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• 2011:13 Investigation of Discrete-Fracture Network Conceptual Model Uncertainty at Forsmark

  Flow modelling using alternative assumptions regarding conceptual and parametric uncertainty in the spatial and structural relationships among fractures indicates elevated flow rates and groundwater velocities to deposition holes compared to SKB’s flow modelling results. Simulated sampling of fractures in boreholes does not indicate any reason to exclude the proposed spatial and structural...

  Content type: Publications

• 2011:04 Evaluation of the Technical Basis for New Proposals of Fatigue Design of Nuclear Components

  During the recent years fatigue analysis procedures for nuclear components have been investigated. The most common method so far has been the American code ASME III. The basis for the current design procedures in ASME III is quite old and has now been evaluated against modern data leading to the proposal of modified design curves. Also the effect of the environment has been the subject of...

  Content type: Publications

• 2011:30 A fatigue analysis including environmental effects for a pipe system in a Swedish BWR

  The effect of the environment on fatigue design has been the subject of intense study in USA, Japan and elsewhere. Several reports indicate a potentially large influence of the environment, leading to the proposal of entirely new analysis procedures. SSM has in an earlier project sponsored research to evaluate the technical basis for these proposals, see SSM Research Report 2011:04. In the...

  Content type: Publications

• 2011:26 The influence of temperature and fluid pressure on the fracture network evolution around deposition holes of a KBS-3V concept at Forsmark, Sweden

  In preparation for the review of SKB’s license application for disposal of spent nuclear fuel, SSM is conducting studies to evaluate the performance of the multi-barrier principle on which the KBS-3 concept is based. Copper canisters containing the spent nuclear fuel are placed into granitic bedrock at about 500 m depth and embedded in clay. Thus, the rock, the clay and the copper canister...

  Content type: Publications

• 2011:12 Analysis of Barrier Performance: Modelling of Copper corrosion scenarios with and without buffer erosion

  The purpose of this project was to develop a numerical modelling capacity to address the corrosion of the copper canister under gradually changing transport conditions caused by buffer erosion and removal of buffer mass. Due to the complexity of this task, such a model cannot be realistic in all respects, but the present effort should address the feasibility of solving numerical and...

  Content type: Publications

• 2011:11 Handling Interfaces and Time-varying Properties in Radionuclide Transport Models

  Quintessa’s QPAC code has been used to investigate the Qeq approach. The conclusions from this simulation study are the following. The basic approach to calculating Qeq values is sound, however, narrow channels could lead to the same release as larger fractures with the same pore velocity, so a channel enhancement factor of √10 should be considered. A spalling zone that increases the area of...

  Content type: Publications

• 2011:19 Experimental evaluation of influence from residual stresses on crack initiation and ductile crack growth at high primary loads

  Cracked components are usually subjected to loads causing both primary and secondary stresses, e.g. welding components. Engineering assessment approaches, such as the ASME XI code and the R6 procedure, are commonly used to conduct integrity assessment of such components. There has been an ongoing debate how to treat secondary stresses using engineering assessment methods. The nature of these...

  Content type: Publications

• 2011:29 Research and Development Program in Reactor Diagnostics and Monitoring with Neutron Noise Methods, Stage 17

  This report constitutes Stage 17 of a long-term research and development program concerning the development of diagnostics and monitoring methods for nuclear reactors. Results up to Stage 16 were reported in SKI and SSM reports, as listed below and in the Summary. The results have also been published in international journals and have been included in both licentiate- and doctor’s degrees.

  Content type: Publications

• 2011:17 Structural Health Monitoring of Piping in Nuclear Power Plants – A Review of Efficiency of Existing Methods

  SSM needs to acquire knowledge about new applied Non-Destructive Engineering (NDE) techniques and their efficiency. One area that is discussed more frequently is Structural Health Monitoring (SHM). SSM needs to investigate the international experiences of SHM from the nuclear industry. SSM also wants to have more information about the capabilities and the limitations of NDE methods The first...

  Content type: Publications

• 2011:33 Mathematical modelling of ultrasonic testing of components with defects close to a non-planar surface

  The report describes work that has been performed in order to model ultrasonic testing of components that contain a defect close to a non-planar surface. The studies have been performed in both 2D and 3D, and in 2D in both the anti-plane (SH) and the in-plane (P-SV). The results show that the presence of a non-planar back wall can reduce the detectability of defects close to the surface. The...

  Content type: Publications