Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

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34757 Publications

Experimentelle Realisierung einer freien Flüssigmetalloberfläche

Gerbeth, G.

  • Other report
    Machbarkeitsstudie / Abschlußbericht für DARA GmbH, September 1995

Permalink: https://www.hzdr.de/publications/Publ-1802
Publ.-Id: 1802


Epitaxial aluminum carbide formation in 6H-SiC by high dose Al+ implantation

Stoemenos, J.; Pecz, B.; Heera, V.

Aluminum carbide precipitates are formed after Al ion implantation with dose 3x1017 cm-2 at 500°C into single crystalline 6H SiC. The aluminum carbide (Al4C3) precipitates are in epitaxial relation with 6H-SiC matrix, having the following orientation relation, [0001]6H-SiC//[11-20]Al4C3 and [11-20]6H-SiC//[11-20]Al4C3 , as transmission electron microscopy reveals. The aluminum carbide appears around the maximum of the Al depth distribution. Si precipitates were also detected in the same zone.

Keywords: high dose implantation; silicon carbide; phase formation

  • Applied Physics Letters 74 (1999) 2602

Permalink: https://www.hzdr.de/publications/Publ-1801
Publ.-Id: 1801


Unterstützung der ukrainischen Genehmigungs- und Aufsichtsbehörde bei der Einrichtung einer verbesserten betrieblichen Überwachung für das KKW Rovno (5. Realisierungsstufe)

Beyer, M.; Carl, H.; Kriks, J.

In Analogie zum Pilotprojekt für den 5. Block vom KKW Saporoshje - WWER-1000/W-320 - wurde für die beiden WWER-440/W-213 Blöcke vom KKW Rovno eine verbesserte betriebliche Überwachung eingerichtet. Dazu werden dem Vor-Ort-Inspektor am KKW Standort und der Aufsichtsbehörde in Kiew einmal pro Minute 55 aktuelle sicherheitsrelevante Parameter pro Block und 7 standortspezifische Parameter zur Erfassung und Bewertung mittels moderner technischer Mittel on-line zur Verfügung gestellt. Die zur Ausstattung des Arbeitsplatzes des Vor-Ort-Inspektors unbedingt benötigten Ausrüstungen wurden unter Berücksichtigung der aktuellen Anforderungen des KKW Rovno spezifiziert, beschafft und der ukrainischen Seite unentgeltlich überlassen. Bei Funktionstests Ende 1998/Anfang 1999 wurden Datensätze aus dem lokalen Rechnernetz des KKW Rovno fehlerfrei nach Kiew übertragen und auf einem Rechner im Informations- und Krisenzentrum in Form von Tabellen, Grafiken und Schemata dargestellt.

Keywords: betriebliche Überwachung von Kernkraftwerken; KKW Saporoshje; KKW Rovno; WWER-1000/W-320; WWER-440/W-213

  • Open Access Logo Wissenschaftlich-Technische Berichte / Forschungszentrum Rossendorf; FZR-260 Mai 1999
    ISSN: 1437-322X

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Permalink: https://www.hzdr.de/publications/Publ-1800
Publ.-Id: 1800


Unterstützung der ukrainischen Genehmigungsbehörde NARU beim Aufbau eines technischen Systems zur verbesserten betrieblichen Überwachung des KKW Saporoshje (4. Realisierungsstufe)

Beyer, M.; Carl, H.; Nowak, K.; Schumann, P.; Seidel, A.

Das vor zwei Jahren im KKW Saporoshje in Betrieb genommene System zur verbesserten betrieblichen Überwachung wurde an die Kiewer Zentrale der ukrainischen Aufsichtsbehörde angeschlossen. Dazu wurden die für den Anschluß und die Ausstattung dieser Zentrale in der ersten Ausbaustufe unbedingt erforderlichen technischen Mittel einvernehmlich spezifiziert, in Deutschland beschafft, im notwendigen Umfang erprobt, in die Ukraine überführt und dem Partner am Einsatzort unentgeltlich überlassen. Bei der Erprobung des Informationstransfers aus dem KKW Saporoshje in die Kiewer Zentrale wurde nachgewiesen, daß die von der ukrainischen Behörde gemietete Standleitung die notwendigen technischen Anforderungen erfüllt. Bei Funktionstests Mitte Januar 1998 wurden On-line-Daten aus dem Saporoger System der verbesserten betrieblichen Überwachung fehlerfrei nach Kiew übertragen.
Ferner sind der ukrainischen Seite zum Anschluß des KKW Rovno an die Kiewer Zentrale die gleichen technischen Mittel zur Verfügung gestellt worden.

Keywords: betriebliche Überwachung; KKW Saporoshje; KKW Rovno; ukrainische Kernkraftwerke; Schutzziele; Kontrollaufgaben; Betriebssicherheit von Kernkraftwerken; WWER-1000/W-320

  • Open Access Logo Wissenschaftlich-Technische Berichte / Forschungszentrum Rossendorf; FZR-259 Mai 1999
    ISSN: 1437-322X

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-1799
Publ.-Id: 1799


Einfluß von Orographie und Rauhigkeit auf das Windenergiepotential in ausgewählten Gebieten Sachsens

Freund, T.

  • Other report
    Diplomarbeit Technische Universität Dresden, Fakultät Maschinenwesen, Nr. 1549, 28.09.1995

Permalink: https://www.hzdr.de/publications/Publ-1798
Publ.-Id: 1798


Prozeß- und Anlagendiagnostik

Altstadt, E.; Carl, H.; Hessel, G.; Schmitt, W.; Schumann, P.; Weiß, F.-P.

  • Lecture (Conference)
    Ein Überblick über die Arbeiten des Institutes für Sicherheitsforschung, FZR, März 1995

Permalink: https://www.hzdr.de/publications/Publ-1797
Publ.-Id: 1797


Void Fraction Measurements in Transient Bubble Columns by Needle-Shaped Conductivity Probes

Prasser, H.-M.; Schlenkrich, C.

The presented work aimed at the experimental determination of rapidly changing void fraction distributions. The main idea was to apply arrays of needle shaped conductivity probes to a transient two-phase flow. The goal was to provide a time resolution in the range of tenth of a second. For a first application, a bubble column was investigated. The transient process was initiated by sudden changes of the flow rate of the injected gas (air). The experimental setup consisted in a vertical cylindrical column with an inner diameter of 0.24 m and a height of 2 m. In the bottom of the column a special injection plate was installed. About 200 steel cannulae served as injection nozzles. The injection nozzles were divided into two groups, which were fed from separate air distribution chambers. Both groups were equally distributed over the cross section of the column. This measure allowed to double or to halve the air flow rate without effecting the diameter of the generated bubbles, when the air supply of one of the distribution chambers is switched on and off. For the purpose of gas fraction measurement, 8 single wire probes were mounted on a movable probe comb. The diameter of the sensitive tip was 0.2 mm. The tran-sient void fraction distribution was measured on elevations of 0.4, 0.8 and 1.2 m. The transient process was initiated repeatedly by opening and closing the magnetic valve of the air supply system. After the changes, the air flow was kept constant for intervals of 10 s. The signals of the 8 void fraction probes were recorded and averaged over periods of 0.2 s for each realisation of the transient process. The data acquisition process was synchronised with the control of the magnetic valve. Afterwards, the obtained void fraction courses were superimposed. By repeating the transition process more than 400 times, an effective measuring time of at least 80 s for each void fraction value was achieved. The rapid change of the gas fraction pofiles and the gas fraction wave propagating through the column was measured.

  • Lecture (Conference)
    33rd European Two Phase Flow Group Meeting, Hertogenbosch, The Nederlands, 30 May - 02 June 1995
  • Contribution to proceedings
    33rd European Two Phase Flow Group Meeting, Hertogenbosch, The Nederlands, 30 May - 02 June 1995, paper F2

Permalink: https://www.hzdr.de/publications/Publ-1795
Publ.-Id: 1795


Ligth scattering by different liquid surfaces

Kolevzon, V.; Gerbeth, G.

  • Lecture (Conference)
    Lecture at: Fachtagung "Lasermethoden in der Strömungsmeßtechnik", Rostock, September 1995

Permalink: https://www.hzdr.de/publications/Publ-1794
Publ.-Id: 1794


Fördermöglichkeiten für Energieprojekte in Sachsen

Maletti, R.

  • Lecture (Conference)
    ILK-Symposium, Dresden, 12.01.1995

Permalink: https://www.hzdr.de/publications/Publ-1793
Publ.-Id: 1793


Comparative Study of a Boron Dilution Scenario in VVER Reactors

Ivanov, K.; Grundmann, U.; Mittag, S.; Rohde, U.

Subsequent studies have identified many scenarios which can lead to reactivity excursions due to boron dilution. The comparative study, presented in this paper, deals with the so-called "restart of the first reactor coolant pump" scenario and its reactor-dynamic consequences for the both VVER reactor types - VVER-440 and VVER-1000.
The transient simulations have been performed using the three-dimensional core dynamics code DYN3D. The DYN3D modeling features, including recent developments, as well as the cross-section generation methodology, involved in these calculations, are described. The analyzed accident scenario is outlined together with the assumptions made. The results of core response in this boron dilution accident for both VVER reactors have been compared within ranges, determined by the two reactivity values of interest: the criticaly limit and the reactivity initiated accident (RIA) limit.

  • Lecture (Conference)
    Specialist Meeting on Boron Dilution Reactivity Transients, State College, PA, USA, 18 - 20 October, 1995

Permalink: https://www.hzdr.de/publications/Publ-1792
Publ.-Id: 1792


Comparsions of Different Options for Coupling DYN3D-ATHLET

Grundmann, U.; Rohde, U.

  • Lecture (Conference)
    Meeting of AER Working Greoup D "VVER-Reactor Safety Analysis", VTT Energy, Espoo, Finland, 17 - 19 May, 1995

Permalink: https://www.hzdr.de/publications/Publ-1791
Publ.-Id: 1791


DYN3D-Results of 3rd Kinetic Benchmark of AER

Grundmann, U.; Rohde, U.

  • Lecture (Conference)
    Meeting of AER Working Group D "VVER-Reactor Safety Analysis", VTT Energy, Espoo, Finland, 17 - 19 May, 1995

Permalink: https://www.hzdr.de/publications/Publ-1790
Publ.-Id: 1790


High-Temperature Deformation and Burst Behaviour of Zirconium-Niobium Cladding Tubes Compared to Zircaloy

Erbacher, F. J.; Böhmert, J.

  • Lecture (Conference)
    11th ASTM Symposium on Zirconium in the Nuclear Industry, Garmisch-Patenkirchen, Sept. 11 - 14, 1995

Permalink: https://www.hzdr.de/publications/Publ-1789
Publ.-Id: 1789


Neutral Particle Balance in GDT with Fast Titanium Coating of the First Wall

Baryansky, P. A.; Krahl, S.; Noack, K.; Bender, E. D.; Ivanov, A. A.; Karpushov, A. N.; Murahtin, S. V.; Shikhovtsev, I. V.

  • Lecture (Conference)
    IEEE International Conference on Plasma Science, July 1995, Madison, Wisconsin, USA, Proceedings p. 200
  • Contribution to proceedings
    IEEE International Conference on Plasma Science, July 1995, Madison, Wisconsin, USA, Proceedings p. 200

Permalink: https://www.hzdr.de/publications/Publ-1788
Publ.-Id: 1788


Energy balance and stability of GDT plasma under intense neural beam heating

Anikeev, A. V.; et. al.; Noack, K.; Kumpf, H.; Otto, G.; Krahl, S.

  • Poster
    22nd EPS Conference on Controlled Fusion and Plasma Pysics, July 2 -7 1995, Bounemouth, UK, Proceedings Vol. 19C, Part IV, pp. 193-196
  • Contribution to proceedings
    22nd EPS Conference on Controlled Fusion and Plasma Pysics, July 2 -7 1995, Bounemouth, UK, Proceedings Vol. 19C, Part IV, pp. 193-196

Permalink: https://www.hzdr.de/publications/Publ-1787
Publ.-Id: 1787


Nutzung von Fluktuationssignalen und deren Auswertung mit Fuzzy-Logik / neuronalen Netzen zur Früherkennung von unerwünschten Betriebszuständen in chemischen Reaktoren

Weiß, F.-P.

