TY - CONF A1 - Krietsch, Torsten A1 - Wolff, Dietmar A1 - Knopp, U. A1 - Brocke, H.-D. T1 - Behaviour of neutron moderator materials at high temperatures in CASTOR-casks - qualification and assessment T2 - 14th International Symposium on the Packaging and Transportation of Radioactive Materials CY - Berlin, Germany DA - 2004-09-20 KW - Transport Packagings KW - Radioactive Materials KW - Neutron Shielding Materials PY - 2004 UR - http://www.iaea.org/inis/collection/NCLCollectionStore/_Public/37/088/37088730.pdf VL - 14 IS - 235 SP - 1 EP - 8(?) PB - BAM CY - Berlin AN - OPUS4-11226 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wieser, Günter A1 - Qiao, Linan A1 - Völzke, Holger A1 - Wolff, Dietmar A1 - Droste, Bernhard T1 - Safety analysis of casks under extreme impact conditions KW - Aircraft crash KW - Impact load KW - Simulation KW - Lid-seal system KW - Storage cask KW - Metallic seal KW - Leakage rate PY - 2004 SN - 1746-5095 SN - 1746-5109 SN - 0957-476X VL - 15 IS - 2 SP - 141 EP - 147 PB - Ramtrans Publ. CY - Ashford AN - OPUS4-14441 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wolff, Dietmar T1 - Long-term storage facility for reactor compartments in Sayda Bay - German support for utilization of nuclear submarines in Russia - T2 - 11th International Conference on Environmental Remediation and Radioactive Waste Management ICEM2007, Qud Sint-Jan Hospital Conference Center CY - Bruges, Belgium DA - 2007-09-02 PY - 2007 AN - OPUS4-15893 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Erhard, Anton A1 - Völzke, Holger A1 - Noack, Volker A1 - Weber, Wolfgang A1 - Wolff, Dietmar A1 - Rittscher, D. A1 - Schmidt, H. T1 - Long term interim storage facility for nuclear reactor compartments of submarines - German support for utilization of nuclear submarines in Russia T2 - PATRAM 2007, 15th International Symposium on the Packaging and Transportation of Radioactive Materials CY - Miami, Florida, USA DA - 2007-10-21 PY - 2007 SP - 155 PB - Institute of Nuclear Materials Management AN - OPUS4-16157 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wille, Frank A1 - Wolff, Dietmar A1 - Droste, Bernhard A1 - Völzke, Holger T1 - Requirements for transport packages after interim storage N2 - In Germany the concept of dry interim storage of spent fuel and vitrified high active waste in dual purpose metal casks is implemented (currently for periods of up to 40 years). The casks being used have an approved package design in accordance with the international transport regulations. The license for dry storage is granted on the German Atomic Energy Act with respect to the guidelines of the German Reactor Safety Commission for dry interim storage of spent fuel. Currently part of the assessment process of the cask design for transport on public routes is to evaluate the suitability of the used materials with respect to their properties and their compatibility for possible transport periods. For transport on public routes during or after long term interim storage periods, it has to be ensured that the transport and storage casks fulfill the specifications of the transport approval or other sufficient properties which satisfy the proofs for the compliance of the safety objectives at that time. This paper describes the state-of-the-art technology in Germany and points out arising prospective challenges and which related questions have to be answered in future. Present research and knowledge concerning the long term behavior of transport and storage cask components (such as gaskets and shielding components) have to be consulted as well as experiences from interim cask storage operations. Challenges in the safety assessment are therefore i.e. the behavior of aged metal and elastomeric gaskets under IAEA test conditions to ensure that the results of drop tests can be transferred to the compliance of the safety objectives at the time of transport after the interim storage period (aged package). Assessment methods for the material compatibility, the behavior of fuel assemblies and the aging behavior of shielding parts (e. g. influence of radiation) are further issues as well. T2 - 52nd INMM Annual meeting CY - Palm Desert, CA, USA DA - 17.07.2011 KW - Transport package design KW - Interim storage KW - Inspections KW - Log term behavior KW - Dual purpose casks PY - 2011 SP - 1 EP - 9 AN - OPUS4-24172 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Völzke, Holger A1 - Probst, Ulrich A1 - Wolff, Dietmar A1 - Nagelschmidt, Sven A1 - Schulz, Sebastian T1 - Investigations on the long term behavior of metal seals for spent fuel storage casks N2 - Metal seals are in common use as an essential component for the leak tight closure of transport and storage casks for spent fuel and vitrified high active waste from reprocessing. They are placed between the massive monolithic cask body made of ductile cast iron or forged steel and the primary and secondary lids, which are fixed with screws around the lid circumference, in order to ensure long term safe enclosure of the radioactive cask inventory. Hereby, long term reliable pressure forces in combination with a tight surface contact are as important as well maintained seal and surface qualities and dry and clean conditions during seal assembly and operation. A few years ago BAM started systematic investigation on the long term seal behavior with re-spect to longer storage periods and seal behavior in accidental cask scenarios with dynamic de-formations of the seal groove geometry or short term drop in pressure force up to lid lifting. BAM has developed test flanges for seals with full scale cross section diameter but much small-er outer diameter to gain representative data for metal-sealed lid systems. They are placed in appropriate testing machines for relevant mechanical loading under static and dynamic condi-tions with the ability to measure the standard helium leakage rate continuously during each test phase. This paper focuses on BAM long term tests of different seal types with aluminum and silver jackets at three different temperatures of +20°C, +100°C and +150°C under static conditions over longer periods of time. Due to creeping effects, a reduction of the pressure force does ap-pear during loading and unloading depending on prior holding times. So far, test results of up to 2 years indicate a clear correlation between seal pressure forces and holding time, temperature and seal type allowing for extrapolating to much longer periods of time. The paper presents basic correlations, test and evaluation procedures as well as important provisional results and gives an outlook on further investigations. T2 - 52nd INMM Annual meeting CY - Palm Desert, CA, USA DA - 17.07.2011 PY - 2011 SP - 1 EP - 9 AN - OPUS4-24173 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Erhard, Anton A1 - Völzke, Holger A1 - Probst, Ulrich A1 - Wolff, Dietmar T1 - Ageing management for long term interim storage casks T2 - PATRAM 2010 - 16th International symposium on the packaging and transport of radioactive materials CY - London, UK DA - 2010-10-03 KW - Ageing management KW - Lifetime KW - Material degradation PY - 2010 SP - 1 EP - 17 (Tuesday/T20/61) AN - OPUS4-23907 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Erhard, Anton A1 - Völzke, Holger A1 - Probst, Ulrich A1 - Wolff, Dietmar T1 - Aging management for long-term interim storage casks N2 - The aging management system for the mechanical components of nuclear power plants (NPPs) must be established and used by the licensee in such a way that the quality of safety relevant components is guaranteed for the completely designed lifetime of the NPP. This demands an extensive plant life management with special emphases on the knowledge of the degradation in material properties. The basic safety concept in Germany observes this circumstance. Lifetime extension of the German NPPs is an aim of the current valid coalition agreement of the German government. Operational extension of interim storage facilities requires, in comparison to the aging management system for NPP, an aging management system adapted to the Special circumstances of spent fuel storage casks. Extension of interim storage periods for spent fuel casks beyond the designed lifetime requires, in comparison to the components of an NPP, an increasing knowledge of material degradation with potential impact on