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After a few more major breakthroughs we'll be where fission was in 1942 after Fermi made the first man made neutron chain reaction. After that, we can see what
by acidburnNSA 4y ago
After a few more major breakthroughs we'll be where fission was in 1942 after Fermi made the first man made neutron chain reaction. After that, we can see what a practical electricity producing plant looks like, and see how much people actually care about small amounts of tritium radiation.
At the moment fuel costs in fission are like 5-10% of total costs for a fission fleet. In fusion it could be lower, but that will not be any means mean the overall system will be cheaper.
We'll have to see the cost tradeoffs: fusion makes much less radioactive material per kWh than fission (but it still makes some) vs. simplicity. Fission is relatively trivial: just put special rocks in a grid and pump water over them as they pour out their star energy.
Progress is good and exciting, but I don't see any reason to think this will have major implications for energy systems anytime soon. Would be happy to be wrong though.
Disclaimer: I switched from studying fusion energy to advanced fission 16 years ago.
- SuperFine 4y ago>After that, we can see what a practical electricity producing plant looks like I guess we still don't have anything better than boiling water, right?
- acidburnNSA 4y agoRight. But slapping boiling water around the burning plasma is kind of a rube goldberg usually. See LLNL's LIFE design for example [1]. Things like molten salt walls circulating through a steam turbine and all that. There are other ideas too, but it's hard to beat a Rankine cycle. [1] https://en.wikipedia.org/wiki/Laser_Inertial_Fusion_Energy https://en.wikipedia.org/wiki/Laser_Inertial_Fusion_Energy
- eternalban 4y agoHILIFE-II Inertial Confinement Fusion Power Plant Design: https://web.archive.org/web/20150404075829/https://hifweb.lbl.gov/public/Sharp/HIF_documents/Moir-HYYLIFE%20II%20design.pdf https://web.archive.org/web/20150404075829/https://hifweb.lb...
- pfdietz 4y agoYou can't just slap boiling water around the burning plasma in a DT reactor, since you need almost all the neutrons to make more tritium. Water would absorb too many neutrons. The IFE designs use thick showers of liquid lithium or molten FLiBe for this reason.
- svantana 4y agoWell, there is hydro, wind and photovoltaic. And in the fusion field there are startups working on aneutronic fusion, which can generate power directly from charged particles. LPPFusion is one that seemed promising a few years ago, but unfortunately less so now.
- knodi123 4y agoI'm surprised too. I've looked into this before, and it's absolutely right - just not intuitive to me. We do have radio-photo-voltaic devices, but they're so inefficient it's laughable. And we have RTG generators, which are only practical in limited situations, and again have a very low efficiency. So hot water it is!!
- IX-103 4y agoI think we just haven't found the right fusion design. If we use a reaction that primarily produces beta radiation or other high energy charged particle, sending it through a coil of wire would induce a voltage that we could extract as electric energy. For that matter, appropriately located coils could be used to extract thermal energy from the plasma directly. The trick there is that we can't get much with the current tokamak and stellarator designs -- the thermal energy is too disordered to use a large coil and the plasma flow is not sufficiently confined to use small coils. There are almost certainly better configurations, but the electrohydrodynamics simulations are tricky. If we keep at it I'm sure we can find a stable configuration with fewer degrees of freedom.
- panick21_ 4y agoAs some-point maybe aneutornic fusion will be a thing. That will be more like solar panels.
- deleted 4y ago[deleted]
- Izikiel43 4y agoSince you seem to be an expert in that field, what is your perspective on fission for the short term? Are smrs really viable ?