  • Contribution to proceedings
    Workshop "Reaktionsführung bei chemischen Synthesen in techn. Maßstab mit Unterstützung durch moderne Methoden elektronischer Datenverarbeitung", Bonn, 24.05.1995, Proc. S. 76 - 84

Permalink: https://www.hzdr.de/publications/Publ-1786
Publ.-Id: 1786


Anwendung der Verbundprobentechnik zur Mehrfachprüfung von Proben mit Charpy-Geometry

Viehrig, H.-W.; Böhmert, J.

  • Contribution to proceedings
    Vortrags- und Diskussionstagung "Werkstoffprüfung '95", Bad Nauheim, Proc. S. 447 - 456

Permalink: https://www.hzdr.de/publications/Publ-1785
Publ.-Id: 1785


Rechnungen zum 1%-Leck an der Versuchsanlage PMK-2 mit dem Code ATHLET

Schäfer, F.; Krepper, E.

Die ungarische Versuchsanlage PMK-2 ist ein im Volumenmaßstab 1:2070 skaliertes Modell einer Reaktoranlage vom Typ WWER-440. Das Experiment „1%-Leck im kalten Strang" ist die Wiederholung eines Experiments von 1990 mit erweiterter
Instrumentierung - insbesondere Nadelsonden aus dem FZ Rossendorf. Das Leck befindet sich am oberen Teil des Ringspalts und hat einen Durchmesser von 1 mm. Für das Experiment wird angenommen, daß zur Notkühlung nur das Hochdrucknotkühlsystem (HPIS) verfügbar ist. Im Forschungszentrum Rossendorf wurden Nachrechnungen zu dem vorgestellten Experiment mit dem Code ATHLET Mod1.1 Cycle A durchgeführt. Wie der Vergleich von Rechnung und Experiment zeigt, werden alle Phänomene des Experiments in der Rechnung gut wiedergegeben. Insbesondere konnten die beobachteten Instabilitäten im Naturumlauf sehr gut modelliert werden.

  • Lecture (Conference)
    Proc. Jahrestagung Kerntechnik, Nürnberg, 16. - 18. Mai 1995, S. 79 - 82
  • Contribution to proceedings
    Proc. Jahrestagung Kerntechnik, Nürnberg, 16. - 18. Mai 1995, S. 79 - 82

Permalink: https://www.hzdr.de/publications/Publ-1783
Publ.-Id: 1783


Analysis of a Boron Dilution Accident for WWER-440 Combining the Use of the codes DYN3D and SiTAP

Rohde, U.; Elkin, I.; Kalinenko, V.

The existence of Main Isolating Valves (MIV) in the hot leg and the cold leg of each primary circuit loop is a special feature of WWER­440 type reactors. MIV's availability permits the disconnection of any loop during the work of all others, for example, in the case of leaks. The connection of a previous disconnected loop is a potential way for inducing a boron dilution accident, when infringements of rules and failure of technical systems occur. By combining the use of the codes SiTAP and DYN3D, more realistic boundary conditions were obtained than in previous investigations, were a plug of water with diluted boron concentration was supposed to travel through the core while keeping the other boundary conditions constant.

  • Lecture (Conference)
    Jahrestagung Kerntechnik, Nürnberg, 16. -18. Mai 1995, pp. 111 - 114
  • Contribution to proceedings
    Jahrestagung Kerntechnik, Nürnberg, 16. -18. Mai 1995, pp. 111 - 114

Permalink: https://www.hzdr.de/publications/Publ-1782
Publ.-Id: 1782


Convective, Absolute and Global Instabilities of Thermocapillary-Buoyancy Driven Flows in a Horizontal Liquid Layer

Priede, J.; Gerbeth, G.

  • Bulletin of the American Physical Society, Series II, Vol. 40, No. 12, 1995, pp. 1955 - 56
  • Lecture (Conference)
    Lecture at: American Pysical Society, 48th Annual Meeting of the Division of Fluid Dynamics, Irvine, 20.11.1995

Permalink: https://www.hzdr.de/publications/Publ-1781
Publ.-Id: 1781


Solaranlagen in Sachsen: eine Zwischenbilanz

Maletti, R.

  • Sonnenenergie und Wärmetechnik 1995, H. 5, S. 21

Permalink: https://www.hzdr.de/publications/Publ-1780
Publ.-Id: 1780


Energie-Förderung durch das Sächsische Staatsministerium für Wirschaft und Arbeit im Jahre 1994

Maletti, R.; Ulrich, M.

  • Energieanwendung 44 (1995), H. 4, S. 50

Permalink: https://www.hzdr.de/publications/Publ-1779
Publ.-Id: 1779


105 Mio. DM Zuschüsse - Energie-Förderung durch das SMWA

Maletti, R.; Ulrich, M.

  • IHK Wirtschaftsdienst 6 (1995), H. 6, S. 20

Permalink: https://www.hzdr.de/publications/Publ-1778
Publ.-Id: 1778


Post Test Calculations to 11% Break LOCA Experiments in the Integral Test Facility ISB-VVER Using the Thermalhydraulic Code ATHLET

Krepper, E.

The considered test was a break on the upper plenum with different modes of emergency core cooling. The reference case was the non-availability of emergency cooling. Injecting the emergency coolant into the cold leg, no increasing of rod cladding temperatures was observed, but natural circulation instabilities occurred. Injecting the cooling into the hot leg, the cooling situation was getting worse. Due to the injected cold emergency coolant, the fluid density in the discharge volume was enhanced and the break mass flow increased. The observed events in the test were reproduced by the code with good agreement

  • Contribution to proceedings
    Proc. Jahrestagung Kerntechnik, Nürnberg, 16. - 18. Mai 1995, pp. 83 - 87
  • Contribution to proceedings
    Conference "Thermopysical Aspects of WWER-Type Reactor Safety", Obninsk, Russia, Nov. 1995, Proc. Vol. 2, pp. 150 - 154

Permalink: https://www.hzdr.de/publications/Publ-1777
Publ.-Id: 1777


Supramolekulare Rezeptoren zur Anionen- und Kationenerkennung

Stephan, H.

Die Entwicklung supramolekularer Rezeptoren zur selektiven Komplexbildung von Anionen, Kationen und Neutralmolekülen ist von großem Interesse im Hinblick auf Anwendungen in der Analytik, Medizin und Technik. Die besondere Rolle der supramolekularen Chemie resultiert dabei aus der grundlegenden Überlegung, in biologischen Systemen genutzte Wirksysteme einer hochselektiven Erkennung und Bindung von Spezies sowie ihres Transportes mit Hilfe komplexer organisierter molekularer Funktionseinheiten auf die Lösung praxisrelevanter Probleme zu übertragen.
Möglichkeiten der selektiven Bindung und des Phasentransfers werden am Beispiel von ditopen Guanidiniumverbindungen für Oxoanionen sowie makrobi- bzw. -tricyclischer Carbonsäuren für Erdalkali-Ionen diskutiert.

  • Lecture (Conference)
    Institutskolloquium, FZ Karlsruhe/INE, 20. 05. 1999

Permalink: https://www.hzdr.de/publications/Publ-1776
Publ.-Id: 1776


Comparsion of Rod-Ejection Transient Calculations in Hexagonal-Z Geometry

Knigth, M. P.; Brohan, P.; Grundmann, U.; Rohde, U.; Finnemann, H.; Hüsken, H.

This Paper proposes a set of 3-dimensional benchmark rod ejection problems for a VVER reactor, based on the wellknown NEACRP PWR rod-ejection problems defined by Siemens/KWU. Predictions for these benchmarks deriving using three hexagonal-z nodal transient codes, the PANTER code of Nuclear Electric, the HEXTIME code of Siemens/KWU and the DYN3D code of FZ-Rossendorf are presented and compared.

  • Lecture (Conference)
    International Conference on Mathematics and Computations, Reactor Physics and Environment Analysis, Portland, Oregon/USA, April 30 - May 5, 1995, Proc. Vol. 2, pp. 1248 - 1258
  • Contribution to proceedings
    International Conference on Mathematics and Computations, Reactor Physics and Environment Analysis, Portland, Oregon/USA, April 30 - May 5, 1995, Proc. Vol. 2, pp. 1248 - 1258

Permalink: https://www.hzdr.de/publications/Publ-1775
Publ.-Id: 1775


Calculation of Neutron Noise Due to Control Rod Vibrations Using Nodal Methods for Hexagonal-Z-Geometry

Hollstein, F.; Meyer, K.

  • Contribution to proceedings
    Proc. Specialists Meeting on Reactor Noise, SMORN VII, Avignon, France, 19 - 23 June, 1995, Vol. 2, 12.1

Permalink: https://www.hzdr.de/publications/Publ-1774
Publ.-Id: 1774


Acoustic Leak Monitoring Using Neural Networks

Hessel, G.; Schmitt, W.; Weiß, F.-P.

  • Contribution to proceedings
    Proc. Annual Meeting on Nuclear Technology '95, Nürnberg, May 16 - 18 1995, pp. 231 - 234

Permalink: https://www.hzdr.de/publications/Publ-1773
Publ.-Id: 1773


COMPARATIVE ANALYSIS OF THE THIRD THREE­DIMENSIONAL DYNAMIC AER BENCHMARK PROBLEM WITH THE HELP OF THE CODE DYN3D

Grundmann, U.; Rohde, U.

The paper presented concerns a comparative analysis of the third three­dimensional dynamic benchmark of AER by using different options of the DYN3D code developed in the RC Rossendorf. The benchmark was defined as a control rod ejection accident in a VVER­440 core without reactor scram including the whole core thermal hydraulics. For the basic analysis with the help of DYN3D, some modifications of the code were made to meet the specifications of the benchmark (thermal properties of fuel and cladding, heat transfer in the gas gap, DNBR­correlation, hydrau lic model) as close as possible (case A). An additional analysis was carried out by using the standard version of DYN3D without any modifications. The conditions of the benchmark were approa ched only via input data (case B). In the first part of the paper, a description of the thermohy draulic model of DYN3D is given. Specific aspects concerning the modelling of the benchmark conditions are outlined. In the second part, a c!
omparative analysis of the results obtained by different DYN3D options is given. In addition to the demonstration of the applicability of the DYN3D code for solving the problem without any modifications, the goal of the investigations was to get a feeling for the sensitivity of the results with respect to ther mohydraulic modelling. The global parameters like reactivity, nuclear power, power to coolant and total mass flow rate were obtained with good agreement between the cases A and B. However, differences occur in detailled parameters, especially for the hot channel, where heat transfer crisis occurs.

  • Lecture (Conference)
    Fifth Symposium of AER, Dobogokö, Hungary, 15 - 19 October, 1995, Proc. pp. 329 - 343
  • Contribution to proceedings
    Fifth Symposium of AER, Dobogokö, Hungary, 15 - 19 October, 1995, Proc. pp. 329 - 343

Permalink: https://www.hzdr.de/publications/Publ-1772
Publ.-Id: 1772


Coupling the Advanced Thermohydraulic Code ATHLET with the 3D-Core Model DYN3D

Grundmann, U.; Lucas, D.; Rohde, U.

The coupling of advanced thermohydraulic codes with 3-dimensional neutron kinetic codes corresponds to the effort to replace conservative estimations by best estimate calculations. In the past advanced thermohydraulic codes and detailed core models were devoloped in most cases separatly. But it is often nesessary to consider the feedback between the coolant circuits and space dependent neutron kinetics. Examples for such cases are boron dilution accidents or inadverdant connection of a loop filled with cold water.
ATHLET is an advanced thermohydraulic code, developed by the German Gesellschaft fr Anlagen- und Reaktorsicherheit (GRS). Up to now only point kinetics and 1-dimensional neutron kinetics have been included. The DYN3D code, developed in the Research Centre Rossendorf (FZR) for the improvement of the simulation of reactivity initiated accidents in VVER-type reactors comprises 3- dimensional neutron kinetics, models for the thermohydraulics of the core including heat transfer from the fuel to the coolant, a fuel rod behavior model and a mixing model for the lower plenum.

  • Contribution to proceedings
    International Topical Meeting on VVER Safety, Prague, September 21 - 23, 1995, Proc. pp. 197 - 200
  • Poster
    Internat Topical Meeting on VVER Safety, Prague, September 21 -23, 1995

Permalink: https://www.hzdr.de/publications/Publ-1771
Publ.-Id: 1771


ASAXS-Investigations of Irradiation - Induced Precipitates in VVER-440-Type Reactor Pressure Vessel Steel with High Cu Content

Große, M.; Böhmert, J.; Brauer, G.; Eichhorn, F.

  • Contribution to external collection
    HASYLAB-Jahresbericht 1994, Hamburg, Januar 1995, S. 535

Permalink: https://www.hzdr.de/publications/Publ-1770
Publ.-Id: 1770


Experimental Investigation of Accidental Thermohydraulic Processes under Circuit Depressurization at ISB-VVER Safety Integral Test Facility

Gaschenko, M. P.; Prasser, H.-M.; Zippe, W.; et. al.

The paper presents the results of small-break loss-of-coolant tests carried out at the test facility ISB-VVER located in Elektrogorsk, Russia. Presently, it is the only operating integral model of the Sovjet type VVER-1000 reactor suitable for thermalhydraulic investigations. A small leak in the upper plenum of the reactor vessel was chosen for the test scenario. Different emergency core cooling (ECC) injection modes were applied and compared. It was show that the best results of ECC injection are obtained by a combined injection into both hot and cold leg. It is possible to maintain a reliable core cooling even without an injection by the safety injection tanks, which were assumed to be not available. The tests provided data suitable for code verification. Applied needle shaped void fraction probes delivered detailed information about the two-phase flow in the primary circuit.

  • Contribution to proceedings
    International Symposium on Two-Phase Flow Modelling and Experimentation, Rom, Italy, October 09 - 11, 1995, p. 537
  • Lecture (Conference)
    International Symposium on Two-Phase Flow Modelling and Experimentation, Rom, Italy, October 09 - 11, 1995

Permalink: https://www.hzdr.de/publications/Publ-1769
Publ.-Id: 1769


Detection of Irradiation-Inducted Microstructures Changes of VVER-Type RPV Steel by Small Angle Scattering Methods

Böhmert, J.; Große, M.

  • Contribution to proceedings
    Proc. International Topical Meeting on VVER-Safety, Prague, Sept. 1995, Session III, paper 7

Permalink: https://www.hzdr.de/publications/Publ-1768
Publ.-Id: 1768


Aufbau eines technischen Systems zur Verbesserung der betrieblichen Überwachung des KKW Saporoshje durch die staatliche Aufsichtsbehörde der Ukraine (in Russisch)

Beyer, M.; Carl, H.; Langer, L.; Nowak, K.; Seidel, A.; Schumann, P.; Tolksdorf, P.; Zschau, J.

Es wird die Struktur eines technischen Computersystems zur betrieblichen Überwachung der Zuverlässigkeit und Sicherheit ukrainischer KKW durch die staatlichen Aufsichtsbehörden beschrieben. Nach Auffassung der Autoren führt der Aufbau eines solchen Überwachungssystems, unabhängig von den Kontrollsystemen des Betreibers, zu einer schnellen, signifikanten und kostengünstigen Sicherheitserhöhung beim Betrieb der Reaktoranlagen vom Typ WWER-1000.

  • Atomnaja Technika sa Rubeshom, Heft 3 (1995), S.3

Permalink: https://www.hzdr.de/publications/Publ-1767
Publ.-Id: 1767


Ultraschallverfahren zur Messung des duktilen Rißfortschritts bei quasistatischer Dreipunktbiegung

Bergmann, U.; Böhmert, J.; Bergner, F.

Es wird ein Ultraschall-Laufzeit-Bewegungsverfahren vorgestellt, mit dem der duktile Rißfortschritt in 3-Punkt-Biegeproben kleiner Abmessungen gemessen werden kann. Das Verfahren erfüllt die Genauigkeitsanforderungen nach DIN 54120 und arbeitet quasikontinuierlich.

  • Contribution to external collection
    27. Vortragsveranstaltung des DVM-Arbeitskreises Bruchvorgänge, Köln, 14. - 15. Februar 1995, Proc. S. 177

Permalink: https://www.hzdr.de/publications/Publ-1766
Publ.-Id: 1766


Punktquelle-Punktempfänger-Modell zur Rißfortschrittsmessung mit Ultraschall

Bergner, F.; Bergmann, U.

  • Contribution to proceedings
    DVM Arbeitsgemeinschaft Werkstoffe, Tagung "Werkstoffprüfung", Bad Nauheim, 5. - 6. Dezember 1995, Proc. S. 419

Permalink: https://www.hzdr.de/publications/Publ-1765
Publ.-Id: 1765


Development of potential tumour imaging agents by 4-[18F]

Mäding, P.; Scheunemann, M.; Steinbach, J.; Bergmann, R.; Iterbeke, K.; Tourwe, D.; Johannsen, B.

The 4-[18F]fluorobenzoyl compounds of Neurotensin(8-13) (NT(8-13)) as well as [Arg8pseudo(CH2NH)Arg9]NT(8-13) were obtained by reaction of N-succinimidyl 4-[18F]fluorobenzoate ([18F]SFB) with these peptides in aqueous buffered solutions at pH 8.3 in r.c.y. of up to 43 % (related to [18F]SFB; decay-corrected) within 80 min (including HPLC purification). This is the first example for the specific radiolabelling of the alpha-amino group at the N-terminal arginine unit of peptides using [18F]SFB.

Keywords: Neurotensin(8-13); 18F-labelling; [18F]SFB; neurotensin receptor; pseudopeptide

  • Lecture (Conference)
    8th Conference of Central European Division of International Isotope Society, Bad Soden, 10.-11.6.1999
  • Abstract in refereed journal
    J. Labelled Compd. Radiopharm. 42 (1999) 987-1022

Permalink: https://www.hzdr.de/publications/Publ-1764
Publ.-Id: 1764


Bestimmung eines repräsentativen Wertes aus einer Folge von Meßwerten

Schuhmann, P.

  • Other report
    Fachbericht FWSF 02/96, August 1996

Permalink: https://www.hzdr.de/publications/Publ-1763
Publ.-Id: 1763


Spezifikation und Struktur der Altlastenbewertung mit dem Programmsystem XUMA-GEFA

Ferse, W.; Geiger, W.; Reitz, T.; u. a.

  • Other report
    Bericht Forschungszentrum Rossendorf, Institut für Sicherheisforschung, 1996

Permalink: https://www.hzdr.de/publications/Publ-1761
Publ.-Id: 1761


ECON - Ein System zur Lastmodellierung

Ferse, W.; Kruber, S.

  • Other report
    Bericht Forschungszentrum Rossendorf, Institut für Sicherheitsforschung, 1996

Permalink: https://www.hzdr.de/publications/Publ-1760
Publ.-Id: 1760


Herstellung und Prüfung von Charpy-V-Verbundproben

Viehrig, H.-W.

  • Lecture (Conference)
    Jahressitzung 1996 der DVM-Arbeitsgruppe "Instrumentierter Kerbschlagbiegeversuch", Merseburg, 13.09. 1996

Permalink: https://www.hzdr.de/publications/Publ-1759
Publ.-Id: 1759


Determination of Fracture Mechanical Values Using Charpy Size SENB Specimes and Correlation with Charpy-V Impact Test Results

Viehrig, H.-W.; Böhmert, J.; Richter, H.

  • Lecture (Conference)
    AMES TG1C Workshop on Property-Property Correlation, Petten, 1 - 2 Oct. 1996

Permalink: https://www.hzdr.de/publications/Publ-1758
Publ.-Id: 1758


Dampfgehaltsmessungen bei der Druckentlastung von Ethanol

Prasser, H.-M.; Steinkamp, H.; Wehmeier, G.

Bei Druckentlastungsexperimenten mit Ethanol an einem Versuchsreaktor von 105 l Volumeninhalt der Hoechst AG wurden nadelförmige Leitfähigkeitssonden zur Messung von Dampfgehalt, Gasgeschwindigkeit und Blasengröße eingesetzt. Es wurden insgesamt 5 Sonden im oberen Bereich des Reaktors auf verschiedenen Höhenmarken eingebaut. Hiervon dienten 4 Einpunktsonden ausschließlich der Dampfgehaltsmessung. Die Spitze der Sonde steht in Kontakt mit der elektrisch leitenden Flüssigkeit. Durch Versorgung mit einer kleinen Gleichspannung wird ein Strom hervorgerufen, der unterbrochen wird, wenn die Sondenspitze sich in einer Dampfblase befindet. Der Gasgehalt des zweiphasigen Gemisches wird aus der Integration der Kontaktzeit mit der Gasphase bezogen auf die gesamte Meßzeit berechnet. Bei einer weiteren Sonde handelte es sich um eine Zweipunktsonde, die zusätzlich die Bestimmung der Geschwindigkeit der Dampfblasen erlaubt. Dies geschieht durch Auswertung der Zeit, die zwischen dem Eintreffen der Blasen an deren vorderer Elektrode und dem Umschließen der hinteren Elektrode verstreicht. Mit dem bekannten axialen Abstand der zwei Elektroden wird hieraus die Geschwindigkeit berechnet. Durch Kombination der Geschwindigkeitsinformation mit der Dauer des Blasenkontakts wurden Blasengrößen bestimmt. Es konnte gezeigt werden, daß Leitfähigkeitssonden trotz des geringen elektrischen Leitwerts von Ethanol benutzt werden können. Es wurden insgesamt 4 Versuche mit einem Anfangsdruck von maximal 0,98 MPa durchgeführt. Bei der Druckentlastung kam es zum Aufsieden des Behälterinhalts und zum Auftreten eines Zweiphasengemischs. Durch das Anwachsen des Dampfgehalts an der Entlastungsöffnung kommt es zur Beschleunigung des Druckabbaus, woraufhin der Dampfgehalt an den Sondenpositionen zunimmt. Die Sonden registrieren schließlich infolge der Verringerung des Behälterinhalts nacheinander den Durchgang Gemischspiegels. Mit Hilfe der Zweipunktsonde wurden Blasengrößen bestimmt. Durch den zufälligen Charakter der Berührung Blase - Sonde werden Sehnenlängen der Blasen und damit deren Größe bestimmt. Die Meßwerte lassen den Schluß zu, daß eine heterogene Blasenströmung mit einem hohen Anteil von Großblasen vorgelegen hat. Mit dem eindimensionalen Rechenmodell BLDN konnten nach Implementierung eines Stoffdatensatzes für Ethanol die gemessenen Gasgehaltsverläufe gut reproduziert werden.

  • Lecture (Conference)
    42. Sitzung des DECHEMA/GVC-Arbeitsausschusses "Sicherheitsgerechtes Auslegen von Chemieapparaten", Rossendorf, 15. - 16.10. 1996

Permalink: https://www.hzdr.de/publications/Publ-1757
Publ.-Id: 1757


BLDN - Modell zur Berechnung der axialen Dampfgehaltsverteilung bei der Druckentlastung

Prasser, H.-M.

