of the estimation procedure are compared with the results of a dynamic finite element calculation. T2 - 15th European Conference of Fracture CY - Stockholm, Sweden DA - 2004-08-11 KW - Ductile cast iron KW - Container design KW - Safety assessment KW - Fracture mechanics KW - Dynamic load conditions PY - 2004 UR - http://www.structuralintegrity.eu/pdf/esis/Documents/Conference/ECF/15/Zencker%20U%20et%20al.pdf SP - 1 EP - 8(?) CY - Stockholm AN - OPUS4-3763 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Zencker, Uwe A1 - Qiao, Linan A1 - Droste, Bernhard T1 - Entwicklung von Beurteilungsmethoden für Transport- und Lagerbehälter mit erhöhten metallischen Reststoffanteilen - Abschließende Untersuchungen (EBER III) T2 - 6. KONTEC ; 6. Internationales Symposium "Konditionierung Radioaktiver Betriebs- und Stilllegungsabfälle" ; 6th International Symposium "Conditioning of Radioactive Operational & Decommissioning Wastes" CY - Berlin, Deutschland DA - 2003-03-19 PY - 2003 SN - 3-9806415-6-2 VL - 6 SP - 623 EP - 630 CY - Hamburg AN - OPUS4-2398 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zencker, Uwe A1 - Qiao, Linan A1 - Droste, Bernhard T1 - Dynamic Fracture Mechanical Safety Assessment of Cask Designs PY - 2002 SN - 0957-476X VL - 13 IS - 3-4 SP - 291 EP - 296 PB - Nuclear Technology Publ. CY - Ashford, Kent AN - OPUS4-2807 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe T1 - Assessment of dynamically loaded cracks in fillets T2 - 15th European Conference of Fracture - Advanced Fracture Mechanics for Life and Safety Assessments CY - Stockholm, Sweden DA - 2004-08-11 PY - 2004 AN - OPUS4-5186 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe T1 - Die Anwendung der Bruchmechanik im Sicherheitsnachweis von Transportbehältern für die Beförderung radioaktiver Stoffe T2 - 36. Tagung DVM-Arbeitskreis Bruchvorgänge CY - Cologne, Germany DA - 2004-02-18 PY - 2004 AN - OPUS4-5188 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Karsten A1 - Ballheimer, Viktor A1 - Droste, Bernhard A1 - Rödel, Roland A1 - Völzke, Holger A1 - Zencker, Uwe T1 - Die Anwendung der Bruchmechanik im Sicherheitsnachweis von Transportbehältern für die Beförderung radioaktiver Stoffe T2 - 36. Tagung des DVM-Arbeitskreises Bruchvorgänge CY - Köln, Deutschland DA - 2004-02-17 KW - Gusseisen mit Kugelgraphit KW - Bruchmechanischer Sicherheitsnachweis KW - Stoßbeanspruchung KW - Transportbehälter KW - Radioaktive Stoffe KW - Ductile iron KW - Fracture mechanics safety assessment KW - Mechanical impact KW - Transport casks KW - Radioactive material PY - 2004 SN - 0943-3473 IS - 236 SP - 225 EP - 238 PB - DVM CY - Berlin AN - OPUS4-5336 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe T1 - Entwicklung von Beurteilungsmethoden für Transport- und Lagerbehälter mit erhöhten metallischen Reststoffanteilen T2 - KONTEC 2003, 6. International Symposium "Konditionierung radioaktiver Betriebs- und Stillegungsabfälle" / 6. Statusbericht des BMBF "Stillegung und Rückbau kerntechnischer Anlagen", ESTREL CY - Berlin, Germany DA - 2003-03-19 PY - 2003 AN - OPUS4-5280 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe T1 - Modern Safety Assessment of Cubic Iron Containers Under Mechanical Impact T2 - 17. International Conference on Structural Mechanics in Reactor (SmiRT 17) CY - Prague, Czech Republic DA - 2003-08-17 PY - 2003 AN - OPUS4-5282 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe A1 - Qiao, Linan A1 - Droste, Bernhard T1 - Entwicklung von Beurteilungsmethoden für Transport- und Lagerbehälter mit erhöhten metallischen Reststoffanteilen - Ein zusammenfassender Überblick T2 - 7. Internationales Symposium "Konditionierung radioaktiver Betriebs- und Stilllegungsabfälle" (KONTEC 2005) CY - Berlin, Deutschland DA - 2005-04-20 KW - Duktiles Gusseisen KW - Behälterdesign KW - Sicherheitstechnische Bewertung KW - Bruchmechanik KW - Dynamische Belastungsbedingungen PY - 2005 SP - 797 EP - 804 PB - KONTEC CY - Hamburg AN - OPUS4-11550 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zencker, Uwe A1 - Qiao, Linan A1 - Droste, Bernhard T1 - Development of assessment methods for transport and storage containers with a higher content of recycled metal KW - Ductile iron KW - Container design KW - Safety assessment KW - Fracture mechanics KW - Dynamic loading conditions PY - 2004 SN - 1746-5095 SN - 1746-5109 SN - 0957-476X VL - 15 IS - 3-4 SP - 215 EP - 221 PB - Ramtrans Publ. CY - Ashford AN - OPUS4-11551 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Zencker, Uwe A1 - Müller, Karsten A1 - Droste, Bernhard A1 - Rödel, Roland A1 - Völzke, Holger T1 - The Application of Fracture Mechanics to the Safety Assessment of Transport Casks for Radioactive Materials N2 - BAM is the responsible authority in Germany for the assessment of the mechanical and thermal design safety of packages for the transport of radioactive materials. The assessment has to cover the proof of brittle fracture safety for package components made of potentially brittle materials. This paper gives a survey of the regulatory and technical requirements for such an assessment according to BAM's new 'Guidelines for the application of ductile cast iron for transport and storage casks for radioactive materials'. Based on these guidelines, higher stresses than before will be permissible, but it is necessary to put more effort into the safety assessment procedure. The fundamentals of such a proof using the methods of fracture mechanics are presented. The recommended procedure takes into account the guidelines of the IAEA's advisory material which are based on the prevention of crack initiation. Examples of BAM's research and safety assessment practices are given. Recommendations for further developments towards package designs with higher acceptable stress levels will conclude the paper. KW - Ductile iron KW - Cask design KW - Safety assessment KW - Fracture mechanics KW - BAM GGR 007 PY - 2004 DO - https://doi.org/10.1179/174650904775295847 SN - 1746-5095 SN - 1746-5109 SN - 0957-476X VL - 15 IS - 3-4 SP - 191 EP - 198 PB - Ramtrans Publ. CY - Ashford AN - OPUS4-11553 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe A1 - Müller, Karsten A1 - Droste, Bernhard A1 - Rödel, Roland A1 - Völzke, Holger T1 - The application of fracture mechanics to the safety assessment of transport casks for radioactive materials T2 - 14th International Symposium on the Packaging and Transportation of Radioactive Materials CY - Berlin, Germany DA - 2004-09-20 KW - Ductile iron KW - Cask design KW - Safety assessment KW - Fracture mechanics KW - BAM GGR 007 PY - 2004 UR - http://www.iaea.org/inis/collection/NCLCollectionStore/_Public/37/088/37088572.pdf IS - 235 SP - 1 EP - 7(?) PB - BAM CY - Berlin AN - OPUS4-11477 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe A1 - Qiao, Linan A1 - Droste, Bernhard T1 - Development of Assessment Methods for Transport and Storage Containers with Higher Content of Metallic Recycling Material T2 - 14th International Symposium on the Packaging and Transportation of Radioactive Materials CY - Berlin, Germany DA - 2004-09-20 KW - Ductile iron KW - Container design KW - Safety assessment KW - Fracture mechanics KW - Dynamic loading conditions PY - 2004 UR - http://www.iaea.org/inis/collection/NCLCollectionStore/_Public/37/088/37088594.pdf IS - 235 SP - 1(?) EP - 7(?) PB - BAM CY - Berlin AN - OPUS4-11478 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Qiao, Linan A1 - Wieser, Günter A1 - Zencker, Uwe A1 - Droste, Bernhard T1 - Dynamische Analyse eines mit Stoßdämpfern ausgerüsteten Gefahrgutbehälters beim 9 m - Fallversuch T2 - 18. ABAQUS-Benutzerkonferenz 2006 CY - Erfurt, Deutschland DA - 2006-09-18 KW - Gefahrgutbehälter KW - Fallversuch KW - Finite-Elemente-Methoden PY - 2006 SP - 1 EP - 11(?) PB - ABAQUS CY - Aachen AN - OPUS4-13207 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe T1 - Sicherheitstechnische Analyse von Transport- und Lagerbehältern aus Gusseisen mit erhöhten metallischen Reststoffanteilen mittels Fallversuchen T2 - 8. Internationales Symposium "Konditionierung radioaktiver Betriebs- und Stilllegungsbfälle" einschließlich 8. Statusbericht des BMBF "Stilllegung und Rückbau kerntechnischer Anlagen" CY - Dresden, Germany DA - 2007-03-21 PY - 2007 AN - OPUS4-14708 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe A1 - Qiao, Linan A1 - Weber, Mike A1 - Kovacs, Oliver A1 - Droste, Bernhard T1 - Sicherheitstechnische Analyse von Transport- und Lagerbehältern aus Gusseisen mit erhöhten metallischen Reststoffanteilen mittels Fallversuchen T2 - KONTEC 2007 CY - Dresden, Deutschland DA - 2007-03-21 KW - Behälterdesign KW - Bruchmechanik KW - Duktiles Gusseisen KW - Dynamische Belastungsbedingungen KW - Sicherheitstechnische Bewertung PY - 2007 SP - 869 EP - 875 PB - Gesellschaft für technische Kommunikation mbH / Kerntechnische Gesellschaft CY - Dresden AN - OPUS4-14712 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - 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 - 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 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 AN - OPUS4-48915 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe T1 - Stress wave propagation with finite element mesh transitions N2 - A reliable finite element analysis presupposes a qualified model of the object to be analyzed. The finite element mesh density may significantly vary throughout a model. A transition between dissimilar meshes can be accomplished by a gradual change of element size or by an interface with constraint conditions. Some issues may arise from such mesh transitions. Generally, a finer mesh can transmit signals of higher frequency than a coarser mesh. Stress wave propagation through the model could be affected by the transition region or the artificially induced interface. Stress waves generated within the fine mesh could be partly encapsulated by the surrounding coarse mesh. Therefore poor mesh transitions could result in reflections or shape changes of stress waves. A thin rod is investigated to demonstrate the effects. This study supports the development of the ASME Guidance Document "Use of Explicit Finite Element Analysis for the Evaluation of Nuclear Transport and Storage Packages in Energy-Limited Impact Events". T2 - 19th International Symposium on the Packaging and Transportation of Radioactive Materials (PATRAM 2019) CY - New Orleans, LA, USA DA - 04.08.2019 KW - Stress Wave Propagation KW - Thin Rod KW - Finite Element Mesh Transition PY - 2019 AN - OPUS4-48916 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 - Weber, Mike A1 - Ballheimer, Viktor A1 - Wille, Frank A1 - Zencker, Uwe T1 - Numerical approach to determine a package dependent bar length for the iaea pin drop test N2 - The Federal Institute for Materials Research and Testing (BAM) is assessing the mechanical and thermal safety performance of packages for the transport of radioactive materials. Drop testing and numerical calculations are usually part of the safety case concepts, where BAM is performing the regulatory tests at their own test facility site. Among other mechanical tests the 1 meter drop onto a steel puncture bar shall be considered for accident safe packages. According to the IAEA regulations “the bar shall be of solid mild steel of circular section, 15.0 ± 0.5 cm in diameter and 20 cm long, unless a longer bar would cause greater damage…”. Particularly with regard to the German transport- and storage cask designs, often made from ductile cast iron, an accurate determination of the puncture bar length to guarantee a load impact covering the worst case scenario can be imperative. If the fracture mechanical proof for the cask material shall be provided by a test, small deviations in the concentrated load applied can be decisive for the question if the cask fails or not. The most damaging puncture bar length can be estimated by iterative procedure in numerical simulations. On the one hand, a sufficient puncture bar length shall guarantee that shock absorbers or other attachments do not prevent or reduce the local load application to the package, on the other hand, a longer and thus less stiff bar causes a smaller maximum contact force. The contrary influence of increasing puncture bar length and increasing effective drop height shall be taken into account if a shock absorber is directly placed in the target area. The paper presents a numerical approach to identify the bar length that causes maximum damage to the package. Using the example