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Nukleonika

The Journal of Instytut Chemii i Techniki Jadrowej

Open access

Magdalena Orszulik, Adam Fic and Tomasz Bury

Abstract

This study deals with numerical modeling of passive autocatalytic hydrogen recombiners (PARs). Such devices are installed within containments of many nuclear reactors in order to remove hydrogen and convert it to steam. The main purpose of this work is to develop a numerical model of passive autocatalytic recombiner (PAR) using the commercial computational fluid dynamics (CFD) software ANSYS-FLUENT and tuning the model using experimental results. The REKO 3 experiment was used for this purpose. Experiment was made in the Institute for Safety Research and Reactor Technology in Julich (Germany). It has been performed for different hydrogen concentrations, different flow rates, the presence of steam, and different initial temperatures of the inlet mixture. The model of this experimental recombiner was elaborated within the framework of this work. The influence of mesh, gas thermal conductivity coefficient, mass diffusivity coefficients, and turbulence model was investigated. The best results with a good agreement with REKO 3 data were received for k-ɛ model of turbulence, gas thermal conductivity dependent on the temperature and mass diffusivity coefficients taken from CHEMKIN program. The validated model of the PAR was next implemented into simple two-dimensional simulations of hydrogen behavior within a subcompartment of a containment building.

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Natalia Krawczyk, Jacek Kaczmarczyk, Monika Kubkowska and Leszek Ryć

Abstract

The paper presents comparison of two silicon drift detectors (SDD), one made by Amptek, USA, and the second one by PNDetector, Germany, which are considered for a soft X-ray diagnostic system for W7-X. The sensitive area of the first one is 7 mm2 × 450 μm and the second one is 10 mm2 × 450 μm. The first detector is cooled by a double-stage Peltier element, while the second detector is cooled by single-stage Peltier element. Each one is equipped with a field-effect transistor (FET). In the detector from Amptek, the FET is mounted separately, while in the detector from PNDetector, the FET is integrated on the chip. The nominal energy resolution given by the producers of the first and the second one is 136 eV@5.9 keV (at -50°C) and 132 eV@5.9 keV (at -20°C), respectively. Owing to many advantages, the investigated detectors are good candidates for soft X-ray measurements in magnetic confinement devices. They are suitable for soft X-ray diagnostics, like the pulse height analysis (PHA) system for the stellarator Wendelstein 7-X, which has been developed and manufactured at the Institute of Plasma Physics and Laser Microfusion (IPPLM), Warsaw, in collaboration with the Max Planck Institute for Plasma Physics (IPP), Greifswald. The diagnostic is important for the measurements of plasma electron temperature, impurities content, and possible suprathermal tails in the spectra. In order to choose the best type of detector, analysis of technical parameters and laboratory tests were done. Detailed studies show that the most suitable detector for the PHA diagnostics is the PNDetector.

Open access

Yashashri Patil, S. Khirwadkar, S. M. Belsare, Rajamannar Swamy, M. S. Khan, S. Tripathi and K. Bhope

Abstract

This paper is focused on various aspects of the development and testing of water cooled divertor PFCs. Divertor PFCs are mainly designed to absorb the heat and particle fluxes outflowing from the core plasma of fusion devices like ITER. The Divertor and First Wall Technology Development Division at the Institute for Plasma Research (IPR), India, is extensively working on development and testing of divertor plasma facing components (PFCs). Tungsten and graphite macro-brush type test mock-ups were produced using vacuum brazing furnace technique and tungsten monoblock type of test mock-ups were obtained by hot radial pressing (HRP) technique. Heat transfer performance of the developed test mock-ups was tested using high heat flux tests with different heat load conditions as well as the surface temperature monitoring using transient infrared thermography technique. Recently we have established the High Heat Flux Test Facility (HHFTF) at IPR with an electron gun EH300V (M/s Von Ardenne Anlagentechnik GmbH, Germany) having maximum power 200 kW. Two tungsten monoblock type test mock-ups were probed using HHFTF. Both of the test mock-ups successfully sustained 316 thermal cycles during high heat flux (HHF) tests. The test mock-ups were non-destructively tested using infrared thermography before and after the HHF tests. In this note we describe the detailed procedure used for testing macro-brush and monoblock type test mock-ups using in-house transient infrared thermography set-up. An acceptance criteria limit was defined for small scale macro-brush type of mock-ups using DTrefmax value and the surface temperature measured during the HHF tests. It is concluded that the heat transfer behavior of a plasma facing component was checked by the HHF tests followed by transient IR thermography. The acceptance criteria DTrefmax limit for a graphite macro-brush mock-up was found to be ~3°C while for a tungsten macro-brush mock-up it was ~5°C.

Open access

Thomas Neugebauer, Hans Hingmann, Jonas Buermeyer, Volker Grimm and Joachim Breckow

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Ewa Fabiszewska, Iwona Grabska and Katarzyna Pasicz

assurance tests according to §16, paragraphs 2 and 3 of the German x-ray ordinance at x-ray systems used for examination of humans UFO-Plan Vorhaben 3608S20001 . German Ministry for Environment, Nature Protection and Reactor Security. Braunschweig: PTB. (in German). Available from http://doris.bfs.de/jspui/handle/urn:nbn:de:0221-2012111310226/ . 6. van der Burght, R., Thijssen, M., & Bijkerk, R. (2010) Manual contrast – detail phantom CDMAM type 3.4 . The Netherlands: Artinis Medical Systems BV. 7. Young, K. C., Alsager, A., & Oduko, J. M. (2008). Evaluation

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Sofija Forkapić, Kristina Bikit, Vesna Arsić, Jovana Ilić, Gordana Pantelić and Miloš Živanović

the determination of gamma emitting radionuclides Vienna IAEA 7. Foerster, E., Beck, T., Buchroder, H., Doring, J., & Schmidt, V. (2012). Instruments to measure radon activity concentration or exposure to radon – interlaboratory comparison 2012. Salzgitter: German Federal Office for Radiation Protection (BfS). (BfS-SW-13/12). Foerster E. Beck T. Buchroder H. Doring J. Schmidt V. 2012 Instruments to measure radon activity concentration or exposure to radon – interlaboratory comparison 2012 Salzgitter German Federal Office for

Open access

Erzsébet Sóki and István Csige

. Csegzi S. 2001 The Radamon radon detector and an example of application Radiat. Meas. 34 1/6 437 440 10.1016/S1350-4487(01)00202-5 9. Genrich, V. (1993). AlphaGUARD PQ2000/MC50. Multiparameter Radon Monitor. Characterisation of its physical properties under normal climatic and severe environmental conditions. User manual. Frankfurt, Germany: Genitron Instruments GmbH. Genrich V. 1993 AlphaGUARD PQ2000/MC50. Multiparameter Radon Monitor. Characterisation of its physical properties under normal climatic and severe environmental

Open access

Francesco Cardellini, Enrico Chiaberto, Luisella Garlati, Daniele Giuffrida, Federica Leonardi, Mauro Magnoni, Gianfranco Minchillo, Anna Prandstatter, Elena Serena, Rosabianca Trevisi, Rosamaria Tripodi and Miriam Veschetti

References 1. Daraktchieva, Z., Howarth, C. B., & Aigar, R. (2013). Results of the 2012 HPA intercomparison of passive radon detectors. Chilton, Didcot: P.H.E. (PHE-CRCE-001). Daraktchieva Z. Howarth C. B. Aigar R. 2013 Results of the 2012 HPA intercomparison of passive radon detectors Chilton, Didcot P.H.E. (PHE-CRCE-001) 2. Foerster, E., Beck, T., Buchröder, H., Döring, J., & Schmidt, V. (2014). Instruments to measure radon-222 activity concentration or exposure to radon-222: Intercomparison 2014. Germany: BfS

Open access

Mariusz Hasiak, Marcel Miglierini, Narges Amini and Marek Bujdoš

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