Das Programm BLDN (BLow-DowN) basiert auf einem eindimensionalen Strömungsmodell zur Beschreibung der axialen Dampfgehaltsverteilung in einem stehenden zylindrischen Druckbehälter bei einem Abblasevorgang unter Beschränkung auf eine Komponente. Zur Beschreibung der axialen Dampfgehaltsverteilung werden für Dampf und Flüssigkeit die gemeinsamen Massen- und Energieerhaltungsgleichungen gelöst. Es wird von thermodynamischem Gleichgewicht ausgegangen. Die zum Abschluß des Systems notwendige Phasendriftbeziehung wird in Form einer Phasendifferenzgeschwindigkeit als Funktion vom Dampfgehalt und den Stoffwerten verwendet. Mit Hilfe dieser Beziehung werden die Geschwindigkeiten beider Phasen gekoppelt. Der Impuls des Strömungsmediums wird vernachlässigt. Die Impulsgleichungen bleiben deshalb unberücksichtigt. Im Druckgefäß wird lediglich ein hydrostatisches Druckprofil berechnet, mit dessen Hilfe die Meßwerte von Differenzdruckgebern simuliert werden können. Die Anwendbarkeit des Modells ist wegen der fehlenden Impulsgleichungen auf kleine Lecks beschränkt. Der trägheitsbedingte Druckimpuls, der auf die Differenzdruckgeber in den ersten Zehntelsekunden des Aufsiedens wirkt, wird nicht nachgebildet. Die Verbindung zwischen Leckmassenstrom und Druckabfallgeschwindigkeit wird durch integrale Massen- und Energiebilanzen hergestellt, die über den gesamten Behälter gebildet werden. Je nach Option wird der Druckabfall aus dem Leckmassenstrom (BLDN) oder umgekehrt (BLDN_PV) berechnet. Der Wärmestrom, der von den Behälterwänden infolge des Absinkens der Fluidtemperatur während des Druckentlastungsvorgangs ausgeht, wird mit einer Wärmeübergangszahl für gesättigtes Sieden berechnet. Die momentane Temperatur an der Behälterinnenwand wird durch analytische Lösung der Wärmeleitungsgleichung in der Wand bestimmt. Der Verlauf des Massenhöhenstands (collapsed level) wird durch Integration des Leckmassenstroms bestimmt. Der Gemischspiegel wird unter Vorgabe des jeweiligen Massenhöhenstands aus der axialen Dampfgehaltsverteilung ermittelt. Bei der Berechnung des Dampfgehalts am Leckort wird die Lage des Gemischspiegels und die Höhe der Sprudelschicht (Schaumzone) berücksichtigt. Letztere bildet sich am Übergang von der Blasenströmung zum Dampfraum heraus.

  • Lecture (Conference)
    42. Sitzung des DECHEMA/GVC-Arbeitsausschusses "Sicherheitsgerechtes Auslegen von Chemieapparaten", Rossendorf, 15. - 16.10. 1996

Permalink: https://www.hzdr.de/publications/Publ-1756
Publ.-Id: 1756


Diskusion eines Kriteriensystems zur Bewertung der Ansiedlung von Industrie in urbanen Gebieten

Polte, A.

  • Lecture (Conference)
    KOVERS-Seminar, ETH Zürich, 28. November 1996

Permalink: https://www.hzdr.de/publications/Publ-1755
Publ.-Id: 1755


Beiträge zur Einführung der Positronen-Emissions-Tomographie bei der Schwerionen-Tumortherapie

Hinz, R.

Today tumour diseases are the second most cause of death in Western countries. But only 45 percent of the patients can be cured by the established treatment methods. The further improvement of the these forms of therapy and the development of new therapeutical approaches is urgent. A substantial proportion of the patients could benefit from particle therapy with heavy ions. Beams of accelerated heavy ions (e.g. carbon, nitrogen or oxygen) with an energy between 70 and 500 AMeV are characterised by physical and biological properties superior to the radiation used in conventional radiotherapy (photons, electrons, neutrons). They form a sharp dose maximum (Bragg peak) shortly before coming to rest and are scarcely scattered while penetrating tissue. Because of the increased relative biological efficiency of these ions in the Bragg peak region they are suitable for precision therapy of deeply seated, compact, radioresistant tumours near to organs at risk. For a safe application of heavy ions close to radiosensitive structures (brain stem, optical nerves, eyes) an in situ monitoring of the therapy is desirable. This can be accomplished by positron emission tomography (PET), since fragmentation reactions between the stable ions of the therapy beam and the atomic nuclei of the tissue generate a dynamic spatial distribution of positron emitters (ß+-emitters) that can be observed by a positron camera. At the Gesellschaft für Schwerionenforschung in Darmstadt a medical treatment site for heavy ion therapy has been established in co-operation with the Radiologische Universitätsklinik Heidelberg, the Deutsches Krebsforschungszentrum Heidelberg and the Forschungszentrum Rossendorf. The fast variation of the beam energy in conjunction with the vertical and horizontal beam deflection by dipole magnets (raster scanning) allows the three-dimensional, strictly tumour shape conformed irradiations. The dual head positron camera BASTEI has been installed at the treatment place in order to measure the decay of the ß+-emitters during the irradiation and a few minutes after. Two ways to verify the treatment plan by PET are possible.
  • In critical situations when the beam has to pass very heterogeneous structures and radiosensitive organs are situated in the direction of the beam behind the Bragg peak, a monoenergetic low dose beam pulse can be applied to the patient. The range of the particles can be derived from the simultaneous PET scan, so that the correct range calculation of the treatment plan is ensured before the therapeutical irradiations are started.
  • During each fraction of the heavy ion therapy the ß+-activity distributions are measured routinely. Based on the time course of every individual therapy fraction the expected ß+-emitter distribution is computed. By comparing the simulated with the measured data the precision of the dose deposition of this single therapy fraction is assessed. If a considerable disagreement between these two distributions is revealed by this comparison the treatment plan has to be modified before proceeding with the following therapy fraction.
The PET data are recorded in list mode, together with a protocol of important accelerator parameters of the irradiation. Because of the half-lives of the most abundant ß+-emitters 11C and 15O it is on principle impossible to obtain the precise position of the 12C therapy beam by PET during the irradiation. ...

Keywords: PET; Schwerionen-Therapie; bildgebende Verfahren

  • Other report
    Dissertation TU Dresden, Fakultät Elektrotechnik
  • Open Access Logo Wissenschaftlich-Technische Berichte / Forschungszentrum Rossendorf; FZR-286 Februar 2000
    ISSN: 1437-322X

Downloads:

Permalink: https://www.hzdr.de/publications/Publ-1754
Publ.-Id: 1754


Analytical Model to Calculate the Transfer Functions of Neutron Noise coused by Random Pendulum Motions of a VVER-440 Control Element

Meyer, K.; Hollstein, F.

  • Lecture (Conference)
    IMORN-26, Piestany, May 27 - 29, 1996

Permalink: https://www.hzdr.de/publications/Publ-1753
Publ.-Id: 1753


3D Neutronic Codes coupled with Thermal-hydraulic System Codes for PWR, BWR and VVER reactors

Langenbuch, S.; Lizorkin, M.; Rohde, U.; Velkov, K.

  • Lecture (Conference)
    OECD/CSNI Workshop on Transient Themal-Hydraulics and Neutronic codes Requirements, Annapolis, Md (USA), November 5 - 8, 1996

Permalink: https://www.hzdr.de/publications/Publ-1752
Publ.-Id: 1752


Die Praxis-Anwendung der Entscheidungsanalyse für die Bewertung und Auswahl optimaler Sanierungskonzepte

Kruber, S.

  • Lecture (Conference)
    KOVERS-Seminar, ETH Zürich, 28. September 1996

Permalink: https://www.hzdr.de/publications/Publ-1751
Publ.-Id: 1751


Identifikation und diagnostische Überwachung von Zweiphasenströmungen in Rohleitungen

Kossok, N.; Prasser, H.-M.; Schütz, P.

Die Analyse von Ultraschall-Transmissionssignalen zeigte, daß eine laufende Identifikation des Stromungszustandes in Rohrleitungen durch einen Aufbau von Relationen zwischen den physikalischen Parametern einer Zweiphasenströmung und den charakteristischen Mustern gemessener Signale möglich ist. Auf dieser Grundlage werden Ergebnisse eines Systems, welches aus einer Ultraschall-Meßeinheit, einer Datenbankeinheit und einer Mustererkennungseinheit besteht, vorgestellt. Dieses System liefert am Ausgang vier Parameter: einen Identifikator fur die Strömungsform, die separaten Volumenströme der flüssigen und der gasformigen Phase und den abgeleiteten Gasgehalt. Der Parametersatz dient als einer von mehreren Eingabensätzen fur das übergeordnete Überwachungs- oder Diagnosesystem. Die mit diesem System erzielten Erkennungsraten liegen zwischen 87 % und 94%.

  • Lecture (Conference)
    IV. Kolloquium "Technische Diagnostik", Dresden, 15. 03. 1996

Permalink: https://www.hzdr.de/publications/Publ-1750
Publ.-Id: 1750


Entspannungsverdampfung während der Druckentlastung von Co2 aus dem überkritischen Anfangszustand

Gebbeken, B.; Eggers, R.; Prasser, H.-M.

Druckentlastungsexperimente der TU Hamburg/Harburg von überkritischem CO2 aus einem Druckbehälter werden vorgestellt. Dabei wurden mit einer Gamma-Durchstrahlung axiale Dampfgehaltsprofile im System CO2-flüssig und CO2-gasförmig sowie Druck- und Temperaturverläufe gemessen. Die Experimente, insbesondere die lokalen Gasgehalte, können durch das Programm BLDN des FZR mit Erfolg nachgerechnet werden, wobei verschiedene Driftansätze auf ihre Anwendbarkeit auf CO2 hin überprüft wurden.

  • Lecture (Conference)
    GVC-Fachausschuß Mehrphasenströmungen, Vortrag 2.27, Lahnstein, 06. - 08. März 1996

Permalink: https://www.hzdr.de/publications/Publ-1749
Publ.-Id: 1749


Experiments on thermocapillary migration of drops in a drop tower

Galindo, V.; Teuner, M.; Gerbeth, G.

  • Lecture (Conference)
    Escuela de Fisico-Quimica de Fluidos: Drops, bubbles and film, Santander, September 9 - 13, 1996

Permalink: https://www.hzdr.de/publications/Publ-1748
Publ.-Id: 1748


Die Anwendung der Entscheidungsanalyse zur Unterstützung öffentlicher Entscheidungen

Ferse, W.

  • Lecture (Conference)
    KOVERS-Seminar, ETH Zürich, 28. November 1996

Permalink: https://www.hzdr.de/publications/Publ-1747
Publ.-Id: 1747


Die Struktur des wissensbasierten Systems XUMA-GEFA

Ferse, W.

  • Lecture (Conference)
    Seminar der Anwenderländer des Baden-Württemberger Altlastenbewertungssystems, Bad Schandau, August 1996

Permalink: https://www.hzdr.de/publications/Publ-1746
Publ.-Id: 1746


SANS Investigations of the Irradiation-Caused Structural Damages in VVER-440-Type Reactor Pressure Vessel Steels

Böhmert, J.; Große, M.; Nitzsche, P.

Small-angle neutron scattering (SANS) experiments were performed at KWS2 facility of the KFA Jülich for investigating the defect structures, which are produced by neutron irradiation in Russian Cr-Mo-V alloyed reactor pressure vessel steel. Irradiation and post-irradiation annealing considerably change both SANS intensity and its course in the Guinier plot, which was analysed by the Glatter method. As a rule, bimodal size distribution functions were found with a first maximum at a radius of 1-2 nm and a second maximum at 6-8 nm. Irradiation increases the first maximum annealing reduces it.

  • Lecture (Conference)
    1st European Conference on Neutron Scattering, Interlaken (Switzerland), Oct. 1996

Permalink: https://www.hzdr.de/publications/Publ-1745
Publ.-Id: 1745


Second Experimental studies on diefferent phenomena at freee metal surface

Bojarevics, A.; Gelfgat, Y.; Gerbeth, G.; Cramer, A.

  • Lecture (Conference)
    European Symposium Fluids in Space, Neapel, April 22 - 26, 1996

Permalink: https://www.hzdr.de/publications/Publ-1744
Publ.-Id: 1744


A novel experimental technique to study different phenomena at a free liquid metal surface

Bojarevics, A.; Gelfgat, Y.; Gerbeth, G.

  • Lecture (Conference)
    The 125th TMS meeting, Experimental methods in Microgravity, Anaheim (USA), February 4 - 8, 1996

Permalink: https://www.hzdr.de/publications/Publ-1743
Publ.-Id: 1743


Ein FE-Schwingungsmodell zur Unterstützung der Diagnose von Reaktoren des Typs WWER

Altstadt, E.; Grunwald, G.; Weiß, F.-P.

