Publications Repository - Helmholtz-Zentrum Dresden-Rossendorf

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33407 Publications

Characterisation of Irradiation-Induced Precipitates in VVER-Type RPV Steel 15Kh2MFA by Anomalous Small Angle Ray Scattering

Böhmert, J.; Brauer, G.; Große, M.; Eichhorn, F.
Irradiation-induced precipitates are the cause for neutron embrittlement of reactor pressure vessel steels. It can be shown that for the VVER-type steel 15Kh2MFA the shift in the ductile-brittle transition temperature depends nearly linearly on the volume fraction of these precipitates.
The nature of the irradiation-induced precipitates has been investigated at the steel 15Kh2MFA. This steel differes from ASTM-type A503 and 533 steels mainly in its content of the carbide forming elements chromium, molybdenum and vanadium.
Small angle neutron scattering (SANS) experiments using the SANS-2 facility at the FRG-1 reactor in Geesthacht (Germany) were employed in the past. SANS gives information about size and volume fraction of the precipitates, but hardly about the chemical composition.
In order to prove and to characterize the nature of the irradiation-induced precipi- tates anomalous small angle X-ray scattering (ASAXS) has been carried out at the JUSIFA facility of Hamburg synchrotron laboratory HASYLAB (Germany) at present. By the method of contrast variation, it is also possible to get information on the chemical composition.
ASAXS experiments with contrast variation at energies near the vanadium-K -absorption-edge reveal the content of vanadium within the irradiation-induced precipitates. The scattering density of the precipitates is lower than the scattering density of the iron matrix. The chemical shift of the vanadium K -absorption-edge shows that vanadium does not precipitate in an elementary state. Assuming, the precipitates are vanadium carbide these results can be explained. The results are in accordance with those of SANS experiments and former positron annihilation spectroscopy experiments.
  • Lecture (Conference)
    5th Meeting of the International Group on Radiation Damage Mechanisms, Santa Barbara, May 1994

Permalink: https://www.hzdr.de/publications/Publ-1836
Publ.-Id: 1836


High Precision Neutron Fluence Calculations, Activation Measurements and Spectrum Adjustment for the Rheinsberg Pressure Vessel Steel Irradiation Program

Barz, H.-U.; Böhmer, B.; Konheiser, J.; Stephan, I.
The overall approach comprises the pure calculation part, the gamma spectrometric analyses of fluence monitors and the comparison of theoretical and experimental results using the spectrum adjustment procedure. Monte Carlo methods were used to perform the transport calculations. By application of special measures of variance reduction the statistical errors could be reduced so much that accurate 3-dimensional Monte Carlo methods could be generally used in reasonable calculation time. The uncertainties of the results due to the use of different group values of neutron cross sections were assessed by testing different group sets. In that way it could be shown that the kind of group data is of minor influence.
  • Lecture (Conference)
    Presentation to the EWGRD, WGRD-VVER Meeting, Rez, Tschechien, April 18 - 22, 1994

Permalink: https://www.hzdr.de/publications/Publ-1835
Publ.-Id: 1835


Aufgaben und Probleme bei der Bestimmung der Neutronenbelastung für den WWER-1000

Barz, H.-U.; Böhmer, B.; Konheiser, J.; Stephan, I.
Es werden Erfahrungen der auf diesem Gebiet tätigen Mitarbeiter in Rossendorf bei der Berechnung und Messung von Neutronenfluenzen sowie bei der Anwendung der Spektrumsjustierung dargelegt. An Hand dieser Erfahrungen wird auf noch offene Probleme eingegangen, die insbesondere bei neutronendosimetrischen Problemen zum Reaktor WWER-1000 auftreten. Es werden Möglichkeiten zur Bewältigung dieser Probleme diskutiert und auf eigene Vorstellungen eingegangen. Insbesondere wird betont, daß man mit Hilfe moderner Verfahren der Varianzreduktion die genaue 3-dimensionale Monte-Carlo Methode als Standardverfahren für die Transportrechnungen anwenden kann.
  • Lecture (Conference)
    5. Deutsch-Russisches WTZ-Seminar der Arbeitsgruppe Komponentensicherheit, Stuttgart, 03. - 05. Oktober 1994

