Din avgränsning ger 332 träffar.
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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...
Innehållstyp: Publikationer -
2011:06 Reliability Data Handbook for Piping Components in Nordic Nuclear Power Plants – R Book, Phase 2
The Nordic PSA Group (NPSAG) has undertaken to develop a piping reliability parameter handbook for use in risk-informed applications that involve the consideration of structural integrity of piping systems. The scope of the handbook is to establish high quality reliability parameters that account for the Nordic and worldwide service experience with safety-related and non-safety-related piping...
Innehållstyp: Publikationer -
2011:05 Overview and Evaluation of the NESC Projects for Fracture Assessments of Nuclear Components
The Network for Evaluation of Structural Components (NESC) was started in 1993 and since then six different projects have been carried out. A seventh NESC-project is still in progress. The overall objective of these projects has been to study the reliability of the entire process of structural integrity assessment within an international framework. The network is coordinated by the European...
Innehållstyp: Publikationer -
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...
Innehållstyp: Publikationer -
2010:36 Guidance for the Definition and Application of Probabilistic Safety Criteria
Safety goals are defined in different ways in different countries and also used differently. Many countries are presently developing them in connection to the transfer to risk-informed regulation of both operating nuclear power plants (NPP) and new designs. However, it is far from self-evident how probabilistic safety criteria should be defined and used. On one hand, experience indicates that...
Innehållstyp: Publikationer -
1986:12 Chernobyl - its impact on Sweden
In case of a radiological emergency in Sweden, the Swedish National Institute of Radiation Protection (SSI) has the responsibility of organ1z1ng a special task force with experts both from SSI and from other authorities. Reports of increased radiation l evels reached SSI around 10 am on April 28, 1986, and the task force convened at 1030 am. A large number of measurements were made all over...
Innehållstyp: Publikationer -
2020:13 Core data Research at Uppsala University
SSM perspective Background This project is to support a research group at Uppsala University in the research field of nuclear data for applications. Nuclear data research is about measuring microscopic cross-sections and developing theoretical nuclear models to create evaluated nuclear data libraries. These nuclear data libraries are used in different applications such as, nuclear technology,...
Innehållstyp: Publikationer -
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