of two typical package masses the sensitivity of contact forces and puncture bar deformations to the initial length are calculated and assessed with regard to the international IAEA package safety requirements. T2 - PATRAM 2019 CY - New Orleans, LA, USA DA - 04.08.2019 KW - IAEA KW - 1-m-punch-bar-drop-test KW - Numerical approach KW - Bar length KW - Finite element analysis PY - 2019 UR - https://www.inmm.org/INMM-Resources/Proceedings-Presentations/PATRAM-Proceedings.aspx SP - 1 EP - 10 AN - OPUS4-49016 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 - Kömmling, Anja A1 - Simbruner, Kai A1 - Grelle, Tobias A1 - Jaunich, Matthias A1 - Zencker, Uwe A1 - Wolff, Dietmar A1 - Orellana Pérez, Teresa A1 - Völzke, Holger T1 - Research at BAM for evaluating long term safety of container systems and components N2 - 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. T2 - Annual Meeting on Nuclear Technology 2019 CY - Berlin, Germany DA - 07.05.2019 KW - Radioactive Waste KW - Long-term safety PY - 2019 SN - 978-3-926956-95-8 SP - 1 EP - 5 AN - OPUS4-51486 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 - Weber, Mike A1 - Kömmling, Anja A1 - Jaunich, Matthias A1 - Wolff, Dietmar A1 - Zencker, Uwe A1 - Völzke, Holger A1 - Schulze, Dietmar T1 - Testing and numerical simulation of elastomeric seals under consideration of time dependent effects N2 - Due to delays in the siting 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, extended periods of interim storage will become more relevant in Germany. BAM is involved in most of the cask licensing procedures and is responsible for the evaluation of cask-related long-term safety issues. Elastomeric seals are widely used as barrier seals for containers for low and intermediate level radioactive waste. In addition they are also used as auxiliary seals in spent fuel storage and transportation casks (dual purpose casks (DPC)). To address the complex requirements resulting from the described applications, BAM has initiated several test programs for investigating the behavior of elastomeric seals. These include experiments concerning the hyperelastic and viscoelastic behavior at different temperatures and strain rates, the low temperature performance down to -40°C, the influence of gamma irradiation and the aging behavior. The first part of the paper gives an overview of these tests, their relevant results and their possible impact on BAM’s work as a consultant in the framework of approval and licensing procedures. The second part presents an approach of the development of a finite element model using the finite element code ABAQUS®. The long-term goal is to simulate the complex elastomeric behavior in a complete lid closure system under specific operation and accident conditions. T2 - ASME 2016 Pressure Vessels & Piping Conference (PVP2016) CY - Vancouver, BC, Canada DA - 17.07.2016 KW - Elastomeric seals KW - Testing KW - Low temperature behavior KW - Aging KW - Simulation KW - Time dependent effects PY - 2016 SN - 978-0-7918-5045-9 VL - 7 SP - Paper 63192, 1 EP - 10 AN - OPUS4-37046 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jaunich, Matthias A1 - Weber, Mike A1 - Kömmling, Anja A1 - Zencker, Uwe A1 - Wolff, Dietmar A1 - Völzke, Holger T1 - Performance of elastomer seals in transport and storage casks N2 - Elastomer seals are widely used as barrier seals in containers for low and intermediate level radioactive waste and for spent fuel transportation casks. In addition, they are also used for spent fuel storage and transportation casks (dual purpose casks (DPC)) as auxiliary seals to allow leakage rate measurements of metal barrier seals for demonstration of their proper assembling conditions. Depending on the area of use, the rubber materials have to demonstrate proper sealing performance with regard to mechanical, thermal, and environmental conditions as well as irradiation during the entire operation period. Concerning DPC, degradation effects should be limited in a way that, for example, effects from potentially released decomposition elements may not harm e.g. metal barrier seals. Leakage rate measurements should be possible also after long interim