Permalink: https://www.hzdr.de/publications/Publ-1834
Publ.-Id: 1834


Analysis of two-Phase Flow Phenomena with Conductivity Probes in Integral Reactor Safety Experiments

Weber, P.; Kusch, S.; Prasser, H.-M.
The thermalhydraulic behaviour of a PWR during beyond-design-basis accident scenarios is important for the verification and optimisation of accident management measures and code development. Analyses require integral experiments, such as PKL III at Siemens / KWU, which simulates a 1300 MWe KWU-design PWR with scaling factor of 1:145.
The paper presents PKL III results obtained by needle shaped conductivity probes developed in the Forschungszentrum Rossendorf [1]. The probes provided local void fractions and particle frequences within an averaging period of 2s. This time resolution is sufficient to characterize slow transients. A special flow pattern map developed for the probes enabled the calculation of the length of an average bubble. The measured information was used to determine the changing flow regimes.
At first, a secondary side feed-and-bleed procedure was investigated. Two probes were installed in the feed water line close to the steam generators. A depressurization of the secondary side caused flashing of the feed water and discharge of two-phase flow. A comparison of the measured void fraction with the density reading of a radiation densitometer installed next to the probes shows good agreement. The experimentally found flow regimes are also consistent with expected trends from flow regime maps developed by other researchers (e.g. [2]). Both show slug flow at the beginning of the secondary-side depressurization.
In the second experiment, a primary-side feed-and-bleed following steam generator tube rupture, four probes were installed at one location in the vertical part of the pressurizer surge-line, but at different radial positions. Another set of probes was installed in the horizontal pressurizer bleed-line. Two of them were used for time-of-flight measurements providing velocity values directly. Flow regimes such as stratified flow in the horizontal tube or annular flow in the vertical tube were found during the depressurization.
  • Contribution to proceedings
    European Two-Phase Flow Group Meeting, Piacenca, Italy, June 6 - 8, 1994,
  • Other report
    Erlangen: Siemens AG, Power Generation Group (KWU), Paper I.1, 1994

Permalink: https://www.hzdr.de/publications/Publ-1833
Publ.-Id: 1833


Acoustic Leak Detection at Complicated Topologies Using Fuzzy Classifiers and Neural Networks

Schmitt, W.; Hessel, G.; Weiß, F.-P.
A method for detecting and localizing leaks at complicated three-dimensional topologies by measuring the leak induced structure-borne and airborne sound and by applying pattern recognition procedures is being developed. The sound patterns necessary to train fuzzy logic classifiers and neural networks are generated with simulated leaks at the original structure. As features for characterizing the occurrence and the location of a leak, coherence values between high-frequency microphone signals as well RMS-values of acoustic emission sensors are used. The method is even applicable when localization based on propagation time differences or sound attenuation differences fail. The method is prototypically developed for a soviet-type pressurized VVER-reactor.
  • Contribution to proceedings
    Proc. of the XIII IMEKO World Congress, Torino, September 05 - 09, 1994, pp. 1259 - 1264

Permalink: https://www.hzdr.de/publications/Publ-1832
Publ.-Id: 1832


Ultrasonic Two-Phase Flow Measurements Based on Pattern Recognition Techniques

Prasser, H.-M.; Hensel, F.; Schütz, P.
The state-of art of ultrasonic two-phase flow measurements is characterised by a number of different approaches commonly based on the identification and characterisation of individual voids (bubbles, plugs etc.) applying the techniques of ultrasonic testing. The recorded individual events are integrated to extract parameters as void fraction or volume flow rates. The main limitation of these methods arises from the complicated structure of two-phase flow at higher void fractions which leads to multiple diffractions of the sound beam. The measurement is therefore limited to low void fractions or a simple flow structure.
The main idea of the present work was to overcome these limitations by means of pattern recognition. An ultrasonic beam crossing the two-phase flow is modulated by the changing structure of the voids passing by and therefore the through-transmission signal must contain information about the parameters of the two-phase flow even if information about individual flow effects cannot be derived. Therefore it was supposed that a pattern recognition algorithm trained with signals obtained at known conditions is able to identify the set of the flow parameters (flow rates, void fraction etc.) in an unknown situation.
  • Contribution to proceedings
    From Measurement to Innovation. Proceedings of the XIII IMEKO World Congress, Vol.2, p. 1112-111
  • Lecture (Conference)
    XIII IMEKO World Congress, Torino September 5-9, 1994

