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

I’m trying to organize a series of statements which reflect the primary pressures pushing civilization towards collapse. Ideally, I could be as concise as possible and provide additional resources for understanding and sources in defense of each. Any feedback would be helpful, as I would like to incorporate them into a general guide for better understanding collapse.

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We are overwhelmingly dependent on finite resources.

Fossil fuels account for 87% of the world’s total energy consumption. 1 2 3

Economic pressures will manifest well before reserves are actually depleted as more energy is required to extract the same amount of resources over time (or as the steepness of the EROEI cliff intensifies). 1 2

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We are transitioning to renewables very slowly.

Renewables have had an average growth rate of 5.4% over the past decade. 1 2 3 4

Renewables are not taking off any faster than coal or oil once did and there is no technical or financial reason to believe they will rise any quicker, in part because energy demand is soaring globally, making it hard for natural gas, much less renewables, to just keep up. 1

Total world energy consumption increased 15% from 2009 to 2016. New renewables powered less than 30% of the growth in demand during that period. 1

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Transitioning to renewables too quickly would disrupt the global economy.

A rush to build an new global infrastructure based on renewables would require an enormous amount resources and produce massive amounts of pollution. 1 2

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Current renewables are ineffective replacements for fossil fuels.

Energy can only be substituted by other energy. Conventional economic thinking on most depletable resources considers substitution possibilities as essentially infinite. But not all joules perform equally. There is a large difference between potential and kinetic energy. Energy properties such as: intermittence, variability, energy density, power density, spatial distribution, energy return on energy invested, scalability, transportability, etc. make energy substitution a complex prospect. The ability of a technology to provide ‘joules’ is different than its ability to contribute to ‘work’ for society. All joules do not contribute equally to human economies. 1 2 3

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Best-case energy transition scenarios will still result in severe climate change.

Even if every renewable energy technology advanced as quickly as imagined and they were all applied globally, atmospheric CO2 levels wouldn’t just remain above 350 ppm; they would continue to rise exponentially due to continued fossil fuel use. So our best-case scenario, which was based on our most optimistic forecasts for renewable energy, would still result in severe climate change, with all its dire consequences: shifting climatic zones, freshwater shortages, eroding coasts, and ocean acidification, among others. Our reckoning showed that reversing the trend would require both radical technological advances in cheap zero-carbon energy, as well as a method of extracting CO2 from the atmosphere and sequestering the carbon. 1

The speed and scale of transitions and of technological change required to limit warming to 1.5°C has been observed in the past within specific sectors and technologies {4.2.2.1}. But the geographical and economic scales at which the required rates of change in the energy, land, urban, infrastructure and industrial systems would need to take place, are larger and have no documented historic precedent. 1

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Global economic growth peaked forty years ago.

Global economic growth peaked forty years ago and is projected to settle at 3.7% in 2018. 1 2 3

The increased price of energy, agricultural stress, energy demand, and declining EROEI suggest the energy-surplus economy already peaked in the early 20th century. 1 2

The size of the global economy is still projected to double within the next 25 years. 1

Our institutions and financial systems are based on expectations of continued GDP growth perpetually into the future. Current OECD (2015) forecasts are for more than a tripling of the physical size of the world economy by 2050. No serious government or institution entity forecasts the end of growth this century (at least not publicly). 1

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Global energy demand is increasing.

Global energy demand has increased 0.5-2% per year from 2011-2017, despite increases in efficiency. 1 2 3

Technological change can raise the efficiency of resource use, but also tends to raise both per capita resource consumption and the scale of resource extraction, so that, absent policy effects, the increases in consumption often compensate for the increased efficiency of resource use. 1 2 3 4

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World population is increasing.

World population is growing at a rate of around 1.09% per year (2018, down from 1.12% in 2017 and 1.14% in 2016. The current average population increase is estimated at 83 million people per year. The annual growth rate reached its peak in the late 1960s, when it was at around 2%. The rate of increase has nearly halved since then, and will continue to decline in the coming years. 1 2

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Our supplies of food and water are diminishing.

Global crop yields are expected to fall by 10% on average over the next 30 years as a result of land degradation and climate change. 1

An estimated 38% of the world’s cropland has been degraded or reduced water and nutrient availability. 1 2

Two-thirds of the world (4.0 billion people) lives under conditions of severe water scarcity at least one month per year. 1

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Climate change is rapidly destabilizing our environment.

An overwhelming majority of climate scientists agree humans are the primary cause of climate change. 1

A comparison of past IPCC predictions against 22 years of weather data and the latest climate science find the IPCC has consistently underplayed the intensity of climate change in each of its four major reports released since 1990. 1

15,000 scientists, the most to ever cosign and formally support a published journal article, recently called on humankind to curtail environmental destruction and cautioned that “a great change in our stewardship of the Earth and the life on it is required, if vast human misery is to be avoided.” 1

Emissions are still rising globally and far from enabling us to stay under two degrees of global average warming. 1 2

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Climate feedback loops could exponentially accelerate climate change.

In addition to increased atmospheric concentrations of greenhouse gases, many disrupted systems can trigger various positive or negative feedbacks within the larger system. 1 2 3 4 5

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Biodiversity is falling rapidly.

The current species extinction rate is 1,000 to 10,000 times greater than the natural background rate. 1 2

World wildlife populations have declined by an average 58% in the past four decades. 1

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The marginal utility of societal complexity is declining.

Civilization solves problems via increased societal complexity (e.g. specialization, political organization, technology, economic relationships). However, each increase in complexity has a declining marginal utility to overall society, until it eventually becomes negative. At such a point, complexity would decrease and a process of collapse or decline would begin, since it becomes more useful to decrease societal complexity than it would be to increase it. 1 2 3