Projects / Programmes
January 1, 2004
- December 31, 2008
| Code |
Science |
Field |
Subfield |
| 2.13.00 |
Engineering sciences and technologies |
Process engineering |
|
| 2.03.00 |
Engineering sciences and technologies |
Energy engineering |
|
| Code |
Science |
Field |
| T160 |
Technological sciences |
Nuclear engineering and technology |
nuclear engineering, safety analyses, design-basis accidents, severe accidents,thermal hydraulics, turbulent flow, boiling, water hammer, steam explosions, aerosols, atmosphere mixing,structural mechanics, ageing, micro-cracks,probabilistic safety assessment, reliability, genetic algorithms, human factor
Researchers (21)
Organisations (1)
| no. |
Code |
Research organisation |
City |
Registration number |
No. of publicationsNo. of publications |
| 1. |
0106 |
Jožef Stefan Institute |
Ljubljana |
5051606000 |
90,753 |
Abstract
The Reactor Engineering research programme includes basic and applied research in nuclear energy, engineering and safety. Phenomena that occur during transients, incidents and severe accidents in nuclear power plants are being investigated. Appart from contributing to the improvement of nuclear safety, research results are applicable to a wide range of industrial processes.
In the field of thermal-hydraulic safety research, the following basic phenomena that occur during design-basis accidents in light-water-reactor nuclear power plants are being investigated: heat transfer in single-phase and two-phase turbulent flow, subcooled nucleate boiling flow in vertical channels, as well as single-phase and two-phase water-hammer phenomena in piping systems. Basic phenomena which are specific to severe accidents are also being investigated: steam explosions due to interaction between coolant and molten reactor core, atmosphere mixing and stratification in the containment, steam condensation in the presence of non-condensable gases and aerosol behavior (transport, condensation and settling) in the containment. In addition, both design-basis and severe accidents are being modeled on integral scales using system computer codes.
In the field of structural safety research, new models are being developed to allow prediction of micro-damages and the study of their influence on the macroscopic behavior of materials. The investigations include simulations of initiation and growth of intergranular cracks in the random grain structure.
In the field of probabilistic safety assessment (PSA), new methods are being developed by including time as an additional dimension. PSA is integrated with optimization methods, such as simulated annealing. The influence of human factor on the reliability of complex technological systems is also being investigated.
Significance for science
Research in the field of thermal-hydraulic safety analyses will contribute to the following developments of science: — prediction of thermal loads of pressure vessels and pipings due to fast temperature variations in liquids, — prediction of water hammer caused by steam condensation on cold liquid in horizontally stratified flow, — fluid-structure interaction (coupling of fluid mechanics and elasto-mechanics equations), — heat flux partitioning and evaporation mass flow rate in subcooled convective boiling in heated tubes, — coupling of descriptions of two-phase dispersed flow on different length scales, — local mechanisms of critical heat flux and transition to boiling crisis, — interaction of turbulent and buoyancy effects in the mixing of a multi-component atmosphere, — influence of material properties on steam explosion intensity, — assessment of uncertainty of simulation results of complex phenomena. Research in the field of structural safety analyses will contributes to the resolution of the following issues: — relation between macroscopic behaviour of material and laws and properties on lower structure scales, — micro-structurally short cracks propagation in polycrystalline materials, — ageing processes in metals and alloys. Research in the field of probabilistic safety assessment will enable the following advancements in the development of science: — evaluation of human factor by integrating mathematical models and measured data on human effectiveness, — evaluation of causal relationship between power system reliability and nuclear power plant safety, — integration of optimization methods and probabilistic safety assessment, which is the standpoint for risk-informed decision-making.
Significance for the country
The results of the three aspects and proposed fields of research and their mutual interre-lation and complementarity are a necessary theoretical basis for safety analyses, related with the safe and stable operation of the Krško nuclear power plant, as well as for the exe-cution of the most demanding expert tasks for the Krško NPP and the Slovenian Nuclear Safety Administration. The results thus directly and indirectly contribute to the level of the safety culture in Slovenia. In more detail: Research in the field of thermal-hydraulic safety analyses, including combi-ned research with structural and probabilistic safety analyses, are especially important for interdisciplinary analyses and expert tasks that involve transient phenomena and hypothe-tical accidents. In this way, the research contributes to the long-term availability of compe-titive electrical energy, and to the protection of the population and the environment. Research in the field of structural safety analyses enables a more accurate prediction of the lifetime of important components of the Krško NPP, which has a direct influence on the availability of electricity. At the same time, the purposes of the research are set to enable direct knowledge transfer in support of the life-time extension of the existing plant and the planned construction of the new nuclear plant in Slovenia. The acquired knowledge will also be usefull in the process and mechanical industries. Research in the field of probabilistic safety assessment and risk contributes to the establishment of risk-informed decision-making and accelerates the development of regulations and standards based on risk analyses.
Most important scientific results
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Most important socioeconomically and culturally relevant results
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