This is a record for something I say in a video going out of date. I said that Kairos is working on getting a construction permit from the NRC for their Hermes II test reactor. Well, they got it today, just a few hours after I dropped this video. www.nrc.gov/cdn/doc-collection-news/2024/24-081.pdf
Because those reactors aren’t available for civilian use. The NuScale design is similar to a navy one in architecture, but has many additional safety features.
The military doesn’t usually release their designs publicly, and those reactors didn’t receive NRC approval, so they wouldn’t be that valuable. The NuScale design is similar to the Navy reactors (pressurized light water) and no one is interested in buying their reactors because they’re too expensive.
Another point is, they run on highly enriched uranium, 20% at least. Iirc there are legal or administritive hurdles to that, because of proliferation issues.
20% was chosen because that’s they highest they can go without running into those hurdles. HALEU fuel (20% U235) is actually considered low-enrichment. That’s what the LE stands for.
Why not use argon instead of helium or liquid sodium? Argon must transfer more heat than helium because higher density at the same pressure. It seems to me air cooled thorium pebbles (or argon) looks like the least difficult new technology.
Pebble’s don’t work for the thorium fuel cycle because you can’t separate the Pa233 from the thorium and let it sit away from the neutrons. I talk more about pebble bed reactors in this video. th-cam.com/video/Fu5NNiRTR78/w-d-xo.htmlsi=bMO3M8ucGx21ly8_
@ perhaps pebbles need to be reprocessed every 1000 hours to remove Pa233, or removed every 100 hours and left outside the neutron rich part of the reactor while Pa233 decays before being put back where critical mass sustainment is occurring. pa233 has 27 day half life so 90% is gone in 3 months.
The point of the pebbles is that they are mini containment vessels, so breaking them open is difficult. That’s why most thorium concepts are molten salt, which makes getting to the Pa233 relatively easy.
@ but why not a duty cycle? let them sit outside the high neutron density volume for 3 months to eliminate 90% of the Pa233, then put them back in. They can still be generating useful heat during the 3 months.
The advantage of pebbles is to contain the fission products safely. For thorium you need to process the spent fuel to extract the Pa233/U233, so the pebble containment makes that more difficult.
This is a record for something I say in a video going out of date. I said that Kairos is working on getting a construction permit from the NRC for their Hermes II test reactor.
Well, they got it today, just a few hours after I dropped this video.
www.nrc.gov/cdn/doc-collection-news/2024/24-081.pdf
Another good analysis. There sould be a (youtube) hub for scientist videos.
Enjoying the video! your voice is clipping slightly - might need to lower the microphone a little
I’ve been thinking of getting a better microphone. Maybe now’s the time.
Why don't data center companies use the same nuclear power that we use to power our subs and aircraft carriers?
Because those reactors aren’t available for civilian use. The NuScale design is similar to a navy one in architecture, but has many additional safety features.
@@Decarbonize11 I'm sure the design of the ones the Navy uses are public knowledge, it would be great if the private sector could use them.
The military doesn’t usually release their designs publicly, and those reactors didn’t receive NRC approval, so they wouldn’t be that valuable.
The NuScale design is similar to the Navy reactors (pressurized light water) and no one is interested in buying their reactors because they’re too expensive.
Another point is, they run on highly enriched uranium, 20% at least. Iirc there are legal or administritive hurdles to that, because of proliferation issues.
20% was chosen because that’s they highest they can go without running into those hurdles. HALEU fuel (20% U235) is actually considered low-enrichment. That’s what the LE stands for.
Why not use argon instead of helium or liquid sodium? Argon must transfer more heat than helium because higher density at the same pressure.
It seems to me air cooled thorium pebbles (or argon) looks like the least difficult new technology.
Pebble’s don’t work for the thorium fuel cycle because you can’t separate the Pa233 from the thorium and let it sit away from the neutrons.
I talk more about pebble bed reactors in this video.
th-cam.com/video/Fu5NNiRTR78/w-d-xo.htmlsi=bMO3M8ucGx21ly8_
@ perhaps pebbles need to be reprocessed every 1000 hours to remove Pa233, or removed every 100 hours and left outside the neutron rich part of the reactor while Pa233 decays before being put back where critical mass sustainment is occurring. pa233 has 27 day half life so 90% is gone in 3 months.
The point of the pebbles is that they are mini containment vessels, so breaking them open is difficult. That’s why most thorium concepts are molten salt, which makes getting to the Pa233 relatively easy.
@ but why not a duty cycle? let them sit outside the high neutron density volume for 3 months to eliminate 90% of the Pa233, then put them back in. They can still be generating useful heat during the 3 months.
The advantage of pebbles is to contain the fission products safely. For thorium you need to process the spent fuel to extract the Pa233/U233, so the pebble containment makes that more difficult.