This will probably need to be updated soon. There are rumors NIF recently achieved a gain of ~4.4 and ~10% fuel burn up. Being able to ignite more fuel is notable in and of itself.
Progress toward fusion energy gain as measured against the Lawson criteria
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Re: Progress toward fusion energy gain as measured against the Lawson criteria
#42I heard that NIF was never intended to be a power plant, not even a prototype of one. It's primarily a nuclear weapon research program. For a power plant you would need much more efficient lasers, you would need a much larger gain in the capsules, you would need lasers that can do many shots per second, some automated reloading system for the capsules, and you would need a heat to electricity conversion system around…
The primary purpose of the NIF is to maintain the US nuclear stockpile without nuclear tests. The lasers very inefficient (iirc about 2%). The success they claimed is that the energy released by the burning plasma exceeds the laser energy put into the fuel capsule. Since NIF was never intended to be a power plant they don't use the most efficient lasers.
Re: Progress toward fusion energy gain as measured against the Lawson criteria
#43The money being spent on fusion should be being spent building next generation fission power plants and liquid salt reactors.
What's the ROI on that versus current and near-term expected pricing for solar+storage? Is fission getting safer/cheaper at the same rate that solar and batteries are?
I wonder if it would make sense to make ultra heavy spent nuclear fuel into gigantic flywheels for short-term grid energy storage
Re: Progress toward fusion energy gain as measured against the Lawson criteria
#44Earlier quoted context omitted.
Tossing out your opinions as fact doesn't do much to win hearts and minds, or educate us bystanders to the basis for your point of view. Presumably your comment is either to persuade or to inform; it does neither. I'm very curious about this field and its future, do you care to try again?
I'm a different person, but I tend to agree. ITER began building in 2013, first plasma is expected for 2034. DEMO is expected to start in 2040. So, ITER is taking an estimated 20 years. It's being built for a reason, so I imagine follow-ups want to wait to see how that shakes out. So certainly, DEMO needs to start a few years after ITER is finally done. Then DEMO isn't a production setup either, it's going to be the…
If Jesus Christ himself came to earth and hand delivered a durable and workable reactor design WITH high uptime WITH a near-optimal confinement scheme WITH zero neutronicity AND he included a decade of free perfectly packaged and purified fuel, it would still not pencil out as anything other than water-hungry staff-intensive baseload requiring significant state support.
This is the reality. It’s not happening. It’s a welfare program for bullshit artists that depends on a credulous public.
Re: Progress toward fusion energy gain as measured against the Lawson criteria
#45Earlier quoted context omitted.
You’ve disputed nothing I’ve said and unless a dramatically higher temperature fusion reaction that does not generate a neutron flux is achieved, it will generate radioactive waste as a matter of factual physics. Thank you though!
I mean, yes, you're right, but it's not a permanently radioactive waste. Quote: A fusion power plant produces radioactive waste because the high-energy neutrons produced by fusion activate the walls of the plasma vessel. The intensity and duration of this activation depend on the material impinged on by the neutrons. The walls of the plasma vessel must be temporarily stored after the end of operation. This waste quan…
The amount of radioactive scrap produced by hypothetical decommissioned radioactive fusion containment vessels is laughably trivial compared to fission waste streams. Even accounting for the most pessimistic irradiation models of first-wall materials, the total radioactive burden remains orders of magnitude below legacy technologies.
The half-lives of such activated components like predominantly steel alloys and ceramic composites trend dramatically shorter than actinide-laden spent fuel, with activity levels plummeting to background within mere decades rather than geological timescales. This makes waste management a single-generation engineering challenge rather than a multi-millennial obligation
Re: Progress toward fusion energy gain as measured against the Lawson criteria
#46Earlier quoted context omitted.
You’ve disputed nothing I’ve said and unless a dramatically higher temperature fusion reaction that does not generate a neutron flux is achieved, it will generate radioactive waste as a matter of factual physics. Thank you though!
I mean, yes, you're right, but it's not a permanently radioactive waste. Quote: A fusion power plant produces radioactive waste because the high-energy neutrons produced by fusion activate the walls of the plasma vessel. The intensity and duration of this activation depend on the material impinged on by the neutrons. The walls of the plasma vessel must be temporarily stored after the end of operation. This waste quan…
Hey, there it is! Lots of radioactive waste being generated on a continuous business but maybe baby with dreams and creams we can decommission it with robots and recycle it all. Meanwhile a reactor is offline for refurbishment for days, weeks, months, blowing a hole in the economics of it all.
Unironically: you’re the first person I’ve come across to openly acknowledge this issue. Thank you.
Re: Progress toward fusion energy gain as measured against the Lawson criteria
#47It should be noted that "breakeven" is often misleading. There's "breakeven" as in "the reaction produces more energy than put into it", and there's breakeven as in "the entire reactor system produces more energy than put into it", which isn't quite the same thing.
In the laser business, the latter is called "wall plug efficiency," which is laser power out per electrical power in.
Re: Progress toward fusion energy gain as measured against the Lawson criteria
#48I've heard of q-plasma and q-total. What is q-science?
It’s the ratio of fusion energy released to heating energy crossing the vacuum vessel boundary.
Re: Progress toward fusion energy gain as measured against the Lawson criteria
#49I heard that NIF was never intended to be a power plant, not even a prototype of one. It's primarily a nuclear weapon research program. For a power plant you would need much more efficient lasers, you would need a much larger gain in the capsules, you would need lasers that can do many shots per second, some automated reloading system for the capsules, and you would need a heat to electricity conversion system around…
Nothing about the NIF looks like a power plant to me. It's like the laser weapons guy and the nuclear weapons guy found a way to spend giant piles of money without having to acknowledge the weapons angle.
A lot of people think so, but the US government openly spends way more money on nuclear weapons than on fusion research. We'll spend almost a trillion dollars on nuclear weapons over the next decade.[1] The government's fusion funding was only $1.4 billion for 2023.[2]
So it seems more likely to me that some physicists figured out how to get their fusion power research funded under the guise of weapons research, since that's where the money is. NIF's original intent was mostly weapons research but it's turned out to be really useful for both, and these days, various companies are attempting to commercialize the technology for power plants.[3]
[1] https://theaviationist.com/2025/04/26/us-nuclear-weapons-wil...
[2] https://www.fusionindustryassociation.org/congress-provides-...
[3] NYTimes: https://archive.is/BCsf5
Re: Progress toward fusion energy gain as measured against the Lawson criteria
#50Earlier quoted context omitted.
Tossing out your opinions as fact doesn't do much to win hearts and minds, or educate us bystanders to the basis for your point of view. Presumably your comment is either to persuade or to inform; it does neither. I'm very curious about this field and its future, do you care to try again?
I'm a different person, but I tend to agree. ITER began building in 2013, first plasma is expected for 2034. DEMO is expected to start in 2040. So, ITER is taking an estimated 20 years. It's being built for a reason, so I imagine follow-ups want to wait to see how that shakes out. So certainly, DEMO needs to start a few years after ITER is finally done. Then DEMO isn't a production setup either, it's going to be the…
ITER/DEMO is an exceptionally slow fusion project and arguably obsolete since it uses older superconductors. CFS uses the same design, with modern superconductors that can support much stronger magnetic fields. Tokamak output scales with the fourth power of magnetic field strength, so this should let them get results similar to ITER in a reactor a tenth the size. They'll have it running long before ITER is ready.