Speaker
Description
Tokamak Energy is developing a liquid metal breeder blanket for the ST-E1 power plant. Due to spatial constraints, the blanket in a spherical tokamak can only be installed in the outboard region. The breeder material is natural lithium, while the walls are designed to be manufactured from the vanadium alloy V44.
The breeder circulates through the blanket at a very low flow rate, determined by the requirements of tritium extraction. In the baseline design, both surface and volumetric heat are removed by helium flow. To achieve this, the blanket walls incorporate channels for helium circulation, and the blanket volume also contains a network of cooling pipes.
The strong temperature gradients generated within the blanket induce natural convective flows, whose intensity can at least be comparable to that of the externally imposed throughput flow. These convective flows exhibit a distinctive structure, strongly influenced by the intense toroidal magnetic field. Fluid motion in the poloidal direction is significantly suppressed. In contrast, fluid movement in the toroidal direction (along magnetic field lines) occurs with velocity magnitudes on the order of mm/s.
Our 3D numerical analysis, conducted for a representative section of the blanket module, indicates that natural convection can make a significant contribution to the thermal balance under the conditions and dimensions specified in the ST-E1 blanket module design. Moreover, understanding these convective flows is essential for accurately predicting the tritium distribution within the blanket volume.
| Speaker affiliation | Tokamak Energy |
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