Permalink: https://www.hzdr.de/publications/Publ-1831
Publ.-Id: 1831


Neutron-Physical Development of Reflectors for the Pulsed Reactor IBR-2

Noack, K.
The pulsed fast reactor IBR-2, Dubna, is at present the most powerful pulsed neutron source used for condensed matter research. The neutron pulses are generated periodically by reactivity modulation, which is accomplished by a rotating two-reflector system. The neutron physics which has been involved in the development of various reflectors is analysed with respect to the neutron pulse length. Two new reflectors are proposed.
  • Kerntechnik 59 (1994) 6, S. 291 - 297, München: Hanser Verlag, 1994

Permalink: https://www.hzdr.de/publications/Publ-1829
Publ.-Id: 1829


Post-Test Calculations of the IAEA-SPE4

Krepper, E.; Schäfer, F.
In the Research Center Rossendorf post test calculations of the SPE4 were performed using the thermohydraulic code ATHLET. The SPE-4 experiment was a small break loss of coolant accident in the cold leg with unavailable high pressure injection system. For the prevention of core damage the secondary side bleed and feed was used. The experiment was performed at the Hungarian PMK-2 test facility, modelling the Paks VVER-440 reactor. In the calulations different nodalizations were tested for modelling the hydroaccumulators and the horizontal steam generator. Deviations between calculation and experiment were observed especially in the primary pressure decay and consequently in the behaviour of accumulator injection. It was found, that the prediction of observed core dry out depends on the correct calculation of the low pressure injection setpoint.
  • Lecture (Conference)
    Proc. 2. SPE-4 Workshop, Budapest, May 1994
  • Contribution to proceedings
    Proc. 2. SPE-4 Workshop, Budapest, May 1994

Permalink: https://www.hzdr.de/publications/Publ-1828
Publ.-Id: 1828


Anwendung neuronaler Netze zur akustischen Leckortung an komplizierten Strukturen

Hessel, G.; Schmitt, W.; Weiß, F.-P.
Eine Methode zur Erkennung und Ortung von Lecks an Druckanlagen komplizierter 3-dimensionaler Topologie ist entwickelt worden. Sie basiert auf der Merkmalsextraktion aus dem leckinduzierten Körper- und Luftschall und wendet neuronale Netze zur Mustererkennung an. Die zum Anlernen der neuronalen Netze notwendigen Schallmuster werden mit Hilfe von simulierten Lecks an einer Originalstruktur erzeugt. Als Merkmale zur Charakterisierung des Leckortes werden Kohärenzwerte zwischen hochfrequenten Mikrofonsignalen und RMS-Werte von Schallemissionssensoren angewendet. Die Methode ist sogar einsatzfähig, wenn die Leckortung auf der Basis von Laufzeit- oder Dämpfungsdifferenzen versagt. Die Methode wird prototypisch für einen russischen WWER-Druckwasserreaktor entwickelt. Die Anwendung neuronaler Netze ermöglicht eine Adaption der Leckortungsmethode an Druckanlagen unterschiedlicher Topologie.
  • Contribution to proceedings
    Preprint VDI/GVC Düsseldorf - Fachtagung Prozeß- und Anlagensicherheit, November 1994, S. 135 - 146

Permalink: https://www.hzdr.de/publications/Publ-1827
Publ.-Id: 1827


Investigations on a Boron Dilution Accident for a VVER-440 Type Reactor by the Help of the Code DYN3D

Grundmann, U.; Rohde, U.
A reactivity initiated transient caused by entering a plug of water with reduced boron concentration into the core during incorrect loop startup in a VVER-440/W-213 reactor is analyzed . Due to the asymmetric distribution of the boron dilution, significant space-dependent effects are expected. That requires the use of a three-dimensional reactor core model. The analysis was carried out with the help of the code DYN3D/M2 developed for investigations on reactivity initiated accidents in thermal reactors with hexagonal fuel elements. A semi-analytical model adjusted to experimental data on coolant mixing in VVER-440 type reactors is used for the estimation of boron concentration distribution at core inlet. For comparisons, the two limiting cases, ideal mixing and no mixing, are investigated.
  • Lecture (Conference)
    Proc. ANS Topical Meeting on Advances in Reactor Physics: Reactor Physics Faces the 21st Century, Knoxville (Tennessee), 11. - 15. April 1994, Vol. 3, pp. 464 - 471
  • Contribution to proceedings
    Proc. ANS Topical Meeting on Advances in Reactor Physics: Reactor Physics Faces the 21st Century, Knoxville (Tennessee), 11. - 15. April 1994, Vol. 3, pp. 464 - 471

Permalink: https://www.hzdr.de/publications/Publ-1826
Publ.-Id: 1826


Effective coupling of Re/Tc-MAG3 complexes with amines and nucleobases in aprotic solvents.

Kniess, T.; Noll, S.; Noll, B.; Spies, H.; Johannsen, B.
The coupling of Re- and 99mTc-MAG3 complexes with amines and nucleobases was carried out with good yields using O-(benzotriazol-1-yl-)N,N,N',N'-tetramethyl-
uronium-tetrafluoroborate (TBTU), and base in polar aprotic solvents (NMP, DMF, DMSO). The one step reaction followed by simple gel chromatography makes the method well appropriate for preparations at the low no-carrier-added level of technetium-99m.
Keywords: Re/Tc-MAG3, nucleobases, coupling, TBTU
  • Journal of Radioanalytical and Nuclear Chemistry, 240, No. 2 (1999), 657-660

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Permalink: https://www.hzdr.de/publications/Publ-1824
Publ.-Id: 1824


Synthesis and receptor binding of novel progestin-rhenium complexes

Wüst, F.; Skaddan, M. B.; Carlson, K. E.; Leibnitz, P.; Katzenellenbogen, J. A.; Spies, H.; Johannsen, B.
A series of rhenium "n+1" mixed-ligand, thioether-carbonyl and organometallic complexes of 21-substituted progesterone have been synthesized. The conjugates contain the rhenium metal at several oxidation states, being +5, +3 and +1. The complexes were used in a competitive receptor-binding assay (rat-uterus, 0°C) to determine their binding to the progesterone receptor. The best affinity of 9% (RU 5020=100%) was obtained with a "3+1" mixed-ligand complex, containing a NMe group as the central donor atom in the tridentate ligand part.
  • Book (Authorship)
    Technetium, Rhenium and Other Metals in Chemistry and Nuclear Medicine (Edited by Nicolini M., Mazzi U.) SGE Editoriali Padova (1999) pp. 491-495

Permalink: https://www.hzdr.de/publications/Publ-1823
Publ.-Id: 1823


Tc(V) and Re(V) complexes with Mercaptoacetylglysine (MAG1

Noll, B.; Noll, S.; Leibnitz, P.; Jankowsky, R.; Spies, H.; Johannsen, B.
Mercaptoacetyl glycine (MAG1) (1) forms, in the presence of appropriate monodentate ligands, tridentate/monodentate (3+1) coordinated complexes with Tc(V) and Re(V). Exchange of the chlorine by monodentate ligands in [MO(MAG1)Cl]- (2) gives access to new mixed-ligand complexes [MO(MAG1)(XR)] (3) . Some representatives have been prepared and characterized by elemental analysis, ir and uv spectroscopy and EXAFS. Thiobenzoate as monodentate ligand gives the complex (4) that, after debenzoylation, reacts with halogen containing compounds under displacement of the halogen by a [MO(SNO)S] moiety.
  • Book (Authorship)
    Technetium, Rhenium and Other Metals in Chemistry and Nuclear Medicine (Edited by Nicolini M., Mazzi U.) SGE Editoriali Padova (1999) pp. 241-244

Permalink: https://www.hzdr.de/publications/Publ-1822
Publ.-Id: 1822


Derivates of 6-methyl-8alpha-amino-ergoline: Sythesis and affinity to the dopamine D2 receptor

Spies, H.; Noll, B.; Noll, S.; Hilger, C. S.; Brust, P.; Syhre, R.; Johannsen, B.
Organic derivatives (2) of 6-methyl-8alpha-amino-ergoline 1 and derived complexes of rhenium (3,5) and technetium (4) have been prepared and evaluated with regard to their affinity to the dopamine D2 receptor. The molecular structure of the rhenium complex 3 was determined. The affinity of the benzoyl derivative 2b is comparable with that of terguride (IC50 values 2.7 for 2b vs. 4.8 nMol), while the affinities of the related Tc and Re complexes are in the range from 54 to 165 nMol.
  • Book (Authorship)
    Technetium, Rhenium and Other Metals in Chemistry and Nuclear Medicine (Edited by Nicolini M., Mazzi U.) SGE Editoriali Padova (1999) pp. 237-240