storage periods prior to subsequent transportation. Because of the complex requirements resulting from the various applications of containers for radioactive waste and spent nuclear fuel, BAM has initiated several test programmes for investigating the behaviour of elastomer seals. In this contribution the current status is described and first results are discussed. T2 - International conference on management of spent fuel from nuclear power reactors: An integrated approach to the back end of the fuel cycle CY - Vienna, Austria DA - 15.06.2015 KW - Ageing KW - Elastomer KW - Glass-rubber transition KW - Irradiation KW - Material model PY - 2015 SP - 1 EP - 8 AN - OPUS4-33553 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 - In order to demonstrate the safety of both spent fuel and the storage system, a good understanding of the processes that might cause deterioration is required. The International Atomic Energy Agency (IAEA) continued the coordinated research on Spent Fuel Performance Assessment and Research (SPAR) into a fourth phase starting in 2015 to evaluate fuel and materials performance under wet and dry storage and to assess the impact of interim storage on associated spent fuel management activities (such as handling and transport). BAM’s understanding and experiences in the field of long-term storage of spent fuel and especially spent fuel characterization are presented to assist the preparation of the final project report. T2 - IAEA CRP SPAR-IV Third Research Coordination Meeting (RCM3) CY - Buenos Aires, Argentina DA - 07.10.2019 KW - Fuel rod KW - Cladding KW - Radial hydrides KW - Ring compression test KW - Failure analysis PY - 2019 AN - OPUS4-56006 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 - The integrity of fuel rods and cladding tubes must be demonstrated throughout the dry interim storage of spent nuclear fuel in Germany. For at least a relevant number of casks, an extension of interim storage between 40 and 100 years is foreseeable. The drying procedure for the fuel rods in conjunction with the thermomechanical storage conditions may change the microstructure of the cladding tubes and lead to their possible embrittlement. The failure probability might increase under mechanical load by handling procedures (transport after storage) on potentially embrittled cladding tubes of fuel rods especially at low temperatures after long-term storage. Results of ring compression tests on unirradiated pre-hydrided as well as irradiated samples with radial hydrides are investigated by finite element analyses to be able to describe the failure process and to identify failure criteria. T2 - EPRI Extended Storage Collaboration Program (ESCP) Winter 2019 Meeting CY - Charlotte, NC, USA DA - 04.11.2019 KW - Fuel rod KW - Cladding KW - Radial hydrides KW - Ring compression test KW - Failure analysis PY - 2019 AN - OPUS4-56005 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Zencker, Uwe T1 - Spent Fuel Characterization - Current Activities in Germany N2 - The characterization of spent fuel and radioactive waste is essential in the evaluation of the ability of these materials to meet acceptance criteria. Prior to determining a method for spent fuel characterization, it is necessary to identify the type of data required to support safety and other analyses for the storage, transportation and final disposal of spent fuel. BAM’s understanding and capabilities in the field of spent fuel characterization are presented for the scope of a coordinated research project on the topic. T2 - IAEA Technical Meeting on Spent Fuel Characterization for Management of Spent Fuel in the Back End of the Fuel Cycle CY - Vienna, Austria DA - 12.11.2019 KW - Nuclear fuel cycle KW - Back end KW - Spent fuel characterization KW - Storage KW - Transportation PY - 2019 AN - OPUS4-55866 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Qiao, Linan A1 - Keller, Christian A1 - Zencker, Uwe A1 - Völzke, Holger T1 - Three-dimensional finite element analysis of O-ring metal seals considering varying material properties and different seal diameters N2 - 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. KW - Sensitivity analysis KW - Transport and storage cask KW - O-ring metal seal KW - Lid-system KW - Finite element analysis KW - Stochastic variation of material properties PY - 2019 DO - https://doi.org/10.1016/j.ijpvp.2019.103953 VL - 176 SP - 102953 PB - Elsevier Ltd. CY - Amsterdam AN - OPUS4-49263 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Liu, Yung A1 - Völzke, Holger A1 - Zencker, Uwe A1 - Jaunich, Matthias T1 - Cooperation in Advanced Technologies Associated with the Back End of Nuclear Fuel Cycle N2 - A Memorandum of Understanding (MOU) between Argonne National Laboratory (Argonne) and the German Bundesanstalt für Materialforschung und -prüfung (BAM) was signed in October 2014. Its objectives are to promote cooperation among scientists and specialists at Argonne and BAM and establish a framework for collaboration in advanced technologies associated with the back end of the nuclear fuel cycle. Collaborative activities involving Argonne and BAM may be implemented through the promotion of joint research activities and scientific workshops and conferences; exchange of technical information; and visits by scientists, specialists, and graduate, postgraduate, and Ph.D. students. The MOU was renewed in January 2020 for another five years. Highlights of the progress and achievements are provided in identified topical areas for collaboration on ageing management guidance, storage, transportation and disposal R&D, joint conference activities, and conclude with the benefits of the MOU in fostering Argonne and BAM collaboration. T2 - 26th International Conference on Structural Mechanics in Reactor Technology - SMiRT 26 CY - Potsdam, Germany DA - 10.07.2022 KW - Nuclear fuel cycle KW - Back end KW - Spent fuel performance KW - Storage KW - Transportation PY - 2022 SP - 1 EP - 10 AN - OPUS4-55861 LA - eng 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 - JOUR A1 - Kasparek, Eva Maria A1 - Völzke, Holger A1 - Scheidemann, Robert A1 - Zencker, Uwe A1 - Wolff, Dietmar T1 - Experimental and numerical studies of shock absorbing materials for containers for radioactive waste N2 - Safety assessments of Containers for Transport and storage of radioactive materials involvedrop scenarios prescribed in the regulations of the International Atomic Energy Agency - IAEA or potential accidents that might occur in a specific nuclear facility. Hereby, the design of impact limiters and foundation properties of the handling Region have a major effect on the mechanical loading of the cask and lid System. Reliable numerical simulations, which very often constitute a relevant part of such safety proofs, require systematic information About the energy absorption potential of the respectiye materials and its implementation in FEM (finite element) programs. However, when performing drop tests, BAM (BAM Bundesanstalt für Materialforschung und -prüfung, Federal Institute for Materials Research and Testing) identified significant differences between numerical and experimental results, which most likely result from numerical methods that do not sufficiently reproduce the behaviour of impact limiting structures. Particularly concerned are Container impact limiter made of wood or Polyurethane foam as well as damping concrete bricks, which are embedded in foundations of German interim storages. PY - 2012 SN - 1431-5254 VL - 57 IS - 6 SP - 397 EP - 401 PB - Inforum CY - Berlin AN - OPUS4-26261 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kasparek, Eva Maria A1 - Völzke, Holger A1 - Scheidemann, Robert A1 - Zencker, Uwe T1 - Numerical and experimental investigations of polyurethane foam for use as cask impact limiter in accidental drop scenarios N2 - Rigid, closed-cell polyurethane foams are frequently used as cask impact limiters in nuclear materials and hazardous waste transport due to their high energy-absorption potential. When assessing the cask integrity in accidental scenarios based on numerical simulations, a description of the foam damping properties is required for different strain rates and for a wide temperature ränge with respect to waste heat generation in conjunction with critical operating and environmental conditions. Implementation and adaption of a respective finite element material model strongly relies on an appropriate experimental data base. Even though extensive impact experiments were conducted e.g. in Sandia National Laboratories, Savannah River National Laboratory and by Rolls Royce plc, not all relevant factors were taken into account. Hence, BAM who is in Charge of the mechanical evaluation of such packages within the approval procedure in Germany, incorporated systematic test series into a comprehensive research project aimed to develop numerical methods for a couple of damping materials. In a first step, displacement driven compression tests have beenperformed on confined, cubic specimens at five loading rates ranging from 0.02 mm/s to 3 m/s attemperatures between +90°C and -40°C. Materials include two differentPolyurethane foam types called FR3718 and FR3730 having densities of 280 kg/m3 and 488 kg/m3 from the product line-up of General Plastics Manufacturing Company. Their data was used to adapt an advanced plasticity model allowing for reliably simulating cellular materials under multi-axial compression States, Therefore, an automated parameter identification procedure had been established by combining an artificial neural network with local optimization techniques. Currently, the selected numerical material input values are validated and optimized by means of more complex loading configurations with the prospect of establishing methods applicable to impact limiters under severe accidental conditions. The reference data base is provided by experiments, where weights between 212 kg and 1200 kg have been dropped from heights between 1.25 m and 7 m on confined 10 cm cubic foam specimens. By presenting the deviations between experimental values and the corresponding Output of finite element simulations, the Potentials and restrictions of the resulting models are highlighted. T2 - WM2012 - Waste management conference CY - Phoenix, AZ, USA DA - 26.02.2012 KW - Plasticity KW - Finite elements KW - Material models KW - Rate dependency KW - Temperature dependency KW - Compression tests KW - Drop tests KW - Parameter identification PY - 2012 SN - 978-0-9836186-1-4 N1 - Serientitel: WM Symposia – Series title: WM Symposia IS - Paper 12099 SP - 1 EP - 9 AN - OPUS4-26270 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Ammerman, D. J. A1 - Bignell, J. L. A1 - Bjorkman, G. S. A1 - Breach, M. R. A1 - Broz, V. A. A1 - Jordan, J. A1 - Kuehner, S. A1 - Molitoris, D. P. A1 - Reinhardt, W. A1 - Rigato, A. B. A1 - Rosvall, E. S. A1 - Sakalaukus Jr., P. J. A1 - Shih, P. Y.-K. A1 - Siromani, D. A1 - Snow, S. D. A1 - Tso, C.-F. A1 - Yaksh, M. C. A1 - Zencker, Uwe A1 - Zhang, X. T1 - Guidance document - Use of explicit finite element analysis for the evaluation of radioactive material transport packages and storge casks in energy-limited impact events N2 - The purpose of this document is to provide guidance for developing quality finite element models to ensure, with reasonable certainty, that the model produces accurate results for comparison with the strain-based or stress-based acceptance criteria of Section III, Division 3 of the ASME Boiler and Pressure Vessel Code, but could be applicable to other Sections of the Code or other codes. Models developed following the guidance provided in this document meet the definition of a "Quality Model," as described in Paragraph EE 1240 of the Nonmandatory Appendix EE (Strain-Based Acceptance Criteria Definitions and Background Information). It cannot be emphasized enough, however, that the guidance supplied here does not constitute requirements. Rather, the intent of the guidance is to give practical direction to analysts (i.e., this is not a set of regulatory requirements). This guidance document is an "evolving" document. It will undergo revision as computing capability and FEA techniques progress, and as example problems are developed. KW - Computational modeling KW - Explicit dynamics PY - 2025 SN - 978-0-7918-7749-4 VL - NTB-6 SP - 1 EP - 153 PB - Americal Society of Mechanical Engineers (ASME) CY - New York, NY ET - 2025 AN - OPUS4-65759 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -