Filtered generated 217 hits.
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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 -
2009:27 Analysis Strategy for Fracture Assessment of Defects in Ductile Materials
SSM has supported research for investigating the role of secondary stresses when fracture assessments are performed for cracked structures made of ductile materials. There are evidences that indicate that some secondary stresses, such as weld residual stresses, are not as important as primary stresses for estimating the safety margin against rupture (measured by the J-integral) for the type...
Content type: Publications -
2015:50 Assessment of structures subject to concrete pathologies (ASCET)
Many Nuclear Power Plants around the world are at the moment approaching, or in, their Long Term Operation stage of their operational phase. In addition, several NPPs have recently been carrying out uprate and life extension projects and comprehensive maintenance work including the exchange of components important to safety, in order to extend their lifetime. As a result, ageing management...
Content type: Publications -
2015:38 Evaluation of fatigue in austenitic stainless steel pipe components
Background Transferability of experimental results obtained for smooth test specimens under constant amplitude loading to realistic components subjected to variable amplitude loading is an important issue in the design against fatigue. There is a lack of experimental fatigue data for austenitic steel components and the present study is an important contribution to fill this gap. Objective The...
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 -
2016:04 Uncertainty assessment of the SCANAIR V_7_5 computer program in analyses of BWR reactivity initiated accidents
In this work, we assess uncertainties that can be expected in computational analyses of boiling water reactor reactivity initiated accidents with the SCANAIR V_7_5 computer program. The work is intended to supplement a similar uncertainty assessment, focussed on pressurized water reactor accidents, which is currently being organized as an international benchmark exercise by the OECD Nuclear...
Content type: Publications -
2016:37 PARTRIDGE project: Review and evaluation of the probabilistic fracture mechanics code PRO-LOCA
Background The Swedish Radiation Safety Authority (SSM) and the Swedish nuclear power plant owners have financed Inspecta Technology in Sweden to evaluate the PRO-LOCA code. It is a computer code, developed by Battelle in the USA, in which the leak- and rupture probabilities of piping in nuclear power plants are analysed. The pipe systems may contain the damage mechanisms fatigue and/or...
Content type: Publications -
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