Page 71 - Fundamentals of Magnetic Thermonuclear Reactor Design

54 Fundamentals of Magnetic Thermonuclear Reactor Design

FIGURE 3.12 Vacuum vessel module. (Copyright ITER Organization, 2017).

The two half sectors models were welded into one unit, which was tested
successfully to prove that the technical decisions were correct [6].

3.5 IN-VESSEL COMPONENTS

3.5.1 First-Wall Panels
The blanket water-iron shield blocks, lined with panels, are mounted on the
VV interior surface (Fig. 3.13). They comprise the first wall that separates the
plasma from the reactor functional systems.
The panels are designed to withstand quasi-stationary heat and particle flux-
2
es emitted by the plasma column with densities up to 5 MW/m . The modules
are fixed with a system of supports that are flexible in the toroidal and poloidal
directions. This allows compensating thermo-mechanical module deformations
and enhancing the reliability of the modules’ hydraulic and electric communica-
tions. The panels have a multi-layer structure. A layer directly facing the plasma
is made of beryllium. It is followed by a heat sink (CuCrZr) layer that has high
heat conductivity. This layer is connected with a steel structural backbone, pen-
etrated by water-cooling channels.
To allow maintenance, the module needs to be removed from the vessel us-
ing a remote-handled machine that travels on a rail inside the VV. The machine
is equipped with a multifunctional actuating unit, which can cut waterpipe feed-
ers, dismantle the module and move it to the equatorial access port. Once in the