Antares were the first ones: https://www.energy.gov/articles/department-energy-celebrates...
And closely followed by Valar Atomics two weeks later: https://www.energy.gov/articles/department-energy-celebrates...
Antares achieves criticality of Mark-0 reactor
101–110 of 122 posts
Re: Antares achieves criticality of Mark-0 reactor
#102TRISO fuel so.. pebble bed? Is there a reluctance to market on this? The Chinese were all-in. Great to see engineering deliver on time. I wonder if Rolls Royce will also have a smooth ride. It's a PWR.
TRISO increases fuel cycle costs. It's harder to make, harder to dispose of, and (IIRC) uses higher enrichment.
The positive schpiels say it gets higher utilisaton ("burn") of the fuel inside the micropellets, so it may be HEU, but there's more taken out so less made overall.
I'm unsure where the H in HEU comes from, probably nasty sources, and probably nasty radiochemistry.
Re: Antares achieves criticality of Mark-0 reactor
#103Earlier quoted context omitted.
Costs are out of control due to nuclear regulation.
This is the conspiracy theory reasoning I was talking about. Nuclear is wonderful, but a global omnipotent green conspiracy has hobbled it. Or, maybe, it really is complicated and needs regulation to keep it sufficiently safe in a world where corners are always cut.
Right or wrong, I don't think conspiratorial is the right descriptor here. The pro-nuclear claim is that the very loud, very public anti-nuclear movement was influential in setting regulations of the industry. It's not "an evil cabal of shadowy green elites secretly control everything", it's "democracy works; fellow citizens were/are dumb; legislation improvements move slowly".
Re: Antares achieves criticality of Mark-0 reactor
#104Earlier quoted context omitted.
China does: all of the above, where it makes sense. Renewables and batteries to keep your AC, workplace EV charger, stove, pool heater and (since recently) green ammonia producer going, nuclear to prevent e.g. aluminium smelters from seizing up. Also the cheapest way to make renewables work 24/7 is to build HVDC lines - they cost as much as a highway per unit length and even undersea cables would deploy for less and…
China is also still building coal and has passed Europe and will (if they don’t change course) soon pass the US and Canada and the other big ones on a per capita emitter basis. They already passed everyone as top emitter in an absolute sense. https://ourworldindata.org/grapher/co-emissions-per-capita Not saying they’re not also building renewables and nuclear, but it seems like the policy is more “build anything and…
> They already passed everyone as top emitter in an absolute sense.
They also passed everyone as top emitter of produced goods, which almost everyone else has outsourced to there. So what?
Buy less? Buy American? European? More expensive? Reshore?
Re: Antares achieves criticality of Mark-0 reactor
#105Is anyone working in the US on a waste solution that isn’t a big hole with a straight out of cyberpunk sci-fi warning plaque? The French reprocess and recycle fissile material but that’s kind of a gnarly industrial process. Still they do it and it works. The long term solution is to create a second kind of reactor that has a higher burn fraction which means a more fuel efficient fast reactor. Those would be, ideally,…
IMO, the long term solution will be to simply launch the waste into space. With low enough launch costs the extra mass needed to armor the waste against accidents becomes tolerable.
Haven't you seen https://en.wikipedia.org/wiki/Space:_1999 ?
Re: Antares achieves criticality of Mark-0 reactor
#106Antares were the first ones: https://www.energy.gov/articles/department-energy-celebrates... And closely followed by Valar Atomics two weeks later: https://www.energy.gov/articles/department-energy-celebrates...
Actually this guy achieved criticality before either of them: https://i.imgflip.com/a0w01q.png
Re: Antares achieves criticality of Mark-0 reactor
#107Earlier quoted context omitted.
$10/kg isn’t fantasy land if we have fusion rockets, but then we don’t need fission power anymore. :)
Fusion would be useless for launch to orbit. Even fission sucks for that. It's really hard to beat the cost and power density of chemical rockets.
Depends. If we get explosive inertial confinement fusion to work you could build a pure fusion version of a nuclear pulse rocket. Look up Project Orion.
Orion (in its fission bomb form) is impractical and would be insane to launch from Earth, but it holds the title of being the only “torch ship” drive we know how to build. We could technically build it.
Re: Antares achieves criticality of Mark-0 reactor
#108Earlier quoted context omitted.
Footnote has the backup. 2-3x is guesstimate, but it doesn't really matter. The answer is there's just not much waste to store
Sure there isn't a prohibitive quantity either way but regardless I think the 120k number might be off by one or two orders of magnitude even before reprocessing reduces the amount by ~95%.
you'll have to take that up with the folks from worldnuclearwastereport.org
Re: Antares achieves criticality of Mark-0 reactor
#109Earlier quoted context omitted.
I don't think that's the case, if launch costs are low enough. The options you describe there are quite expensive. Reprocessing costs somewhere in the neighborhood of $1000/kg. Even fast reactor have trouble disposing of the seven very long lived fission products. A fully reusable launcher might get costs down to $10/kg to LEO. Even if one had to wrap the waste in 10x its mass in launch armor this could be much cheap…
The problem with launching anything into orbit using current rocket motor technologies is that heavier stuff costs more to put into orbit. The elements that are used in nuclear reactors (particularly Uranium and Plutonium) are pretty dense, and thus heavy.
That's true, but the cost of reprocessing is also very high, per kg. And aren't the nuclear bros always telling us how little nuclear waste is actually produced? There's about 30 tons of spent fuel per GW(e)-year from today's burner reactors. At $10/kg to space that would be just $300,000 (yes, ignoring lots of costs there, at $10/kg is aggressive, but this is for comparison), a pittance compared to the value of energy produced from the power plant: at $0.05/kWh it produces > $300 M in electrical energy, three orders of magnitude higher.
Re: Antares achieves criticality of Mark-0 reactor
#110Earlier quoted context omitted.
> Cost is not only relevant, it's paramount. Efficiency is only important insofar as it affects overall cost. Oh sorry, I thought you were talking about efficiency. Ok, what is the cost is for these plants? > A single full time employee, like a security guard, will cost a good chunk of that. I dunno, a 1MW nuclear plant could end up being pretty small. It might easily be economic to install them places that already h…
Back in the 1950's, as part of a study for putting ICBM bases in Greenland, the US Army built a 2MW reactor (PM-2A) and deployed it to the test base (Camp Century) in Greenland. It powered the camp for about three years, modulo a little problem where it was shut down for a while after a prototype (SL-1) killed two soldiers and a sailor in Idaho. In addition, the Navy operated another one (PM-3A, 1.75MW) for a decade…
The SL-1 accident was something. One of the casualties was missing for a short time until they found him speared to the ceiling by a control rod that had been ejected from the reactor.
They were all buried in shielded caskets, several feet deeper than normal.