TY - CONF A1 - Musolff, André A1 - Komann, Steffen A1 - Droste, Bernhard A1 - Müller, Karsten A1 - Quercetti, Thomas T1 - Drop test program with a HLW cask model - performance, measurements and results N2 - BAM (Federal Institute for Material Research and Testing) is the competent authority for mechanical and thermal safety assessment of transport packages for spent fuel and high level waste (HLW) in Germany. In context with package design approval of the new German HLW cask CASTOR HAW28M, BAM performed several drop tests with a half-scale model of the CASTOR HAW/TB2. The test model was manufactured by GNS (Gesellschaft fur Nuklear Service mbH) and tested under accident transport conditions on the 200 tons BAM drop test facility at the BAM Test Site Technical Safety. For this comprehensive test program the test specimen CASTOR HAW/TB2 was instrumented at 21 measurement planes with altogether 23 piezo-resistive accelerometers, five temperature sensors and 131 tri-axial strain gauges in the container interior and exterior, respectively. The strains of four representative lid bolts were recorded by four uniaxial strain gauges per each bolt. Helium leakage rate measurements were performed before and after each test in the above noted testing sequence. The paper presents some experimental results of the half-scale CASTOR HAW/TB2 prototype (14,500 kg) and measurement data logging. T2 - 52nd INMM Annual meeting CY - Palm Desert, CA, USA DA - 17.07.2011 KW - Drop test results KW - Spent fuel transport cask KW - Impact limiter KW - Measurement methods KW - Drop test program PY - 2011 SP - 1 EP - 9 AN - OPUS4-24245 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Musolff, André A1 - Quercetti, Thomas A1 - Müller, Karsten A1 - Droste, Bernhard A1 - Komann, Steffen T1 - Drop test program with the half-scale model CASTOR HAW/TB2 T2 - PATRAM 2010 - 16th International symposium on the packaging and transport of radioactive materials CY - London, UK DA - 2010-10-03 KW - Spent fuel transport cask KW - Drop test KW - Impact limiter KW - Measurement procedure PY - 2010 SP - 1 EP - 8 AN - OPUS4-22771 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Musolff, André A1 - Quercetti, Thomas A1 - Müller, Karsten A1 - Droste, Bernhard A1 - Komann, Steffen T1 - Drop test program with half scale model CASTOR HAW/TB2 N2 - Federal Institute for Materials Research and Testing (BAM) is the competent authority for mechanical and thermal safety assessment of transport packages for spent fuel and high level waste in Germany. In context with package design approval of the new German high level waste cask CASTOR® HAW28M, BAM performed several drop tests with a half scale model of the CASTOR® HAW/TB2. The cask is manufactured by Gesellschaft für Nuklear Service mbH and was tested under accident transport conditions on the 200 tons BAM drop test facility at the BAM Test Site Technical Safety. For this comprehensive test program, the test specimen CASTOR® HAW/TB2 was instrumented at 21 measurement planes with altogether 23 piezo resistive accelerometers, five temperature sensors and 131 triaxial strain gauges in the container interior and exterior respectively. The strains of four representative lid bolts were recorded by four uniaxial strain gauges per each bolt. Helium leakage rate measurements were performed before and after each test in the above noted testing sequence. The paper presents some experimental results of the half scale CASTOR® HAW/TB2 prototype (14 500 kg) and measurement data logging. It illustrates the extensive instrumentation and analyses that are used by BAM for evaluating the cask performance to the mechanical tests required by regulations. Although some of the quantitative deceleration, velocity and strain values cannot be shown because of confidentially issues, they are provided qualitatively to illustrate the types of measurements and methodologies used at BAM. KW - IAEA drop testing KW - Half scale model KW - Experimental test PY - 2011 DO - https://doi.org/10.1179/1746510911Y.0000000013 SN - 1746-5095 SN - 1746-5109 SN - 0957-476X VL - 22 IS - 3 SP - 154 EP - 160 PB - Ramtrans Publ. CY - Ashford AN - OPUS4-25293 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Lars A1 - Komann, Steffen A1 - Wille, Frank A1 - Droste, Bernhard T1 - Sicherheitstechnische Begutachtung der strukturmechanischen Auslegung von Castor-Behältern N2 - Die Sicherheitsanforderungen, die an Behälter für den Transport radioaktiver Stoffe auf öffentlichen Verkehrswegen gestellt werden, orientieren sich an dem Gefährdungspotenzial des radioaktiven Inhalts. So müssen für den Transport abgebrannter Brennelemente oder hochradioaktiver Abfalle aus nuklearen Anlagen Behälter eingesetzt werden, die auch schweren Unfällen standhalten. Zu ihnen gehören z. B. die CASTOR®-Behälter (Cask for Storage and Transport of Radioactive Material). T2 - BTU Stahlbau-Symposium 2014 CY - Cottbus, Germany DA - 23.05.2014 PY - 