Permalink: https://www.hzdr.de/publications/Publ-1821
Publ.-Id: 1821


Solution structure of technetium(V) and rhenium(V) peptide complexes as studied by EXAFS spectroscopy and capillary electrophoresis (CE)

Jankowsky, R.; Kirsch, S.; Spies, H.; Johannsen, B.
Structural investigations on rhenium and technetium peptide complexes have been carried out using X-ray absorption spectroscopy (EXAFS) and capillary electrophoresis. Small cysteine containing peptides with altered amino acid sequences were used as model systems to study the metal complexation behaviour. By means of capillary electrophoresis, complex species existing over the pH range could be identified as well as protonable groups in these complexes. EXAFS measurements in solution delivered information about the complex coordination spheres. The metal complexation modes and complex stoichiometries of directly labelled metal complexes of large biologically active peptides could be elucidated.
  • Book (Authorship)
    Technetium, Rhenium and Other Metals in Chemistry and Nuclear Medicine (Edited by Nicolini M., Mazzi, U.) SGE Editoriali Padova (1999) pp.229-235

Permalink: https://www.hzdr.de/publications/Publ-1820
Publ.-Id: 1820


A novel method to investigate ion-beam-induced defect evolution in Si

Posselt, M.
  • Invited lecture (Conferences)
    5th International Symposium on Process Physics and Modeling in Semiconductor Device Manufacturing, 195th Meeting of the Electrochemical Society, Seattle, WA, USA, May 2-6, 1999 (invited lecture)
  • Book (Authorship)
    pp. 58-74 in: Process Physics and Modeling in Semiconductor Technology (Edited by C. S. Murthy, G. R. Srinivasan, S. T. Dunham), Proceedings Volume 99-1, The Electrochemical Society, Pennington, NJ

Permalink: https://www.hzdr.de/publications/Publ-1819
Publ.-Id: 1819


PET-Untersuchungen mit 18-F-FDG: Strahlenbelastung der MTAs beim Aufziehen der Spritzen

Wittmüß, A.; Schröder, H.; Beuthien-Baumann, B.; Linemann, H.; Burchert, W.
Für eine gute Bildqualität bei gleichzeitig möglichst niedriger Strahlenbelastung für den Patienten ist es bei PET-Untersuchungen erforderlich, die Aktivität möglichst genau auf die Spritzen aufzuziehen. Dabei kommt es zu einer kaum vermeidbaren deutlichen Strahlenbelastung der Hände und insbesondere der Finger. Dies ist die Folge der nicht ganz einfachen Handhabung der Spritzen beim Füllen. Es ist fast unmöglich, die gewünschte Dosis - trotz Berechnung - beim ersten Mal genau aufzuziehen. Dadurch ist die Hand immer wieder in unmittelbarer Nähe der Aktivität, was letztlich die hohe Strahlenbelastung der Hand bedingt. Um diese Strahlenbelastung beim Abfüllen zu vermindern, sind neben den bereits bestehenden Strahlenschutzmaßnahmen, wie z.B. der Bleiburg mit Bleiglassichtfenster und dem mit Blei abgeschirmten Aufbewahrungsgefäß für das mit Aktivität gefüllte Vial, weitere hinzugekommen.
So werden bei größeren Mengen benötigter Aktivität (bei mehr als 3 Patienten) zwei Abfüllungen aus der Radiochemie angefordert, wobei die zweite Abfüllung erst dann in das Labor geholt wird, wenn die erste Abfüllung aufgebraucht ist. Weiterhin wird beim Aufziehen der Spritzen mit einer Zange, zum Halten der Spritze, sowie einer Pinzette, zum Halten und Fixieren der Kanüle, gearbeitet. Beide Maßnahmen dienen zur Vergrößerung des Abstandes von der Aktivität. Zur Registrierung der Strahlendosis wurde jeweils ein Fingerring pro Hand, eine Filmdosimeter und ein elektronisches Dosimeter getragen.
Es wird die mit den zusätzlichen Strahlenschutzmaßnahmen erreichte Verminderung der Strahlenbelastung der Hände vorgestellt, sowie die Bedeutung in Beziehung zur maximal zulässigen jährlichen Strahlendosis gewertet.
  • Poster
    37. Internationale Jahrestagung der Deutschen Gesellschaft für Nuklearmedizin Ulm, 14.-17. April 1999
  • Abstract in refereed journal
    Nuklearmedizin 38 (1999) A107