cask integrity, e.g. leak tightness. Dry interim storage in Germany has been approved for 40 years. After that time, according to the present strategy, a final repository should be available. However, until now, such a final facility still does not exist, and the German exploration and licensing process is heavily delayed. Currently, discussions are continuing regarding further exploration of the Gorleben salt mine. There is willingness to overcome this situation that is clearly described in the available coalition agreement of the federal government. Anyway, however, the prediction is viewed; a repository for heat generating radioactive waste in Germany will not be available in the near future and may not be available when first storage facilities and casks reach their 40 years of approved lifetime, which will occur in ~25 years starting from now. Therefore, the question must be asked: what has to be done with the existing storage casks in the interim facilities? May these casks be fit for continued use, with an extension of the storage period? One option is to have an aging management system, which creates enough information about the technical condition of safety relevant cask properties. This is the basis for safety evaluation for extended storage periods. In the present paper, possible aging mechanisms for high level waste storage casks are discussed, as well as the influence of the time dependent changes of the component properties. KW - Long term interim storage KW - Storage casks KW - Aging mechanisms KW - Degradation mechanisms KW - Metal seals KW - Larson-Miller parameter PY - 2011 DO - https://doi.org/10.1179/1746510910Y.0000000013 SN - 1746-5095 SN - 1746-5109 SN - 0957-476X VL - 22 IS - 1 SP - 46 EP - 53 PB - Ramtrans Publ. CY - Ashford AN - OPUS4-23890 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wolff, Dietmar T1 - Nachweisstrategien zur Behältersicherheit unter Berücksichtigung von Alterungseffekten und Störfallszenarien T2 - 3. RAM-Behältersicherheitstage 2012, BAM CY - Berlin, Germany DA - 2012-03-22 PY - 2012 AN - OPUS4-25660 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wolff, Dietmar T1 - Long-termin Storage and Aging Management issues in Dry Interim Cask Storage (international and national perspectives) T2 - Workshop KAERI (Korean Atomic Energy Research Institute) - BAM CY - Daejeon, South Korea DA - 2012-09-11 PY - 2012 AN - OPUS4-26815 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wolff, Dietmar T1 - Experiences in safety evaluation of spent fuel cask designs for interim storage T2 - Workshop KAERI (Korean Atomic Energy Research Institute) - BAM CY - Daejeon, South Korea DA - 2012-09-11 PY - 2012 AN - OPUS4-26816 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wolff, Dietmar T1 - Updating report on R&D concerning technical data gaps - Germany (BAM) - Long Term Behavior of Sealing systems and Neutron Shielding Materials T2 - 8th International Subcommittee meeting as part of the Extended Storage Collaboration Program (ESCP) CY - Munich, Germany DA - 2013-05-24 PY - 2013 AN - OPUS4-28998 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wolff, Dietmar T1 - Extended Storage after Long-term Storage 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 - OPUS4-29009 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wolff, Dietmar T1 - Behavior of rubber seals at low temperatures and neutron radiation shielding material under influence of gamma radiation T2 - Savannah River National Laboratory Workshop CY - Aiken, SC, USA DA - 2012-12-03 PY - 2012 AN - OPUS4-27395 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Herbrich, Uwe A1 - Nagelschmidt, Sven A1 - Weber, Wolfgang A1 - Wolff, Dietmar A1 - Völzke, Holger T1 - Die sicherheitstechnische Behälterbegutachtung für die trockene Zwischenlagerung bestrahlter Brennelemente aus Sicht der BAM N2 - Die Aufbewahrung von Kernbrennstoffen ist im Gesetz über die friedliche Verwendung der Kernenergie und den Schutz gegen ihre Gefahren (Atomgesetz-AtG) geregelt, insbesondere sind im § 6 AtG Regelungen für die Genehmigung zur Aufbewahrung außerhalb der staatlichen Verwahrung sowie deren Voraussetzungen enthalten. Als Voraussetzung zur Erteilung einer Genehmigung zur Aufbewahrung von Kernbrennstoffen ist u.a. durch die Antragstellerin die nach dem Stand von Wissenschaft und Technik erforderliche Vorsorge gegen Schäden durch dessen Aufbewahrung zu treffen. Das Bundesamt für Strahlenschutz (BfS) als Genehmigungsbehörde gemäß § 6 und § 23, Abs. 1, Nr. 4 AtG kann entsprechend § 20 AtG Sachverständige zur Prüfung der Genehmigungsvoraussetzungen hinzuziehen. Die BAM wird vom BfS in Genehmigungsverfahren nach § 6 AtG seit mehr als 30 Jahren mit der Beurteilung behälterspezifischer Fragen bei der Aufbewahrung von radioaktiven Stoffen in Behältern einer Bauart in einem (zentralen oder dezentralen) Zwischenlager beauftragt. Derzeit erfolgen solche behälterspezifischen Begutachtungen im Fachbereich 3.4 Sicherheit von Lagerbehältern der BAM. T2 - Jahrestagung Kerntechnik 2013 CY - Berlin, Germany DA - 14.05.2013 PY - 2013 SP - 1 EP - 6 AN - OPUS4-28585 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Feutlinske, Karl A1 - Wolff, Dietmar A1 - Völzke, Holger T1 - Sicherheitsbewertung von Lagerbehältern bei Auslaufen einer befristeten Zwischenlagergenehmigung N2 - Bei der sicherheitstechnischen Begutachtung der behälterspezifischen Aspekte nach Ablauf einer Zwischenlagergenehmigung ist entsprechend einer Neubeantragung zu verfahren. Die Sicherheitsbewertung erfolgt nach dem aktuellen Stand von Wissenschaft und Technik bei Berücksichtigung der zur Behälterbauart bereits vorliegenden Sicherheitsnachweise und Begutachtungsergebnisse sowie der physikalischen und chemischen Alterungseinflüsse der bisherigen Zwischenlagerung. Am Beispiel einer beantragten weiteren Zwischenlagerung nach Auslaufen einer auf 20 Jahre befristeten Genehmigung und dem notwendigen Behältertransport zu einem neuen Zwischenlager werden Erfahrungen bzgl. der durchgeführten Sicherheitsbewertung zur Erfüllung der Technischen Annahmebedingungen des neuen Behälterlagers dargestellt. T2 - Jahrestagung Kerntechnik 2013 CY - Berlin, Germany DA - 14.05.2013 PY - 2013 IS - Paper 8816 SP - 1 EP - 6 AN - OPUS4-28587 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Völzke, Holger A1 - Wolff, Dietmar A1 - Kasparek, Eva Maria A1 - Botsch, W. A1 - Drotleff, H.-W. A1 - Hinterding, P. A1 - Smalian, S. T1 - Safety aspects of dry spent fuel storage and spent fuel management N2 - Dry storage Systems are characterized by passive and inherent safety systems ensuring safety even in case of severe incidents or accidents. After the events of Fukushima, the advantages of such passive and inherently safe dry storage systems have become more and more obvious. In Germany dry storage of spent nuclear fuel (SNF) and high level wastes (HLW) in dual purpose casks fulfills both transport and storage requirements. Basic safety requirements consider safe enclosure of the radioactive materials under normal operation and accident conditions, safe decay heat removal, subcriticality and shielding. Mostly, storage facilities are designed as concrete buildings above the ground, but due to regional constraints, one storage facility has also been built as a rock tunnel. The decay heat is always removed by natural air flow; further technical equipment is not needed. Safe enclosure, subcriticality and shielding are mainly guaranteed by massive thick-walled metal casks. TÜV NORD Nuclear and BAM present their long experience concerning the licensing process for sites and casks and inform about spent fuel management and issues concerning dry storage of spent fuel and high level waste. T2 - ENC 2012 - European Nuclear Conference CY - Manchester, UK DA - 10.12.2012 KW - Spent nuclear fuel (SNF) KW - High level waste (HLW) KW - Dry storage systems KW - Safety assessment PY - 2012 SN - 978-92-95064-14-0 SP - 1 EP - 5 PB - European Nuclear Society CY - Brussels, Belgium AN - OPUS4-27557 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Völzke, Holger A1 - Probst, Ulrich A1 - Wolff, Dietmar A1 - Nagelschmidt, Sven A1 - Schulz, Sebastian T1 - Seal and closure performance in long term storage N2 - In Germany thick walled metallic transport and storage casks are the established concept for dry interim storage of spent nuclear fuel and high active waste