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zimirken t1_j18v10a wrote

Reply to comment by [deleted] in How do fusion scientists expect to produce enough Tritium to sustain D-T fusion (see text)? by DanTheTerrible

The amount of lithium you'll be consuming to breed tritium is orders of magnitude less than you think. One ton of duterium fused with one ton of tritium produces the same energy as 29 billion tons of coal.

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Lasarte34 t1_j18vxk4 wrote

How many tons of lithium are needed to generate a ton of tritium? (I figure nothing close the billion tons of coal, but I would love to know the math still)

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EvanDaniel t1_j18xaek wrote

That ratio is just the atomic mass ratio.

One atom of lithium-6 (or 7) produces one atom of tritium. Atomic masses are 6 (or 7) for the Li, 3 for the tritium.

So for one ton of tritium you need 2 tons (or a little more) of lithium. And some amount more than that of beryllium, though I don't know what ratio that's proposed to be used at.

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Game_Minds t1_j198wil wrote

A ton of tritium would also go a pretty long way for the cost of the exchange

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Wyrggle t1_j19u0pg wrote

It's a molar ratio. In a perfect world, you need the same number of atoms as opposed to mass.

Neutron flux from fission reactors is on the order of 10^19 to 10^25 neutrons/cm^2/s depending on location in the core and would light be similar for fusion reactors. So you're correct you'd need the same amount of source material to generate 1 ton of tritium from 2 tons of Li-6 with 100% efficiency. However, you'd lose tritium via decay and hydrogen diffusion along with uncaptured neutrons paint through the Li-6 target.

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