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[en] The stress corrosion cracks as seen for example in PWR steam generator tubing made of Inconel 600 usually produce highly irregular kinked and branched crack patterns. Crack initialization and propagation depends on stress state underlying the crack pattern. Numerical analysis (such as finite element method) of interacting kinked and branched cracks can provide accurate solutions. This paper discusses the use of general-purpose finite element code ABAQUS for evaluating stress fields at crack tips of interacting complex cracks. The results obtained showed reasonable agreement with the reference solutions and confirmed use of finite elements in such class of problems.(author)
Source
Gortnar, O.; Stritar, A. (Nuclear Society of Slovenia (Slovenia)) (eds.); Nuclear Society of Slovenia, Ljubljana (Slovenia). Funding organisation: European Nuclear Society (Switzerland); Ministry of Science and Technology of Slovenia, Ljubljana (Slovenia); Ministry of Economic Affairs of Slovenia, Ljubljana (Slovenia); Inst. Jozef Stefan, Ljubljana (Slovenia); Slovenian Nuclear Safety Administration, Ljubljana (Slovenia); Agency for Radwaste Management, Ljubljana (Slovenia); ENCONET Consulting GmbH, Vienna (Austria); SIAP d.o.o, Pesnica pri Mariboru (Slovenia); S-NET Internet Provider, Ljubljana (Slovenia); 683 p; ISBN 961-6207-13-X; 
; 1999; p. 259-266; Nuclear Society of Slovenia; Ljubljana (Slovenia); International Conference on Nuclear Energy in Central Europe 99; Portoroz (Slovenia); 6-9 Sep 1999; Also available from Nuclear Society of Slovenia, Jozef Stefan Institute, Jamova 39, Ljubljana (SI); 8 refs., 7 figs.
; 1999; p. 259-266; Nuclear Society of Slovenia; Ljubljana (Slovenia); International Conference on Nuclear Energy in Central Europe 99; Portoroz (Slovenia); 6-9 Sep 1999; Also available from Nuclear Society of Slovenia, Jozef Stefan Institute, Jamova 39, Ljubljana (SI); 8 refs., 7 figs.
[en] The stress corrosion cracks as seen for example in PWR steam generator tubing made of Inconel 600 are usually found to be of highly irregular kinked and branched shapes. Numerical analysis of kinked and branched cracks in bi-axial plane stress fields using methods such as finite or boundary element method may provide useful and cost effective solutions. However, accurate analysis of complex shaped cracks requires very fine meshes and, consequently, excessively high computational efforts. This paper discusses some possible strategies of numerical modeling of kinked and branched cracks in general bi-axial stress field using the general-purpose finite element code ABAQUS. The strategies discussed include J-integral and stress intensity factor solutions with different mesh densities. The accuracy of the numerical results obtained is compared with reference solutions from the literature. The main result of the paper is an optimal numerical strategy, which maximizes the accuracy of the result at as low computational efforts as feasible. The selected optimal strategy is expected to be used in the future simulations of large networks of inter-granular stress corrosion cracks at the grain-size scale using incomplete random tessellation.(author)
Source
Ravnik, M.; Jencic, I.; Zagar, T. (Nuclear Society of Slovenia, Ljubljana (Slovenia)) (eds.); Nuclear Society of Slovenia, Ljubljana (Slovenia). Funding organisation: European Nuclear Society (Switzerland); Nuclear Power Plant Krsko (Slovenia); Siemens Power Generation Group, Erlangen (Germany); Ministry of Science and Technology of Slovenia, Ljubljana (Slovenia); Institute Jozef Stefan (Slovenia); American Society of Mechanical Engineers (United States); ENCONET Consulting GmbH (Austria); SIAP d.o.o. Pesnica pri Mariboru (Slovenia); Institute for Metal Constructions (Slovenia); Agency for Radwaste management (Slovenia); Slovenian Nuclear Safety Administration (Slovenia); 519 p; ISBN 961-6027-10-5; ; 1998; p. 269-276; Nuclear Society of Slovenia; Ljubljana (Slovenia); Nuclear Energy in Central Europe 98; Terme Catez (Slovenia); 7-10 Sep 1998; Available from Nuclear Society of Slovenia, Jozef Stefan Institute, Jamova 39, Ljubljana (SI); 9 refs., 7 figs.
; 1998; p. 269-276; Nuclear Society of Slovenia; Ljubljana (Slovenia); Nuclear Energy in Central Europe 98; Terme Catez (Slovenia); 7-10 Sep 1998; Available from Nuclear Society of Slovenia, Jozef Stefan Institute, Jamova 39, Ljubljana (SI); 9 refs., 7 figs.
[en] The aflatoxin M1 content in samples of commercial milk as well as in milk directly from farms in Western Slovakia was determined by radioimmunoassay using a commercial Czechoslovak RIA kit. In 25 analyzed samples of commercial milk the limit of 0.1 μg kg-1 aflatoxin M1 was not exceeded. From 110 sample from milk farms, 93 samples (84.5%) contained less than 0.1 μ kg-1 aflatoxin, for 15 samples (13.6%) the content ranged between 0.1 and 0.5 μg kg-1, and 2 samples contained 0.5 to 1.0 μg kg-1 of aflatoxin M1. (author). 2 figs., 20 refs
Journal
[en] The qualitative and quantitative aspects of degradation mechanism causing early retirement of SG tubing are not yet explained to the level allowing for accurate predictions of future behavior. On the other hand, a large amount of data related to tube degradation, inspection, repair, and plant operation have been collected during recent years. It allows for reasonably accurate quantitative predictions, based on statistical analysis of past events and assumption of reasonably constant operating conditions. A computational algorithm was developed to simulate life cycle of ODSCC defects: initiation, growth, measurement, and repair. The main feature of the algorithm is the possibility to address some important changes in the operating parameters, especially those related to the conditions during the plant shutdown. The algorithm can be used to get better insight into the background of SG aging and to predict the future populations of defects, as shown in a realistic numerical example.(author)
Source
Gortnar, O.; Stritar, A. (Nuclear Society of Slovenia (Slovenia)) (eds.); Nuclear Society of Slovenia, Ljubljana (Slovenia). Funding organisation: European Nuclear Society (Switzerland); Ministry of Science and Technology of Slovenia, Ljubljana (Slovenia); Ministry of Economic Affairs of Slovenia, Ljubljana (Slovenia); Inst. Jozef Stefan, Ljubljana (Slovenia); Slovenian Nuclear Safety Administration, Ljubljana (Slovenia); Agency for Radwaste Management, Ljubljana (Slovenia); ENCONET Consulting GmbH, Vienna (Austria); SIAP d.o.o, Pesnica pri Mariboru (Slovenia); S-NET Internet Provider, Ljubljana (Slovenia); 683 p; ISBN 961-6207-13-X; ; 1999; p. 243-250; Nuclear Society of Slovenia; Ljubljana (Slovenia); International Conference on Nuclear Energy in Central Europe 99; Portoroz (Slovenia); 6-9 Sep 1999; Also available from Nuclear Society of Slovenia, Jozef Stefan Institute, Jamova 39, Ljubljana (SI); 7 refs., 1 tab., 6 figs.
; 1999; p. 243-250; Nuclear Society of Slovenia; Ljubljana (Slovenia); International Conference on Nuclear Energy in Central Europe 99; Portoroz (Slovenia); 6-9 Sep 1999; Also available from Nuclear Society of Slovenia, Jozef Stefan Institute, Jamova 39, Ljubljana (SI); 7 refs., 1 tab., 6 figs.
[en] This study describes findings of computed tomography investigations at the Bergische Equine Clinic (Bergische Tierklinik), Germany, of 39 horses with hoof diseases. The most frequently findings were the navicular syndrome (eight horses), laminitis (seven horses), keratnoma (six horses) and ossification of collateral cartilages in the distal phalanx (four horses). The special value of the computed tomography is in evaluating the size and courses fracture/fissure of the navicular and koffin bones, which were diagnose in five horses. In four of horses no pathologic changes of the hoof were determined by computed tomography
Journal
Veterinarski Glasnik; ISSN 0350-2457; ; v. 56; p. 321-328
; v. 56; p. 321-328
[en] International Conference Nuclear Energy in Central Europe is an annual meeting of the Nuclear Society of Slovenia. The proceedings contain 108 articles from Slovenia, surrounding countries and countries of the Central and Eastern European Region. Topics are: thermal hydraulics, severe accidents, probabilistic safety assessment (PSA), nuclear waste, safety analyses, nuclear power plant operation, structural integrity and aging, nuclear energy and public, other related topics, research reactors, education and training and Monte Carlo transport calculations
Source
2000; 13.8 Megabytes; Inst. Jozef Stefan; Nuclear Society of Slovenia; Ljubljana (Slovenia); International Conference Nuclear Energy in Central Europe 2000; Bled (Slovenia); 11-14 Sep 2000; ISBN 961-6303-29-5; ; Also available from Slovenian Nuclear Safety Administration, Zelezna cesta 16, Ljubljana (SI) or Nuclear Society of Slovenia, Jamova 39, Ljubljana (SI); 726 refs., 125 tabs., 557 figs.