from reprocessing. For the long term safe and leak tight closure of the casks metal seals (consisting of an inner helical spring and two outer jackets made of Steel and aluminum or silver) together with screwed lids are major components. So far 40 years storage periods are evaluated and licensed but extended storage periods are expected in the future due to delays in final repository siting and licensing procedures. For that reason additional knowledge of the long term performance of the lid seal Systems is required and BAM has started investigation programs on these issues. Technically, long term reliable pressure forces in combination with a tight surface contact is as important as well maintained seal and surface qualities and dry and clean conditions during seal assembly and Operation to ensure sufficient seal function. To gain representative data BAM has developed test flanges for seals with full scale cross section diameter but much smaller outer diameter to be placed in appropriate testing machines for relevant mechanical loading under static and dynamic conditions with the ability to measure the Standard helium leakage rate continuously during each test phase. This paper presents an update on running long term seal tests at different temperatures (+20°C, +100°C, +15O°C) under static conditions over longer periods with different seal types. Due to creeping effects a reduction of the pressure force over deflection during loading and unloading does appear depending on prior holding times. Analytical approaches on basis of test data are developed and discussed to extrapolate seal performance (pressure force, elastic recovery, leak tightness) to longer periods of cask operation. T2 - PSAM 11 ESREL 2012 - 11th International Probabilistic Safety Assessment and Management Conference & The Annual European Safety and Reliability Conference CY - Helsinki, Finland DA - 25.06.2012 KW - Metal seal KW - Interim storage KW - Long term performance PY - 2012 SP - 1 EP - 8 PB - European Safety and Reliability Association (ESRA) CY - Bruxelles, Belgium AN - OPUS4-26175 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Turky, Gamal A1 - Wolff, Dietmar A1 - Schönhals, Andreas T1 - Confinement effects on the molecular dynamics of liquid-crystalline polymethacrylates - a broadband dielectric spectroscopy study N2 - The molecular dynamics of liquid-crystalline polymethacrylates with biphenyl in the side group forming a highly ordered smectic E phase at low temperatures is investigated by dielectric spectroscopy (DS). Although no glass transition is found by DSC, DS detects a relaxation in the smectic E phase resembling to glassy dynamics. The temperature dependence of its relaxation rate is Arrhenius like at low temperatures, which changes to a VFT law at higher temperatures. Such a behavior is found to be characteristic for glassy dynamics in confining space. It is discussed, considering the structure of the polymers as nanobiphasic consisting of liquid-crystalline layers while the backbones fill the interlayer space. A comparison is made to polymethacrylates having phenyl benzoate as mesogen. KW - Dielectric properties KW - Dynamics in confining space KW - Liquid-crystalline polymers KW - Molecular dynamics PY - 2012 DO - https://doi.org/10.1002/macp.201200361 SN - 1022-1352 SN - 1521-3935 VL - 213 IS - 22 SP - 2420 EP - 2431 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-27129 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wolff, Dietmar T1 - Long term behavior of sealing systems and neutron shielding materials T2 - IAEA - 1st RCM of CRP on demonstrating performance of spent fuel and related system components during very long term storage CY - Villa General Belgrano, Argentina DA - 2013-04-15 PY - 2013 AN - OPUS4-28091 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wolff, Dietmar T1 - Performance of neutron radiation shielding material (U)HMW-PE influenced by gamma radiation T2 - PSAM11 CY - Helsinki, Finland DA - 2012-06-25 PY - 2012 AN - OPUS4-26129 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wolff, Dietmar T1 - Understanding the Long-Term Behavior of Sealing Systems and Neutron Shielding Material for Extended Dry Cask Storage T2 - PSAM 12 CY - Honolulu, HI, USA DA - 2014-06-22 PY - 2014 AN - OPUS4-31026 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wolff, Dietmar T1 - Long-Term behavior of metallic and elastomeric sealing systems and polymer neutron shielding materials T2 - Workshop on Aging Management Issues Related to Long-Term Dry Spent Nuclear Fuel (SNF) Storage CY - Argonne USA DA - 2014-10-15 PY - 2014 AN - OPUS4-32050 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wolff, Dietmar T1 - Long-Term behavior of metal and elastomer sealing systems T2 - IAEA - 2nd RCM of CRP on demonstrating performance of spent fuel and related system components during very long term storage CY - Tokyo, Japan DA - 2014-11-10 PY - 2014 AN - OPUS4-32049 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Wolff, Dietmar A1 - Bevilacqua, A. A1 - Carlsen, B. A1 - Chiguer, M. A1 - González-Espartero, A. A1 - Grahn, P. A1 - Saegusa, T. A1 - Sampson, M. A1 - Seelev, I. A1 - Wasinger, K. A1 - Waters, M. ED - González-Espartero (IAEA), A. T1 - Storing spent fuel until transport to reprocessing or disposal N2 - Spent fuel storage periods well beyond those originally foreseen are a reality. This publication offers several ideas and approaches that may be considered to address the increasingly longer storage times. The aim is to raise awareness, encourage dialogue and provide ideas on how to manage spent fuel. Key messages include the following: - Delays in reprocessing or disposal could result in spent fuel being stored for 100 years or longer. Safe, secure and effective storage of spent fuel manages fuel degradation while preserving future fuel cycle options. - Ageing management programmes apply engineering, operations and maintenance actions to ensure safety is maintained during storage, future handling and transport. - Site selection and facility and equipment design can significantly reduce the risks and costs of spent fuel storage over longer periods. - Spent fuel storage configurations can be selected to accommodate uncertain storage periods, to facilitate ageing management and to provide flexibility needed to accommodate the uncertainty of future end points, such as reprocessing or disposal. - By considering multiple licence renewals, regulatory frameworks can be designed to ensure safe storage until an acceptable end point is achieved. - Safety can be assured by maintaining shielding, containment, decay heat removal and criticality control. Navigating the complexity of societal beliefs and values, as well as political systems, has proven to be a greater challenge for the management of spent fuel than maintaining its safety and security or addressing the technical and economic aspects. - Sustainable spent fuel management requires policies and strategies to provide a clear, consistent and stable direction because they drive the need for spent fuel storage as well as the available options and timing for achieving an acceptable end point. Unless States address spent fuel reprocessing and disposal on a sufficient scale to accommodate their spent fuel discharges, then storage for longer and longer periods becomes the de facto end point — which is not considered to be consistent with the responsibility to protect human health and the environment. An effective, periodic licence renewal process can ensure effective ageing management and strong institutional control. Hence, spent fuel can be safely and securely stored for as long as it may be necessary until transport for reprocessing or disposal. However, the risks and costs of storing the growing inventory of spent fuel will continue to increase; and in the absence of an end point, it will eventually become a significant societal burden. KW - Storing spent fuel KW - Extended storing KW - Unknown storage duration PY - 2019 UR - https://www-pub.iaea.org/MTCD/publications/PDF/P1846_web.pdf SN - 978-92-0-100719-3 SN - 1995-7807 SP - 1 EP - 54 PB - IAEA Publishing Section CY - Wien, Austria AN - OPUS4-47693 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Wolff, Dietmar A1 - Völzke, Holger A1 - Bevilacqua, A. A1 - Alejano, C. A1 - Conde, J.M. A1 - Einziger, R.E. A1 - Fukuda, S.