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Trnava, Slovakia

Figedy S.,VUJE Inc.
World Scientific Proc. Series on Computer Engineering and Information Science 7; Uncertainty Modeling in Knowledge Engineering and Decision Making - Proceedings of the 10th International FLINS Conf. | Year: 2012

In this work an alternative method of in-core sensor validation is outlined. Instead of using direct sensor readings, it is based on neuro-fuzzy modeling of residuals between the experimental values and their theoretical counterparts obtained from reactor core simulator calculations. Throughout the fuel cycle, the neural networks are subject to the incremental training on data prior to the current monitoring period. While for thermocouples the method shows very good sensitivity, for self powered neutron detectors the results are not satisfactory. The purpose of this paper is to present the newest results from considerably long time effort in development of this computational intelligence based approach.

Kovacik J.,VUJE Inc.
Proceedings of the 8th International Scientific Symposium on Electrical Power Engineering, ELEKTROENERGETIKA 2015 | Year: 2015

Power transformers are important parts of substations from financial point of view. Unplanned outage of transformer represent of very high cost in addition. Presentation is dealing about a history of installation online monitoring system of power transformers in industry of Slovakia as well as experiences from their service.

Michal V.,VUJE Inc.
3rd Int. Joint Topical Meeting on Emergency Preparedness and Response and Robotics and Remote Systems 2011, EPRRSD, and 13th Robotics and Remote Systems for Hazardous Environments | Year: 2011

The paper deals with remotely operated and robotics technologies for physical and radiological characterization, retrieval, dismantling, demolition, decontamination and other activities during implementation of the most significant decommissioning projects of European nuclear power plants and other nuclear facilities. Overview of technologies that are developed and used mainly in Belgium, France, Germany, United Kingdom, Slovakia etc. is done. Due to the limited available information only the basic one concerning relevant technologies developed and used in Ukraine (for NPP Chernobyl) and in Russian Federation is provided. Brief history of utilization of remotely operated and robotics technologies for the implementation of relevant decommissioning activities in Europe is described including basic technical background of relevant technologies, the current status and expected future trends for their development and deployment. European approach is compared with the current state-of-the-art worldwide applications. Lessons learned and future trends are summarized in conclusions.

Kubacka J.,VUJE Inc.
IYCE 2013 - 4th International Youth Conference on Energy | Year: 2013

The objective of this paper is to present the preliminary results of design basis reconstitution of the systems, dedicated to prevention of containment boundary failure of the VVER440/V213 unit. The results are based on large set of calculations (using MELCOR code) of various Loss of Coolant Accident scenarios, which have been integrally evaluated and processed to preliminary set of parameters (characteristics) of bubble tower and containment spray system. An accent will be given to the comparison of existing characteristics of relevant systems to the by design basis reconstitution derived ones. The paper will provide recommendations which may lead to the modifications of some parameters of the safety systems. © 2013 IEEE.

The reactor internals are designed to ensure cooling of the fuel, to ensure the movement of emergency control assemblies under all operating conditions including accidents and facilitate removal of the fuel and of the internals following an accident. This paper presents preliminary results of the numerical simulation of the WWER440/V213 reactor vessel internals (RVI) dynamic response to maximum hypothetical Large-break Loss of Coolant Accident (LOCA). The purpose of this analysis is to determine the reactor vessel internals response due to rapid depressurization and to prove no such permanent (plastic) deformations occur in the RVI which would prevent timely and proper activation of the emergency control assemblies. In the case of the LOCA accident it is assumed rapid "guillotine" break of one of the main coolant pipes and rapid depressurization of the primary circuit. The pressure wave spreads at the speed of sound, enters the reactor pressure vessel and causes deformation and stress in reactor vessel internals. The finite element model was created by MSC.Patran (Patran, 2010) and dynamic response was solved using MSC.Dytran (Dytran, 2008) finite element code. The model consists of reactor vessel internals (Lagrangian solid elements) and water coolant (Euler elements) inside the reactor. Arbitrary Lagrangian Eulerian (Belytschko et al.; 2003) coupling was used for simulation of the fluid-structure interaction. The calculation assumes no phase change in the water. No comparison with the experiment was performed up to now, because the required experimental data are not accessible for this type of the reactor. The most important acceptance criteria for the reactor internals demands that the movement of the emergency control assemblies under all operating conditions including accident is ensured (BNS, 2008). The numerical simulation of the WWER440/V213 reactor internals response to a LOCA accident showed that the acceptance criteria for RVI is fulfilled and required NPP safety standards are satisfied. © 2010 Elsevier B.V.

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