Everything I've heard is that micro-reactors produce far worse waste situations than larger scale options.

I think there's a huge opportunity for nuclear power in the world today.

But: all these micro-reactor strike me as disastrously bad idea, that's all too likely to offload incredibly complex nasty gross problem to the future. Costs that alas will likely be handled as network externalities, as drains and damage against humanity and people and government, that the creators and purchasers of these device will skate through with comparatively little injury.

▲

yongjik 3 days ago | parent | next [-]

Considering that fossil fuels "solve" the problem by literally dumping its waste onto the atmosphere, endangering the global ecosystem, and we're still merrily using them...

I think it's a bit melodramatic to say microreactors offload nasty environmental problem to the future. Also, their environmental problem is literally at the scale of "Drop them in an abandoned mine somewhere, where they cause zero harm to the world, and we will have a few centuries to figure it out."

	▲	legulere 3 days ago \| parent [-]
		Recapturing the CO2 from the environment of fossil fuels is almost impossible is almost impossible. Recapturing radionuclides is much much more difficult. Also the duration in which radionuclides are a problem has to be taken into consideration, making even babysitting nuclear waste extremely expensive.

▲

generalizations 3 days ago | parent | prev | next [-]

Counterpoint: we've been powering ships with microreactors for decades.

▲

jauntywundrkind 3 days ago | parent | next [-]

And we're starting to have to decomission them! At absurd costs!

We just awarded $0.5B to decommission the USS Enterprise (CVN 65), the first nuclear aircraft carrier. More will follow! https://theaviationist.com/2025/06/03/uss-enterprise-dismant...

The DoE has been helping to decomission Los Angeles class attack subs for a while now. Here's a piece on that: https://www.defense.gov/News/Feature-Stories/Story/Article/4...

It require enormous care & effort. It's fantastically costly. Do I think it was worth it? For a mission like this: I think yes. For the good of a nation. And a Nation that hopes to still be around to take care of the problem, the complex decomissioning decades latter. But I have so little faith that private interests will endure and bear their own responsibility for this awesome but deeply corrupting irradiating force.

	▲	LgWoodenBadger 3 days ago \| parent [-]
		That CVN also happens to have 8 reactors in it

▲

acidburnNSA 3 days ago | parent | prev | next [-]

Most nuclear-powered ships have reactor powers in the 40-300 MWt range, a bit beyond the typical 10 MW limit for 'microreactors'

	▲	evan_ 3 days ago \| parent [-]
		This was new to me so I looked it up- "MWt" means Megawatts Thermal - e.g. the heat output of a reactor, which would be turned into a smaller value of MWe- Megawatts Electric

▲

zer00eyz 3 days ago | parent | prev | next [-]

We sure have.

And it is a money pit.

And then you have things like this: https://www.navytimes.com/news/your-navy/2019/01/10/two-sail...

It's proof that you can build a robust and safe reactor, but like all things under triple constraints it will not be cheap.

▲

Peteragain 3 days ago | parent | prev | next [-]

Yep. And the Russians have had pluggable nuclear power for years now.. on barges: wikipedia.org/wiki/Akademik_Lomonosov Decommissioning no doubt will consist of scuttling them over a trench. Definitely going to wake the Kraken.

▲

corranh 3 days ago | parent | prev [-]

Hopefully this needs a smaller crew to operate than a Nimitz-class aircraft carrier.

	▲	dylan604 3 days ago \| parent [-]
		The nukes on a carrier are a much smaller team within the carrier's full crew though. So if you extracted the guys that glow in the dark, it might be more inline

▲

acidburnNSA 3 days ago | parent | prev | next [-]

Meh it's a little bit worse, because smaller reactors burn a smaller fraction of their fuel and therefore make more volume of high level waste per kWh generated.

But it's not THAT much worse. Nuclear waste is already ridiculously small in volume per kWh vs. any other fuel-burning energy technology. Right now all of the waste we've accumulated from making 20% of the country's electricity for decades fits on a football field 3 meters high (that's pellets only, if you include individual dry casks it's 135 meters). So if we make lots of small reactors that are a bit less fuel efficient we might need 2 big football fields deep underground rather than 1. Compared to all the particulate and CO₂ emissions other sources make I'm just not that worried about it. Recall that fossil kills ~6 million per year from particulate emissions alone. Commercial nuclear waste has never hurt anyone, and is unlikely to do so in the future.

	▲	AngryData 3 days ago \| parent [-]
		Not to mention if we really wanted to and/or had enough of a supply of it, that higher grade waste can in large part be recycled and used again.

▲

DoctorOetker 3 days ago | parent | prev [-]

From a humanistic species survival perspective, we should conserve nuclear energy for interstellar travel.

▲

XorNot 3 days ago | parent | next [-]

If interstellar travel ever becomes possible you'd already have access to all the resources of the solar system as well as the output of the entire sun.

The scale of the problem l, technologically simply renders earthbound resource constraints irrelevant.

Like you're into "synthesize antimatter with solar power" at that point.

▲

DoctorOetker 3 days ago | parent [-]

> If interstellar travel ever becomes possible you'd already have access to all the resources of the solar system as well as the output of the entire sun.

I'm not going to argue circular conditions, this is precisely why we should preserve dense energy sources, first an alternative abundant energy source must be demonstrated, before squandering it locally.

> The scale of the problem l, technologically simply renders earthbound resource constraints irrelevant.

Hidden in such statements is the implicit assumption that mining the solar system for fissile materials is less energy intensive than mining them locally.

We should make sure interstellar travel remains affordable by the time we decide to afford seeding other star systems.

Nothing prevents interstellar travel with current technology, it would just take a long time. We should keep this mode of travel, where survival on the ship is powered with known feasible technology (nuclear fission) on the table and conserve fissile materials until we succeed in compact fusion plants, in that case this constraint no longer is an argument to preserve fissile materials.

Speculating other energy storage technology like "antimatter storage as a battery to store solar power" before launching to another star is just that: speculation. We shouldn't squander fissile materials on the basis of feel-good speculation.

	▲	XorNot 3 days ago \| parent [-]
		No the assumption is that the magnitude of energy involved in interstellar travel is so large that it dwarfs all other considerations. If you can't afford to expend the energy to travel around the solar system to acquire resources, you definitely can't afford to engage in interstellar travel. And then of course, if you can't afford the energy to sustain a human population on Earth in decent conditions, you also definitely can't afford interstellar travel. Because implicit in your assumption is that somehow the extremely limited number of people who could be put on a slow ship (and by slow we're talking thousands of actual years minimum at "current technology" levels) will somehow be able to command and control all of Earth's fissile resources.

▲

3 days ago | parent | prev | next [-]

[deleted]

▲

9dev 3 days ago | parent | prev [-]

Interstellar travel to… where? It’s like saving your money for an immortality treatment that’ll eventually hit the market. Well yes it might, someday in the far far future. Practically speaking, this money should better be invested in your health now instead, aka. preservation of the only spaceship we have right now—Earth.

	▲	DoctorOetker 3 days ago \| parent [-]
		To different star systems obviously. Short of discovering portals or wormholes (natural or artificial), we should only assume demonstrated space propulsion technology to make the trip. With current technology its a long trip, and its cold and dark inbetween 2 stars. We should definitely conserve fissile materials until we demonstrate fusible materials for reliable power generation.