-I. A1 - González Espartero, A. A1 - Gouzy-Portaix, S. A1 - Haddad Andalaf, R.E. A1 - Hambley, D. A1 - Issard, H. A1 - Kessler, J. A1 - Kurpaska, L. A1 - Legat, A. A1 - Qureshi, A.H. A1 - Ruiz, J. A1 - Shirai, K. A1 - Šmaižys, A. A1 - Verrastro, C.A. ED - González Espartero, A. T1 - Demonstrating performance of spent fuel and related storage system components during very long term storage - Final report of a coordinated research project N2 - This publication summarizes the work carried out during an IAEA coordinated research project (CRP) on safe and reliabe management of spent nuclear fuel. This work contributes to the overall goal of demonstrating the performance of spent nuclear fuel and related storage systems components over long durations, and facilitates the transfer of this knowledge to Member States. The technical areas addressed by the CRP participants were related to potential degradation mechanisms in metal casks and concrete overpacks, such as stress corrosion cracking; long term integrity and performance of the fuel cladding; thermo-mechanical behaviour of the metal seals; and long term gamma and neutron shielding capability. The participants also considered past and ongoing demonstration programmes. For each technical topic addressed the main conclusions have been drawn, including information on the development of specific monitoring and inspection techniques as well as future opportunities for closing relevant data gaps. A major achievement is also the establishment of a worldwide network of experts working on current research projects to demonstrate the long term performance of spent fuel in dry storage systems. KW - Spent fuel KW - Storage system components KW - Very long term storage PY - 2019 UR - https://www.iaea.org/publications/13553/demonstrating-performance-of-spent-fuel-and-related-storage-system-components-during-very-long-term-storage SN - 978–92–0–103319–2 SN - 1011–4289 VL - 1878 SP - 1 EP - 198 PB - IAEA Publishing Section CY - Vienna, Austria AN - OPUS4-48519 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wolff, Dietmar T1 - Ageing management issues for extended SF and HLW dry storage in Germany – Challenges, approach, examples N2 - In this presentation, the history and actual situation of the German nuclear waste management policy of spent fuel (SF) and high-level waste (HLW) is reported. Beside the description of the restructuration of responsible authorities and organizations in Germany, the principle of dry interim storage of SF and HLW in dual purpose casks is explained. The need for extended interim storage towards disposal implicates additional challenges for the nuclear waste management strategy in Germany. (Extended)interim storage, subsequent transportation, and final disposal are closely linked. Integrated approaches concerning waste package designs and operations are supposed to be beneficial for the establishment of efficient long-term SF and HLW management strategies. Knowledge management and staff recruiting, education and training during phase out and beyond nuclear power plant operation are major issues. 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 PY - 2019 AN - OPUS4-48514 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kömmling, Anja A1 - Jaunich, Matthias A1 - Wolff, Dietmar T1 - Revealing effects of chain scission during ageing of EPDM rubber using relaxation and recovery experiment N2 - Both chain scission and crosslinking reactions occur during ageing of EPDM rubber. However, with many conventional polymer analysis methods such as hardness and DMA, it is hardly possible to obtain information about the contribution of each reaction type to the measured data. For example, hardness and Tg both increase during ageing of EPDM, indicating crosslinking during ageing, but it is not clear whether this is partly counterbalanced by chain scission reactions which would lower hardness and Tg. An indication that chain scission reactions probably counteract the hardness or Tg increase by crosslinking is given by Compression Set (CS) measurements. CS exhibits a higher change than hardness or Tg, as CS increases additively through both chain scission and crosslinking reactions. In order to elucidate the share of chain scission reactions in the total degradation, a method testing relaxation and recovery behaviour using DMA equipment was applied. The method revealed the strong influence of chain scissions, leading to more pronounced relaxation and higher residual strain after compression. KW - Compression set KW - DMA KW - Nnetwork KW - Crosslinking PY - 2016 DO - https://doi.org/10.1016/j.polymertesting.2016.10.026 SN - 0142-9418 SN - 1873-2348 IS - 56 SP - 261 EP - 268 PB - Elsevier Ltd. AN - OPUS4-38012 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jaunich, Matthias A1 - Grelle, Tobias A1 - Kömmling, Anja A1 - Wolff, Dietmar A1 - Völzke, Holger ED - Stuke, M. T1 - Long-term evaluation of sealing systems for radioactive waste packages N2 - The investigation of the long-term performance of sealing systems employed in containers for radioactive waste and spent nuclear fuel is one research focus area for division 3.4 “Safety of Storage Containers” at the Bundesanstalt für Materialforschung und -prüfung (BAM). Our investigations comprise investigations on metallic and elastomeric seals and covers experimental investigations to get a database on the component/material behaviour, work on analytical descriptions and numerical analysis. Our aim is to understand the long-term behaviour of the sealing systems for evaluation of their performance during possible extended interim storage and subsequent transportation. T2 - 3rd Workshop on Safety of Extended Dry Storage of Spent Nuclear Fuel CY - Garching, Germany DA - 05.06.2019 KW - Seal performance KW - Rubber seal KW - Metallic seal KW - Ageing PY - 2019 SP - 57 EP - 62 AN - OPUS4-48225 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CHAP A1 - Jaunich, Matthias A1 - Kömmling, Anja A1 - Wolff, Dietmar ED - Grellmann, W. ED - Langer, B. T1 - Investigations of elastomeric seals – Low temperature performance and aging behavior N2 - Due to their simple and reliable application, elastomers are used for many tasks. Many fields of application like transport, aviation and process technology, entail low temperatures where proper functionality of the employed seals has to be ensured. Therefore, understanding the low temperature behavior of elastomeric seals is important for safe seal operation to restrict the temperature application range. For all areas of application, the question of seal lifetime is also important for replacement or maintenance intervals. The lifetime is especially important in applications that allow no seal replacement. Since the seal can determine the lifetime of storage in such cases, reliable lifetime estimation is necessary for these applications, and requires an extensive knowledge of the specific aging behavior. KW - Seal KW - Rubber KW - Ageing KW - Replacement PY - 2017 SN - 978-3-319-41877-3 SN - 978-3-319-41879-7 DO - https://doi.org/10.1007/978-3-319-41879-7_30 SN - 0933-033X SN - 2196-2812 VL - 247 SP - 431 EP - 443 PB - Springer Verlag AN - OPUS4-41167 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Beckmann, Jörg A1 - Schade, U. A1 - von der Ehe, Kerstin A1 - Jaunich, Matthias A1 - Wolff, Dietmar A1 - Aziz, E. F. T1 - THz and Mid IR Fourier transform spectroscopy on polyethylene irradiated with Gamma- Co60 radiation N2 - THz and mid IR spectroscopy of high molecular PE (HMW) and ultra high molecular PE (UHMW) reveals modifications of the molecular structure induced by γ-Co60 radiation. UHMW-PE and HMW-PE can be distinguished. The integral absorption in the B1u THz-region can quantitatively describe the amorphization of crystallinity. The formation of trans vinylene unsaturations and the decay of vinyl can be followed by mid IR spectroscopy T2 - IRMMW-THz 2014 - 39th International conference on infrared, millimeter, and terahertz waves CY - Tucson, Arizona, USA DA - 14.09.2014 KW - Thz and Mid IR Fourier transform spectroscopy KW - Polyethylene KW - Gamma-Co-60 radiation KW - Fourier transform spectroscopy KW - Infrared spectroscopy KW - Light absorption KW - Molecular electronic states KW - Polymers KW - MidIR Fourier transform spectroscopy KW - Terahertz spectroscopy KW - THz spectroscopy KW - γ-Co60radiation KW - HMW KW - High molecular PE KW - Ultrahigh molecular PE KW - Molecular structure modifications KW - UHMW-PE KW - HMW-PE KW - Integral absorption KW - B1uTHz-region KW - Crystallinity amorphization KW - Transvinylene unsaturation formation KW - Vinyl decay KW - Absorption KW - Radiation effects KW - Temperature measurement KW - Spectroscopy PY - 2014 UR - http://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=6956355&isnumber=6955975 SN - 978-1-4799-3877-3 DO - https://doi.org/10.1109/IRMMW-THz.2014.6956355 IS - IEEE Catalog No.: CFP14IMM-ART SP - 1 EP - 2 AN - OPUS4-32699 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Grelle, Tobias A1 - Wolff, Dietmar A1 - Probst, Ulrich A1 - Jaunich, Matthias A1 - Völzke, Holger T1 - Component and material investigations on metal seals for high level radioactive waste containers N2 - Long-term investigations performed at BAM look to extend the state of knowledge on safety-related components of interim storage containers. Metal seals act as the primary sealing barrier in the bolted double lid closure system of the containers. The behaviour of metal seals has been investigated for ageing times up to 8.5 years and for various temperatures. The main cause for reduction in useable resilience overtime was due to creep deformation of the outer jacket of the seal. KW - Metal seal KW - Radioactive waste containers KW - Creep KW - Long-term behaviour PY - 2018 SN - 1745-2058 SP - 32 EP - 34 PB - Nuclear Institute CY - London AN - OPUS4-48206 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jaunich, Matthias A1 - Wolff, Dietmar T1 - An approach to improve the understanding of elastomeric seals in use in storage containers N2 - Elastomers are widely used as main sealing materials in Containers for low and intermediate level radioactive waste and as additional component to metal seals in spent fuel and high active waste Containers. They are applied due to their special material properties and easy use [1]. For this application several challenging prerequisites must be met for the essential reliable Operation of the seal. T2 - 45th Annual meeting on nuclear technology CY - Frankfurt, Germany DA - 06.05.2014 PY - 2014 SN - 978-3-926956-99-6 SP - 1 EP - 4 AN - OPUS4-31250 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Kömmling, Anja A1 - Jaunich, Matthias A1 - Wolff, Dietmar T1 - Alterung von Elastomerdichtungen für Lagerbehälter N2 - Unsere Aufgabe im Fachbereich 3.4 der Bundesanstalt für Materialforschung und prüfung (BAM) ist die sicherheitstechnische Begutachtung von Transport- und Lagerbehältern für radioaktiven Abfall, die für langfristige Zwischenlagerung ausgelegt sind. Ein Arbeitsschwerpunkt ist die Bewertung der Lebensdauer von Metall- und Elastomerdichtungen in den Behältern im Hinblick auf die Anforderungen für langfristige Behältersicherheit (min. 40 Jahre in Deutschland). Um die Eigenschaftsänderungen der Elastomerdichtungen während einer beschleunigten Alterung über lange Zeiträume (bis zu fünf Jahre) untersuchen zu können, wurde ein Alterungsprogramm an ausgewählten Elastomeren (HNBR, EPDM, FKM) begonnen. Im Gegensatz zu Normalterungsverfahren altern wir keine Normteile, sondern O-Ringe im unverpressten sowie verpressten Zustand. Diese Vorgehensweise ermöglicht die Bewertung des Einflusses der Verpressung auf die Alterung sowie die Untersuchung des Bauteilversagens mittels Leckageratenmessungen unter anwendungsnahen Bedingungen. Weitere Charakterisierungsmethoden sind Härtemessung, dynamisch-mechanische Analyse (DMA), Thermogravimetrie (TGA), Druckspannungsrelaxation, Druckverformungsrest (DVR), Dichtebestimmung und Zugversuch. Das Ziel ist, die Leckagerate mit anderen Eigenschaften bzw. Methoden zu korrelieren, um so ein aussagekräftiges und leichter zu bestimmendes Lebensdauerkriterium für elastomere O-Ringe abzuleiten. Während der Alterung können in Abhängigkeit von Material sowie Alterungsdauer und –temperatur Inhomogenitäten aufgrund von diffusionsbegrenzter Oxidation auftreten, durch die sich unterschiedliche Eigenschaften an der Oberfläche und im Volumen der Dichtung ergeben, was zu falschen Lebensdauerabschätzungen führen kann. Mittels Mikrohärtemessung über den Querschnitt werden diese Effekte charakterisiert und bei der Extrapolation mittels Zeit-Temperatur-Verschiebung und Arrheniusgraph berücksichtigt. Bisher liegen Daten von bis zu einem Jahr bei vier verschiedenen Temperaturen (75 °C, 100 °C, 125 °C und 150 °C) gealterten Proben vor. Nach 100 Tagen bei 150 °C weisen HNBR und EPDM schon einen DVR von über 80 % auf, aber noch keinen signifikanten Anstieg der Leckagerate. Diese sinkt zunächst während der Alterung, da die Permeabilität aufgrund von Vernetzungsreaktionen sinkt. Bei HNBR ist dies aufgrund der dominanteren Vernetzungsreaktionen während der Alterung noch stärker ausgeprägt als bei EPDM. T2 - Technomer 2015 - 24. Fachtagung über Verarbeitung und Anwendung von Polymeren CY - Chemnitz, Germany DA - 12.11.2015 KW - Aging KW - Elastomer KW - Seal KW - Leakage KW - Compression PY - 2015 SN - 978-3-939382-12-6 SP - 43 CY - Chemnitz AN - OPUS4-35050 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Weber, Mike A1 - Zaghdoudi, Maha A1 - Brandt, Guido A1 - Kömmling, Anja A1 - Jaunich, Matthias A1 - Wolff, Dietmar T1 - Coefficients of Friction in Dependence on Aging State of Elastomers – Experimental Identification and Numerical Simulation of the Experiment N2 - Elastomer seals are mounted as barrier seals in lid systems of containers designed for transport and disposal of negligible heat generating radioactive waste and as auxiliary seals in spent fuel storage and transportation casks (dual purpose casks (DPC)). When the behavior of mounted seals under normal and hypothetical accident conditions of disposal and transport is to be simulated, a comprehensive knowledge of their complex mechanical properties at every state of aging is necessary. In previous works, BAM’s efforts in experimental investigations on specimen artificially aged at different temperatures and times and the implementation of the found results in finite element material models were presented. Additionally, our approaches to reproduce the aging process itself and to extrapolate the results of artificially accelerated aging to longer times were presented. Numerical simulations have shown that the behavior of the seal during mounting and one-sided pressurizing and the resulting performance values such as leakage rate strongly depend on the coefficient of friction (COF) between flange and seal. The friction coefficient, in turn, depends on the aging state of the elastomer material as several publications suggest (see below). Dynamic COF between an exemplary ethylene propylene diene rubber (EPDM) material and a stainless steel ball were determined by using a self-designed linear oscillation tribometer. Unaged and artificially aged EPDM specimen stored for 30 days and 100 days at a temperature of 150 °C were tested. A stainless steel ball (d=10 mm) is brought in contact with the specimen’s surface und loaded by normal forces of 2.5 N, 5 N, 10 N and 20 N. During a reciprocating movement of the EPDM sheet, the horizontal force/friction force is continuously measured, and the COF can be derived. It is well known that friction is a complex phenomenon especially in soft materials. It cannot be excluded that the measured friction force is influenced by additional force components, resulting from the ball’s grooving through the elastomer’s surface. This force depends on the penetration depth of the ball and on the resistance of the elastomer in its different states of aging. The latter results from microstructural changes i.e., chain scission and additional crosslinking that occur during aging which in turn influence the softening or hardening of the material. A finite element (FE) ABAQUS® model was developed to reproduce the measurement process. It should help to better understand the physical mechanisms and to quantify the percentage of measured forces resulting from real friction on the one hand and forces resulting from unintended side effects that could falsify the result on the other hand. The behavior of the elastomer in its different states of aging is reproduced by a FE material model already presented in previous works of BAM. T2 - ASME 2022 Pressure Vessels & Piping Conference (PVP2022) CY - Las Vegas, NV, USA DA - 