Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Radical hydrogen-boron reactor leapfrogs current nuclear fusion tech?

newatlas.com

Post reply on HN
Print view View original

271–280 of 285 posts

Re: Radical hydrogen-boron reactor leapfrogs current nuclear fusion tech?

#271

Post by deadundead »

throwaway010718 wrote: post #233
acidburnNSA wrote: post #76

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…

> because it makes less radiologically hazardous material Why is there any radioactive material produced by a fusion reactor ?

Considering the DT reaction D + T = a + n.

Neutrons produced in this reaction, being chargeless, cannot be contained within the electromagnetic field, thus leaving plasma and reacting with the surrounding material (e.g. tokamak chamber walls) and producing radioactive elements. This leads to activation and radioactive degradation of the reactor itself.

Re: Radical hydrogen-boron reactor leapfrogs current nuclear fusion tech?

#272

Post by ncmncm »

philipkglass wrote: post #188
ncmncm wrote: post #145

Earlier quoted context omitted.

There is no actual expectation of ever getting useful power generation from magnetic confinement fusion (ITER, Tokamak): it has always been, instead, a jobs program for high-neutron flux physicists, to maintain a population to draw on for weapons work. p-boron fusion is interesting as a possibly practical energy source. The hurdles are a matter of engineering and finance, not fundamental design flaws. But it's useles…

I think that you have that backwards. It's the laser driven inertial confinement fusion approach that is useful for weapons insights. The very low density and slow kinetics of fusion in a tokamak are much less like weapon fusion reactions. Lawrence Livermore -- a nuclear weapons lab -- has studied inertial confinement fusion for decades. They don't have a tokamak. https://en.wikipedia.org/wiki/National_Ignition_Facil…

It's all about the neutrons.

Re: Radical hydrogen-boron reactor leapfrogs current nuclear fusion tech?

#273

Post by rebuilder »

willis936 wrote: post #115
wolfram74 wrote: post #104

Earlier quoted context omitted.

The 2015 paper cites 3 other groups with experimental results supporting their claims though.

You misinterpreted what I said. I said that I don't have evidence that inertial electrostatic confinement is not based in fairy tales. As in, they are a reasonable route to explore.

Double negatives are tricky! Now you seem to be saying they probably are based in fairy tales, or at least have no reason to think otherwise. The first time around, you seemed to mean the opposite, which is what you say you actually meant.

Re: Radical hydrogen-boron reactor leapfrogs current nuclear fusion tech?

#274

Post by marktangotango »

DennisP wrote: post #24
jabl wrote: post #17

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…

Yes, but Rider based that on various assumptions, and included an appendix on various ways those assumptions might be violated to achieve net power with aneutronic fuels. I think this reactor would qualify, since it doesn't rely on thermal heating.

Polywell claimed to circumvent it as well, I was never clear on their basis for that belief. At least Brussard seemed adamant when he was alive.

Re: Radical hydrogen-boron reactor leapfrogs current nuclear fusion tech?

#275

Post by perl4ever »

acidburnNSA wrote: post #113
pier25 wrote: post #102

Earlier quoted context omitted.

Good answer! > Same can be said for fission, but it only powers 5% of the world due to what can be called complications But weren't these complications obvious before deciding to scale up fission power plants? The ones I know about: - Radioactive waste - Risk of failure - Unavoidable EOL

Certainly the generation of radioactive material in fission plants was considered potentially fatal all the way back to Fermi, who said way back when: > It is not clear that the public will accept an energy source that produces this much radioactivity and that can be subject to diversion of material for bombs. However, the nuclear fission industry has arguably shown that it can technically manage radioactive wastes w…

Just reading Wikipedia at random, made me feel like the solution to the waste problem and global warming is simply to build lots of breeder reactors and forget about non-proliferation. Everything else is just avoiding the only feasible solution. Take the waste and burn it to make more power.

Re: Radical hydrogen-boron reactor leapfrogs current nuclear fusion tech?

#276

Post by coda_ »

acidburnNSA wrote: post #252
coda_ wrote: post #248

Earlier quoted context omitted.

Appreciate all your comments here. As someone that knows a lot about this stuff, may I ask... would you have any concerns living near (say 5 miles) from a deep geological repository, like what is described here: https://www.nwmo.ca/en/A-Safe-Approach/Facilities/Deep-Geolo...

I spent the first 17 years of my life 5 miles from an operating nuclear power plant. The stored nuclear waste from this plant is still there (though the plant itself was decommissioned). When I visit my family, I am right there next to it. It sits in dry casks exactly like these [1]. I feel 100% safe being in that situation at all times, and I know in elaborate detail the characteristics of nuclear waste and radiatio…

Amazing. Thank you very much for your message on this.

Re: Radical hydrogen-boron reactor leapfrogs current nuclear fusion tech?

#277

Post by [deleted] »

pfdietz wrote: post #223
rklaehn wrote: post #197

Earlier quoted context omitted.

Once the capacitor plate has a voltage in the range of the kinetic energy of the particles, this is exactly what will happen. The particles convert their kinetic energy into electrical energy by rolling "uphill" against the electric potential.

And all the free electrons produced in that target are helpfully just sitting there, right?

[deleted]

Re: Radical hydrogen-boron reactor leapfrogs current nuclear fusion tech?

#278

Post by ncmncm »

anonuser123456 wrote: post #236
russfink wrote: post #83

Earlier quoted context omitted.

Start looking for unexplained helium signatures among the exoplanets, as evidence of a civilization that applied this method successfully.

And when you don't find them because said civilizations were smart enough to just go build Dyson spheres around red dwarfs then what?

Nobody will bother with Dyson spheres, or any sort of solar power collection, once they have portable fusion generation. Once you have that, stars and planets are superfluous except as raw material.

Re: Radical hydrogen-boron reactor leapfrogs current nuclear fusion tech?

#279

Post by ncmncm »

acidburnNSA wrote: post #85
eveningcoffee wrote: post #23

Cool thing about this is that it will be a direct energy capture if I understand it correctly. "The hydrogen/boron fusion creates a couple of helium atoms," he continues. "They're naked heliums, they don't have electrons, so they have a positive charge. We just have to collect that charge. Essentially, the lack of electrons is a product of the reaction and it directly creates the current."

Presumably the lasers have produced enough energy to ionize helium generated in the target. It's quite unclear how a net energy gain will be extracted simply by grabbing the moving ions electrically. That sounds like a huge extra challenge on top of achieving net positive controlled fusion. There will inevitably be a lot of heat produced that has to be cooled. Generally people plan to use the coolant as the working f…

The coolant will be forced air to clear the reaction chamber for the next shot. When you are collecting enough power from the accelerated nuclei and X-rays by direct conversion, heat is uninteresting.

Re: Radical hydrogen-boron reactor leapfrogs current nuclear fusion tech?

#280

Post by mcswell »

microtherion wrote: post #207
lallysingh wrote: post #163

Earlier quoted context omitted.

If these reactors are low heat, not radioactive, and use plentiful fuel, what's the threat model? Is it just worried about availability of power?

According to the article, the energy is generated by alpha particles, which are in principle a very dangerous form of radiation. It's not clear to me, though, whether the radiation stops as soon as the fusion does or not.

Up until a decade or two ago, tritium--which emits alpha radiation--was commonly on wristwatch dials, precisely because they were not dangerous. Alpha radiation is easily stopped; it's only dangerous if you breathe it (or drink it, if that's even possible).
Post reply on HN