Entwicklung einer Methode zur Berechnung der elektromagnetischen Kraefte durch Magnetfeldaenderungen in ferromagnetischen Strukturen und Anwendung dieser Methode auf den Plasmaabbruch in einem Tokamakreaktor

DEMO is the only step between ITER and a prototype of a commercial fusion reactor. The high neutron fluence characteristic for DEMO imposes the choice of a martensitic steel as structural material. The steel MANET (MArtensitic for NET) has been chosen for the European DEMO blanket designs. MANET is a ferromagnetic material with a nonlinear magnetic behaviour which alters the distribution of the magnetic field inside and outside the blanket structure in such a way that during a plasma disruption, as eddy currents are induced in the blanket structure, strong electromagnetic forces occur whose magnitude can be substantially greater than in the case without ferromagnetic structural material. Within the activities of the Karlsruhe Research Centre for the DEMO solid breeder blanket design, a computer code which can take into account the presence of ferromagnetic material has been developed. The new code - named AENEAS (advanced eddy-current nonlinear electromagnetic analysis system) - has been derived from CARIDDI/FZK, a code already in use for electromagnetic calculations with non-magnetic conducting structures. The magnetic properties of MANET in relation to reactor conditions are discussed together with the modelling of the magnetization curve. The mathematical and numerical formulation of the code as well as its structure are then explained. Furthermore, the results of calculations performed for two test problems - a magnetostatic and a transient nonlinear problem - are presented and compared with the corresponding experimental data. Finally, the code AENEAS has been applied to the Karlsruhe DEMO Solid Breeder Blanket design for a reference case of a plasma disruption. The results show that during a plasma disruption, even if the mechanical load on the structure increases due to the presence of ferromagnetic material, the mechanical integrity of the blanket is preserved. (orig.)51 refs.Available from TIB Hannover: ZA 5141(5683) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

European Helium Cooled Pebble Bed (HCPB) test blanket ITER design description document. Status 1.12.1996

The Helium Cooled Pebble Bed (HCPB) blanket is based on the use of separate small lithium orthosilicate and beryllium pebble beds placed between radial toroidal cooling plates. The cooling is provided by helium at 8 MPa. The tritium produced in the pebble beds is purged by the flow of helium at 0.1 MPa. The structural material is martensitic steel. It is foreseen, after an extended R and D work, to test in ITER a blanket module based on the HCPB design, which is one of the two European proposals for the ITER Test Blanket Programme. To facilitate the handling operation the Blanket Test Module (BTM) is bolted to a surrounding water cooled frame fixed to the ITER shield blanket back plate. For the design of the test module, three-dimensional Monte Carlo neutronic calculations and thermohydraulic and stress analyses for the operation during the Basic Performance Phase (BPP) and during the Extended Performance Phase (EPP) of ITER have been performed. The behaviour of the test module during LOCA and LOFA has been investigated. Conceptual designs of the required ancillary loops have been performed. The present report is the updated version of the Design Description Document (DDD) for the HCPB Test Module. It has been written in accordance with a scheme given by the ITER Joint Central Team (JCT) and accounts for the comments made by the JCT to the previous version of this report. This work has been performed in the framework of the Nuclear Fusion Project of the Forschungszentrum Karlsruhne and it is supported by the European Union within the European Fusion Technology Program. (orig.)Das HCPB Feststoffblanket ist aus Schichtungen kleiner Lithium-Orthosilikat-und Berylliumkugeln aufgebaut, die durch radial-toroidal verlaufende Kuehlplatten voneinander getrennt sind. (HCPB steht fuer die englische Bezeichnung helium cooled pebble bed.) Die Kuehlung erfolgt durch gasfoermiges Helium bei einem Druck von 8 MPa. Das in den Kugelschichten erzeugte Tritium wird durch einen separaten Heliumstrom von 0.1 MPa herausgespuelt. Das Strukturmaterial ist martensitischer Stahl. Das Blanket-Testprogramm fuer ITER sieht vor, unter anderen, zwei europaeische Blanketvarianten in Form von Testeinsaetzen (Module) zu untersuchen, darunter auch das HCPB. Um die Handhabung zu erleichtern, wird das Blanket-Testmodul (BTM) in einen wassergekuehlten Halterahmen montiert, der seinerseits an der Rueckwand des ITER Abschirmblankets befestigt ist. Die Auslegung des Testmoduls erfolgte an Hand dreidimensionaler Analysen fuer die Neutronik (mit Monte-Carlo-Methoden) sowie fuer das thermohydraulische und das mechanische Verhalten fuer beide in ITER geplanten Betriebsphasen, die sogenannte basic performance phase (BPP) und die extended performance phase (EPP). Auch wurde das Stoerfallverhalten des Testmoduls bei Kuehlmittelverlust (LOCA) und Durchsatzstoerungen (LOFA) untersucht. Hierzu wurden Konzepte fuer die erforderlichen Kuehl- und Hilfssysteme erarbeitet. Der vorliegende Bericht ist das sogenannte ITER Design Description Document (DDD) fuer das HCPB Testmodul. Er entspricht in seiner Gliederung dem vom ITER Joint Central Team (JCT) vorgegebenen Schema. Die vom JCT abgegebenen Kommentare zum ersten Entwurf dieses Berichtes wurden beruecksichtigt. Die vorliegende Arbeit wurde im Rahmen des Projekts Kernfusion des Forschungszentrums Karlsruhe durchgefuehrt und ist ein von der Europaeischen Union gefoerderter Beitrag im Rahmen des Fusionstechnologieprogramms. (orig.)Available from FIZ Karlsruhe / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

European DEMO BOT Solid Breeder Blanket

Book-report KfK 5429 pubblicato da Kernforschungszentrum Karlsruh

European Helium Cooled Pebble Bed (HCPB) test blanket ITER design description document. Status 1.12.1998

The helium cooled pebble bed (HCPB) blanket is based on the use of separate small lithium orthosilicate and beryllium pebble beds placed between radial toroidal cooling plates. Cooling is provided by circulating helium at 8 MPa. The tritium produced in the pebble beds is purged by a separate flow of helium at 0.1 MPa. The structural material is martensitic steel. A milestone for the development of the HCPB demo blanket design is the test in ITER. For this purpose a test blanket system - a test module placed in plasma contact and its ancillary systems - has been designed. The analyses performed show that the test blanket system allows to conduct a suitable test programme in ITER and meets all the integration requirements in the fusion reactor. Finally, the test system will operate with sufficient reliability and will not impede the safe operation of ITER. (orig.)11 refs.SIGLEAvailable from TIB Hannover: ZA 5141(6127) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekDEGerman