Page 326 - Fundamentals of Magnetic Thermonuclear Reactor Design

Blanket Chapter | 10 305

FIGURE 10.7 TFC-region vertical cross-section of the Russian Li–V DEMO-S reactor.

The Korean HCML (Helium-Cooled Molten Lithium) test blanket module
(TBM) employs molten lithium solely as a tritium breeder, and gas helium as
a coolant for the FW and the module as a whole. Two layers of graphite are
inserted as a reflector in the BZ (Fig. 10.9). The Korean blanket design differs
from the Russian version in that the lithium circulation rate is within a few cen-
timetres a second, that is, around 100 times lower than in DEMO-S.
This is characteristic of all blankets, which employ a liquid metal for the
tritium breeding purpose only. Such a low flow rate allows the HCML design
to do without the MHD-loss reducing electrically insulating barriers at the duct
wall/liquid metal interface.
The Indian lead–lithium cooled ceramic breeder (LLCB) test blanket has a
modular structure (Fig. 10.10) [9].
3
It measures 1.66 × 0.97 × (0.97–1.16) m in the poloidal, toroidal and
radial directions, respectively. The FW, the sides and the lids are cooled with
helium. The BZ consists of lithium ceramics pebble beds encased in ferritic
steel boxes. The Pb–Li eutectic alloy, flowing poloidally between the pebble
beds, removes heat released by neutrons interacting with the pebbles and the
molten metal. Tritium is bred by the pebbles and the liquid metal. It is ex-
tracted from the pebbles by purge gas (helium with hydrogen) and from the
molten metal using an external extraction system. The molten metal flow rate
is within 0.5 m/s.