2014 SN - 1611-5023 N1 - Serientitel: Schriftenreihe Stahlbau – Series title: Schriftenreihe Stahlbau IS - 8 SP - 33 EP - 40 AN - OPUS4-31148 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Lars A1 - Scheidemann, Robert A1 - Neumeyer, Tino A1 - Komann, Steffen A1 - Wille, Frank T1 - Tightness Verification Procedures of Welded Lids for Encapsulations for Damaged Spent Nuclear Fuel in the Design Approval Process of Dual-Purpose Cask (DPC) N2 - Damaged spent nuclear fuel (DSNF) can be loaded in Germany in dual-purpose casks (DPC) for transport and interim storage. Therefore, special encapsulations are needed to guarantee a safe handling and a reliable tight closure. These encapsulations must be durable and leak-tight for a possible long interim storage term and the transport thereafter. Because components inside the package containment like these special encapsulations are not accessible within periodical inspections of the DPC. Due to the general design of DPCs for standard fuel assemblies, specific requirements needed to be considered for the design of the special encapsulations for DSNF to ensure the loading in existing package designs. Especially the content of the encapsulations with damaged spent nuclear fuel must be avoided to enter in the inner space of the DPC, due to the possible higher amount of corrosive and radioactive material as well as greater quantities of water, which can be trapped in defect fuel rods. The main difference of the encapsulations for damaged spent nuclear fuel is that they have no replaceable sealing as tightness barrier. They have a specific welded lid. Therefor the tightness needs to be shown in the design approval process for all transport conditions especially for accident conditions, where high internal impact loads can occur. As German competent authority, BAM is responsible for the safety assessment of the mechanical and thermal design, the release of radioactive material and the quality assurance aspects of manufacturing and operation. Concerning the mechanical package design BAM carried out a comprehensive safety assessment for the specific encapsulations during the package design approval process of the commonly used DPC. For the proof of tightness of the welded lid no representative standards are available. For minor loads the German KTA standards can verify the tightness of a weld seam but only for low stresses. For higher impact loads physical tests are required. These tests were performed with representative drop tests and highly sensitive leak tests. The present paper gives an overview of the applied assessments by BAM and points out the main findings of the mechanical design for the welded sealing. Both verification procedures are described, on one hand with German standards for lower loads and on the other hand with physical tests for higher impact loads. The drop tests based on complex numerical pre-calculations by the applicant which result in optimized dimensions and properties of the test specimens and representative drop heights for the drop tests. The horizontal drop orientation with a plane-parallel impact on the unyielding basement was most challenging and led to specific adaptations during preparation and conduction of the drop tests performed by BAM. With leak tests and the corresponding test evaluation, it could be finally approved that the specific welded sealing of an encapsulations for DSNF is tight for all transport conditions. T2 - ASME PVP 2024 CY - Bellevue, WA, USA DA - 28.07.2024 KW - Tightness verification KW - Weld seams KW - Drop tests KW - Encapsulations for damaged spent nuclear fuel KW - Helium leak tests PY - 2024 SN - 978-0-7918-8851-3 SP - 1 EP - 10 CY - New York AN - OPUS4-61351 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Lars A1 - Scheidemann, Robert A1 - Neumeyer, Tino A1 - Neumann, Martin A1 - Komann, Steffen A1 - Wille, Frank T1 - Thightness Assessment of welded Lids for Encapsulations of damaged Spent Nuclear Fuel in the Design Approval Process of Dual-Purpose Casks (DPC) N2 - The disposal of spent nuclear fuel in Germany is ensured using dual-purpose casks (DPC) for transport and interim storage. The leak tightness of the DPC and resulting containment is one of the most important aspects. Additional encapsulations are required for damaged spent nuclear fuel (DSNF) to guarantee safe handling and a separate tight closure. Due to the general design of DPCs for standard fuel assemblies should special requirements be considered for the design of the encapsulations for DSNF to ensure the loading in existing package designs. The absence of a replaceable sealing in the tightness barrier is the main difference for the encapsulations for damaged spent nuclear fuel. Instead, they are welded shut with a lid. The leak tightness of the encapsulation shall be proven in the design approval process for all transport conditions. This is especially valid for accident conditions of transport, where