Filtered generated 374 hits.
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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...
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...
Content type: Publications -
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)...
Content type: Publications -
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...
Content type: Publications -
2017:19 Numerical simulations of headed anchors break in reinforced and non-reinforced concrete structures, Phase 2
Background In the design of anchorage equipment in concrete structures the beneficial effects of reinforcement are, in most cases, not considered. The American ASCI 349-06 code opens up for a more detailed analysis where the beneficial impact of reinforcement on anchor capacity can be taken into account. How this analysis can be done is, however, not explicitly described in the code. The...
Content type: Publications -
2017:34 Human capability to cope with unexpected events är publicerad
Background In the light of the Fukushima accident, it stood clear that the challenge of the unexpected is of great importance to both regulators and licensees. For SSM, as for many other national regulators, there was a selfevident need to learn more about the capabilities and actions of people when the unexpected arises and conditions are potentially extreme. A task group was set up within...
Content type: Publications -
2023:11 Study of degradation of spent fuel’s structural material and core components under long-term wet storage
SSM perspective Background Sweden is managing the spent nuclear fuel and core components from its commercial nuclear reactors with a national strategic plan. The fuel and core components are initially stored at the reactor site. After an on-site storage period to comply with transportation limits on decay heat and radiation, these materials are shipped to the Clab (Central Interim Storage...
Content type: Publications -
2023:13 TPR 2023 Fire Protection Swedish National Assessment Report
Executive Summary The European Union’s Nuclear Safety Directive 2014/87/EURATOM (NSD) requires the member states to undertake topical peer reviews (TPR) every 6 years. The first topical peer review concerned Ageing management and started in 2017. The member states, acting through the European Nuclear Safety Regulators Group (ENSREG), decided that the topic for the second topical peer review...
Content type: Publications -
2024:18 Modelling Environmental Sensitization of Chromia Forming Nickel Base Alloys Toward Stress Corrosion Cracking in Light Water Reactors by Atomistic Simulations
SSM perspective Background Stress corrosion cracking (SCC) in load bearing structures has been a longstanding issue both in pressurized and boiling water reactors. The specific environment in nuclear power applications consists of high temperatures and pressures that together with the effects of the radiation field on the coolant composition provide tough conditions for the materials used in...
Content type: Publications -
2016:25 Licensing of safety critical software for nuclear reactors
It is widely accepted that the assessment of software cannot be limited to verification and testing of the end product, ie the computer code. Other factors such as the quality of the processes and methods for specifying, designing and coding have an important impact on the implementation. Existing standards provide limited guidance on the regulatory and safety assessment of these factors. An...
Content type: Publications