Filtered generated 280 hits.
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2016:28 Fatigue fracture surface characterization and investigation
Background In a previous study (SSM research report 2015:38) fatigue experiments were performed on welded austenitic stainless steel piping components. The fatigue experiments offer an opportunity to examine the obtained fatigue cracks with an optical microscope. Objective The present study performs a fractographical examination of the obtained fatigue cracks with the aim of determine where...
Content type: Publications -
2016:31 Measures and method characteristics for early evaluation of safe operation in nuclear power plant control room systems
The Swedish Radiation Safety Authority’s (SSM) experience is that there is a need to develop evaluation methods in parallel with the development of control rooms in conjunction with construction modifications and other changes. This includes more indepth analysis of the methods used today. Another aspect is that conventional methods of evaluating control rooms and issues need to be...
Content type: Publications -
2015:20 The effects of mild, acute hypoxia on cognitive performance
Room air with reduced oxygen levels that prevent materials to ignite and combust is a cost-effective and increasingly popular fire prevention method. For system safety reasons, the effects of hypoxia, that is, the lack of sufficient oxygen (that is, less than 21% oxygen which is the approximate oxygen level of normal air), on cognitive performance of persons working under such conditions are...
Content type: Publications -
2016:26 Ensemble for deterministic sampling with positive weights
The aim of this project is to find a reliable method for determining an ensemble for Deterministic Sampling with only positive weights. This report is intended to work as a presentation of the project, as well as to work as a beginner’s guide to DS. In the report several methods for generating DS ensembles are presented, which can encode up to four moments and represent any kind of...
Content type: Publications -
2007:26 Safety Culture Enhancement Project Final Report
At the International Conference on Safety Culture in Nuclear Installations, organized by IAEA in 2002, one concluding remark was that the regulators should encourage a sincere interest in safety culture among licensees. In line with this SKI wanted to explore a proactive path to encourage the licensees in their safety culture work. SKI also had the ambition to gain more information on the MTO...
Content type: Publications -
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 -
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 -
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 -
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