high internal impact forces may occur. BAM as German competent authority is responsible for the safety assessment of mechanical and thermal design, retention of radioactive material and quality assurance aspects of manufacturing and operation. BAM carried out a comprehensive safety assessment concerning the mechanical package design. As there are no representative standards for verifying the leak tightness of a welded lid, two approaches were being pursued. Established German standards may be used for verifying the leak tightness of a weld - but limited to low stresses. Therefore, physical tests were required for higher impact loads. Representative drop tests and highly sensitive leakage tests were performed. The paper presents an overview of the containment assessment by BAM and points out the main findings for the design of welds regarding leak tightness. Both verification procedures are described, on one hand with German standards for lower loads and on the other hand with physical tests for higher impact loads. The leak tightness of the encapsulation weld could be approved based on leakage tests and a corresponding evaluation for all transport conditions. T2 - PATRAM 2025 CY - San Antonio, Texas, USA DA - 27.07.2025 KW - Transport packages KW - Tightness assessment KW - Welded lids KW - Encapsulations PY - 2025 VL - 2025 SP - 1 EP - 11 PB - Institute of Nuclear Materials Management (INMM) CY - Indianapolis AN - OPUS4-64023 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Lars A1 - Scheidemann, Robert A1 - Schönfelder, Thorsten A1 - Komann, Steffen A1 - Wille, Frank T1 - Drop tests assessment of internal shock absorbers for packages loaded with encapsulations for damaged spent nuclear fuel N2 - Damaged spent nuclear fuel (DSNF) can be loaded in German dual-purpose casks (DPC) for transport and interim storage. Encapsulations are needed to guarantee a safe handling and a tight closure, separated from the package enclosure. These encapsulations shall be durable and leak-tight for a long storage period, because they are usually not accessible within periodical inspections of the DPC. Due to the general design of DPCs for standard fuel assemblies, specific requirements have to be considered for the design of encapsulations for DSNF to ensure the loading in existing package designs. Especially the primary lid system of a DPC is designed for maximum loads due to the internal impact of the content during drop test conditions. The main difference of encapsulations for damaged spent nuclear fuel is that they have usually a much higher stiffness than standard fuel assemblies. Therefore the design of an internal shock absorber, e.g. at the head of an encapsulation is required to reduce mechanical loads to the primary lid system during impacts. BAM as part of the German competent authority system is responsible for the safety assessment of the mechanical and thermal package design, the release of radioactive material and the quality assurance of package manufacturing and operation. Concerning the mechanical design of the encapsulation BAM was involved in the comprehensive assessment procedure during the package design approval process. An internal shock absorber was developed by the package designer with numerical analyses and experimental drop tests. Experimental drop tests are needed to cover limiting parameters regarding, e.g. temperature and wall thickness of the shock absorbing element to enable a detailed specification of the whole load-deformation behavior of the encapsulation shock absorber. The paper gives an overview of the assessment work by BAM and points out the main findings which are relevant for an acceptable design of internal shock absorbers. The physical drop tests were planned on the basis of pre-investigations of the applicant concerning shape, dimension and material properties. In advance of the final drop tests the possible internal impact behavior had to be analyzed and the setup of the test facility had to be validated. The planning, performance and evaluation of the final drop tests were witnessed and assessed by BAM. In conclusion it could be approved that the German encapsulation system for damaged spent nuclear fuel with shock absorbing components can be handled similar to standard fuel assemblies in existing package designs. T2 - Pressure Vessels & Piping Conference 2020 CY - Online meeting DA - 03.08.2020 KW - Encapsulations for damaged spent nuclear fuel KW - Drop tests KW - Internal shock absorber KW - Design assessment of RAM packages PY - 2020 SP - 1 EP - 9 AN - OPUS4-51546 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Lars A1 - Schilling, O. A1 - Ballheimer, Viktor A1 - Wille, Frank A1 - Komann, Steffen T1 - Assessment strategy of numerical analyses of RAM package components - 14619 N2 - In Germany current package design safety cases include more and more advanced numerical methods, e. g. finite element analysis (FEA), often in combination with local concepts of strength evaluation of the structure. This approach requires extensive modeling and verification procedures. As a consequence the efforts of authority assessment of design safety analysis increase as well. Only the check of pre- and post-data of numerical calculations is often not sufficient for the safety assessment. On the other hand own analyses of the mechanical problem by performing an Independent numerical modeling and analyzing is not always realizable. Therefore it is necessary to look for optimized procedures of the assessment, without loss of safety. This paper shows possibilities for the assessment strategy of numerical analyses with focus on simple analytical approaches as comparative calculations. Such approaches can be helpful to support evaluation of numerical calculations in the whole assessment procedure. Three examples are considered to Show which possibilities and limits exist to support the assessment of numerical analyses using analytical comparative calculations. Two examples of bolt and lid analysis show the influence of component and boundary stiffness on the results. Thickness to length/width ratios are partially exceeded and only fixed or free boundary conditions can be analyzed analytical. Nevertheless These analytical approaches can help to evaluate the numerical results for the assessment. The example of a trunnion demonstrates the limits of analytical approaches. The trunnion shows a complex deformation behavior and local stresses. A single basic theory isn’t matching and a construct of several approaches is not useable for calculations of local stresses. Therefore numerical calculations during assessment are necessary. Analytical approaches are not always purposeful but often effective to reduce the effort of assessment for numerical analysis of complex and safety relevant components of RAM packages. T2 - WM2014 Conference CY - Phoenix, Arizona, USA DA - 02.03.2014 PY - 2014 SN - 978-0-9836186-3-8 SP - Paper 14619, 1 EP - 14 AN - OPUS4-31047 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Müller, Lars A1 - Schönfelder, Thorsten A1 - Komann, Steffen A1 - Ballheimer, Viktor A1 - Wille, Frank ED - Müller, Lars T1 - Assessment experience on packages loaded with damaged spent nuclear fuel for transport after storage N2 - In 2017 the first German package approval certificate was issued for a dual purpose cask (DPC) design with encapsulated damaged spent nuclear fuel. At the Bundesanstalt für Materialforschung und -prüfung (BAM) a comprehensive assessment procedure was carried out with respect to the mechanical and thermal design, the containment design and quality assurance for manufacturing and operation. Main objective of this procedure was to verify the Package Design Safety Report (PDSR) fulfils the requirements according to the IAEA regulations SSR-6. Until now only standard spent nuclear fuel assemblies were designated for interim storage and transports. Due to nuclear phase out in Germany all other kinds of SNF in particular damaged fuel has to be packed. Therefore specific requirements have to be considered in accordance with international experiences written in IAEA technical reports. In Germany damaged spent nuclear fuel (DSNF) needs a tight encapsulation with special encapsulations and clearly defined properties. Due to the limited amount of DSNF these encapsulations are designed for storage and transport in existing packages. From the assessment experience it has been seen, corresponding PDSR need an extensively expansion to cover the design of these encapsulations and their influences on the package. Then such well-defined encapsulations can be handled like standard fuel assemblies. The main difference to standard package components is, encapsulations with permanent closure achieve their specified condition not after manufacturing but only during operation after loading and closing. Thus specific handling instruction and test procedures are necessary especially for welding, where BAM is able to survey the quality of this first part of operation. T2 - 11th International Conference on the Transport, Storage and Disposal of Radioactive Materials CY - London, UK DA - 15.05.2018 KW - Assessment KW - Dual purpose cask KW - Spent nuclear fuel PY - 2018 SP - Paper 18524, 1 EP - 8 AN - OPUS4-45258 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - GEN A1 - Pasternak, H. A1 - Komann, Steffen ED - Gizejowski, ED - Kozlowski, ED - Sleczka, ED - Ziólko, T1 - A new design formula for determining the load-bearing capacity of locally supported shells T2 - XI. Miedzynarodowa Konferencja Naukowo-Techniczna "Konstrukcje Metalowe" CY - Rzeszów, Poland DA - 2006-06-21 KW - Cylindrical shell KW - Stability KW - Steel KW - Buckling KW - Longitudinal stiffeners PY - 2006 SN - 0-415-40120-8 SP - 160 EP - 161 PB - Taylor & Francis CY - London, UK AN - OPUS4-19152 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -