261–270 of 285 posts
Why a pellet? Why not a gas of boron and hydrogen? Easier to feed continuously.
Probably had to do with density, if the target is cascading reactions by nuclei to nuclei contact. Solids have a higher chance of contact.
Earlier quoted context omitted.
A number of these steps become easier if the reactor is physically small. A plant that fits in a shipping container has a way easier path to commercial viability. Small plants require less capital. They're easier to manufacture. They can iterate faster. They have less environmental impact, and therefore fewer regulatory hurdles. They require less labor to build and a smaller supply chain. I expect that the engineerin…
I expect that you lose efficiencies with respect to security. I.e., it's not easy to secure one large nuclear reactor (fission or fusion), but it's a lot easier than securing dozens of small reactors.
Earlier quoted context omitted.
Nuclear fission reactors need more security than other power plants because of the implications of stolen fuel/waste, or fallout from sabotage. A fusion reactor like the one this group is working on probably doesn't have as high as security concerns. In fact the only concern might be that it is critical infrastructure(like our entire power grid), and a distribution of smaller reactors would be better for reliability…
Traditional fusion reactors do produce fast neutron radiation, which, in addition to causing problems like weakening the structure (which can be mitigated with better materials, better engineering, and by replacing subcomponents over time) is able to irradiate U238 into PU239. Drop a chunk of U238 in/near the fusion reactor somewhere, let it absorb stray neutrons, and you'll soon have some plutonium. That's bad for c…
Why a pellet? Why not a gas of boron and hydrogen? Easier to feed continuously.
Always happy to see people doing new and interesting stuff with fusion. I got into nuclear technology because of ITER back in the early 2000s. Worked on it continuously (mostly in advanced fission) ever since. > "The timeline question is a tricky one," he says. "I don't want to be a laughing stock by promising we can deliver something in 10 years, and then not getting there. First step is setting up camp as a company…
I am very skeptical of this approach. The big problem I have is the direct conversion approach being suggested. The idea, as I understand it, was that the target is placed at the center of a large sphere, and is negatively charged, so the alpha particles from fusion slow down as they go up the potential to the surrounding spherical collector. You see the problem with this, I hope. The violent and energetic event at t…
My worry is whether the specific fusion reactor concept itself is viable.
Earlier quoted context omitted.
Traditional fusion reactors do produce fast neutron radiation, which, in addition to causing problems like weakening the structure (which can be mitigated with better materials, better engineering, and by replacing subcomponents over time) is able to irradiate U238 into PU239. Drop a chunk of U238 in/near the fusion reactor somewhere, let it absorb stray neutrons, and you'll soon have some plutonium. That's bad for c…
A simple security camera or hank the security guard could easily guard against someone setting up shop and producing plutonium.
I am very skeptical of this approach. The big problem I have is the direct conversion approach being suggested. The idea, as I understand it, was that the target is placed at the center of a large sphere, and is negatively charged, so the alpha particles from fusion slow down as they go up the potential to the surrounding spherical collector. You see the problem with this, I hope. The violent and energetic event at t…
The direct conversion stuff doesn't seem that critical. If that doesn't work out immediately, surely the first generation can use good old steam rankine power conversion (or sCO2 Brayton, if that is deemed mature enough). My worry is whether the specific fusion reactor concept itself is viable.
And yes, the physics of the target is also something that needs external verification.
Earlier quoted context omitted.
The big problem with H-B11 and other heavier fusion processes is that the energy radiated away as brehmsstrahlung is greater that the energy gain from the fusion. This was worked out by Todd Rider in his 1995 PhD thesis. Yeah, in theory it might be possible to capture the brehmsstrahlung and pump it back into the reactor with sufficiently high efficiency, but we're pretty far away from that. That being said, all thes…
> brehmsstrahlung Bremsstrahlung FTFY
Earlier quoted context omitted.
Traditional fusion reactors do produce fast neutron radiation, which, in addition to causing problems like weakening the structure (which can be mitigated with better materials, better engineering, and by replacing subcomponents over time) is able to irradiate U238 into PU239. Drop a chunk of U238 in/near the fusion reactor somewhere, let it absorb stray neutrons, and you'll soon have some plutonium. That's bad for c…
A simple security camera or hank the security guard could easily guard against someone setting up shop and producing plutonium.