Permalink: https://www.hzdr.de/publications/Publ-1818
Publ.-Id: 1818


Tc(V) and Re(V) complexes of N-(MAG1)-Histamine

Hilger, C. S.; Noll, B.; Blume, F.; Leibnitz, O.; Johannsen, B.
The synthesis of N-(MAG1)-histamine and the preparation of its Tc and Re complexes are reported. As proven by spectroscopic methods, HPLC investigations and by X-ray structure analysis, N-(MAG1)-histamine forms stable, neutral and square pyramidal 1:1 coordination compounds with MO3*-cores of Tc and Re. The preparation of the isostructural 99mTcO(V)-N-(MAG1)-histamine complex has been achieved with 80-95% radiochemical yield.
  • Book (Authorship)
    Technetium, Rhenium and Other Metals in Chemistry and Nuclear Medicine (Edited by NicoliniM., Mazzi U.) SGE Editoriali Padova (1999) pp. 221-224
  • Poster
    36. Intern. Jahrestagung DGN, Leipzig, 01.-04.04.1998
  • Abstract in refereed journal
    Nuklearmedizin 37 (1998) A53

Permalink: https://www.hzdr.de/publications/Publ-1816
Publ.-Id: 1816


Melanoma affine Tc-99m complexes of N-(2-diethylaminoethyl)benzamides.

Eisenhut, M.; Mohammed, A.; Mier, W.; Friebe, M.; Haberkorn, U.
Objectives: In the past a series of I-123 labeled N-(dialkylaminoalkyl)benzamides have been successfully applied to image human melanoma metastases. This prompted the development of Tc-99m complexes which should mimic the biological characteristics of these benzamide derivates.
Methods: Four N-(2-diethylaminoethyl)benzamide derivatives have been synthesized comprising the following phenyl substituents for Tc-99m complexation: 4-(Bz-S-Ac-Gly-Gly-NH) 1, 3-(NH2)-4-(Bz-S-Ac-Gly-NH) 2, 3-(Bz-S-Ac-NH)-4-(Bz-S-Ac-NH) 3, and 4-HS 4. The Tc-99m complexes were obtained by treating ligands 1-3 at 100°C for 10 minutes with Tc-99m pertechnetate, tartaric acid and stannous chloride as a reducing agend. Complex 4 was formed accordingly in the presence of N-methyl-3-azapentan-1,5-dithiol at 50°C. Biodistribution time-course studies were performed using C57B1/6 mice with subcutaneous B16 murine melanoma.
Results: The highest melanoma uptake was obtained with complex 1(3.42 and 4.48 %ID/G at 1 and 6 hr pi, respectively). The melanoma affinity decreased in the order 1>>4>2>>3.The melanoma uptake corresponded proportional with the blood values. Thus bioavailability of the Tc-complexes in the blood seemed to control melanoma uptake. A similar dependency was observed with radioiodinated benzamides.
Conclusion: Among the compounds tested so far complex 1 proved to exhibit high melanoma affinity and deserves further investigations as a melanoma seeking radiopharmaceutical.
  • The Journal of Nuclear Medicine, 40 (1999) 120-121

Permalink: https://www.hzdr.de/publications/Publ-1815
Publ.-Id: 1815


The Application of the Expert System XUMA in the State of Saxony

Ferse, W.
In the last years contaminated sites have become a relevant problem in the Federal Republic of Germany because there exist a large number of these sites. That's why in Germany more intensive efforts are undertaken in order to start necessary remediations. Basic initial conditions for an effective execution of these works are on the one side a systematic registration of these sites and on the other side the creation of a uniform evaluation capability for the assessment of environmental hazards.

