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2022:09 Assessment of modelling approaches for axial gas flow inside LWR fuel rods
SSM perspective Background The fuel rod analysis program SCANAIR has been developed by IRSN (Institut de Radioprotection et de Sûreté Nucléaire) for analysis of reactivity initiated accidents (RIA) in light water reactors. The Swedish Radiation Safety Authority (SSM) has access to SCANAIR in exchange for annual contributions for its further development. The development and administration...
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2022:04 Warm Pre-Stressing mechanisms
SSM perspective Background Swedish nuclear power plants (NPP) were originally designed and analyzed with an assumed operating period of approximately 40 years. As Swedish NPPs reach their original technical design life the safety of the additional operating time has to be verified. With increased operating time, the shift in the fracture toughness curve of the reactor pressure vessel (RPV)...
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2022:03 Effect of Neutron Irradiation on the Oxidation and Corrosion of Austenitic Stainless Steels
SSM perspective Background Reactor pressure vessel internal components of austenitic stainless steel located close to the core are subject to a high neutron flux. Irradiation by fast neutrons induces changes in the material that affect microstructure, mechanical properties and microchemistry. These changes eventually lead to an increased susceptibility to irradiation assisted stress corrosion...
Content type: Publications -
2021:20 Effects of additives on UO2 fuel behavior: expanded edition
SSM perspective Background The Swedish Radiation Safety Authority (SSM) follows the development of nuclear fuel closely. Fuel with additives like chromia and gadolinia is used in Swedish reactors and fuel with even better thermal and mechanical properties is under development. This project is an in-depth study of data and models regarding the impact of additives on the properties of uranium...
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2021:10 Establishment and use of attention values in environmental fatigue assessments
SSM perspective Background As Swedish NPPs reach their original technical design life, re-assessment of the fatigue life of structural components is needed for safe long term operation (LTO). In these re-assessments one must consider that new knowledge has shown that environmental effects on fatigue life must be considered. One common method to verify the fatigue life of structural components...
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2021:09 Mechanisms important for material modelling in weld residual stress analysis
SSM perspective Background The prediction of weld residual stresses (WRS) is very complex as many mechanisms and phenomena influence the development of WRS during welding. For accurate prediction, the constitutive material models used are essential and must be able to describe the material response of the weldment constituents. For example, selection of a material model should only depend on...
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2021:05 Cladding tube rupture under LOCA: Data and models for rupture opening size
SSM perspective Background The Swedish Radiation Safety Authority (SSM) follows the research on fuel performance closely. One aspect that is currently being studied in several research projects is the risk of release of fragmented fuel into the primary coolant in case of an accident. This risk depends on complex conditions were one is the possibility and size of a rupture of the fuel rod...
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2021:04 Calibration of models for cladding tube high-temperature creep and rupture in the FRAPTRAN-QT-1.5 program
SSM perspective Background In Swedish Light Water Reactors (LWR), stress corrosion cracking of reactor components and welds occurs from time to time. As the nuclear power plants are ageing, it is essential to study and further understand the mechanism for environmentally induced sensitization. Natural cracking is a phenomenon that is difficult to predict and very hard to study since it occurs...
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2021:02 On Water Induced Sensitization of Ni (Fe,Cr) alloys towards Stress Corrosion Cracking in LWR Piping from 1st Principles Modelling
SSM perspective Background In Swedish Light Water Reactors (LWR), stress corrosion cracking of reactor components and welds occurs from time to time. As the nuclear power plants are ageing, it is essential to study and further understand the mechanism for environmentally induced sensitization. Natural cracking is a phenomenon that is difficult to predict and very hard to study since it occurs...
Content type: Publications -
2021:01 In situ NMR condition monitoring of cable insulations in Nuclear Power Plants
Prof. István Furó, Dr. Payam Pourmand, Dr. Pavel Yushmanov SSM English...
Content type: Publications