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Comment by Zarathust | Hacker News Reader

This is a critical part to consider in "current" fusion research. Most of it rely on the deuterium / tritium fusion which will probably require a classic nuclear plant to generate the fuel. This makes the whole "infinite clean energy" claim pretty bogus for now.

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Not only the "infinite" part in that statement is indeed bogus - but the immense neutron flux makes me skeptical of the "clean" part as well.

We know how to contain strong neutron flux. We know how to contain short to medium lived activated materials, we know to avoid cobalt is hardened materials, we don't have to deal with water based corrosion in a fusion containment, though neutron embitterment may be a similar issue.

It is very unclean, especially since it requires conventional fission reactors to produce the tritium. It’s theoretically possibl to breed tritium in the reactor blanket of the fusion reactor, but that’s a totally unsolved problem. The high neutron flux of the D-T reaction also destroys all known materials in short order by disrupting the atomic structure of the materials through atomic spallation. There are plenty of other hurdles to making a fusion power plant as oppposed to just a research reactor, but those are big ones.

There is currently a good stock of tritium that would power many such reactors for a while. So it's not insane to put off the tritium problem for later.

The global inventory of tritium is estimated around 20Kg, that's barely enough for research purposes and ITER. Fueling DEMO, the first commercial fusion reactor will require about 10Kg, and at 2-4GW thermal it will require about 300g of tritium per day, completely depleting the existing stockpile in a single month of operation.

So the existing stock is insuficient for even a single commercial reactor. Talking about container sized fusors without ensuring tritium self-sufficiency is a particularity distilled form of insanity.

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