Regarding this background the Research Centre Rossendorf (FZR) together with Nuclear Engineering and Analytics, Inc. Rossendorf apply and modify the computer code system XUMA (German synonym for expert system on environmental hazards of contaminated sites) which is a joint project of the Institute for Applied Information Science of the Karlsruhe Nuclear Research Centre and the State Institute for Environmental Protection of Baden-Württemberg. XUMA is a knowledge based computer system, which shall support the staff of the responsible governmental offices in the uniform evaluation of the hazard potential, the preparation of analysis plans, and the assessment of contaminated sites and mines.

To enable the registration and evaluation of contaminated sites at engineering offices FZR developes an interface program which can be generated automatically from the knowledge base of the expert system XUMA. This interface program can be executed at each IBM-compatible PC without any additional runtime environment.
  • Contribution to proceedings
    Proceedings of 4th Workshop on Information Managem,ent in Nuclear Safety, Radiation Protection and Environmental Protection, GRS-105, Köln, January 1994

Permalink: https://www.hzdr.de/publications/Publ-1813
Publ.-Id: 1813


Irradiation Programme in the Rheinsberg VVER-2 Reactor to Evaluate the Susceptibility of Russian Reactor Pressure Vessel Steels against Neutron Embrittlement

Böhmert, J.; Viehrig, H.-W.
An extensive irradiation programme was performed in the Rheinsberg VVER-2 reactor from 1984 to 1988. The programm comprised 25 different heats from base or weld metal of VVER-440- and 1000-type reactor pressure vessel steels using specimens of variant geometry (CT, COD, tension, Charpy-V). Mainly, it focused on validating of the safety assessment procedure and on determining of fracture mechanics parameters in their dependence of fluence and thermal annealing.
At present the investigation of the irradiated specimen is still outstanding. In the unirradiated state all VVER-type steels investigated show good toughness and strength properties and are comparable with A 533 class 1 and A 508 class 3 steels. The scattering between the different heats of same materials is partly large and does not correlate with the chemical composition or the heat treatment. The results of irradiated specimens up to now do not always confirm the values which are obtained on the base of the valid safety assessment procedure in a conserva- tive wise. That supports the urgency to extend the data base for irradiated VVER-type pressure vessel steels.
  • Contribution to proceedings
    Jahrestagung Kerntechnik, Stuttgart, 17. - 19. Mai 1994, Proc. pp. 388 - 391

Permalink: https://www.hzdr.de/publications/Publ-1809
Publ.-Id: 1809


Solarwärmeeinspeisung in ein Nahwärmenetz durch dachintegrierte Kollektorfelder und einen saisonalen Speicher

Nollau, M.
  • Other report
    Diplomarbeit Nr. 1542 Technische Universität Dresden, Institut für Energietechnik 1995

Permalink: https://www.hzdr.de/publications/Publ-1807
Publ.-Id: 1807


Entwurf eines solar unterstützten Nahwärmesystems in einer zu sanierenden Wohnsiedlung

Noack, M.
  • Other report
    Diplomarbeit Nr. 708 Technische Universität Dresden, Institut für Thermodynamik und Technische Gebäudeausrüstung 1995

Permalink: https://www.hzdr.de/publications/Publ-1806
Publ.-Id: 1806


Modellierung der axialen Gasgehaltsverteilung bei transienten Vorgängen in einer Zweiphasenströmung

Kern, T.
  • Other report
    Diplomarbeit Technische Universität Dresden, Institut für Verfahrens- und Umwelttechnik, November 1995

Permalink: https://www.hzdr.de/publications/Publ-1805
Publ.-Id: 1805


Entwicklung und Erprobung eines Photovoltaik-Generator-Kennlinienmeßgerätes

Ihle, T.
  • Other report
    Diplomarbeit Technische Universität Dresden, Fakultät Elektrotechnik, Nr. 22/94, 01.12. 94 - 31. 05. 1995

Permalink: https://www.hzdr.de/publications/Publ-1804
Publ.-Id: 1804


Hydrogen Prototype of a Plasma Neutron Source

Gorbovsky, A. I.; et. al. (INP); Kumpf, H.; Noack, K.; Otto, G.; Krahl, S.; Robouch, V.
  • Other report
    Novosibirsk 1995, Budker INP 95-90

Permalink: https://www.hzdr.de/publications/Publ-1803
Publ.-Id: 1803


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

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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

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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

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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

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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

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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

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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

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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

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


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