Present status of the Liquid Breeder Validation

One of the objectives of IFMIF (International Fusion Materials Irradiation Facility), as stated in its specifications, is the validation of breeder blanket concepts for DEMO design. The so-called Liquid Breeder Validation Module (LBVM) will be used in IFMIF to perform experiments under irradiation on functional materials related to liquid breeder concepts for future fusion reactors. This module, not considered in previous IFMIF design phases, is currently under design by CIEMAT in the framework of the IFMIF/EVEDA project. In this paper, the present status of the design of the LBVM is presented

Design and Thermal-Structural Analyses of Ancillary Components for the Optical Steering Mirror (M4) for the ITER ECH Upper Launcher

Each of the four ITER Electron Cyclotron Heating Upper Launcher (ECHUL) features eight transmission lines (TLs) that are used to inject 170-GHz microwave power into the plasma at a level of up to 1.31 MW (at the TL diamond window) per line. The millimeter waves are guided through a quasi-optical section consisting of three fixed mirror sets (M1, M2, and M3) and one front steering mirror set (M4), with a steering range of & x005B;& x2212;7, & x002B;7 & x005D;& x00B0;. The M4 mirror assembly (upper and lower) will each reflect nearly four Gaussian beams at the correct location in the plasma for suppression of the/1 NTMs. EPFL-SPC has developed a novel steering mirror assembly (SMA) actuator system, which is based on four pressure-controlled, helium-filled bellows working against six helicoidally machined, preloaded, compressive springs, that rotate around two frictionless flexure pivots. This article will outline the design and thermal & x2013;mechanical analysis of such bellows, springs, housing (stator), and the remote-handling compatible support frame

Design Concept and Thermal & x2013;Mechanical Analysis of the Optical Mirror (M3) for the ITER ECH Upper Launcher

The mirror M3 is a part of the in-vessel quasi-optical beam propagation system for the ITER electron cyclotron heating upper launcher (ECHUL). The millimeter waves are guided through fixed mirror sets (M1, M2, and M3) and the front steering mirror set (M4) to aim at the correct location in the plasma for suppression of the /1 NTMs. The design of the M3 shall guarantee the optimal propagation of the beams during their transmission taking into consideration: 1) thermal loads coming from the beams themselves and the plasma operation; 2) mechanical loads coming from the pressurized water circuits and the bolted joint; and 3) the port plug space restrictions in the front-end region. This article reports the main design features of the M3 and the fluid-dynamic analyses carried out to validate the capability to dissipate & x007E;30 kW of deposited power. Finally, the thermomechanical analyses are also reported to prove the design compliance to the structural design code for the ITER in-vessel components (SDC-IC) using a design by analysis (DBA) approach for the normal operation (NO) scenario

Design and Numerical Analyses of the M4 Steering Mirrors for the ITER Electron Cyclotron Heating Upper Launcher

Four electron cyclotron heating upper launchers (ECHULs) will be used at ITER to counteract magnetohydrodynamic plasma instabilities by targeting them with up to 24 MW of mm-wave power at 170 GHz. This mm-wave power is injected through eight ex-vessel (EV) waveguide assemblies for each ECHUL to the in-vessel (IV) waveguides. The mm-wave power exiting the eight IV waveguides inside the ECHUL is reflected by three fixed mirror sets and finally aimed by two independent steering mirrors to specific plasma locations. These two steering mirrors have recently experienced an important redesign in order to deal with the new requirements. This article reports the status of the steering mirrors as well as the fluid dynamic and thermomechanical analyses carried out to validate the design for the normal operation (NO) scenario. The fluid dynamic analyses show that the power dissipated in both steering mirrors due to the mm-wave radiation, nuclear heating, and plasma heat flux can be properly removed with an acceptable mass flow generating admissible pressure drop, temperature rise, and corrosion rate values. The results obtained in the thermomechanical simulation, validated using the American Society of Mechanical Engineers (ASME) code, shows that the steering mirror design is capable of withstanding the expected loads taking place during NO

Thermo-mechanical analysis of an ITER ECH&CD Upper Launcher mirror

The Mirror one Lower (LM1) is part of the in-vessel quasi-optical beam propagation system for the ITER Electro Cyclotron (EC) Upper Launcher (UL), where eight beams are reflected through four mirrors during its passage to the plasma. The mirrors are grouped into two rows of four beams each and the mirror LM1 refers to a four mirror set. High power millimeter (mm) waves are generated by the gyrotrons and delivered to the in-vessel components via corrugated wave-guides. The design of the LM1 shall guarantee the optimal propagation of the beams during their transmission through the optical system taking into consideration 1) the shape of the reflecting surfaces, 2) loads coming from the beams themselves, the plasma and nuclear reactions as well as off-normal events and 3) the port plug space restrictions. This paper reports the Ohmic loss assessment at LM1 as function of frequency, surface roughness and resistivity using the most suitable material and the power input (1.31 MW at 170 GHz). It describes the design investigation of the cooling solutions for the normal scenario via computational fluid dynamic analyses, based on the ITER Primary Heat Transfer System (PHTS) cooling boundary conditions, needed to remove similar to 20 kW of power deposition on the mirror surface. Finite element analyses are performed to guide the design choices in an effort to minimize the maximum mirror surface temperature and thus diminishing the deformation of the reflecting surfaces. The conclusion of this study will provide a feasible design solution for the LM1 and Upper Mirror 1 (UM1)

Seismic analyses of the Double Closure Plate Sub-Plate for the ITER Electron Cyclotron Upper Launcher during the Vacuum Vessel baking scenario

The Double Closure Plate Sub-Plate (DCPSP) was introduced in the Electron Cyclotron Upper Launcher (EC UL) design in order to minimize the openings exposing the interior of the Port Plug (PP) to the port cell; avoiding thus the near environment activation in case of maintenance or intervention on the In-Vessel (IV) components. The load combination Vacuum Vessel (VV) baking + Seismic level 2 is considered as one of the most relevant accidental events in terms of structural conformity affecting the DCPSP. The modal analysis of the DCPSP shows that the natural frequencies are far from the peaks of the ITER reference spectra at the PP flange. Therefore, the feasibility of analyzing the seismic event by using a static method, as a replacement of the Response Spectrum approach, is also investigated. Next, the results due to the seismic event are combined with those produced by loads on the DCPSP that occur during the VV baking scenario. The comparison of the categorized stresses and the allowable design limits showed that the mechanical integrity of the DCPSP is preserved during this load combination