Fusion Engineering and Design 89 (2014) 1809–1813 Contents lists available at ScienceDirect Fusion Engineering and Design jo ur nal home p age: www.elsevier.com/locate/fusengdes The ITER EC H&CD Upper Launcher: Seismic analysis G. Aiello a,∗ , A. Vaccaro a , D. Combescure b , R. Gessner a , G. Grossetti a , A. Meier a , G. Saibene b , T. Scherer a , S. Schreck a , P. Spaeh a , D. Strauss a a Karlsruhe Institute of Technology, Association KIT-EURATOM, Institute for Applied Materials, P.O. Box 3640, D-76021 Karlsruhe, Germany b Fusion for Energy, C/ Josep Pla 2, Torres Diagonal Litoral-B3, E-08019 Barcelona, Spain h i g h l i g h t s • We run a seismic analysis of the ITER EC H&CD UL port plug (PP). • We use the ITER reference seismic event SL-2 and the response spectrum approach. • No resonance condition occurs for the PP during this seismic event. • The maximum equivalent stress is relatively small, being lower than 30 MPa. • The PP oscillates mainly in the vertical direction with amplitude less than 2 mm. a r t i c l e i n f o Article history: Received 5 September 2013 Accepted 12 March 2014 Available online 13 April 2014 Keywords: ITER Upper Launcher Seismic analysis Response spectrum Newmark’s rule a b s t r a c t The electron cyclotron heating and current drive (EC H&CD) upper launcher (UL) is a component of the ITER tokamak machine devoted to inject localized high microwave power, in order to counteract plasma instabilities (MHD activity). The UL consists of an assembly of ex-vessel waveguides (with diamond windows and isolation valves) and an in-vessel port plug (PP). The PP, with length close to 6 m, is fixed by a support flange into the upper port of the vacuum vessel (VV) as a cantilevered structure and the nominal gap between PP and port is 25 mm only. During an earthquake, accelerations generated by seismic events cause oscillations of the PP which might be amplified in case of resonance with the natural frequencies. A seismic analysis is therefore required in order to check the response of the UL PP to earthquakes. This paper shows the procedure used for the seismic analysis of the UL PP and results are given in terms of displacements and stresses. The ITER reference earthquake named SL-2 seismic event was considered. The response spectrum method was used in the analysis and floor response spectra (plots of acceleration versus frequency) provided by ITER/F4E at the upper level of the tokamak were applied to the supports as load. A seismic analysis of the UL PP integrated in the upper port is also here reported. The natural frequencies of the PP are far from the frequencies of the peaks in the applied spectra, so no resonance condition occurs. The obtained displacements and stresses of the PP are relatively small. The maximum total displacement is lower than 2 mm and the maximum equivalent stress is below 30 MPa. Since the highest excitation is the vertical one, most part of the total displacement is in the vertical direction. Afterwards, these results due to the seismic loads must be combined with displacements and stresses due to other loads affecting the PP such as the electromagnetic loads. © 2014 Karlsruhe Institute of Technology. Published by Elsevier B.V. All rights reserved. 1. Introduction and background The ITER EC H&CD UL is a component used to direct high power microwave beams into the plasma for control of the magneto- hydrodynamic (MHD) instabilities. The UL consists of an assembly ∗ Corresponding author. Tel.: +49 721 608 22735; fax: +49 721 608 24567. E-mail address: gaetano.aiello@kit.edu (G. Aiello). of ex-vessel waveguides (with diamond windows and isolation valves) and an in-vessel PP. The UL is part of the first confinement system and therefore it has the most stringent requirements in the ITER safety, quality, vacuum, seismic and tritium classifications. In case of an earthquake, the structural stability and the confinement function of the UL has to be maintained [1,2]. In this work, the resistance of the UL PP to the seismic events was checked by means of FEM analyses performed in ANSYS Workbench. The seismic analysis of the PP was carried out using http://dx.doi.org/10.1016/j.fusengdes.2014.03.036 0920-3796/© 2014 Karlsruhe Institute of Technology. Published by Elsevier B.V. All rights reserved.