; Also available from Slovenian Nuclear Safety Administration, Zelezna cesta 16, Ljubljana (SI) or Nuclear Society of Slovenia, Jamova 39, Ljubljana (SI); 726 refs., 125 tabs., 557 figs.
[en] Combination of mechanical loads and aggressive environment causes a development of random interacting branched cracks in materials with grain structure (e.g. Inconel 600 in PWR steam generator tubing). Understanding and predicting behavior of such cracks are important for the safety of nuclear facilities and also for economical reasons in common process industry. Reliable and robust analysis of such cracks is possible only with numerical methods, among which finite element method is the most suitable for the task. The paper proposes procedure, which enables analysis of large number of random interacting branched cracks for linear elastic materials. The proposed procedure consists of numerical analysis of crack pattern with finite element method (using the general-purpose finite element code ABAQUS with calculation of J-integral) and mixed mode decomposition of J-integral using displacements at crack surfaces. Proposed procedure is used to evaluate different patterns of random two-dimensional complex shaped cracks in general biaxial stress field. The accuracy of the numerical results obtained is compared with reference solutions from the literature. (author)
Source
Mavko, B.; Cizelj, L.; Kovac, M. (Nuclear Society of Slovenia (Slovenia)) (eds.); Nuclear Society of Slovenia, Ljubljana (Slovenia); Inst. Jozef Stefan, Ljubljana (Slovenia). Funding organisation: Ministry of Science and Technology of Slovenia, Ljubljana (Slovenia); Ministry of Economic Affairs of Slovenia, Ljubljana (Slovenia); European Nuclear Society, Brussels (Belgium); American Society of Mechanical Engineers, New York, NY (United States); NPP Krsko (Slovenia); Westinghouse Electric Systems Europe S.A., Brussels (Belgium); CAE, Toronto (Canada); Siemens AG, Erlangen, Offenbach (Germany); Faculty of Mathematics and Physics, Univ. of Ljubljana (Slovenia); Framatome, Paris (France); Inetec, Zagreb (Croatia); SIAP d.o.o, Pesnica pri Mariboru (Slovenia); IBE d.d. Consulting Engineers, Ljubljana (Slovenia); Inst. of Metals and Technology, Ljubljana (Slovenia); NUMIP d.o.o, Krsko (Slovenia); Q Techna d.o.o., Krsko (Slovenia); Elmont d.o.o., Krsko (Slovenia); Slovenian Nuclear Safety Administration, Ljubljana (Slovenia); Agency for Radwaste Management, Ljubljana (Slovenia); ENCONET Consulting GmbH, Vienna (Austria); The Inst. of Metal Constructions, Ljubljana (Slovenia); The Milan Vidmar Electroinstitute, Ljubljana (Slovenia); Welding Inst., Ljubljana (Slovenia); 13.8 Megabytes; ISBN 961-6303-29-5; ; 2000; [10 p.]; International Conference Nuclear Energy in Central Europe 2000; Bled (Slovenia); 11-14 Sep 2000; Also available from Slovenian Nuclear Safety Administration, Zelezna cesta 16, Ljubljana (SI) or Nuclear Society of Slovenia, Jamova 39, Ljubljana (SI); 18 refs., 7 figs.
; 2000; [10 p.]; International Conference Nuclear Energy in Central Europe 2000; Bled (Slovenia); 11-14 Sep 2000; Also available from Slovenian Nuclear Safety Administration, Zelezna cesta 16, Ljubljana (SI) or Nuclear Society of Slovenia, Jamova 39, Ljubljana (SI); 18 refs., 7 figs.
[en] Extreme loadings during severe accident conditions might cause failure or rupture of the pressure boundary of a reactor coolant system. Reliable estimation of the extreme deformations can be crucial to determine the consequences of such an accident. One of important drawbacks of classical continuum mechanics is idealization of inhomogenous microstructure of materials. This paper discusses the mesoscopic approach to modeling the elastic-plastic behavior of a polycrystalline material. The main idea is to divide the continuum (e.g., polycrystalline aggregate) into a set of sub-continua (grains). The overall properties of the polycrystalline aggregate are therefore determined by the number of grains in the aggregate and properties of randomly shaped and oriented grains. The random grain structure is modeled with Voronoi tessellation and random orientations of crystal lattices are assumed. The elastic behavior of monocrystal grains is assumed to be anisotropic. Crystal plasticity is used to describe plastic response of monocrystal grains. Finite element method is used to obtain numerical solutions of strain and stress fields. The analysis is limited to two-dimensional models.(author)
Source
Jencic, I.; Glumac, B. (Nuclear Society of Slovenia (Slovenia)) (eds.); Nuclear Society of Slovenia, Ljubljana (Slovenia). Funding organisation: Inst. Jozef Stefan, Ljubljana (Slovenia); European Nuclear Society, Brussels (Belgium); Ministry of Education, Science and Sport of Slovenia, Ljubljana (Slovenia); Slovenian Nuclear Safety Administration, Ljubljana (Slovenia); Agency for Radwaste Management, Ljubljana (Slovenia); Faculty of Mechanical Engineering, Univ. of Ljubljana (Slovenia); Graduate Program Nucelar Engineering, Univ. of Ljubljana (Slovenia); Inst. of Metals and Technology, Ljubljana (Slovenia); The Inst. of Metal Constructions, Ljubljana (Slovenia); The Milan Vidmar Electroinstitute, Ljubljana (Slovenia); Welding Inst., Ljubljana (Slovenia); NPP Krsko (Slovenia); Framatome, Paris (France); Westinghouse Electric Systems Europe S.A., Brussels (BE); Elmont d.o.o., Krsko (Slovenia); Inetec, Zagreb (Croatia); NUMIP d.o.o, Krsko (Slovenia); Q Techna d.o.o., Krsko (Slovenia); SIAP d.o.o., Krsko (Slovenia); 97.2 Megabytes; ISBN 961-6207-17-2; ; 2001; [9 p.]; International Conference Nuclear Energy in Central Europe 2001; Portoroz (Slovenia); 10-13 Sep 2001; Also available from Slovenian Nuclear Safety Administration, Zelezna cesta 16, Ljubljana (SI) or Nuclear Society of Slovenia, Jamova 39, Ljubljana (Slovenia); 14 refs., 6 figs.
; 2001; [9 p.]; International Conference Nuclear Energy in Central Europe 2001; Portoroz (Slovenia); 10-13 Sep 2001; Also available from Slovenian Nuclear Safety Administration, Zelezna cesta 16, Ljubljana (SI) or Nuclear Society of Slovenia, Jamova 39, Ljubljana (Slovenia); 14 refs., 6 figs.
[en] As a rule the continuum mechanics assumes homogeneity and isotropicity of the involved material. These assumptions are satisfactory for engineering load capability analysis and the engineering lifetime analysis of the parts that are significantly larger than the order of the material inhomogeneities and are only moderately deformed. However, the inhomogeneity of the material becomes more and more important when analyzing the initiation and propagation of cracks or load capability of the material in the vicinity of the limit strength. The inhomogeneity and anisotropicity of the material can be modeled by dividing the continuum into limited number of randomly shaped grains with variable material properties. However, this procedure is numerically quite demanding. The solution to this problem is envisioned by the development of methods that transfer the significant data on the inhomogeneity into the classical macroscopic models. The interesting method is the usage of the correlation length. The correlation length can be used to estimate the domain of influence of the individual inhomogeneities in the simulated aggregate of randomly oriented and shaped crystal grains. This article deals with several issues related to the calculation of correlation length from a 2D stress field.(author)
Source
Jencic, I.; Tkavc, M. (Nuclear Society of Slovenia (Slovenia)) (eds.); Nuclear Society of Slovenia, Ljubljana (Slovenia). Funding organisation: Inst. Jozef Stefan, Ljubljana (Slovenia); European Nuclear Society, Brussels (Belgium); Ministry of Education, Science and Sport of Slovenia, Ljubljana (Slovenia); Slovenian Nuclear Safety Administration, Ljubljana (Slovenia); Agency for Radwaste Management, Ljubljana (Slovenia); Faculty of Mechanical Engineering, Univ. of Ljubljana (Slovenia); Graduate Program Nucelar Engineering, Univ. of Ljubljana (Slovenia); Inst. of Metals and Technology, Ljubljana (Slovenia); Inst. of Metal Constructions, Ljubljana (Slovenia); NPP Krsko (Slovenia); Framatome, Paris (France); Westinghouse Electric Systems Europe S.A., Brussels (Belgium); Canberra-Packard Central Europe, Schwadorf (Austria); Elmont, Krsko (Slovenia); ENCONET International, Zagreb (Croatia); Inetec, Zagreb (Croatia); NUMIP, Krsko (Slovenia); Q Techna, Krsko (Slovenia); SIAP, Maribor (Slovenia); [602 p.]; ISBN 961-6207-20-2; ; 2002; [8 p.]; International Conference Nuclear Energy in Central Europe 2002; Kranjska Gora (Slovenia); 9-12 Sep 2002; Also available from Slovenian Nuclear Safety Administration, Zelezna cesta 16, Ljubljana (SI) or Nuclear Society of Slovenia, Jamova 39, Ljubljana (SI); 8 refs., 6 figs.
; 2002; [8 p.]; International Conference Nuclear Energy in Central Europe 2002; Kranjska Gora (Slovenia); 9-12 Sep 2002; Also available from Slovenian Nuclear Safety Administration, Zelezna cesta 16, Ljubljana (SI) or Nuclear Society of Slovenia, Jamova 39, Ljubljana (SI); 8 refs., 6 figs.
[en] During severe accidents the pressure boundary of reactor coolant system can be subjected to extreme loadings, which might cause failure. Reliable estimation of the extreme deformations can be crucial to determine the consequences of severe accidents. Important drawback of classical continuum mechanics is idealization of inhomogenous microstructure of materials. Classical continuum mechanics therefore cannot predict accurately the differences between measured responses of specimens, which are different in size but geometrical similar (size effect). A numerical approach, which models elastic-plastic behavior on mesoscopic level, is proposed to estimate minimum size of polycrystalline aggregate above which it can be considered macroscopically homogeneous. The main idea is to divide continuum into a set of sub-continua. Analysis of macroscopic element is divided into modeling the random grain structure (using Voronoi tessellation and random orientation of crystal lattice) and calculation of strain/stress field. Finite element method is used to obtain numerical solutions of strain and stress fields. The analysis is limited to 2D models.(author)
Source
Jencic, I.; Tkavc, M. (Nuclear Society of Slovenia (Slovenia)) (eds.); Nuclear Society of Slovenia, Ljubljana (Slovenia). Funding organisation: Inst. Jozef Stefan, Ljubljana (Slovenia); European Nuclear Society, Brussels (Belgium); Ministry of Education, Science and Sport of Slovenia, Ljubljana (Slovenia); Slovenian Nuclear Safety Administration, Ljubljana (Slovenia); Agency for Radwaste Management, Ljubljana (Slovenia); Faculty of Mechanical Engineering, Univ. of Ljubljana (Slovenia); Graduate Program Nucelar Engineering, Univ. of Ljubljana (Slovenia); Inst. of Metals and Technology, Ljubljana (Slovenia); Inst. of Metal Constructions, Ljubljana (Slovenia); NPP Krsko (Slovenia); Framatome, Paris (France); Westinghouse Electric Systems Europe S.A., Brussels (Belgium); Canberra-Packard Central Europe, Schwadorf (Austria); Elmont, Krsko (Slovenia); ENCONET International, Zagreb (Croatia); Inetec, Zagreb (Croatia); NUMIP, Krsko (Slovenia); Q Techna, Krsko (Slovenia); SIAP, Maribor (Slovenia); [602 p.]; ISBN 961-6207-20-2; ; 2002; [9 p.]; International Conference Nuclear Energy in Central Europe 2002; Kranjska Gora (Slovenia); 9-12 Sep 2002; Also available from Slovenian Nuclear Safety Administration, Zelezna cesta 16, Ljubljana (SI) or Nuclear Society of Slovenia, Jamova 39, Ljubljana (SI); 15 refs., 4 figs.
; 2002; [9 p.]; International Conference Nuclear Energy in Central Europe 2002; Kranjska Gora (Slovenia); 9-12 Sep 2002; Also available from Slovenian Nuclear Safety Administration, Zelezna cesta 16, Ljubljana (SI) or Nuclear Society of Slovenia, Jamova 39, Ljubljana (SI); 15 refs., 4 figs.
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