  • Lecture (Conference)
    IV. Kolloquium "Technische Diagnostik", Dresden, 15. März 1996

Permalink: https://www.hzdr.de/publications/Publ-1742
Publ.-Id: 1742


Sichere Bewertung des Materialzustandes in Altanlagen durch Probenkonstitution

Viehrig, H.-W.; Böhmert, J.

  • Lecture (Conference)
    INNOMATA 1996, 2. Ausstellungstagung für Materialtechnologie und Werkstoffanwendung, Dresden, Mai 1996, Comp. S. 323
  • Contribution to proceedings
    INNOMATA 1996, 2. Ausstellungstagung für Materialtechnologie und Werkstoffanwendung, Dresden, Mai 1996, Comp. S. 323

Permalink: https://www.hzdr.de/publications/Publ-1741
Publ.-Id: 1741


Proposed Post Service Investigation on Decommissioned Greifswald Units

Valo, M.; Böhmert, J.; von Estorff, U.; Törrönen, K.

The first four Greifswald reactor units belong to the WWER 440/230 reactor family and they are the only ones permanently shut-down. The status of the WWER 440 units as concerns the plant specific material data is shortly described in the paper. The lack of material data is a real problem of the 230 model reactors and the high lead factor in the surveillance irradiations of the more modern 213 units is an essential uncertainty in the safety assessment of the units. In addition most aof the 230 units have been and some of the 213 units will be annealed. Greifswald units are fully representative WWER 440 units and they represent irradiated, irradiated-annealed and irradiated-annealed-reirradiated material conditions. In this paper a basic material research programme is proposed, which can greatly support the operating WWER units.

  • Lecture (Conference)
    Proc. of the CSNI/CEC Workshop on Aged and Decommissioned Material Collection and Testing for Structural Integrity Purposes, Mol (Belgium), June 1995, OECD/GD !1996) 10, pp. 131 - 146
  • Contribution to proceedings
    Proc. of the CSNI/CEC Workshop on Aged and Decommissioned Material Collection and Testing for Structural Integrity Purposes, Mol (Belgium), June 1995, OECD/GD !1996) 10, pp. 131 - 146

Permalink: https://www.hzdr.de/publications/Publ-1740
Publ.-Id: 1740


A numerical 3d stability analysis of the MHD cylinder wake flow

Shatrov, V.; Mutschke, G.; Gerbeth, G.

In the present paper the stability of the time-dependent, three-dimensional, incompressible flow around a circular cylinder exposed to an external magnetic field is investigated numerically. We perform a linear 3d stability analysis of the 2d flow being either steady or quasiperiodic as known from previous work. By monitoring the time evolution of the integral energy of the 3d disturbances in the computational domain we decide whether the flow is globally unstable or stable. The results are compared and validated with recent results for the purely hydrodynamic problem. We restrict the analysis to a magnetic field being aligned with the oncoming flow. For this case we numerically confirm the general result of Hunt that in the (Re, N)-plane parameter regions above the 2d-neutral stability curve exist where the flow is 3d-unstable but 2d stable (steady) because the magnetic field acts in a different way on 2d and 3d instabilities.

  • Contribution to proceedings
    8th Beer-Sheva International Seminar on MHD flows and turbulence, Jerusalem, February 25 - 29, 1996, to appear in: Progress in Astronautics and Aeronautics, Ed.: Branover, H; Unger, Y; Washington

Permalink: https://www.hzdr.de/publications/Publ-1739
Publ.-Id: 1739


On the role of thermal boundary conditions in the instability of thermocapillary driven low-Prandtl-number convection

Priede, J.; Gerbeth, G.

  • Contribution to proceedings
    Proc. of the Second European Symposium Fluids in Space, Neapel, April 22 - 26, 1996, pp. 508 - 511

Permalink: https://www.hzdr.de/publications/Publ-1738
Publ.-Id: 1738


Spektrale Simulation in einer Blasensäule

Prasser, H.-M.; Thess, A.

Die Beschreibung der Strömungsfelder in Blasensäulen ist Grundlage für die Bestimmung der Stoff und Wärmetransportvorgänge. Dabei steht die Untersuchung der instationären Zirkulationsbewegung der flüssigen Phase im Mittelpunkt, die mit Hilfe spektraler Verfahren berechnet wird. Das Modell wird für ein zweidimensionales rechteckiges Gebiet in kartesischen Koordinaten (Strömungsbox) aufgestellt. Hierbei wird die nichtlineare Wirbeltransportgleichung durch den spektralen Ansatz für free-slip Randbedingungen gelöst, der die Wirbeltransportgleichung in ein System von gekoppelten, nichtlinearen gewöhnlichen Differentialgleichungen umwandelt, die die zeitliche Entwicklung der Fourier-Koeffizienten an,m(t) und damit die Evolution der einzelnen Wirbelmoden beschreiben. Die nichtlinearen Terme werden durch explizite Berechnung der Konvolutionssummen gemäß dem traditionellen Galerkin-Verfahren ermittelt. Für die diskrete Phase wird angenommen, daß das Gas durch eine bestimmte Anzahl von Düsen im Boden der Säule eingespeist wird. Es werden Blasen mit konstantem Durchmesser angenommen, die diskret modelliert werden, d.h. ihre momentanen Koordinaten werden durch Partikeltracking ermittelt. Die Momentangeschwindigkeit einer Blase ergibt sich aus der Vektorsumme der Geschwindigkeit der Flüssigkeit am Ort der Blase und der Relativgeschwindigkeit der Blase als Folge des lokalen Druckgradienten. Die Blasenkoaleszenz wird nicht berücksichtigt. Die Blasen verlassen das Strömungsgebiet bei Erreichen des oberen Randes. Es wird angenommen, daß jede einzelne Blase eine Kraftwirkung auf die Flüssigkeit verursacht, die in der Wirbeltransportgleichung im Volumenkraftterm berücksichtigt wird. Hierbei wird näherungsweise eine Dirac-Funktion angenommen, deren Stärke der Auftriebskraft entspricht. Die Kraftwirkungen aller Blasen im Strömungsgebiet werden addiert. Rechenergebnisse für eine rechteckige Strömungsbox mit Gaseinspeiusung über eine oder mehrere im Boden angeordnete Kanülen zeigen die Anregung von Wirbeln, die zu einer Deformation der Blasentrajektorie führen. Dabei treten typische typische instationäre Zirkulationszellen auf. Wichtig ist, daß die spektralen Verfahren auch bei Begrenzung auf wenige Moden in der prinzipiell Lage sind, großräumige Zirkulationszellen in der Blasensäule zu beschreiben. Klassische Verfahren erfordern demgegenüber stets eine feine räumliche Nodalisierung. Hieraus folgt, daß mit spektralen Verfahren grundlegende Erkenntnisse bei Anwendung von Wenigmodenmodellen mit geringem Rechenaufwand erzielt werden können.

  • Contribution to proceedings
    DECHEMA-Jahrestagung '96, Wiesbaden, 21. - 23. Mai 1996, Band II, S. 308 - 309
  • Lecture (Conference)
    DECHEMA-Jahrestagung '96, Wiesbaden, 21. - 23. Mai 1996

Permalink: https://www.hzdr.de/publications/Publ-1737
Publ.-Id: 1737


Experiences with the parallel version of MCNP-4A on a SUN workstation network and on the CONVEX SPP-1000system

Noack, K.; Rogov, A. D.

  • Lecture (Conference)
    Proc. of the International Conference on Computation Modelling and Computing in Physics, Dubna, Russia, Sept. 16 - 21, 1996, p. 52
  • Contribution to proceedings
    Proc. of the International Conference on Computation Modelling and Computing in Physics, Dubna, Russia, Sept. 16 - 21, 1996, p. 52

Permalink: https://www.hzdr.de/publications/Publ-1736
Publ.-Id: 1736


Burnup and Rod Worth Calculations for Paks-2 Using the Code DYN3D with two Different Group Data Libraries

Mittag, S.

The AER benchmark problem defined by L. Korpas et al. for the calculation of VVER­440 control rod worth was solved by using the code DYN3D in 1994. The KAB MAGRU library, generated by the NESSEL code was used then as a source of macroscopic group data. Now DYN3D calculations have been repeated with a new group data library created in EGP Prague by the KASSETA code. Burnup calculations have been carried out for the cycles 4 to 7 of Paks­2 NPP. The critical boron concentrations as a function of time, calculated with both data libraries, were compared to the values measured in the progress of the cycles. The results are in good agreement. The comparison of the fuel­element averaged burnup values after calculating 4 full cycles shows a maximum deviation of about 2 percent between the two data libraries. Concerning the control rod efficiencies the relative deviation is higher. This is due to relatively great differences in the macroscopic group data produced for the control rod!
s by NESSEL and KASSETA. The deviations between results calculated by the same code with different group data indicate that using different data libraries by the AER benchmark participants may be a main reason for the high differences between their results.

  • Contribution to proceedings
    Proc. of the 6th Symposium of AER, Kirkkonummi (Finland), 23 - 26 September 1996, p. 499

Permalink: https://www.hzdr.de/publications/Publ-1735
Publ.-Id: 1735


Experimental and Calculation Characterization of Irradiation Facility KORPUS

Markina, N. V.; Riasanov, D. K.; Tellin, A. I.; Lichadeev, V. V.; Pavlov, V. V.; Tsikanov, V. A.; Brodkin, E. B.; Egorov, A. L.; Zaritsky, S. M.; Bars, B.; Stephan, I.; Voorbrack, W.; Nolthenius, H.; Ait Abderrahim, H.

The preliminary results of the activation measurements and calculations in the different points of the irradiation facility KORPUS are shortly described and analyzed. The tasks of these investigations are the dosimetry characterization of the facility and creation of the international dosimetry benchmark.

  • Contribution to proceedings
    Proc. 9th International Symposium on Reactor Dosimetry, Prague, Sept. 2 - 6, 1996

Permalink: https://www.hzdr.de/publications/Publ-1734
Publ.-Id: 1734


Results Three-Dimension Hexagonal Dynamic Benchmark Problems for VVER Type Reactors

Kyrki-Rajamäki, R.; Grundmann, U.; Kereszturi, A.

A series of three-dimensional hexagonal dynamic benchmark problems have been defined during 1992 - 1994 in the international VVER cooperation forum AER. All three problems are asymetric control rod ejections from low power level in a realistic VVER-440 core with fuel of three different enrichments and given nuclear data. However, the complexity of the models needed in the benchmark solutions is continuosly increased beginning from pure reactor kinetics and extending to real core thermal hydraulics modelling with a hot channel and DNB effects. Solutions calculated by six organizations with five different mostly nodal codes are included. Agreement of neutron kinetics results is very good. More differneces are induced by thermal hydraulics modelling.

  • Contribution to proceedings
    Proc. of the Int. Conference on the Physics of Reactors PHYSOR '96, Mito (Japan), 16. - 20. 09. 1996, pp. J - 229 - J - 238

Permalink: https://www.hzdr.de/publications/Publ-1732
Publ.-Id: 1732


Ligth scattering analysis of waves destabilization at a liquid gallium surface

Kolevzon, V.; Gerbeth, G.

  • Contribution to proceedings
    Proceedings of the Second European Symposium Fluids in Space, Neapel, April 22 - 26, 1996, pp. 447 - 453

Permalink: https://www.hzdr.de/publications/Publ-1731
Publ.-Id: 1731


Anwendungsmöglichkeiten neuronaler Netze zur Früherkennung in Chemieanlagen

Hessel, G.; Schmitt, W.; van der Vorst, K.; Weiß, F.-P.; Neumann, J.; Schlüter, S.

  • Contribution to proceedings
    DECHEMA-Jahrestagung '96, Wiesbaden, 21. - 23. MAi 1996, Tagungsband II, S. 86 - 88

Permalink: https://www.hzdr.de/publications/Publ-1730
Publ.-Id: 1730


Anwendung neuronaler Netze zur akustischen Leckortung und Leckratenabschätzung

Hessel, G.; Schmitt, W.; van der Vorst, K.; Weiß, F.-P.

  • Contribution to proceedings
    IV. Kolloquium "Technische Diagnostik", Dresden, 14./15 .03. 1996, Tagungsband S. 203 - 211

Permalink: https://www.hzdr.de/publications/Publ-1729
Publ.-Id: 1729


Comparsion between Neural Networks and Fuzzy Classification for Acoustic Leak Monitoring

Hessel, G.; Schmitt, W.; van der Vorst, K.; Weiß, F.-P.

The capability of neuronal networks and fuzzy pattern classification is compared using measuring data that originate from experiments on leakage detection. The classification procedures are to localize simulated acoustically active leaks and to determine the leak rate. Different types of neural networks are needed to perform these two tasks. Alternatively fuzzy classifiers can be applied. Concerning the generalization capability, i.e. the recognition of positions and leak rates that could not be trained, neural networks clearly superior over fuzzy classification.

  • Lecture (Conference)
    Proc. of the Fourth European Congress on Intelligent to Techniques and Soft Computing EUFIT '96, Aachen, September 2-5, 1996, pp. 1492 - 1496
  • Contribution to proceedings
    Proc. of the Fourth European Congress on Intelligent to Techniques and Soft Computing EUFIT '96, Aachen, September 2-5, 1996, pp. 1492 - 1496

Permalink: https://www.hzdr.de/publications/Publ-1728
Publ.-Id: 1728


The Reactor Code DYN3DR - Transient Calculations of NEACRP Benchmarks for PWR and BWR

Grundmann, U.; Rohde, U.

The new version DYN3DR of the code DYN3D/M2, initially designed for hexagonal-z
core analysis, has been developed for reactor cores with rectangular fuel assemblies.
The neutronic part of the two code versions can be used for steady-state and transient
calculations of reactor cores. The neutron kinetics in both versions is based on the
solution of the two group neutron diffusion equation by nodal methods being different
for hexagonal and rectangular geometry. The thermal-hydraulic module FLOCAL
simulating the two phase flow of coolant and the fuel rod hehaviour is used in both
versions. The accuracy of DYN3DR is demonstrated by comparisons with rod ejection
benchmarks for a PWR with rectangular fuel assemblies. The two phase flow model of
FLOCAL also allows the simulation of BWR transients. Results for the transient BWR
benchmark initiated by increase of inlet subcooling are shown.

The neutron kinetic part is parallelized for running on SUN workstations with several
processors. The speedup for steady state neutronic calculations is presented.

  • Lecture (Conference)
    Jahrestagung Kerntechnik '96, Mannheim, 21. - 23. Mai 1996, Tagungsbericht S. 23 - 26
  • Contribution to proceedings
    Jahrestagung Kerntechnik '96, Mannheim, 21. - 23. Mai 1996, Tagungsbericht S. 23 - 26

Permalink: https://www.hzdr.de/publications/Publ-1727
Publ.-Id: 1727


Coupling of the thermohydraulic code ATHLET with the 3D neutron kinetic model DYN3D

Grundmann, U.; Kliem, S.; Lucas, D.; Rohde, U.

The coupling of advanced thermohydraulic codes with 3-dimensional neutron kinetic codes corresponds to the effort to replace conservative estimations by best estimate calculations. ATHLET is an advanced thermohydraulic code, developed by the German "Gesellschaft für Anlagen- und Reaktorsicherheit" (GRS). The DYN3D code, developed at Forschungszentrum Rossendorf (FZR) for the simulation of reactivity initiated accidents in nuclear reactors with hexagonal and Cartesian fuel element cross section geometry comprises 3-dimensional neutron kinetics, models for the thermohydraulics of the core and the thermomechanical fuel rod behaviour.

The reactor core model DYN3D was coupled with ATHLET according to two basically different strategies. The first way of coupling uses only the neutron kinetics part of DYN3D (internal coupling). In the second way, the whole core is cut out from the ATHLET plant model and is completely described by DYN3D (external coupling). In this case the values of pressure, mass flow rate, enthalpy and boron acid concentration at the bottom and at the top of the core have to be transferred between the codes. This way of coupling is efficiently supported by the General Control and Simulation Module (GCSM) of ATHLET. Almost no changes of the single programs are necessary.

For plausibility test of the code coupling, comparative calculations between point kinetics, internal and external coupling were performed for different hypothetical accident scenarios. First results of the analysis of a main steam line break scenario for a VVER-440 type reactor by the help of ATHLET-DYN3D are presented. The effect of different assumptions for the coolant mixing in downcomer and lower plenum of the reactor has been investigated.

  • Lecture (Conference)
    Proc. 6th Symposium of AER, pp.179-191, KFKI Atomic Energy Research Institute, Budapest (1996), Kirkkonummi (Finland), 23-26 September 1996
  • Contribution to proceedings
    Proc. 6th Symposium of AER, pp.179-191, KFKI Atomic Energy Research Institute, Budapest (1996), Kirkkonummi (Finland), 23-26 September 1996

Permalink: https://www.hzdr.de/publications/Publ-1726
Publ.-Id: 1726


ASAXS-Investigation of the Structural Changes in Laboratory Heats of the Reactor Pressure Vessel Steel 15 Kh2MFA after Irradation in a Nuclear Power Plant

Große, M.; Brauer, G.; Nitzsche, P.; Böhmert, J.; Goerigk, G.

  • Other report
    DESY, Jahresbericht 1995, HASYLAB am Deutschen Elektronen-Synchrotron, Annual Report II, Jan. 1996, S. 833

Permalink: https://www.hzdr.de/publications/Publ-1725
Publ.-Id: 1725


Influence of the Irradiation Temperature on the Formation of Defects in Reactor Pressure Vessel Steels

Große, M.; Hempel, A.; Böhmert, J.; Brauer, G.; Haggag, F. M.

Two heats of reactor pressure vessel steel type A533-B-1 differing in their Cu content (0.07 and 0.14 wt.-%) were irradiated to a fluence of 1x1018 neutrons/cm2 at temperatures of 60, 121, and 288 °C, respectively. Their microstructure has been studied by SANS, SAXS, and PAS in the as-irradiated and post-irradiation annealed stages and compared to the behaviour of unirradiated material and the results are discussed.

  • Lecture (Conference)
    MRS Fall Meeting 1996 and Proc. of the MRS Fall Meeting 1996, Boston (USA), Dec. 2 - 6, 1996
  • Contribution to proceedings
    MRS Fall Meeting 1996 and Proc. of the MRS Fall Meeting 1996, Boston (USA), Dec. 2 - 6, 1996

Permalink: https://www.hzdr.de/publications/Publ-1724
Publ.-Id: 1724


Drop tower experiments on the thermocapillary drop migration

Galindo, V.; Teuner, M.; Gerbeth, G.; Langbein, D.

  • Contribution to external collection
    Proceedings Drop Tower Days, Bremen, July 8 - 11, 1996, pp. 2 - 10

Permalink: https://www.hzdr.de/publications/Publ-1723
Publ.-Id: 1723


A Risk Evaluation System for Contamined Sites

Ferse, W.; Reitz, T.

  • Contribution to proceedings
    Proc. of the FOURTH INTERNATIONAL WORKSHOP on real-time computing of the environmental consequence of an accident release from a nuclear installation, Aronsborg, Sweden, Oct. 7 - 11, 1996, Paper N ...

Permalink: https://www.hzdr.de/publications/Publ-1722
Publ.-Id: 1722


A Computer System for Evaluation of Contamined Sites

Ferse, W.

  • Other report
    NATO ASI Series: Environment - Vol. 8, Kluver Academie Publishers, 1996

Permalink: https://www.hzdr.de/publications/Publ-1721
Publ.-Id: 1721


MHD turbulence measurements in a sodium channel flow

Eckert, S.; Gerbeth, G.; Langenbrunner, H.; Witke, W.

The knowledge about properties of the anisotropic turbulence in liquid metal flows exposed to an external magnetic field is essential for several technological applications such as the concept of a selfcooled liquid metal blanket for thermonuclear fusion reactors, but also of basic interest for turbulence research. Flow parameters like pressure drop and heat transfer rate are essentially determined by the interaction between the external magnetic field and the liquid metal flow. Several experimental studies revealed that the application of a magnetic field leads not exclusively to a suppression of the turbulent perturbations. Velocity fluctuations remain and demonstrate a distinct anisotropy of the MHD turbulence showing a tendency to become two-dimensional. The properties of the local transport of heat or mass are strongly governed by the anisotropic character of the flow. In this context a number of questions arises regarding the origin, the decay time or the size of the turbulent elements. A typical feature of the two-dimensional turbulence is that the energy becomes concentrated in organised large scale fluctuations. This fact ensures an intensive heat transfer on longer distances. Because of the anisotropy of the electromagnetic dissipation term vortices will be scarcely damped over long distances if their axes are aligned with the magnetic field lines. For practical applications it is important to identify possibilities to promote the formation of such quasi-two-dimensional vortices in order to control the heat or mass transfer rate of the flow. It is well-known that the mentioned perturbations can be generated by rather specific means, for example, mechanical inserts or electrical currents between definitely arranged electrodes, etc.. In this paper we force the turbulence intensity by mechanical means employing a grid of cylindrical bars or flat stripes. Due to the favourable material properties of the used liquid sodium we are able to extend the measurements into the region of high interaction parameters. In this way the obtained results complement the already existing knowledge about the two-dimensional MHD turbulence.

  • Contribution to proceedings
    8th Beer-Sheva Int. Seminar on MHD flows and turbulence, Jerusalem, February 1996, to appear in: Progress in Astronautics and Aeronautics, Ed.: Branover, H; Unger, Y.; Washington

Permalink: https://www.hzdr.de/publications/Publ-1720
Publ.-Id: 1720


Procedure and method of MHD phenomena investigation on juvenile surfaces of liquid metal

Bojarevics, A.; Gelfgat, Y.; Gerbeth, G.; Simanowskis, S.; Mankis, J.

  • Contribution to proceedings
    8th Beer-Sheva Int. Seminar on MHD flows and turbulence, Jerusalem, February 1996, to appear in: Progress in Astronautics and Aeronautics, Ed.: Branover, H.; Unger, Y.; Washington

Permalink: https://www.hzdr.de/publications/Publ-1717
Publ.-Id: 1717


A technical system to improve the operational monitoring of the ukrainian nuclear power plant Zaporosh'ye (Unit 5)

Beyer, M.; Carl, H.; Nowak, K.; Schumann, P.; Seidel, A.; Weiß, F.-P.; Zschau, J.

In order to improve the operational surveillance of a VVER-1000 unit of the Ukrainian nuclear power plant Zaporosh'ye a technical monitoring system has been specified and installed during the last three years.
The technical system enables the operator and supervisory body to monitor the core and the unit continuously during normal and off-normal conditions, to assess the safety status of core and unit, and to impose appropriate measures. The system provides an early indication of any operational incident and of emissions of radioactive materials. Based on the system an immediate warning in emergency situations is possible as well as an effective emergency management. For this purpose 49 different safety related operational parameters of the core and unit - e.g.: neutron flux, pressure - primary and secondary circuit, fuel rod outlet water temperature, boron concentration - primary circuit and so on -, 18 radiological parameters of the unit and the plant side and 6 meteorological parameters are automatically monitored and evaluated.
The system was put into operation at the end of 1995. It is now working under test conditions.
The paper presents the technical solution of the system and the evaluation principles. Additionally the paper gives a short overview about the results obtained during the test operation of the system.

  • Contribution to proceedings
    Proc. of the OECD/NEANSC Specialists' meeting on in-core instrumentation and reactor core assessment, Mito-shi, Japan, Oct. 14 - 17, 1996, Paper-No. 88

Permalink: https://www.hzdr.de/publications/Publ-1716
Publ.-Id: 1716


A technical system to improve the operational monitoring of the Zaporosh'ye nuclear power plant (remote monitoring system in Ukraine - first level of realization)

Beyer, M.; Carl, H.; Schumann, P.; Seidel, A.; Weiß, F.-P.; Zschau, J.; Nowak, K.