17.02.2022 KW - Numerical Simulation KW - Radioactive Waste KW - Elastomers KW - Aging KW - Seal Behavior KW - Leakage Rate KW - Coefficient of Friction KW - Experiment PY - 2022 SP - 1 EP - 8 PB - American Society of Mechanical Engineers (ASME) CY - New York, NY, USA AN - OPUS4-57093 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jaunich, Matthias A1 - Grelle, Tobias A1 - Goral, Milan A1 - Wolff, Dietmar ED - Gehde, M. ED - Wagenknecht, U. ED - Bloß, P. T1 - Further investigations on the low temperature performance of rubber seals N2 - For many sealing applications low temperature performance is required. The overall understanding of the relevant influences on low temperature performance of rubber seals are summarized and the currently running investigations described. The correlation of the physical material properties with seal performance is studied. This includes as well purely static sealing applications as the performance during/after fast partial relief of seals at low temperatures. T2 - Technomer 2017 CY - Chemnitz, Germany DA - 09.11.2017 KW - Seal KW - Low temperature KW - Rubber KW - Recovery PY - 2017 SN - 978-3-939382-13-3 VL - 2017 SP - 40 EP - 40 AN - OPUS4-42845 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Grelle, Tobias A1 - Wolff, Dietmar A1 - Jaunich, Matthias T1 - Temperature-dependent leak tightness of elastomer seals after partial and rapid release of compression N2 - A device has been designed, built and tested that allows the investigation of effects of dynamic loads on the leak tightness of elastomer seals at low temperatures. With the test setup, the compression of the tested seal can be reduced by a defined degree in a time period of less than 1 s. For the evaluation of the leak tightness, leakage rates can be determined. It was shown that the rapid partial release of an elastomer seal leads to its failure already at the beginning of the rubber–glass transition and, therefore, at significantly higher temperatures than the loss of leak tightness observed under static conditions. KW - Sealing material KW - Elastomer KW - Dynamic loading KW - Low temperature behaviour KW - Leakage rate PY - 2015 DO - https://doi.org/10.1016/j.polymertesting.2015.09.009 SN - 0142-9418 VL - 48 SP - 44 EP - 49 PB - Elsevier Ltd. CY - Amsterdam [u.a.] AN - OPUS4-34445 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kömmling, Anja A1 - Jaunich, Matthias A1 - Wolff, Dietmar T1 - Ageing of HNBR, EPDM and FKM O-rings N2 - HNBR, EPDM and FKM O-rings were aged uncompressed and compressed at 75 °C, 100 °C, 125 °C and 150 °C for up to 1 year. HNBR exhibited the strongest ageing effects with high increases of hardness and glass transition temperature. Furthermore, heterogeneous ageing caused by diffusion-limited oxidation effects had a significant influence for HNBR at ageing temperatures of 125 °C and 150 °C. EPDM showed similar property changes as HNBR, but less pronounced. FKM displayed only minor ageing effects. O-rings aged in compression exhibited considerable compression set (CS). CS data was used for a time-temperature shift and resulting master curve construction. Leakage rate measurements showed that O-rings can remain leak tight under static conditions even if material properties have already deteriorated strongly. N2 - HNBR-, EPDM- und FKM-O-Ringe wurden unverpresst und verpresst für bis zu 1 Jahr bei 75 °C, 100 °C, 125 °C und 150 °C gealtert. HNBR wies mit hohen Anstiegen von Härte und Glasübergangstemperatur die stärksten Alterungseffekte auf. Weiterhin hatte heterogene Alterung aufgrund von diffusionsbegrenzten Oxidationseffekten einen wesentlichen Einfluss auf HNBR bei Alterungstemperaturen von 125 °C und 150 °C. EPDM zeigte ähnliche Eigenschaftsänderungen wie HNBR, allerdings schwächer ausgeprägt. FKM wies nur geringfügige Alterungseffekte auf. O-Ringe, die verpresst gealtert wurden, hatten eine starke bleibende Verformung (DVR). Die gemessenen DVRWerte wurden für eine Zeit-Temperatur-Verschiebung und die Konstruktion einer Masterkurve genutzt. Leckageratenmessungen zeigten, dass O-Ringe unter statischen Bedingungen dicht bleiben können, auch wenn die Materialeigenschaften schon stark degradiert sind. KW - Aging KW - Degradation KW - Leakage KW - Compression KW - Seal PY - 2016 SN - 0022-9520 SN - 0948-3276 VL - 69 IS - 4 SP - 36 EP - 42 PB - Hüthig CY - Heidelberg, Germany AN - OPUS4-36336 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jaunich, Matthias A1 - Stark, Wolfgang A1 - Wolff, Dietmar T1 - Properties of elastomeric seals at low temperature T2 - International rubber conference (IRC 2009) CY - Nürnberg, Germany DA - 2009-06-29 PY - 2009 IS - Poster 23 SP - 1 EP - 3 AN - OPUS4-19611 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kömmling, Anja A1 - von der Ehe, Kerstin A1 - Wolff, Dietmar A1 - Jaunich, Matthias T1 - Effect of high-dose gamma irradiation on (U)HMWPE neutron shielding materials N2 - High and ultra-high molecular weight polyethylenes were gamma-irradiated with doses up to 600 kGy. The changes in the material properties were analysed using DSC, DMA, IR spectroscopy, as well as measurements of density and insoluble content. The irradiation led to an increase of the degree of crystallinity because of chain scissions during irradiation, leading to shorter and thus more mobile chains. Both the plateau value of the shear modulus G′ and the insoluble content increased with Irradiation dose, indicating the formation of additional crosslinks. Furthermore, IR spectroscopy revealed irradiation induced oxidation and the formation of double bonds, indicating that some of the hydrogen atoms responsible for the neutron shielding capability have been released. KW - Ultra high molecular weight KW - Polyethylene KW - Gamma irradiation KW - Crosslinking KW - Oxidation PY - 2018 DO - https://doi.org/10.1016/j.radphyschem.2017.02.014 SN - 0969-806X VL - 142 SP - 29 EP - 33 PB - Elsevier AN - OPUS4-42941 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Jaunich, Matthias A1 - Stark, Wolfgang A1 - Wolff, Dietmar T1 - A new method to evaluate the low temperature function of rubber sealing materials N2 - A new method for the evaluation of the low temperature properties of rubber materials is presented. The method emulates the standardized compression set measurement, which is frequently used for sealing materials, but can be performed within a considerably shorter time. The results are compared with the standard test and found to be qualitatively the same. Slight differences are discussed on the basis of the differences in the measurement procedures. Further data evaluation is done by fitting functions to describe the material behaviour. KW - Sealing material KW - Elastomer KW - Compression set KW - Dynamic mechanical analysis KW - Low temperature behaviour PY - 2010 DO - https://doi.org/10.1016/j.polymertesting.2010.07.006 SN - 0142-9418 VL - 29 IS - 7 SP - 815 EP - 823 PB - Elsevier Science CY - Amsterdam [u.a.] AN - OPUS4-21914 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wolff, Dietmar T1 - Long-term behavior of metal and elastomer seals as well as polyethylene as safety relevant components of transport and storage casks for radioactive materials (LaMEP) N2 - In Germany, the concept of dry interim storage in dual purpose metal casks before disposal is being pursued for spent nuclear fuel (SNF) and high level waste (HLW) management. The main safety relevant components are the thick-walled dual purpose metal casks. These casks consist e.g. of a monolithic cask body with integrated neutron shielding components (polymers, e.g. polyethylene) and a monitored double lid barrier system equipped with metal and elastomer seals. The metal seals of this bolted closure system guarantee the required leak-tightness whereas the elastomer seals allow for leakage rate measurement of the metal seals. This presentation provides an overview of BAM proactive R&D projects related to the long-term behavior and degradation effects of metal seals, elastomer seals and polyethylene used as neutron shielding material. Particular attention is paid to the approach and first results of the third-party-founded research project LaMEP with the aim of further closure of existing knowledge gaps of safety relevant aging effects of such cask components. T2 - Symposium Verlängerte Zwischenlagerung CY - Garching (Munich), Germany DA - 22.06.2017 KW - Metal seals KW - Elastomer seals KW - Neutron shielding material KW - Aging PY - 2017 AN - OPUS4-41312 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - von der Ehe, Kerstin A1 - Jaunich, Matthias A1 - Wolff, Dietmar A1 - Böhning, Martin A1 - Goering, Harald T1 - Radiation induced structural changes of (U)HMW polyethylene with regard to its application for radiation shielding N2 - The special properties of high molecular weight polyethylene (HMW-PE) and ultra high molecular weight polyethylene (UHMW-PE) result basically from their extreme chain lengths and their high degree of crystallinity. As high-performance polymers, they are used for a variety of applications. UHMW-PE in particular is often utilized for endoprothesis (due to its excellent slip and wear properties) and due to its high hydrogen content as a neutron moderator in casks for storage and transport of radioactive materials. To prepare the material for instance for its use as a total joint replacement, it is exposed to radiation for several reasons, such as sterilization and crosslinking, leading to partial improvement of the mechanical properties (e.g. fracture toughness, crack propagation resistance, wear resistance) and better chemical stability. To be applicable for long term radiation shielding purposes for instance over a period of 40 years, PE has to withstand any type of degradation affecting safety relevant aspects. The scope of our investigation comprises an estimation of the radiation impact on the molecular and supra molecular structure of two types of PE and to what extent these changes are detectable by thermo-analytical (TA) methods, such as Differential Scanning Calorimetry (DSC), Thermo Mechanical Analysis (TMA), Dynamic Mechanical Analysis (DMA) and Thermo Gravimetric Analysis (TGA). Additionally FT-IR spectroscopy as well as density and gas sorption measurements were carried out. Due to the poor solubility of HMW-PE and UHMW-PE, some classical analytical techniques are not applicable. But TA-methods represent a feasible approach to detect structural and morphological features of these materials as well as changes caused by external influences, such as thermal treatment and/or irradiation. With the combination of the applied TA-techniques it is possible to distinguish between crosslinking and degradation. T2 - PATRAM 2010 - 16th International symposium on the packaging and transport of radioactive materials CY - London, UK DA - 2010-10-03 PY - 2010 SP - 1 EP - 8 (T25/Paper 173) AN - OPUS4-24621 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jaunich, Matthias A1 - Wolff, Dietmar ED - Van Breugel, K. ED - Koenders, E.A.B. T1 - Approach for the investigation of long-term behaviour of elastomeric seals for transport and storage packages N2 - Elastomers are widely used as main sealing materials for Containers for low and intermediate Ievel radioactive waste and as additional component to metal seals in spent fuel and high active waste Containers. According to appropriate guidelines and regulations safe enclosure of the radioactive Container contents has to be guaranteed for long storage periods as well as down to temperatures of -40 °C for transportation. Therefore the understanding of seal behaviour in general is of high importance and ageing of elastomeric seals has to be considered with regard to possible dynamic events taking possibly place during transport after storage. T2 - 1st Ageing of materials & structures 2014 conference CY - Delft, The Netherlands DA - 26.05.2014 KW - O-Ring KW - Seal KW - Ageing KW - Elastomer KW - Compression set PY - 2014 SN - 978-94-6186-313-3 SP - 87 EP - 93 AN - OPUS4-30820 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jaunich, Matthias A1 - Wolff, Dietmar A1 - Stark, Wolfgang A1 - Völzke, Holger T1 - Investigation of elastomer seal behavior for transport and storage packages N2 - Rubbers are widely used as main sealing materials for containers for low and intermediate level radioactive waste and as additional component to metal seals in spent fuel and high active waste containers. According to appropriate guidelines and regulations safe enclosure of the radioactive container contents has to be guaranteed for long storage periods as well as down to temperatures of -40 °C for transportation. Therefore the understanding of seal behavior is of high importance. In this paper we focus on the behavior of elastomer seals at low temperatures with regard to poten-tial decrease of leak-tightness. In addition, changes in material properties due to aging effects over long periods of time and their influence on the seal performance is investigated. It is known that material properties of rubbers are strongly temperature dependent. At low tempera-tures this is caused by the rubber-glass transition (abbr. glass transition). During continuous cool-ing, the material changes from rubber-like entropy-elastic to stiff energy-elastic behavior, that al-lows nearly no strain or retraction due to the glass transition. Hence rubbers are normally used above their glass transition but the minimum working temperature limit is not defined precisely. Aging of elastomer seals is important, as possible dynamic loads may have to be considered during the whole interim storage period (so far approved in Germany for up to 40 years) and for transporta-tion after storage. For the investigations, fluorocarbon (FKM) and ethylene-propylene-diene (EPDM) rubbers were selected as they are often used in radioactive waste containers. Some materials were purchased from a commercial seal producer and some materials were compounded and cured at BAM. The elastom-ers where studied by several thermo-analytical methods and compression set to characterize the material behavior at low temperatures. Additionally component tests were performed to determine the breakdown temperature of the sealing function of complete elastomer O-rings. T2 - PATRAM 2013 - 17th International symposium on the packaging and transportation of radioactive materials CY - San Francisco, CA, USA DA - 18.08.2013 PY - 2013 SP - Paper 227, 1 EP - 8 PB - Omnipress AN - OPUS4-30377 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Jaunich, Matthias A1 - Wolff, Dietmar A1 - Stark, Wolfgang T1 - Investigating low temperature properties of rubber seals N2 - To achieve the required tightness levels of Containers for low and intermediate level radioactive wastes rubbers are widely applied as main sealing materials. The save encapsulation of the radioactive Container contents has to be guaranteed according to legislation and appropriate guidelines for long storage periods as well as down to temperatures of-40 °C during transportation. Therefore the understanding of failure mechanisms that lead to leakage at low temperatures is of high importance. It is known that the material properties of rubbers are strongly influenced by temperature. At low temperatures this is caused by the rubber-glass transition (abbr. glass transition). During continuous cooling the material changes from rubber-like entropy-elastic to stiff energy-elastic behaviour, that allows nearly no strain or retraction. Therefore, rubbers are normally used above their glass transition but the minimum working temperature limit is not defrned precisely, what can cause problems during application. The temperature ränge where full functionality is possible is strongly dependent on the application conditions and the material. For this investigation mainly ethylene propylene diene (EPDM) and fluorocarbon rubbers (FKM) were selected as they are often used for radioactive waste Containers. Differential Scanning Calorimetry (DSC) and Dynamic Mechanical Analysis (DMA) are typically used for the determination of the temperature ränge of the glass transition process. The standardized compression set measurement according to ISO 815 is common for investigation of rubber sealing materials as the test simulates the seal behaviour after release. To reduce the test time of the Standard tests a faster technique giving the same information was developed. Additionally, the breakdown temperature of the sealing function of complete O-ring seals is measured in a component test Setup to compare it with the results of the other tests. The experimental Setup is capable of measuring the leakage rate at low temperatures by the pressure rise method. A