I'm a big fan of nuclear fusion as a concept and hope to shift toward doing active research in the field at some point.

I'd like to open this discussion to talk about topics regarding nuclear fusion as a future energy source. To start, I'll lost a couple of ongoing fusion efforts I'm familiar with.

ITER:Of course the biggest fusion project is ITER, the massive multinational collaboration which is building a massive tokamak reactor in France. Unfortunately ITER will never produce power for average people, as it's purely a test reactor with no plans to be connected to the grid. The following effort to build a functional grid connected reactor, DEMO, isn't set to be built until at least 2050. This has resulted in a considerable number of private ventures trying iut experimental alternative approaches.

HELION:At the time of writing this, there's quite a bit of buzz surrounding Helion energy, both because of the ambitious timeline theyve recently proposed as well as the investment of Sam Altman of OpenAI fame. Helion uses an FRC topology, which I personally think is a really cool idea. Basically it's a tokamak without the physical shell around it, and is kept sustained by the internal plasma physics. Helion also has another interesting quirk, they are not pursuing the typical DT fuel strategy, but are instead planning to use DD fusion to breed He3 and use DHe3 fusion as the primary energy source. I think this is a good idea because DHe3 fusion is "aneutronic", whereas DT fusion produces high energy neutrons that are somewhat of an unsolved problem to deal with. I wonder though, how they intend to deal with the inevitable tritium pollution that DD fusion creates, and how they will separate that out before Iit creates neutrons anyway.

TRIALPHA:In addition, another major company TriAlpha Energy, also pursued FRCs, hoping to use an alternative proton-boron11 mix to achieve aneutronic operation. I think they've sort of pivoted toward being more a neutron source than working toward breakeven.

HB11: A recent proposed approach is HB11, which is also going for proton-boron fusion. Now with Tri Alpha this seemed really dubious, because hydrogen boron has a much lower cross section for fusion than other options, even the DHe3 that Helion is doing. In addition, boron has way more electrons than hydrogen, so a proton boron plasma has more electrons with causes more bremsstrahlung loss. HB11, however, thinks they can overcome this through high energy laser acceleration. They want to use a high power laser to shoot a fuel pellet into a target. This supposedly will work much better than heating the stuff, because the laser will impart a specific impulse and thus the thermal spectrum of the impact will have a much higher Q factor centered around the cross sectional peak. I'm not really convinced on this, just because I feel like that thermal spectrum would only last for the first few atomic layers of impact before it doesn't really matter amymore.

CFS: The next option I would consider to be one if the most popular fusion startups is Commonwealth Fusion Systems. They have what I'd consider the most conservative approach, they are attempting to build a Tokamak design like ITER, but hope to reduce the size considerably by taking advantage of advances in superconductor technology with REBCO tapes.

W7X:The next reactor type I'll mention was in the news a lot a few years back, the Wendelstein-7X in Germany. This is a stellarator design, the crazy twisted car wreck of a thing you may have seen before. The stellarator is shaped that way so that it doesn't require an induced current like the tokamak to have magnetic helicity, because the shape does that automatically.

ZAP:Another well liked dark horse is Zap Energy. They're not as flashy as the other reactors but seem to be working off solid physics that have been proven out over many years. They're trying to do sheared flow z-pinches, which is basically creating a lightning bolt that's perfectly straightened out and super dense.

DPF:One more somewhat obscure option is Eric Lerner's Dense Plasma Focus approach. I'm a little puzzled by this option because it seems to be the exact opposite of Zap, where they make an incredibly twisty lightning bolt instead of a straight one.

FUSOR/POLYWELL:There are a couple reactor types that get mentioned often but are more or less obsolete are the Fusor and the Polywell. A Fusor is a neat device that can be built to fit on a desktop and still produce actual fusion reactions, but has a fundamental design flaw of a physical electrode inside the plasma that introduces too much conductive heat loss. The Polywell is a more advanced concept thay tries to create a "virtual" cathode with orthogonal magnetic mirrors, but I think after many years of experimentation researchers were unable to validate the formation of such a virtual cathode.

NIF:One option that is sort of tangential is the NIF, which you might have heard technically produced more energy than it produced. I dont think its necessarily going to go anywhere, mostly because it's more a weapons program than an energy program, but I think the chirped pulse amplification technology they use is really cool.

GENERAL-FUSION:And finally I'd be remiss if I didn't mention the very highly funded and publicized General Fusion. I definitely give them points for pure childlike wonder. The original pitch was they were going to take a giant swirling tornado of molten metal, fire a ball of plasma into the eye of the storm, then smash the whole thing from all sides with a hundred giant hammers. To be honest is such a wild concept that I don't really know if it really makes any sense or if it's a fever dream. It's undergone a few revisions after finding out that certain parts of its concept just weren't going to work. This doesn't inspire a ton of confidence, but also shows flexibility in their thinking.

There's definitely lots of other companies with other variations, but this gives a general idea of the huge range of ideas and approaches being pursued. I think it's a really cool field to explore and I'd love to hear all your thoughts about it.

So from earliest childhood, I have experienced that from time to time the electrical grid becomes unavailable for use and it can take days or even weeks to restore service. I'm having trouble comprehending the scope, scale and plausibility of what changes would need to be made to increase the electrification of everything in the way that is being pushed by policy advisors.

Everyone is pushing electric cars. I think it's a great idea, but I have questions about how the grid can support it.

People tell me that the next big advancement in the workplace is going to be the incorporation of artificial intelligence. Doesn't AI require servers on a massive scale? How plausible is it for AI to reach all corners of society and economy on our existing grid or reasonable expectations for plausible improvement of the grid?

The banks seem to be lobbying for the substitution of electronic accounts for cash. Again, electric power is not always available. Also some people who need to use money don't have homes and can't reliably charge electronics. If I remember correctly the payment system went down in Canada a while ago and people without cash were out of luck.

What insight can you share with me?

Thanks to @suspended and @deimos for the suggestion!

Hey y’all, I am a basin chemistry engineer for the Department of Energy’s Savannah River Site in South Carolina. Our facility stores spent nuclear fuel from a variety of research and experimental reactors underwater. Our specialty is highly-enriched aluminum-clad fuel, but we have a diverse array of unusual fuels from around the world. A good overview of fuel types can be found here.

My primary responsibility is ensuring the basin water is kept highly pure to minimize corrosion to the fuel, as well as ensure it is free of radionuclides to the extent practicable. I’m happy to answer any questions I can about nuclear fuel, nuclear power, radioactive waste, etc.

More links:
Corrosion of Al-clad fuel
Basin overview

One of my frustrations with political threads generally is that they are often too broad to be meaningful in terms of policy discussion. So I thought I'd narrow the topic of discussion. I am quite interested in political discussion and this seems a fine enough place to have it as any.

So let's talk: Nuclear energy policy!

With the Paris accord attempting to have countries pledged to reduce their carbon footprint to keep the globe from warming past 2 degrees above industrial era temperatures, it seems like a lot of countries have a whole lot of work to do in a rather short period of time. Maybe the US decides to commit to some informal reduction in carbon emissions eventually. Maybe it doesn't. Here we're talking about shoulds.

So for non-US people: how should a given country go about meeting their commitment to the Paris Accord?

For the US peeps: 1.) should the US bother trying to reduce carbon emissions and 2.) how should it go about doing it?

For everyone: What place does nuclear energy have in an energy portfolio that reduces carbon emissions?

After one too many blackouts for the past few years, we're in the market for a backup power solution.

Guidelines include:

• Would rather have multiple smaller units than one large one.
• Should be enough to charge phones, watch a television, run the Keurig. If it can spike up enough to run a heater or keep the fridge from spoiling, that's a bonus.
• Would like to keep it at ~$300 a unit.

We're looking into a whole home generac as well, but this is more of a bandaid trial solution for now.

Given how the 2020s have gone so far, I'm feeling some meaningful concern about the news that we might be getting rolling blackouts if European fuel supplies get too low. I'm not at all sure whether they're overplaying the risk to prepare people, or dramatically underplaying it as they did with the first COVID lockdowns.

I'd be interested to know what, if anything, people recommend as preparation? I don't want to go overkill on something that may not even happen, but it also seems reasonable to consider the issue before everyone starts panic buying supplies.

I'm in the middle of a city, which has definite advantages in terms of walking access to shops and public buildings, but everything I own (including gas boiler and gas stove) needs electricity to run. It seems like a 500Wh LiFePO battery might be a good middle ground in terms of keeping creature comforts up and running, but they aren't exactly cheap so I'd be interested in any opinions and recommendations there?

More broadly it'd be great to hear what people think about the general risks, good preparations to make, and useful supplies that are easy to overlook?