A technical system to improve the operational monitoring of the Zaporozh'ye NPP as a tool for the supervisory authority is presented. The system is mainly directed to monitoring the operational data for early detection of, and information about, anomalous events and gives input data for source term estimation. Additionally, radiological data from the site and the environment as well as meteorological data are integrated in the system for pollution transport calculations. Thus the system's information is well suited to becoming a data source for RODOS system.

  • Contribution to external collection
    Proc. of the FOURTH INTERNATIONAL WOKRSHOP on real-time computing of the environmental consequence of an accident release from a nuclear installation, Aronsborg, Sweden, Oct. 7 - 11, 1996, Paper-N ...

Permalink: https://www.hzdr.de/publications/Publ-1715
Publ.-Id: 1715


Mathematisch-numerische Modellierung der Ultraschallstreuung an oberflächenverbundenen Rissen mit dem EFIT-Code

Bergmann, U.

Ein im Forschungszentrum Rossendorf entwickeltes Ultraschall-Laufzeit-Beugungsverfahren zur experimentellen Beobachtung von stabilem Rißwachstum wurde durch Simulationsrechnungen analysiert. Das Meßverfahren umfaßt die quasistatische Belastung einer einseitig angerissenen stabförmigen Probe in Dreipunktbiegung sowie die wiederholte Messung der Laufzeit eines an der Rißfront gebeugten Ultraschallimpulses. In den 2D-Simulationen wurden Probengeometrie, Rißlänge sowie Ultraschallsende- und Empfangswandler berücksichtigt. Gegenstand der Simulationen waren die Erzeugung des Ultraschallimpulses, die Schallfeldausbreitung und die Signalbildung im Empfangswandler mit Hilfe der Elastodynamischen Finiten Integrationstechnik. Den aufeinanderfolgenden Phasen des Dreipunkt-Biegeversuches wurde durch Einbeziehung von zunehmender Rißlänge und Probendurchbiegung, Rißabstumpfung und Materialschädigung Rechnung getragen. Die Simulationsergebnisse ermöglichen folgende Schlußfolgerungen:
  • Die Natur der empfangenen Meßsignale und die Entstehung jedes einzelnen angeregten Echos wurden vollständig aufgeklärt. Es konnte zweifelsfrei nachgewiesen werden, daß es sich bei dem zur Laufzeitmessung herangezogenen Meßsignal tatsächlich um das an der Rißspitze gebeugte Transversalwellen-echo handelt.
  • Durch Variation der Versuchsparameter (Wellenmode, Aperturfläche, Wandlerposition und Meßfrequenz) in den Simulationsrechnungen konnten Informationen über eine mögliche Optimierung der Meßanordnung zur Erhöhung ihrer Meßgenauigkeit und ihres Aussagegehaltes gewonnen werden.
  • Insgesamt bestätigen die Simulationen die gute Eignung des entwickelten Rißfortschrittsmeßverfahrens zu Rißfortschrittsmessungen an Kleinproben aus duktilem Material.
  • Other report
    Nova Acta Leopoldina Supplementum Nr. 14, S. 361-376 (1996)

Permalink: https://www.hzdr.de/publications/Publ-1714
Publ.-Id: 1714


Das Konzept des Ultraschall-Laufzeit-Prozeßablauf-Bildes

Bergner, F.; Bergmann, U.; Fleischer, U.

  • Lecture (Conference)
    Seminar für zerstörungsfreie Materialcharakterisierung, Jena, Oktober 1996, Berichtsband 54, DGZfP, S. 253 - 258
  • Contribution to proceedings
    Seminar für zerstörungsfreie Materialcharakterisierung, Jena, Oktober 1996, Berichtsband 54, DGZfP, S. 253 - 258

Permalink: https://www.hzdr.de/publications/Publ-1713
Publ.-Id: 1713


Simulation der transienten Naturkonvektion in einem seitlich beheizten Behälter

Aszodi, A.

  • Contribution to proceedings
    Jahrestagung Kerntechnik '96, Mannheim, 21. - 23. Mai 1996, Tagungsbericht S. 106 - 109

Permalink: https://www.hzdr.de/publications/Publ-1712
Publ.-Id: 1712


Plasma confinement and stability studies in the gas-dynamic trap experiment

Anikeev, A.; Noack, K.; Kumpf, H.; Krahl, S.; Otto, G.; Bagryansky, P. A.; Deichuli, P. P.; Ivanov, A. A.; Karpushov, A. N.; Maximov, V. V.; Shichovtsev, I. V.; Stupishin, N. V.; Tsidulko, Y. A.; Voropaev, S. G.; Murakhtin, S. V.

  • Poster
    16th IAEA fusion energy conferency, Montreal, Canada, October 7 - 11, 1996, Proceedings Vol. II, pp. 283-291, IAEA-CN-64/CP-22
  • Contribution to external collection
    16th IAEA fusion energy conferency, Montreal, Canada, October 7 - 11, 1996, Proceedings Vol. II, pp. 283-291, IAEA-CN-64/CP-22

Permalink: https://www.hzdr.de/publications/Publ-1711
Publ.-Id: 1711


High Resolution Void Fraction Measurements for the Validation of Flow Maps and CFD Codes

Krepper, E.; Krüssenberg, A.-K.; Prasser, H.-M.; Schaffrath, A.

The present work is aimed at the investigation of two-phase flow in vertical pipes. Even under these very simple boundary conditions, strong 3D effects are observed. The distribution of the gas phase over the cross section varies significantly between the different flow patterns, which are known for the vertical two-phase flow. The paper presents a new device for measuring the void distribution with a high resolution (242 mea-suring points in a cross section area, measuring frequency approx. 1 kHz). This high resolution allows the calculation of local and averaged void fractions, a flow pattern visualization and the determination of bubble size distributions. Bubble flow appears with void center and boundary maximum distribution. The bubble size distribution allows the classification of the transition from homogeneous to inhomogeneous bubble flow and bubble to slug flow. These criteria are compared with selected empirical or theoretical flow pattern maps. The measurements are also used to assess the capability and the accuracy of the code CFX-4.2. The 3D calculations were still only successful for bubble flow, while the experiments were carried out in a wide range of superficial velocities, including other flow patterns like plug or churn turbulent flow.

Keywords: high resolution void fraction measurement; CFD-code validation; flow maps

  • Lecture (Conference)
    2nd International Symposium on Two phase Flow Modelling and Experimentation, Pisa May 1999, Proc. Vol. III, pp. 1371-1378, ISBN: 88-467-0177-1
  • Contribution to proceedings
    2nd International Symposium on Two phase Flow Modelling and Experimentation, Pisa May 1999, Proc. Vol. III, pp. 1371-1378, ISBN: 88-467-0177-1

Permalink: https://www.hzdr.de/publications/Publ-1710
Publ.-Id: 1710


Experimental and Analytical Investigation of the Operation Mode of the Emergency Condenser of the SWR1000

Schaffrath, A.; Hicken, E. F.; Jaegers, H.; Prasser, H.-M.

The Siemens AG is developing the new innovative boiling water reactor concept SWR1000. New features are the passive safety systems (e.g. emergency condensers, building condensers, passive pressure pulse transmitters, gravity-driven core flooding lines).

For the experimental investigation of the emergency condenser effectiveness, the NOKO test facility has been constructed at the Forschungszentrum Jülich in cooperation with Siemens. This test facility has an operating pressure of 10 MPa and a maximum power of 4 MW for steam production. The emergency condenser bundle consists of eight tubes and is fabricated with planned geometry and material of the SWR1000. In more than 200 experiments, the emergency condenser power was determined as a function of pressure, water level and concentration of noncondensables in the pressure vessel as well of pressure, water level and temperature in the condenser.

Post test calculations of NOKO experiments were performed with an improved version of ATHLET. To calculate the heat transfer coefficients during condensation in horizontal tubes it was necessary to develop the module KONWAR and to implement it in ATHLET. KONWAR is based on the flow regime map of Tandon and includes several semiempirical correlations for the determination of the heat transfer coefficients. The comparison bet-ween calculations and experiments shows good agreement.

Keywords: SWR1000; emergency condenser; ATHLET; KONWAR; condensation inside horizontal and slightly inclinde tubes

  • Nuclear Technology 126 (1999), May 1999, p. 123-142

Permalink: https://www.hzdr.de/publications/Publ-1709
Publ.-Id: 1709


Experimentelle Untersuchungen zur Wirksamkeit passiver Komponenten für den SWR1000

Schaffrath, A.; Fethke, M.; Ringel, H.

Am 29. Oktober 1998 veranstaltete die Ortssektion Sachsen der Kerntechnischen Gesellschaft e.V. an der TU Dresden ein Seminar zum Thema "Experimentelle Untersuchungen zur Wirksamkeit passiver Komponenten für den SWR1000". Diese Thematik erhielt u. a. durch das von Siemens beantragte standortunabhänige Prüfverfahren (vgl. atw 43 (1998), Nr. 10, S. 650) sowie der am 5. November in Königswinter durchgeführten KTG-Tagung "SWR1000 - ein zukunftsweisendes Reaktorkonzept" eine besondere Aktualität. In dem derzeit von der Siemens AG entwickelten innovativen Siedewasserreaktor SWR1000 werden zur Erhöhung der Sicherheit und der Wirtschaftlichkeit aktive Sicherheitssysteme weitestgehend durch passive ersetzt oder mit diesen kombiniert. Hierzu zählen die nachfolgend im Detail beschriebenen Systeme Notkondensator, Gebäudekondensator sowie Passiver Impulsgeber.

Keywords: SWR1000; passive Sicherheitssysteme; Notkondensator; Gebäudekondensator; passiver Impulsgeber; Kerntechnische Gesellschaft

  • atomwirtschaft - atomtechnik 44 (1999)1, S. 35-36
  • Lecture (others)
    Seminar "Experimentelle Untersuchungen zur Wirksamkeit passiver Komponenten für den SWR1000", TU Dresden, 29. Oktober 1998

Permalink: https://www.hzdr.de/publications/Publ-1708
Publ.-Id: 1708


Comparative assessment of condensation models for horizontal tubes

Schaffrath, A.; Krüssenberg, A.-K.; Lischke, W.; Gocht, U.; Fjodorow, A.

The condensation in horizontal tubes plays an important role e.g. for the determination of the operation mode of horizontal steam generators of VVER reactors or passive safety systems for the next generation of nuclear power plants. Two different approaches (HOTKON and KONWAR) for modeling this process have been undertaken by For-schungszentrum Jülich (FZJ) and University for Applied Sciences Zittau/Görlitz (HTWS) and implemented into the 1D-thermohydraulic code ATHLET, which is developed by the Gesellschaft für Anlagen- und Reaktorsicherheit (GRS) mbH for the analysis of anticipated and abnormal transients in light water reactors. Although the improvements of the condensation models are developed for different applications (VVER steam generators - emergency condenser of the SWR1000) with strongly different operation conditions (e.g. the temperature difference over the tube wall in HORUS is up to 30 K and in NOKO up to 250 K, the heat flux density in HORUS is up to 40 kW/m² and in NOKO up to 1 GW/m²) both models are now compared and assessed by Forschungszentrum Rossendorf e.V. Therefore post test calculations of selected HORUS experiments were performed with ATHLET/KONWAR. It can be seen that the calculations with the extension KONWAR as well as HOTKON improve significantly the agreement between computational and experimental data.

Keywords: VVER Steam Generators; Condensation inside Horizontal Tubes; ATHLET

  • Kerntechnik 64 (1999) 4, p. 204-208

Permalink: https://www.hzdr.de/publications/Publ-1707
Publ.-Id: 1707


Verifizierungsuntersuchungen zur Detektion von Rißinitiierung bei duktilem Materialverhalten unter schlagartiger Belastung

Richter, H.

  • Other report
    Abschlußbericht zum Forschungsaufenthalt am VTT Espoo (Finland) an die Deutsche Akademie der Naturforscher Leopoldina, Juli 1997

Permalink: https://www.hzdr.de/publications/Publ-1706
Publ.-Id: 1706


Dodewaard core - Reactor physical modelling and neutron kinetic computer simulations. Progress report on the application of the coupled code DYN3D-ATHLET.

Mittag, S.

