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the_geth t1_iyvg3in wrote

Reply to comment by NetworkLlama in Why not use hydrogen and deuterium in fusion reaction rather than tritium and deuterium? by Curious_user4445

Really? I read about everywhere that it’s easy to produce with the lithium blanket (including in a classical fission reactor if needed). The reason we don’t have much production is simply… that we don’t need it (or rather, that the amount we have is enough for our CURRENT use)

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NetworkLlama t1_iyvlbjf wrote

Lithium blankets are still very much in the research stage. The US gets its tritium for it's nuclear arsenal by irradiating special rods called tritium producing burnable absorber rods (TPBARs) containing lithium-6 in a nuclear reactor, specifically Watts Bar Reactors 1 and 2 at the TVA. Each TPBAR is about ten feet long and less than half an inch in diameter. Over about 500 days of burning, each produces about 1.2 grams of tritium.

Civilian sources are primarily from CANDU reactors, but building more of these can be problematic as they're heavy-water reactors (they produce tritium by deuterium neutron capture) and are considered to be proliferation risks, raising both political and legal problems. They also don't produce that much. According tothis paper on sourcing tritium for fusion use, the CANDU 6 reactor, a 700 MW design, can generate only 130 grams of tritium per year, though not all of this can be captured.

According to ITER's own numbers, 800 MW of fusion-generated electricity will require 300 grams of tritium per day. Lithium blankets are the most promising way to get this done, but they present their own technical challenges. This is why research is happening on other approaches like laser confinement and Z-pinch to find ways of using just deuterium.

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the_geth t1_iyw8h5l wrote

Super interesting, thank you for the thoughtful answer!

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beaded_lion59 t1_iywmi7r wrote

Who’s working on Z-pinch fusion now? I did D-D fusion in the 80’s in a Z-pinch, but the process would require a lot of pulse-power advances to make it practical for energy production.

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beaded_lion59 t1_iyxuv6e wrote

I did this at a 7 TW pulsed power system at a company in the Bay Area using deuterium gas. The system could do 3 shots/day. Sandia’s shot rate is probably less. They’re more like NIF at Livermore.

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Relevant_Monstrosity t1_iyviaco wrote

There's probably both a lack of demand, and necessary capitalization to meet potential demand. So you can look for projects to increase the supply to kick off as new users come online.

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ukezi t1_iyvjnee wrote

It's more of a in theory it should be "easy". There are still a lot of details to figure out.

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the_geth t1_iyw8nz0 wrote

I see. It’s interesting this was not (until I hear it here) mentioned as a potential problem.

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