TY - CHAP A1 - Schartel, Bernhard ED - Troitzsch, J. ED - Antonatus, E. T1 - The Burning of Plastics T2 - Plastics Flammability Handbook N2 - The burning of a polymer is a physico–chemical process strongly influenced by the coupling of a chemical reaction – oxidation of fuel – in the gas phase with a chemical decomposition reaction – pyrolysis – in the condensed phase via heat and mass transfer. The heat and mass flux control the intensity of fire and the ablation of fuel. Indeed, the temperature profile as a function of time may be one of the most important responses of a specimen to understand its burning behavior. Further, several physical phenomena, such as the heat absorption of the materials, thermal conductivity, and also melt flow and dripping, play a major role in determining ignition, flammability, and fire behavior. The burning of a polymer is very complex. The various phenomena interact with each other, e. g., pyrolysis also influences the viscosity of the melt, and, thus, whether dripping or charring results in a protective layer, increasing the shielding effect of the residual protective layer. Only a detailed and comprehensive description opens the door to a well-founded understanding of the burning behavior of polymeric materials. KW - Fire behaviour KW - Plastics KW - Pyrolysis KW - Decomposition KW - Ignition KW - Smoldering KW - Flame spread KW - Steady burning KW - Fire load KW - Fire resistance PY - 2021 SN - 978-1-56990-762-7 SP - 23 EP - 52 PB - Hanser CY - Munich ET - 4th Edition AN - OPUS4-52684 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Erenberg, Marina A1 - Bletzer, Claus A1 - Feldkamp, Martin A1 - Musolff, André A1 - Nehrig, Marko A1 - Wille, Frank T1 - Experimental investigations of the burning behaviour of transport package impact limiters and of fire spread impact onto the cask T2 - Proceedings of the ASME 2018 Pressure Vessels an Piping Conference N2 - Accident safe packages for the transport of spent nuclear fuel and high-level waste shall fulfil international IAEA safety requirements. Compliance is shown by consecutive mechanical and thermal testing. Additional numerical analysis are usually part of the safety evaluation. For damage protection some package designs are equipped with wood filled impact limiters encapsulated by steel sheets. The safety of these packages is established in compliance with IAEA regulations. Cumulative mechanical and fire tests are conducted to achieve safety standards and to prevent loss of containment. Mechanical reliability is proven by drop tests. Drop testing might cause significant damage of the impact limiter steel sheets and might enable sufficient oxygen supply to the impact limiter during the fire test to ignite the wood filling. The boundary conditions of the fire test are precisely described in the IAEA regulatory. During the test the impact limiter will be subjected to a 30 minute enduring fire phase. Subsequent to the fire phase any burning of the specimen has to extinguish naturally and no artificial cooling is allowed. At BAM a large-scale fire test with a real size impact limiter and a wood volume of about 3m3 was conducted to investigate the burning behaviour of wood filled impact limiters in steel sheet encapsulation. The impact limiter was equipped with extensive temperature monitoring equipment. Until today burning of such impact limiters is not sufficiently considered in transport package design and more investigation is necessary to explore the consequences of the impacting fire. The objective of the large scale test was to find out whether a self-sustaining smouldering or even a flaming fire inside the impact limiter was initiated and what impact on the cask is resulting. The amount of energy, transferred from the impact limiter into the cask is of particular importance for the safety of heavy weight packages. With the intention of heat flux quantification a new approach was made and a test bench was designed. T2 - ASME 2018 Pressure Vessels and Piping Conference CY - Prague, Czech Republic DA - 15.07.2018 KW - Shock absorber KW - Impact limiter KW - Wood KW - Thermal testing KW - Fire KW - Smoldering KW - IAEA KW - Fire test PY - 2018 SN - 978-0-7918-5170-8 VL - PVP2018 SP - 84714-1 EP - 84714-10 AN - OPUS4-46984 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Feldkamp, Martin A1 - Erenberg, Marina A1 - Bletzer, Claus Wilhelm A1 - Musolff, André A1 - Nehrig, Marko A1 - Wille, Frank T1 - Investigations of the burning behavior of transport package impact limiters and thermal effects onto the cask N2 - Accident safe packages for the transport of spent nuclear fuel and high-level waste shall fulfil international IAEA safety requirements. Compliance is shown by consecutive mechanical and thermal testing. Additional numerical analysis are usually part of the safety evaluation. For damage protection some package designs are equipped with wood filled impact limiters encapsulated by steel sheets. The safety of these packages is established in compliance with IAEA regulations. Cumulative mechanical and fire tests are conducted to achieve safety standards and to prevent loss of containment. Mechanical reliability is proven by drop tests. Drop testing might cause significant damage of the impact limiter steel sheets and might enable sufficient oxygen supply to the impact limiter during the fire test to ignite the wood filling. The boundary conditions of the fire test are precisely described in the IAEA regulatory. During the test the impact limiter will be subjected to a 30 minute enduring fire phase. Subsequent to the fire phase any burning of the specimen has to extinguish naturally and no artificial cooling is allowed. At BAM a large-scale fire test with a real size impact limiter and a wood volume of about 3m³ was conducted to investigate the burning behaviour of wood filled impact limiters in steel sheet encapsulation. The impact limiter was