1. Institute of Nuclear and Physical Engineering, Faculty of Electrical Engineering and Information Technology, Slovak University of Technology in Bratislava; Ilkovičova 3 812 19 Bratislava Slovakia
2. Department of Nuclear Reactors, Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University in Prague; V Holešovičkách 2 180 00 Prague 8 Czech Republic
3. Department of Mechanics and Materials Science, Wrocław University of Technology; Smoluchowskiego 25 50 370 Wrocław Poland