Filtered generated 278 hits.
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2008:06 Synthetic Aperture Focusing Technique in Ultrasonic Inspection of Coarse Grained Materials
Experience from the ultrasonic inspection of nuclear power plants has shown that large focused transducers are relatively effective in suppressing grain (structure) noise. Operation of a large focused transducer can be thought of as an integration (coherent summation) of individual beams reflected from the target and received by individual points at the transducer surface. Synthetic aperture...
Content type: Publications -
2008:50 Study on Developments in Accident Investigation Methods: A Survey of the “State-of-the-Art”
The objective of this project was to survey the main accident investigation methods that have been developed since the early or mid-1990s. The motivation was the increasing frequency of accidents that defy explanations in simple terms, for instance cause-effect chains or “human error”. Whereas the complexity of socio-technical systems is steadily growing across all industrial domains,...
Content type: Publications -
2007:06 Probabilistic Safety Goals - Phase 1 -Status and Experiences in Sweden and Finland
Based on a series of interviews and on literature reviews as well as on a limited interna- tional over-view, the project has described the history and current status of safety goals in Sweden and Finland. A number of issues were discussed more in detail, including the status of the safety goals in view of the fact that they are often exceeded, strategies for handling violations of safety...
Content type: Publications -
2007:39 Influence of Crack Morphology on Leak Before Break Margins
The SKI regulation SKIFS 2004:2 allows for the use of Leak Before Break (LBB) as one way to provide assurance that adequate protection exists against the local dynamic consequences of a pipe break. The way to demonstrate that LBB prevails relies on a deterministic procedure for which a leakage crack is postulated in certain sections of the pipe based on the leak detection capability of the...
Content type: Publications -
2007:04 Link Between RI-ISI and Inspection Qualification: Relationship between Defect Detection Rate and Margin of Detection
A relationship has been established between defect detection ratio and margin of detection based on blind trails. The results are based on a rather small amount of data produced by personnel from one inspection laboratory but give us indications of how signal to noise ratio is possible to relate to the probability of detection (POD) used in RI-ISI models. The relationship need to be developed...
Content type: Publications -
2007:14 Review of experimental data for modelling LWR fuel cladding behaviour under loss of coolant accident conditions
This project has contributed to the research goal of giving a basis for SKIs supervision by means of evaluating experimental data and modelling the nuclear fuel cladding during a design base accident. The project has also contributed to the research goal to develop the competence about licensing of fuel at high burnup, which is an important safety issue. The results are useful as such, but...
Content type: Publications -
2009:15 Improvement and Validation of Weld Residual Stress Modelling Procedure
Weld residual stresses have a large influence on the behavior of cracks growing under normal operation loads and on the leakage-flow from a through-wall crack. Accurate prediction of these events is important in order to arrive at proper conclusions when assessing detected flaws, for inspection planning and for assessment of leak-before-break margins. Therefore, it is very important to have...
Content type: Publications -
2010:16 Guidance to Risk-Informed Evaluation of Technical Specifications using PSA
No guidance documents for risk-informed analysis and assessment of changes in Limiting Conditions for Operation (LCO:s) in TS (Technical Specifications) have been available in the Nordic countries. In the U.S. several guidance documents, primarily developed by the owners groups for PWRs and BWRs, exist. Guidance for analysis of TS changes in this report generally follows the U.S. Regulatory...
Content type: Publications -
2010:42 Using the EPRI Risk-Informed ISI Methodology on Piping Systems in Forsmark 3
In the SSM regulation SSMFS 2008:13, it is stated that the selection of locations for inspection of mechanical components shall be based upon the risk for core damage or the risk of release of radioactive substances. Both qualitative and quantitative measures of the relative risk are allowed to be used. So far only the PWRs in Sweden are using a quantitative procedure to evaluate the risk...
Content type: Publications -
2009:07 Dependency Analysis Guidance Nordic/German Working Group on Common Cause Failure analysis
The Regulatory Code SSMFS 2008:1 of Swedish Radiation Safety Authority (SSM) includes requirements regarding the performance of probabilistic safety assessments (PSA), as well as PSA activities in general. Therefore, the follow-up of these activities is part of the inspection tasks of SSM. According to the SSMFS 2008:1, the safety analyses shall be based on a systematic identification and...
Content type: Publications