  • Other report
    BWRCA report 4.1.6-2, August 1997

Permalink: https://www.hzdr.de/publications/Publ-1704
Publ.-Id: 1704


Quasi-elastic ligth scattering from capillary waves at the liquid metal surface

Kolevzon, V.

Free surfaces of liquid gallium and mercury were studied by light scattering from thermally exited capillary waves. Great precautions were taken to prepare an oxide-free liquid metal surface inside a small evacuated container. Experimental results are shown in the form of q dependencies of the wave peak frequency wo and the damping constant ?. The observed damping constants of capillary waves differ greatly from those predicted by the classical theoretical treatment of Hg and Ga surfaces as those of simple liquids. This effect is explained in terms of the presence of a surface layer of highly correlated atoms accompanying the liquid-vapor transition. Viscoelastic properties of surface layer are extracted from the fit of experimental spectra with a theoretical form utilizing a well known phenomenological model. Results of the fit demonstrate that the surface viscosity appears to be negative. This implies that the widely used phenomenological model should be replaced by another one incorporating the Maxwell viscoelastic model. Special point has been made on studying the temperature dependence of the wave peak frequency at the free and oxidized Hg surface. This dependence emphasizes negative derivative of the surface tension d?/d? linked with the spatial distribution of free electrons being much
stronger temperature dependent than local surface ordering recently revealed at the mercury-vapor interface. In contrast, ?o(?) dependence collected at the Hg-HgO interface displayed two principally different tendencies: it increased steadily on the Hg surface covered with an oxide monolayer but was nearly constant at the surface covered with a polymolecular film of HgO. This behavior is discussed in the framework
of various theoretical models.

  • Other report
    Dissertation, TU Berlin, Juli 1997

Permalink: https://www.hzdr.de/publications/Publ-1703
Publ.-Id: 1703


Summary Technical Report of PMK-2 Test No. 2:Pressuriser Surge Line Break Verifikation Report

Horche, W.; Krepper, E.; Schäfer, F.; Trostel, I.

The report deals with the results of ATHLET post-test calculations for an experiment at the Hungarian integral test facility PMK-2. The experiment „pressurizer surge line break" was carried out within the PHARE 4.2.6b project. The primary objective of this test was to provid data for the phenomena associated with a pressurizer surge line break transient. The post-test analyses were performed with ATHLET mod1.1 Cycle C by the Forschungszentrum Rossendorf (FZR) and with ATHLET mod1.1 Cycle D by the Atomic Research Institute Budapest (KFKI) and the Gesellschaft für Anlagen- und Reaktorsicherheit (GRS).

  • Other report
    Gesellschaft für Anlagen- und Reaktorsicherheit mbH, Garching, Nov. 1997

Permalink: https://www.hzdr.de/publications/Publ-1702
Publ.-Id: 1702


Upregulation of the Aromatic Amino Acid Decarboxylase under Neonatal Asphyxia

Brust, P.; Bauer, R.; Vorieger, G.; Walter, B.; Bergmann, R.; Füchtner, F.; Steinbach, J.; Zwiener, U.; Johannsen, B.

Perinatal hypoxic-ischemic cerebral injury is a major determinant of neurologic morbidity and mortality in the neonatal period and later in childhood. There is evidence that the dopaminergic system is sensitive to asphyxia. However, the respective enzyme activities have not yet been measured in the living neonatal brain. In this study, we hav used F18-labeled 6-fluoro-L-3,4-dihydroxyphenylalanine (FDOPA) together with positron-emission tomography l(PET) to estimate the activity of the aromatic amino acid decarboxylase (AADC), the ultimate enzyme in the synthesis of dopamine (DA), in the brain of newborn piglets. Simultaneously, the cerebral blood flow (CBF) was measured with colored microspheres. Asphyxia elicited an up to threefold increase of the CBF. Despite this, the blood-brdain transfer of FDOPA as well as the clearance rate constants from brain were unchanged. However, the synthesis rate of FDA from FDOPA was significantly increased in frontal cortex, striatum, and midbrain. The increase of the AADC activity and the decrease of monoamine oxidase activity may contribute to the increase of extracellular DA during asphyxia which is expected to be involved in severe disturbances of neuronal metabolism, e.g., by generating free radicals.

Keywords: asphyxia; aromatic amino acid decarboxylase; DOPA; dopamine metabolism; neonatal pigs; positron-emission tomography

  • Neurobiology of Disease 6, (1999) 131-139

Permalink: https://www.hzdr.de/publications/Publ-1700
Publ.-Id: 1700


Darstellung, Strukturen und EPR-Spektroskopie der Rhenium(II)-Thionitrosylkomplexe trans-[Re(NS)Cl3(MePh2P)2] und trans-[Re(NS)Br3(Me2PhP)2]

Voigt, A.; Kirmse, R.; Abram, U.

Abstract. The paramagnetic rhenium (II) thionitrosyl compounds trans-[Re(NS)Cl3(MePh2P)2] and trans-[Re(NS)Br3(Me2PhP)2] are characterized by crystal structure diffraction and EPR spectroscopy. Trans-[Re(NS)Cl3(MePh2P)2] is formed during the reduction of (a) [ReNCl2(MePh2P)3] with disulphur dichloride (S2Cl2) or (b) of mer-[ReCl3(MePh2P)3] with trithiazyl chloride ((NSCl)3). Trans-[Re(NS)Br3(Me2PhP)2-] is the final product of the ligand exchange reaction of mer-[Re(NS)Cl2(Me2PhP)3-] with bromine whereby the metal occurred to be simultaneusly oxidized.
The crystal structure analyses show for trans-[Re(NS)Cl3(MePh2P)2] (monoclinic, C2/c, a = 13.831 (3) C, b = 13.970 (1) C, c = 14.682 (2) C, b = 95.33 (1), Z = 4) and trans-[Re(NS)Br3(Me2PhP)2-] (monoclinic, C2/c, a = 33.292 (5) C, b = 8.697 (1) C, c = 17.495 (3) C, b = 115.65 (1), Z = 8) linear co-ordinated NS ligands (Re - N - S - angles 180° and 174.8°). The metal atom is octahedrally co-ordinated with the phosphine ligands in trans position to each other.
X-band and Q-band EPR spectra of the rhenium (II) thionitrosyl complexes (5d5 "low-spin" configuration, S = 1/2) are detected in the temperature range 295 ³ T ³ 130 K. They are characterized by well resolved 185,187Re hyperfine patterns.
The hyperfine parameters are used to get information about the spin-density distribution of the unpaired electron in the complexes under study.

Keywords: Thionitrosyl compounds, Rhenium complexes, EPR spectroscopy, X-ray structure

  • Zeitschrift für anorganische und allgemeine Chemie

Permalink: https://www.hzdr.de/publications/Publ-1698
Publ.-Id: 1698


CEMS study of iron disilicide fomation by 57Fe ion implantation into silicon

Dobler, M.; Reuther, H.

Doses from 2 x 1015cm-2 to 2 x 1017cm-2 of 57Fe ions were implanted with 40 keV into n-type Si(111) at 350°C. The iron concentration profiles reach peak maximum concentrations from 0.3 at.% for the lowest dose up to about 34 at.%. For the highest dose a plateau-like profile is formed due to the effect of sputtering. The phase formation of the iron disilicides was studied by 57Fe conversion electron Mössbauer spectroscopy. Depending on the implanted dose two different regions of phase formation are found. For doses £ 1 x 1016cm-2 only the metastable g-FeSi2 is present whereas at values ³ 2 x 1016cm-2 a mixture of a- and b-FeSi2 is formed. The phase composition in this second region is dose dependent and with increasing iron content an enlarged fraction of the b-phase is found. At the highest dose of 2 x 1017cm-2 mostly b-FeSi2 and no a-FeSi2 is present. But additionally to the b-FeSi2 a second component occurs in the Mössbauer spectrum which is observed for the first time. With respect to the iron concentration this subspectrum could be attributed to a new metastable state of the mono silicide. Different annealings of the as-implanted samples at 900°C and 1150°C lead to the formation of the pure b- and a-FeSi2, respectively. Additionally to the measurements of the concentration profiles investigations of the lateral element distributions in the layers were performed with scanning Auger electron microscopy. It can be concluded that during the annealing at 1150°C precipitates of the a-FeSi2 grow in the Si matrix.

  • Nuclear Instruments and Methods in Physics Research B 155 (1999) 468-478

Permalink: https://www.hzdr.de/publications/Publ-1696
Publ.-Id: 1696


Gekoppelte Berechnungen von Thermohydraulik und Neutronenkinetik

Rohde, U.; Langenbuch, S.

Es wird ein Überblick über den Entwicklungsstand und die Anwendung von Computercodes mit Kopplung von thermohydraulischen Anlagenmodellen von Kernkraftwerken und 3D Neutronenkinetik gegeben. Insbesondere wird auf die Ankopplung von Neutronenkinetikmoduln an den Thermohydraulikcode ATHLET eingegangen. Es werden Arbeiten zur Validierung der Codekomplexe durch Nachrechnung von transienten Prozessen in Kernkraftwerken und internationale Programmvergleiche beschrieben. Die Anwendung von ATHLET mit gekoppelter 3D Neutronenkinetik für Störfallanalysen wird an 2 Beispielen demonstriert. Mit den gekoppelten Programmsystemen sind erstmals konsistente Störfallanalysen ohne zusätzliche konservative Annahmen möglich. Entwicklungsbedarf besteht noch bei der Berücksichtigung von 3D Temperatur- und Borkonzentrationsverteilungen innerhalb des Reaktors,
die den hypothetischen Störfallablauf wesentlich beeinflussen können.

  • Lecture (Conference)
    Jahrestagung Kerntechnik, 18. - 20. Mai 1999, Karlsruhe, Sammelband "Neue Ergebnisse aus F+E zur Fluiddynamik und Reaktorphysik", Inforum Verlagsgesellschaft, Bonn, Juni 1999
  • Contribution to proceedings
    Jahrestagung Kerntechnik, 18. - 20. Mai 1999, Karlsruhe, Sammelband "Neue Ergebnisse aus F+E zur Fluiddynamik und Reaktorphysik", Inforum Verlagsgesellschaft, Bonn, Juni 1999

Permalink: https://www.hzdr.de/publications/Publ-1694
Publ.-Id: 1694


Velocity reconstruction in conducting Fluids from magnetic field and electric potential measurements

Stefani, F.; Gerbeth, G.

A possibility for the determination of velocity fields in conducting fluids is presented. Applying a magnetic field from outside, electric and magnetic fields are induced by the fluid motion. These fields can be measured at the walls and outside the fluid volume respectively. The inverse problem of reconstructing the velocity from the measured electric and magnetic fields is solved using Tikhonov regularization.

  • Inverse Problems, 15 (1999), pp. 771-786

Permalink: https://www.hzdr.de/publications/Publ-1693
Publ.-Id: 1693


Crystal and solution structure of oxo rhenium(V) complexes with cysteine and cysteine methyl ester

Kirsch, S.; Jankowsky, R.; Leibnitz, P.; Spies, H.; Johanssen, B.

The mono oxo rhenium(V) complexes of cysteine and cysteine methyl ester were synthesised via ligand exchange reaction starting from rhenium gluconate. Unexpectedly, the obtained oxo Re(V) complex with cysteine methyl ester was partially saponified. Both complexes were fully characterised by common analytical techniques in their solid state. Thus, an octahedral complex structure with 2(NH2,S) coordination in the equatorial plane and one carboxyl group bound trans to the oxo group is proven for both compounds by X-ray diffraction. Furthermore, the existence of a dioxo species at higher pH was proven for the first time with this type of ligands by determing the nearest coordination sphere of the rhenium centre in solution at a pH of 12 using extended x-ray absorption fine structure spectroscopy (EXAFS).

  • Book (Authorship)
    Technetium, Rhenium and Other Metals in Chemistry and Nuclear Medicine (Edited by Nicoloni M., Mazzi U.) SGE Editoriali Padova (1999) pp.225-228
  • Journal of Biological Inorg. Chemistry JBIC (1999) 4: 48-55

Permalink: https://www.hzdr.de/publications/Publ-1692
Publ.-Id: 1692


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