Din avgränsning ger 332 träffar.
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2020:02 Models for axial gas flow and mixing in LWR fuel rods
SSM perspective Background Fission gases inside a fuel rod plays an important role in the behaviour of the fuel, both during normal operation and during events and accidents. Fission gases are released from inside the fuel pellets to the gap between the pellet and the cladding tube and then flow to the plenum volume at the top of the fuel rod. In high burnup fuel, this axial flow to the...
Innehållstyp: Publikationer -
2020:16 Estimates ofJ-integral and COD for circumferential through wall cracks under global bending including the effect of pipe end restraint
SSM perspective Background Leak-before-break (LBB) piping assessments have shown that piping systems can withstand long through-wall cracks before pipe rupture is expected. This is somewhat because pipe ends are restrained. In LBB assessments analyses are often performed for a pipe segment uncoupled from the piping system, as pipe ends are assumed unrestrained. This assumption is conservative...
Innehållstyp: Publikationer -
2021:04 Calibration of models for cladding tube high-temperature creep and rupture in the FRAPTRAN-QT-1.5 program
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 where one is the possibility and size of a rupture of the fuel rod...
Innehållstyp: Publikationer -
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...
Innehållstyp: Publikationer -
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...
Innehållstyp: Publikationer -
2021:17 Inverkan från undergrund och bränslebassänger vid jordbävningsanalyser på svenska kokvattenreaktorer
SSM perspektiv Bakgrund Vattnet i en bassäng, såsom bränsle- och kondensationsbassänger i kärnkraftsreaktorer, har en stor inverkan på strukturens verkningssätt när en sådan konstruktion blir utsatt för seismiska laster. Vattnet bidrar med en ökad massa som sänker strukturens egenfrekvenser och dessutom ger det upphov till hydrostatiskt...
Innehållstyp: Publikationer -
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...
Innehållstyp: Publikationer -
2022:18 Data report – sampling of sea water and marine organisms outside Ringhals NPP
SSM perspective Background The Radiation Safety Authority (SSM) funded the collection of marine biota over an annual cycle at the Ringhals nuclear power plant (NPP) to enable development of analytical methods for C-14. Methods for the C-14 analysis and results in the form of levels of C-14 in various marine organisms have been reported by the Swedish Defense Research Institute (FOI) in FOI...
Innehållstyp: Publikationer -
2017:23 Kalibrering för bestämning av optimal beräkningsmodell
Bakgrund SSM bedömer i tillsynen avancerade datorberäkningar relaterade till drift av kärnkraftverk, utförda av extern part. Inom kärnkraft kan experimentella undersökningar vara olämpliga. Beräkningar blir därför ofta det enda alternativet att undersöka möjliga konsekvenser av planerade förändringar. Beräkningsmodeller...
Innehållstyp: Publikationer -
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...
Innehållstyp: Publikationer