model was developed that allows calculating the minimum working temperature limit of a seal by combining the results of the applied methods. T2 - WM2013 Conference CY - Phoenix, Arizona, USA DA - 24.02.2013 PY - 2013 SN - 978-0-9836186-2-1 SP - 1 EP - 12 CY - Phoenix, Arizona, USA AN - OPUS4-28853 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Grelle, Tobias A1 - Wolff, Dietmar A1 - Probst, Ulrich A1 - Jaunich, Matthias A1 - Völzke, Holger T1 - Component and material investigations on metal seals for high level radioactive waste containers N2 - In Germany casks for interim storage of spent nuclear fuel and high level radioactive waste are equipped with Helicoflex® metal seals as main sealing barrier of the double lid system. The long-term behaviour of those seals is investigated at Bundesanstalt für Materialforschung und –prüfung (BAM) in order to evaluate the safety function of the containment at different temperatures over storage periods of 40 years or more in case extended interim storage becomes necessary. Long-term investigations have been done for ageing times of up to 8.5 years at temperatures ranging from room temperature to 150 °C. It was found that the seal force and useable resilience decrease over time, which is mainly caused by creep deformation of the aluminium (or silver) outer jacket of the seals. This effect becomes stronger with increasing temperature. The ageing processes of the seal material and the overall seal behaviour is under investigation in order to derive analytical descriptions for the long-term seal performance. Thus, standardized tests on the basic seal materials, with focus on aluminium, and additional investigations on the seals as a component are conducted. The current investigations include compression and tension creep measurements as well as tensile testing. Furthermore, ageing of seal segments provides information on the development of the contact area width, jacket thickness and microstructural changes in dependence of time and temperature. The obtained data are used for the development of material models and an analytical approach to describe and predict the time and temperature dependent sealing behaviour in the long-term. T2 - 11th International Conference on the Transport, Storage and Disposal of Radioactive Materials CY - London, UK DA - 15.05.2018 KW - Metal seal KW - Creep KW - Long-term behavior PY - 2018 SP - 18535, 1 EP - 6 AN - OPUS4-45452 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kömmling, Anja A1 - Jaunich, Matthias A1 - Wolff, Dietmar T1 - Effects of heterogeneous aging in compressed HNBR and EPDM O-ring seals N2 - Seals used in containers for dangerous goods need to maintain leak tightness for several decades. For investigating the change in seal material properties during aging, a comprehensive aging program on both uncompressed and compressed EPDM and HNBR seals was started. In order to obtain results closely related to practical conditions, O-rings with a full-scale cord diameter of 10 mm were aged. However, this set-up can lead to heterogeneous aging caused by diffusion-limited oxidation (DLO) effects. These effects depend on material, dimensions, time and temperature. Heterogeneous aging results in distorted bulk properties such as compression stress relaxation and compression set (CS) suggesting that HNBR has better performance than EPDM at 150 °C but which is not the case at 100 °C. The presence of heterogeneous material properties was shown by hardness measurements across the seal cross-section. If DLO-affected data is excluded, extrapolations of CS data are possible using time-temperature shifts and Arrhenius graphs. Exemplary CS values of 50 % and 80 % would be reached after approx. 10 years and 29 years, respectively for HNBR and after approx. 400 years and 1100 years, respectively for EPDM. KW - Ageing KW - Rubber KW - Compression KW - DLO KW - Extrapolation KW - Lifetime prediction PY - 2016 DO - https://doi.org/10.1016/j.polymdegradstab.2016.01.012 VL - 126 SP - 39 EP - 46 PB - Elsevier Science CY - Oxford AN - OPUS4-35775 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wolff, Dietmar A1 - von der Ehe, Kerstin A1 - Jaunich, Matthias A1 - Böhning, Martin T1 - Performance of neutron radiation shielding material (U)HMW-PE influenced by gamma radiation N2 - Due to their extreme high hydrogen contents high molecular weight (HMW-) and ultra-high molecular weight (UHMW-) polyethylene (PE) are a comprehensible choice as neutron radiation shielding material in thick walled metallic casks for storage and transport of radioactive materials. For this application it has to be taken into consideration that gamma radiation – that is a direct consequence of inserting radioactive material in such casks – has a high influence on the molecular structure of polyethylene. In order to be applicable for long-term neutron radiation shielding purposes during the whole storage period (in Germany for instance up to 40 years) PE has to withstand any type of degradation affecting safety relevant aspects. The scope of our work comprises an estimation of the influence of gamma radiation and temperature on the molecular and supra molecular structure of (U)HMW-PE used as cask components for neutron radiation shielding. Therefore it was investigated to what extent these changes are detectable by a combination of conventional polymer characterization techniques such as Differential Scanning Calorimetry (DSC), Thermo Mechanical Analysis (TMA), Dynamic Mechanical Analysis (DMA), and Thermo Gravimetric Analysis (TGA). Additionally optical (FTIR) and weighing methods were applied. For UHMWPE the results are compared with those published for similar UHMW-PE material that is used in medical technology. For this application, gamma irradiation is applied deliberately for purposes such as sterilization and crosslinking, the latter leading to partial improvement of mechanical properties and better chemical stability. As a result the so far observed structural changes of the irradiated material are not safety relevant for the application of polyethylene as neutron shielding material; moreover, some properties actually improve via irradiation. T2 - PSAM 11 ESREL 2012 - 11th International probabilistic safety assessment and management conference & The annual european safety and reliability conference CY - Helsinki, Finland DA - 25.06.2012 KW - (U)HMW-PE KW - Gamma irradiation KW - Shielding material KW - Cask for storage and transport of radioactive materials PY - 2012 SP - 1 EP - 8 AN - OPUS4-26176 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Shirai, K. A1 - Namba, K. A1 - Wataru, M. A1 - Völzke, Holger A1 - Wolff, Dietmar A1 - Probst, Ulrich A1 - Jaunich, Matthias A1 - Schulz, Sebastian T1 - Numerical evaluation of the long-term sealing performance of the silver gasket for dual purpose metal cask under high temperature N2 - It is important to evaluate the effect of thermal ageing on the sealing performance of metal gaskets under high temperature for long-term usage. Therefore, in order to gain representative data for this kind of metal-sealed lid System, BAM is currently performing laboratory tests of different gasket types with aluminum and silver jackets at three different temperatures under static conditions up to four years so far, using test flanges for gaskets with full scale cross section diameter but much smaller outer diameter. On the other hand, in order to investigate the applicability of the numerical methodology to evaluate the long-term behavior of the metal gaskets, such as a correlation between seal pressure force and holding time, CRIEPI is developing a modeling method including material tests (tensile and creep tests) at high temperature. In this paper, the applicability of the finite element method (ABAQUS) to predict the recovery displacement and residual seal pressure force of the gasket complex was verified by comparing the calculated values with BAM’s laboratory test results under the joint research agreement between BAM and CRIEPI. T2 - PATRAM 2013 - 17th International symposium on the packaging and transportation of radioactive materials CY - San Francisco, CA, USA DA - 18.08.2013 KW - Metal seals KW - Extended storage KW - Long-term storage KW - Dual purpose cask PY - 2013 SP - 1 EP - 8 PB - Omnipress AN - OPUS4-31947 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -