Page 44 - Fundamentals of Magnetic Thermonuclear Reactor Design

26 Fundamentals of Magnetic Thermonuclear Reactor Design

FIGURE 2.13 Magnetic force components acting on a TF coil.

2.5.4 Fuel Cycle: Demand for Tritium
Qualitative estimates of ITER fuel cycle characteristics hold for the DEMO
and FPP projects. The expected lifetime of ITER plasma particles is close to
−3
20
10 s. If plasma concentration is ∼10 m and a vacuum chamber volume is
22
3
∼1000 m , fuel consumption of ∼10 particle/s is required. Fuel maintenance
is to be performed by a high-speed pellet injection and deuterium and tritium
gas puffing into the chamber.
20 −1
To achieve a fusion power of 500 MW, a tritium burnout rate of ∼2 × 10 s
is required. Thus, the share of burning tritium is very small and the main part of
it is circulated through the tritium contour.
Burnt-out tritium may be replaced by tritium produced in fission reactors or
a fusion reactor itself. The first option is practicable for experimental machines,
2
including the ITER reactor, where designed neutron fluence of 0.3 MW·year/m
is equivalent to 15 kg of burnt-out tritium. This means that 3 kg of tritium are
needed annually for an approximately 5-year D–T campaign. Twice as much
(around 5 kg/year) is offered currently in the global tritium market. However,
only the second option, namely, tritium production in the fusion breeder blan-