- acidburnNSA 4y agoI'm not super excited about current SMR projects either, sadly. The economies of scale that they explicitly turn away from are very real. The economies of mass production that they rely on can't be achieved unless a lot of people are willing to buy the first N for high cost. But who will buy after the first few boondoggle a bit? I am excited about standardized large light-water reactors at the moment, like the US/Japanese ABWR or Korean's APR-1400 designs. I wish there was more hype around them rather than SMRs and advanced reactors. My favorite idea in nuclear to rapidly deeply decarbonize is to use a shipyard to mass-product large floating reactors. This gives you economies of scale and economies of mass production. Amazingly, this was seriously attempted in the 1970 and 80s in Jacksonville, Fl on Blount Island, where Offshore Power Systems installed the world's largest gantry crane and got an honest-to-goodness manufacturing license from the Nuclear Regulatory Commission to build 8 of these. [1] Sadly, my concern above with SMRs happened to OPS and they couldn't break through. Such a good idea though. [1] https://whatisnuclear.com/offshore-nuclear-plants.html https://whatisnuclear.com/offshore-nuclear-plants.html
- ZeroCool2u 4y agoI'm curious, when you're talking about the SMR projects, does that include the Natrium reactors from TerraPower? I think they're backed by the Gates Foundation? Those seemed pretty interesting to me as a nuclear layman. Also, I don't know a lot about Bill Gates, but he does seem like the kind of guy that if they showed some real success, boondoggle or not, he'd be willing to brute force his way past those issues by throwing money at the problem.
- peteradio 4y agoWouldn't the possible location for floating reactors be much more limited than SMR projects? I would think special financing might get the ball rolling for SMRs, strong decades spanning incentives for first movers.
- eganist 4y agoIt's still decades off but as I understand it, this was the hardest nut to crack. They got what, 2.5 megajoules out of 2.1 in? I might be in the opposite camp as you but this is very much a "where were you when—" moment for me. I'm sure someone will pop in to disappoint me but I think the point is it's no longer a hypothetical exercise.
- acidburnNSA 4y ago> They got what, 2.5 megajoules out of 2.1 in? Of laser energy into a tiny control volume that doesn't consider how much energy went into the laser systems. If you draw the control volume around the building and see that the lasers require vastly more energy than what came out, I think you'll be less excited, right? We've been getting lots of energy out of fusion since the early 1950s with thermonuclear bombs. We know we can get energy out of a control volume. But is it a practical energy source is still the question imho.
- PietdeVries 4y agoI think fusion-plants have always been "15 years away", and most likely will be so for quite a few years... Edit: I was wrong, fusion is always 30 years away: https://www.discovermagazine.com/technology/why-nuclear-fusion-is-always-30-years-away https://www.discovermagazine.com/technology/why-nuclear-fusi...
- soperj 4y agoI don't know what people get out of repeating this on every single fusion article. It's not inventive or insightful, and it doesn't further the discussion in the slightest.
- dylan604 4y agoBecause it's A) true, B) relevant to keep all of the hype in check. The year of Linux on the desktop is always right around the corner too. Yes, they are tropes, but they were not born out of nothing. Someone has to keep the bloviated PR campaigns checked with reality. Otherwise, some crazy fools might actually start believing that fusion is real and gets duped out of their money. If you can't stand a bit of real criticism, then maybe you should sell your scam somewhere else. Otherwise, take it on the chin, retool your message, and come at it honestly.
- augusto-moura 4y agoMuch of fissions complexity comes from safety/damage management. Even after years of advancements we hear about some incidents and radioactive leaks every other decade. Fusion is a much safer alternative both in incidents and fallout
- jemmyw 4y agoIs it? Well I guess it is because we don't have a working fusion power reactor yet so the likelihood of an accident is zero. However, if we did have a fusion reactor it would be producing a lot more radioactive waste than a fission reactor. I definitely wouldn't want to make any broad sweeping statements about something that hasn't been built yet.
- augusto-moura 4y agoI'm a bit at a lost, can you elaborate on how fusion would produce more radioactive waste than fission? We already have a few fusion generators designs so is not a sweeping statement on something totally unknown. AFAIK, the by-product of fusing Tritium/Hydrogen is Helium, which is far from radioactive. I might imagine that some radioactive isotopes might get produced as well, but I can't imagine it being nowhere near as dangerous as spent uranium fuel and contaminated components in fission reactors. In a case of an accident I would also imagine an explosion from a Fusion Reactor, but the fallout of it would not even close as dramatic as a Fission Reactor leak or explosion
- pfdietz 4y agoMore in the sense of a larger mass and volume of activated material. Fission waste has more curies of radioisotopes, but they're concentrated in the fuel rods.
