Qucosa – Hemholtz-Zentrum Dresden-Rossendorf
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Institute of Safety Research; Annual Report 1996
Get PDFThe report gives an overview on the scientific work of the Institute of Safety Research in 1996
Mathematisch-numerische Modellierung der Ultraschallstreuung an oberflächenverbundenen Rissen mit dem EFIT-Code
Get PDFAn ultrasonic time-of-flight diffraction method for measuring stable crack growth in a three point bending specimen was analyzed by simulations of the wave field evolution in the test specimen. To calculate the actual crack length from the experimental measured time of flight of a crack tip diffracted ultrasound pulse the echo trains were successively measured during the whole bending test. The simulations deal with the generation and evolution of the ultrasound field in the specimen and with the design of the received signal. The simulations took into account the actual test geometry, the crack growth process, the blunted crack tip and the process of bending. With these simulations all individual received echoes are reproduced and interpreted. The echo, qualified for measuring the time of flight is undoubtedly the transverse wave diffracted on the crack tip. In order to optimize the test method and to increase the accuracy of measurements during the simulations Parameters like probe position, wave mode, measuring frequency and length of aperture of the probes wem separately varied. From the comparison between the simulations and the experimental measurements it can be concluded, that the developed method is weil suited for measuring stable crack growth in small specimens made from ductile material
Aufbau eines behördlichen Fernüberwachungssystems zur betrieblichen Überwachung des KKW Saporoshje (Block 5), 3. Realisierungsstufe
Get PDFThe report gives an overview of the further development of the remote monitoring system for the Ukrainian nuclear power plant Zaporozh'ye. The proposals for concept, structure and algorithmic design of the user software elaborated by Research Centre Rossendorf and TÜV Rheinland are presented and explained complemented by a short description of the conversion of the German proposals into the user´s software by the State Scientific-Technical Centre of the Ukrainian Supervisory Authority. Furthermore, there is an actual information about the operational use of the components of the monitoring system in the Zaporozh'ye NPP. The realization efforts for the completion of the NPP-site system and for the integration of the Kiev Centre into the system close the report. The industrial testing phase of the system was started in June of 1996. Since then, supervisory authority and operator have been able to fulfil their monitoring duties more efficiently than before by direct access to the actual operational data
A Method for the Intrinsic Calibration of CsI(Tl) Detectors
Get PDFA method for the intrinsic energy calibration of photomultiplier-coupled CsI(Tl) detectors is described. A simple empirical model of the scintillation light pulse-shape of CsI(Tl) crystals for light charged particles has been applied to simulate the particle identification matrix as it follows from the pulse-shape analysis method. The calibration procedure for the large-area CsI(Tl) detectors of the scintillator shell of the 4 π - array FOBOS for ions with Z < 4 at energies below 100 AMeV is based on the energies of the particle punch-through points
Self-Consistent Pushing and Cranking Corrections to the Meson Fields of the Chiral Quark-Loop Soliton
Get PDFWe study translational and spin-isospin symmetry restoration for the two-flavor chiral quark-loop soliton. Instead of a static soliton at rest we consider a boosted and rotating hedgehog soliton. Corrected classical meson fields are obtained by minimizing a corrected energy functional which has been derived by semi-classical methods ('variation after projection'). We evaluate corrected meson fields in the region 300 <= M <= 600 of constituent quark masses M and compare them with the uncorrected fields. We study the effect of the corrections on various expectation values of nuclear observables such as the root-mean square radius, the axial-vector coupling constant, magnetic moments and the delta-nucleon mass splitting
The Binary and Ternary Decay of Hot Heavy Nuclei Produced in the Reaction 14N (34 AMeV) + 197Au
Get PDFEin technisches Informationssystem zur verbesserten betrieblichen Überwachung des Kernkraftwerkes Saporoshje/Ukraine
Get PDFIn 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. The system will enable the state regulatory and supervisory bodies to survey the unit operation independently of operators to assess its safety status, and to impose appropriate conditions. Due to its up-to-date configuration the system provides early indication of any operational incident and emission of radioactive materials connected. Based on the system an immediate warning in mergency situations is possible as well as an effective emergency management. For this purpose 49 different operational parameters of the unit, 18 radiological parameters of the unit and the plant site and 6 meteorological parameters are monitored. The monitoring concept and its technical realization are described
Recriticality Calculations for Uraniumdioxide-Water Systems with MCNP
Get PDFWith the aim of generating a certain feeling for the general dependencies of the multiplication factor k∞ the first section provides some results for two classes of deformations of the original fuel pins. The main part examines UO2-structures of increasing disorder, beginning with the hexagonal close package of fuel spheres and ending up with stochastic geometries. Among these structures the worst case, i.e. the one with the highest k∞ but preserving mechanical stability is identified. The composition and geometric parameter of this case is used to calculate the critical thickness of a slab and critical radius of a sphere