Filtered generated 118 hits.
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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 -
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...
Content type: Publications -
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...
Content type: Publications -
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...
Content type: Publications -
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 -
2021:02 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 -
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...
Content type: Publications -
2020:07 Fibre Clogging in Nuclear Power Plants
SSM perspective Background Emergency core cooling systems in boiling- and pressurized water reactors use strainers. Their purpose is to out foreign material suspended in the cooling water so this material does not reach the reactor. After the 1992 event at Barsebäck nuclear power plant when the strainers of the emergency cooling system was clogged due to fibers in the cooling water,...
Content type: Publications -
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...
Content type: Publications