- Retric 4y agoFuel is hardly the only advantage, the major issue with fission is the enormous costs of trying to avoid problems or cleanup after them. Thus 24/7 security, redundancy on top of redundancy, walls thick enough to stop aircraft etc. Fission is still by far the most expensive power source even with massive subsides and is only even close to economically viable as base load power backed up with peaking power plants. In theory much of that is excessive but there is a long history of very expensive mistakes with massive cleanup efforts. The US talks about three mile island as the largest nuclear accident ignoring the Stationary Low-Power Reactor Number One that killed 3 people. All that complexity and expense comes from trying to avoid real mistakes that actually happened.
- Galaxeblaffer 4y agothis is simply not true. according to IEA https://www.iea.org/reports/projected-costs-of-generating-electricity-2020 https://www.iea.org/reports/projected-costs-of-generating-el... LCOE of nuclear is cheaper than almost all other possibilities we have. sure nuclear is very expensive up front, but a nuclear powerplant can run for 100 years while wind and solar had to be completely replaced every 25 years. your correct that nuclear has had some very expensive accidents, but the chance of a modern gen3+ plant that we'd build today causing any accidents like that in a western country is so very close to 0 that it's not even worth discussing.
- Retric 4y agoYou see a lot of handwaving such as that very close to 0 statement with nuclear but someone’s got to be on the hook. The rate and cost of failures directly relate to insurance costs. A 1 in 100,000 chance per year to cause a 500 billion dollar accident represents a ~5 million per year insurance cost to offset that risk before considering the risk premium associated with insurance. And that’s on top of the normal risks for large complexes that have little to do with nuclear just high voltage equipment etc. Unsubsidized insurance costs are something like 0.2c/kWh which is quite significant for these projects. In the end you see a lot of people talking nonsense around nuclear costs using wildly optimistic numbers, but there hasn’t been a power plant built and operated in the last 20 years that come even close to these numbers. Let alone when you start to compare predictions for decommissioning costs with actual decommissioning costs.
- kelnos 4y agoPersonally I think fission power's failure is a political and marketing one. I don't agree that the waste disposal issues, or the safety issues, are quite the big deal people make of them. (Not saying there are no unsolved issues, just that the issues that exist are not significantly worse than those present burning fossil fuels, and are better in some dimensions. They're just different, and in some ways very emotionally so.) I think it might be fine that fusion power may be more expensive in some ways than fission, as long as its reputation is kept clean (figuratively and literally). Market fusion power as the savior of humanity, and get enough people to believe it, and it'll be fine.
- peanuty1 4y agoNuclear plants are also very expensive, no?
- fundatus 4y agoYep, and fusion reactors will probably be even more expensive (especially the first ones). Looking at the current prices of renewables, I don't see a market for fusion reactors at all to be honest. After all we already have a giant fusion reactor just 12 light-minutes away from us! We just have to harvest that energy. The direction were already going (mostly market-driven nowadays actually!) is generation from renewable sources, flexible grids and storage systems to balance everything out.
- imchillyb 4y ago> ...put special rocks in a grid and pump water over them as they pour out their star energy. I'm pretty sure I saw that in a 'goop' sales pitch.
- panick21_ 4y ago> At the moment fuel costs in fission are like 5-10% of total costs for a fission fleet. Yeah and with a breeder fission reactor we could reduce this to below 1% probably. With a thorium breeder the fuel cost might be essentially 0%. In the vision of Alvin Weinberg you literally just drop some thorium into the fuel salt every once in a while. But the real issue for nuclear energy is currently capital cost and time not fuel cost. And capital cost can go down massively with GenIV reactors as well. So I don't see how fusion will be cheaper. > In fusion it could be lower But eventually you have to start breeding tritium, so wouldn't that make it more expensive. > Disclaimer: I switched from studying fusion energy to advanced fission 16 years ago. Awesome, we desperately need GenIV reactors (even if I dislike that term).