equipped with extensive temperature monitoring equipment. Until today burning of such impact limiters is not sufficiently considered in transport package design and more investigation is necessary to explore the consequences of the impacting fire. The objective of the large scale test was to find out whether a self-sustaining smouldering or even a flaming fire inside the impact limiter was initiated and what impact on the cask is resulting. The amount of energy, transferred from the impact limiter into the cask is of particular importance for the safety of heavy weight packages. With the intention of heat flux quantification a new approach was made and a test bench was designed. A first computational simulation of transport package temperatures taking into account the results of the conducted fire test was performed. T2 - IRSN Conference on Safe Transport of Radioactive Material CY - Fontenay aux Roses, France DA - 13.11.2018 KW - Impact limiter KW - Shock absorber KW - Smoldering KW - Smouldering KW - Burning KW - Thermal testing KW - BAM TTS KW - Combustion KW - Fire KW - Energy release KW - Thermal simulation KW - Heat emission KW - Radioactive KW - Transport KW - IAEA KW - Wood KW - Spruce wood KW - Lid temperature PY - 2018 AN - OPUS4-46882 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Feldkamp, Martin A1 - Erenberg, Marina A1 - Nehrig, Marko A1 - Bletzer, Claus A1 - Musolff, André A1 - Schönfelder, Thorsten A1 - Wille, Frank T1 - Behavior of wood filled impact limiters during the IAEA thermal test T2 - Proceedings-CD, ASME 2017 Pressure Vessels & Piping Conference (PVP 2017) N2 - Packages for the transport of radioactive material are often equipped with impact limiters consisting of wood, encapsulated by steel sheets. These impact limiters shall ensure that transport casks meet the IAEA safety requirements. After damage caused by the mechanical tests the package has to withstand a severe fire scenario. It is required that the mechanical tests have to produce maximum damage, taking into account the thermal test. Furthermore, any damage, which would give rise to increased radiation or loss of containment or affect the confinement system after the thermal test, should be considered. Concerning the thermal test, the IAEA safety requirements state that during and following the fire test, the specimen shall not be artificially cooled and any combustion of materials of the package shall be permitted to proceed naturally. Different works from the French Institute for Radiological Protection and Nuclear Safety (IRSN) and BAM show that additional energy supply from a pre-damaged impact limiter to the cask could occur caused by smoldering of the wood. This effect should be considered within the safety assessment of the package. A heat wave from the fire could overlap with the additional energy from the impact limiter in the sealing system. In 2015 BAM conducted small scale fire tests with wood filled metal drums showing continuing combustion processes during the cooling down phase. As not much is known about smoldering processes in wood filled impact limiters, it is highly complex to define pre-damage of impact limiters, which are conservative, regarding the most damaging energy flow from the impact limiter to the containment system in dependence of time. More research has to be done to develop models to examine the effects of smoldering impact limiters on the containment of packages for the assessment. The process of smoldering is described with regard to the requirements in the thermal safety assessment. Parameters influencing the smoldering process are identified. BAM operates test facilities to examine the issue of mechanical damage, combustion and heat transfer of packages for transport of radioactive material. A thermal test will take place with a wood filled test specimen with a diameter of about 2.3 meters. The aim is to understand the phenomena of smoldering under the consideration of relevant regulatory boundary conditions. T2 - ASME 2017 Pressure Vessels and Piping Conference (PVP2017) CY - Waikoloa, Hawaii, USA DA - 16.07.2017 KW - Fire test KW - Wood KW - IAEA KW - Smoldering KW - Smouldering KW - Shock absorber KW - Thermal test KW - Combustion KW - Impact limiter PY - 2017 SN - 978-0-7918-5802-8 VL - 7 SP - Article UNSP V007T07A038, 1 EP - 9 AN - OPUS4-43172 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Feldkamp, Martin A1 - Nehrig, Marko A1 - Bletzer, Claus A1 - Musolff, André A1 - Erenberg, Marina A1 - Schönfelder, Thorsten A1 - Wille, Frank T1 - Aspects of Assessment of Packages with Wood Filled Impact Limiters during Fire Tests N2 - Packages for the transport of radioactive material are often equipped with impact limiters consisting of wood, encapsulated by steel sheets. These impact limiters shall ensure that the transport casks meet the mechanical and thermal IAEA regulatory test requirements. According to the accident conditions of transport it is mandatory to expose the specimens to a cumulative effect by mechanical and thermal impacts. The mechanical tests consist of a free drop from 9 m onto a flat unyielding target and a 1 m drop onto a puncture bar. After damage caused by mechanical test sequences the package has to withstand a severe fire scenario. Corresponding to the IAEA advisory material it is required that the impact attitudes for the 9 m drop test and for the puncture test have to be such as to produce maximum damage, taking into account the thermal test. Moreover, any damage, which would give rise to increased radiation or loss of containment or affect the confinement system after the thermal test, should be considered. During and following the thermal test, the specimen shall not be artificially cooled and any combustion of materials of the package shall be permitted to proceed naturally. Different works from the French Institute for Radiological Protection and Nuclear Safety (IRSN) and BAM show that additional energy supply from a pre-damaged impact limiter to the cask could occur. This effect should be considered within the safety assessment of the containment. Thermal effects at the closure system of the cask, which might result in an elevated activity release, have to be excluded. BAM conducted small scale tests with wood filled metal buckets showing continuing combustion processes during the cooling down phase. These test results are presented. As not much is known about smouldering processes in wood filled impact limiters, it is highly complex to define pre-damage of impact limiters, which are conservative, regarding the maximum damaging energy flow from the impact limiter to the containment system. More research has to be done to develop models to examine the effects of smouldering impact limiters on the containment of packages for the transport of radioactive material. Aspects of assessment and its difficulties are shown. BAM as a competent authority for the approval of transport casks for radioactive material in Germany operates the test facilities to examine the issue of mechanical damage, combustion and heat transfer for such kind of package systems. For this purpose the knowledge from real drop tests with casks of a mass partly over 100 tons was transferred to a test application. A thermal test will take place with a wood filled test specimen with a diameter of about 2.3 meters. The aim is to understand the phenomena of smouldering under the consideration of relevant regulatory boundary conditions. The process of smouldering is described with regard to the requirements in the thermal assessment of safety of packages for the transport of radioactive material. Requirements concerning the pre-damage of packages for the maximum damage of impact limiters are discussed. Parameters influencing the smouldering process are identified. T2 - WM 2017 Conference CY - Phoenix, Arizona, USA DA - 05.03.2017 KW - Fire test KW - Wood KW - Combustion KW - Smouldering KW - Smoldering KW - Impact limiter KW - Shock absorber KW - Thermal test KW - IAEA PY - 2017 AN - OPUS4-43170 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Feldkamp, Martin A1 - Erenberg, Marina A1 - Nehrig, Marko A1 - Bletzer, Claus A1 - Musolff, André A1 - Wille, Frank A1 - Schönfelder, Thorsten T1 - Aspects of assessment of packages with wood filled impact limiters during fire tests T2 - WM 2017 Conference Proceedings N2 - Packages for the transport of radioactive material are often equipped with impact limiters consisting of wood, encapsulated by steel sheets. These impact limiters shall ensure that the transport casks meet the mechanical and thermal IAEA regulatory test requirements. According to the accident conditions of transport it is mandatory to expose the specimens to a cumulative effect by mechanical and thermal impacts. The mechanical tests consist of a free drop from 9 m onto a flat unyielding target and a 1 m drop onto a puncture bar. After damage caused by mechanical test sequences the package has to withstand a severe fire scenario. Corresponding to the IAEA advisory material it is required that the impact attitudes for the 9 m drop test and for the puncture test have to be such as to produce maximum damage, taking into account the thermal test. Moreover, any damage, which would give rise to increased radiation or loss of containment or affect the confinement system after the thermal test, should be considered. During and following the thermal test, the specimen shall not be artificially cooled and any combustion of materials of the package shall be permitted to proceed naturally. Different works from the French Institute for Radiological Protection and Nuclear Safety (IRSN) and BAM show that additional energy supply from a pre-damaged impact limiter to the cask could occur. This effect should be considered within the safety assessment of the containment. Thermal effects at the closure system of the cask, which might result in an elevated activity release, have to be excluded. BAM conducted small scale tests with wood filled metal buckets showing continuing combustion processes during the cooling down phase. These test results are presented. As not much is known about smouldering processes in wood filled impact limiters, it is highly complex to define pre-damage of impact limiters, which are conservative, regarding the maximum damaging energy flow from the impact limiter to the containment system. More research has to be done to develop models to examine the effects of smouldering impact limiters on the containment of packages for the transport of radioactive material. Aspects of assessment and its difficulties are shown. BAM as a competent authority for the approval of transport casks for radioactive material in Germany operates the test facilities to examine the issue of mechanical damage, combustion and heat transfer for such kind of package systems. For this purpose the knowledge from real drop tests with casks of a mass partly over 100 tons was transferred to a test application. A thermal test will take place with a wood filled test specimen with a diameter of about 2.3 meters. The aim is to understand the phenomena of smouldering under the consideration of relevant regulatory boundary conditions. The process of smouldering is described with regard to the requirements in the thermal assessment of safety of packages for the transport of radioactive material. Requirements concerning the pre-damage of packages for the maximum damage of impact limiters are discussed. Parameters influencing the smouldering process are identified. T2 - WM 2017 Conference CY - Phoenix, AZ, USA DA - 05.03.2017 KW - Fire test KW - Wood KW - Combustion KW - Smouldering KW - Smoldering KW - Impact limiter KW - Shock absorber KW - Thermal test KW - IAEA PY - 2017 SN - 978-0-9828171-6-2 SP - 1 AN - OPUS4-40157 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -