You really want to race me?
Posted on 09/09/2021 11:04:18 AM PDT by Red Badger
“The amount of natural tritium is therefore negligible and to get tritium you have to breed it. “
False. The amount of tritium in the oceans is estimated to be about 26.8 ± 14 kg.
Tritium is also produced by our existing fission power plants.
Exactly. You have to breed it. And the point of fusion power is to avoid unclear fission power, but you need fission to breed the fuel for fusion.
And no one recovers tritium from seawater because it is so dilute that the cost of recovery outweighs the benefit. And furthermore the inventory of tritium in the environment is mostly the result of nuclear testing and greatly outweighs the tritium that exists "naturally" as the result of cosmic ray generated neutrons activating deuterium in seawater.
Sure does, if emissions from manufacture and electricity generation are not counted.
“The amount of natural tritium is therefore negligible and to get tritium you have to breed it. Turns out based on very simple math that even with 100% recovery and conversion efficiency, tritium breeding from fusion is a losing proposition [you get back fewer tritium atoms than you start with]”
Tritium is ‘bred’ using neutrons and Lithium.
“tritium breeding from fusion is a losing proposition [you get back fewer tritium atoms than you start with]. So, this MIT geology professor lied.”
No. Be-Li blankets can make reactor self-sustaining.
No. The math doesn't work out, actually. It gets you close to 1 Tritium bred per fusion created, but it assumes 100% of neutrons go to breeding and it assumes no losses due to hydrogen diffusion into metals, pump losses, etc.
“No. The math doesn’t work out, actually.”
“The results show that even with 6Li 50%, the condition of tritium self-sufficiency is met. Considering the high cost of Li enrichment, the desired results can be achieved at a lower percentage.”
https://www.sciencedirect.com/science/article/pii/S1738573321001066
“No. The math doesn’t work out, actually. It gets you close to 1 Tritium bred per fusion created, but it assumes 100% of neutrons go to breeding and it assumes no losses due to hydrogen diffusion into metals, pump losses, etc.”
Studies show 1.14 TBR for blanket alone.
Thank you for the article. I have read it, and here is the problem. A TBR of 1.14 for the blanket is a problem because that is an ideal breeding ratio before you account for loses in the process of actually extracting the tritium from the blanket and using it some time in the future. Remember tritium is a form of hydrogen which diffuses wonderfully through most materials. Losing >>10% in pumps, vacuum walls etc. is expected. While it is unclear, it seems that the author has also imposed an unphysical boundary condition on his presumed neutron reflectors at each boundary.
But fundamentally, the problem is that a theoretical ideal breeding ratio of 1.14 is woefully insufficient when real world practicalities of losses in processing, transfer and Tritium decay are accounted for.
” TBR of 1.14 for the blanket is a problem because that is an ideal breeding ratio before you account for loses in the process of actually extracting the tritium from the blanket and using it some time in the future.”
You claimed less than 1.0
Due to supply. problems, tritium will be extracted and used in very short times.
” Losing >>10% in pumps,”
I would expect that the tritium would be extracted BEFORE reaching the pumps.
I said overall the TBR is less than one when practical considerations are accounted for. Another point - the calculation ignores fusion neutron interactions with and absorbtion by structural eleements. His materials list assumes pure material. In fact practical structural materials have lots of impurities and there will be neutron losses there before breeding can occur. Same with first wall.
Only the vaccinated will be allowed to enjoy the benefits of nuclear fusion.
“That is true. I will race you from my home in Md Tn to Panama City Beach Fla. this week on sunday afternoon. I got 1000 bucks that say I will be finish my fourth beer on the beach when you cross the Bay County Line. Let me know when you want to give me your money.”
The Tesla S can make it to the county line non-stop. Save your money.
Which is the point. There isn't another source of breeding so to get that 1.14 all fusion neutrons have to reach the blanket and all tritium that is breed has to be extracted.
Oh, there is another huge loss - which is that the plasma loses tritium to the first wall, to vacuum pumps etc. Only a fraction of the tritium in the plasma ever fuses to produce the neutron for which breeding happens in the first place. And recovery of that lost tritium is certainly less than 100%.
“I said overall the TBR is less than one when practical considerations are accounted for. “
Let me correct you: I said overall the TBR is less than one when practical considerations are NOT accounted for.
—————————————YOUR POST———————————
” It gets you close to 1 Tritium bred per fusion created, but it assumes 100% of neutrons go to breeding and it assumes no losses due to hydrogen diffusion into metals, pump losses, etc.”
“Remember tritium is a form of hydrogen which diffuses wonderfully through most materials.”
How is Canada storing their tritium?
How does the tritium stay in H-bombs?
Don’t know about bombs, but normally tritim is stored in special stainless steels that have low diffucion rates for tritium. But these storage systems have no other functional requirements except to store tritium, don’t have to operate at very high temperatures in high neutron flux and x-ray environments, etc. And even so, there is diffusion into the walls of the container. It is just so slow that it doesn’t come through the other side.
You really want to race me?
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