Showing 259
-
2017:25 Evaluation of weld fatigue reduction in austenitic stainless steel pipe components
Background The performed investigation is a continuation of the work performed in SSM 2015:38 where fatigue tests were performed on pressurized welded austenitic stainless steel piping components. The specimens were subjected to a realistic variable amplitude loading with mainly reversed bending deformation and particular focus on high cycle fatigue. The previous fatigue results were quite...
Content type: Publications -
2017:22 Effect of weld repairs on residual stresses in nickel base dissimilar metal welds
Background The driving force for crack growth near welds in nuclear application piping may arise from weld residual stresses. Experience from nondestructive examination show that cracks in dissimilar metal welds are often found near weld repairs. The repair welding may affect the residual stresses through e.g. increased tensile stresses and increased plastic straining on the surfaces of the...
Content type: Publications -
2017:20 Assessment of inertia effects on transient clad-to-coolant heat transfer and coolant flow under reactivity initiated accidents
In this report, simple hydrodynamic models are used for studying the effects of coolant inertia on fuel-to-coolant heat transfer and coolant flow under reactivity initiated accidents in light water reactors. The objective is to assess if the inertia effects are important enough to warrant modification of QT-COOL, a coolant channel module for two-phase flow that has recently been implemented as...
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 -
2017:16 Stress intensity factor solutions for circumferential cracks in cylindrical bars under axisymmetric loading and global bending
Background The case of a circumferential crack in a cylindrical bar has not been available in the ProSACC code. The need for such a geometry, especially considering nonlinear axisymmetric loading and global bending, has motivated the development of new stress intensity factor solutions, also known as K-solutions. These new K-solutions will be available in ISAAC, the successor to ProSACC.
Content type: Publications -
2017:12 Computational assessment of LOCA simulation tests on high burnup fuel rods in Halden and Studsvik
Background Loss of Coolant Accidents (LOCA) are among the most demanding accidents that can happen in a Light Water Reactor (LWR). The lack of cooling and the drop in pressure impose large stresses on the nuclear fuel which would increase the risk of fuel rod damage and the subsequent release of active material. But LOCA is also an accident that the nuclear power plant is designed to...
Content type: Publications -
2017:11 Extended Common Load Model: A tool for dependent failure modelling in highly redundant structures
Background The treatment of dependent failures is one of the most controversial subjects in reliability and risk analyses. The difficulties are specially underlined in the case of highly redundant systems, when the number of redundant components or trains exceeds four. The Common Load Model (CLM), originally defined in the 70’ies, differs from other CCF models, as it relies on a specific...
Content type: Publications -
2017:09 Evaluation of the Swedish participation in the Nordic Nuclear Safety Research (NKS) collaboration
Background NKS is a Nordic collaboration promoting cooperation on nuclear safety and emergency preparedness research. The research program is primarily funded by Nordic radiation safety authorities and responsible ministries. The main purpose of NKS is to finance joint Nordic activities and initiatives, including seminars and workshops, technical reports, exercises and scientific articles.
Content type: Publications -
2017:05 Robust structural verification of pressurized nuclear components subjected to ratcheting, part two – stress-strain curves for cyclic elastoplastic analysis.
Background Pressurized components in nuclear applications that are subjected to cyclic loading may exhibit progressive deformation, so called structural ratcheting. If the component is made out of a material that are deformation hardening, it may also exhibit material ratcheting. The combined effects of structural- and material ratcheting are not taken into account in the methods and material...
Content type: Publications -
2016:39 Recommended residual stress profiles for stainless steel pipe welds
Background The Swedish Radiation Safety Authority (SSM) and the Swedish nuclear power plant owners have financed Inspecta Technology in Sweden to analyze stainless steel pipe welds to obtain good estimations of weld residual stress (WRS) distributions. Detailed knowledge of the residual stress field in different types of welds is important since they can have substantial influence on...
Content type: Publications