In principle, it could be hundreds or even thousands of years before the supply of uranium is a problem, if we used the uranium efficiently, but with today's reactors, with no fuel reprocessing and no breeder reactors, if we used nuclear for all the electrical generation in the world, we would run out in a few decades.

You forgot to add "and did not do any more exploration and any more qualifying of existing reserves, let alone entirely new types of uranium sources"

Your statement requires far too many caveats to be meaningful for anything. Under even the most optimal scenario nuclear won't replace for example existing solar, wind, hydro, etc (and as if the production infrastructure for building more will just go away). Breeder reactors *do exist* and *can be built* if there were any reason to, and then you're burning the 99,3% of 238U instead of the 0,7% of 235U (plus preexisting nuclear waste and depleted uranium). Reserves of uranium are limited by the fact that there's little incentive to explore for more or even quantify more of known deposits. And techs to put many orders of magnitude more uranium on the market at prices still eminently affordable for power generation, like seawater extraction, do exist.

The world is not going to run out of nuclear fuel, period.

That's not the problem. The problem with nuclear is capital costs. And most attempts to try to lower them are a mix of either wishful thinking or a safety risk.

There is one thing I'm optimistic about for improving nuclear's economics, but it has nothing to do with the plants themselves - it's energy storage. Whether you're talking advancing grid batteries, or new tech like storing nuclear heat, if you can timeshift generation to better match demand then you can significantly increase your mean sale price, and thus your economics. Still, its main competition - solar and wind - continue their price declines, so it's a moving target.

Another interesting possibility is what Steady Energy in Finland is doing (a friend of mine works for them): nuclear heating-only plants. On one hand, that sounds stupid - electricity is far more valuable per joule than heat, and you're throwing that away. But in exchange, your plant can be lower temperature and far lower pressure, and is in general way easier to build, and build safely (sort of halfway between the complexity of building a fission power plant and merely having fresh nuclear waste heating up a cooling pond).

EU BEV+PHEV sales are 1/4 of total vehicle sales at present. Should be the lion's share within a couple years. That doesn't make the preexisting fleet go away, but it does throw fuel demand growth into reverse, which makes it ever-easier to supply from friendly (if not outright domestic) sources.

(Unless of course you kneecap the transmission line faerie with a baseball bat)

The transmission line faerie builds much faster than the solar farm and wind turbine faeries.

Well, "a" mistake. Prematurely closing nuclear was also a mistake. There have been lots of mistakes. NIMBYism with gas extraction Groningen was another. Polls showed that a majority if the local population supported more gas extraction after the Russian invasion of Ukraine even without a renegotiated settlement that would give them more royalties. Instead, Europe kept buying Russian gas.

It's always easier to continue consuming products that have externalities so long as it's someone else that has to suffer from those externalities, isn't it? (and cue the game where one points out that everything has externaltiies (true) so all externalities should be treated as equally bad (not even remotely true) ).

Thanks, Obama. :P

I'm sorry, but this is nonsense. Yes, building new nuclear power plants has dubious economics. But the cost of a nuclear power plant is overwhelmingly a capital cost. Prematurely retiring an existing nuclear power plant is economical nonsense.

With nuclear power, trying to built plants quickly is not a good idea.

On some things, safety is paramount. Nuclear power is at the top of that list.

Nuclear is just one of many ways to avoid that strategic mistake.

Except Europe became dependent on Russia for nuclear fuel. Arguably we're having more trouble quitting Russian (and CIS) nuclear fuel than we are their oil and gas.

It's not about nobody seeing it, it's about certain parties taking control in certain countries with some dumb policy ideas.

To be clear, I'm not at all supportive of some mass rollout of new nuclear (beyond it being far too expensive of a source of energy, it's worth mentioning that Europe also imports nuclear fuel from Russia). Solar + wind + batteries is much cheaper (not to mention harder to target in a conflict). But phasing out existing nuclear plants, that you've already paid for, which still have plenty of life left in them, is beyond stupid. And not changing direction after the Russian invasion of Ukraine, even moreso.

Please tell us more about the illegal things you're storing on your computer that you would not want your closest family members to know about.

(outside those few minutes when this is available, being in low-earth orbit)

Their intent is a constellation, not just a single satellite.

Lighting up the battlefield for both sides is noticeably less advantageous than lighting it up for yourself while the enemy stays in the dark.

You don't light up random battlefields at random times. There are times when it is advantageous for you that the battlefield be lit, and there are times when it is advantageous for the battlefield to not be lit. Versus things like flares, this is a dirt-cheap way to create illumination. And vs. spotlights at standoff distances, it is simultaneously far more effective, and far safer for you (it's hard to think of an easier target than a spotlight). For some sorts of options - for example, small drone strikes a dozen or more km from your line - you don't have any options for illumination. Your best option is thermal cameras, though you can hide from those better than from conventional cameras, and they make your drones far more expensive.

And again, it's not only about battlefields, but even mundane things. If light can increase your margin of safety for, say, a midair refuelling operation or a ship-to-ship transfer at night, a couple thousand dollars is pocket change.

A bit of light also doesn't solve the problem of using 4M interceptors for 40k drones

You only use $4M interceptors for $40k drones if you can't target them with cheaper things sooner. Your ability to target them earlier with cheaper things is, among many other parameters, a function of illumination. A Patriot's AN/MPQ-53 radar doesn't care how bright it is outside. Oleksandr in some pickup truck with an antiaircraft gun very much does care how bright it is outside.

Oh, and re: exhaust impacts, I forgot to mention: beyond all the above, atmospheric sensitivity to ozone loss is highly season and latitude dependent. And thus, a high degree of amelioration can be done merely by shifting times and locations of bulk launches.

Your first paper is irrelevant right from the title: "The Climate and Ozone Impacts of Black Carbon Emissions From Global Rocket Launches". The launch industry is switching to methalox. It is not a meaningful black carbon producer. The paper at one point asserts, without reference, "Recently developed hydrocarbon fuels (including methane) are likely to produce BC similar to kerosene fuel", but this is absolutely false. I'm not going to bother reading the rest of the paper, but just from a skim-over I see a lot of stuff that's equally sketchy.

The second paper has the same issue - "Ozone losses are driven by the chlorine produced from solid rocket motor propellant, and black carbon which is emitted from most propellants." It however does refer to a switch to methalox - which is what's happening - as "actions ... key to defining an ozone-safe operating envelope for such vehicles".

It's exactly as I wrote: the worst offenders from exhaust are SRBs. Next is black carbon and NOx. Water vapor is not totally innocuous, but it's quiet minor by comparison. And contrary to the first paper's - and I must stress this, deeply wrong assertion - methalox is not a meaningful black carbon emitter, unlike LOX/Kerosene. Which is actually one of the reasons it's favoured for reusables, not just things like ISP - the high carbon production of LOX/Kerosene gunks up your engines over time, and increases the maintenance cost. Methalox burns quite clean. You can literally see it - the reason why keralox burns so vastly brighter, with a red-yellow glow, is incandescence of the black carbon particles in it (like a lamp mantle). Methalox is almost completely clean by comparison, and thus appears as a faint blue. Kerolox also - unlike methalox - leaves a visible soot trail behind it.

As for your final link: "Although direct health or environmental impacts at ground level are unlikely". And even that is heavily overselling the case. Reentering dust simply is not, and unless we get to Dyson Sphere-engineering levels, never will be - in meaningful quantities vs. terrestrial dust. One is talking about alumina quantities from megaconstellations on the order of 15kT/yr. Terrestrial dust is 25-30 MT *at any given point in time*. Coarse dust has a residence time of a couple hours, fine dust 1-2 weeks. If one assumes a mean residence time of dust of 1d, then the atmosphere gets an addition of 10 *gigatonnes* of dust per year. Megaconstellations are utterly irrelevant compared to that. You simply cannot compete with wind in the game of "adding dust to the atmosphere".

It does need more study, but that "more study" has nothing to do with dust in the troposphere. Rather, we need a good model of alumina catalytic activity *without* the HCl of a SRB's exhaust stream.

(And even if it were deemed a problem, satellite manufacturers would just switch to polymer-based materials for the bulk of satellites anyway and reduce the scale of Al deposition by an order of magnitude)

ED: did my math wrong - the sun is ~450000x brighter than the moon, so the prototype mirror would be 7,5x brighter than the moon (minus reflector losses, and potentially some variation due to different atmospheric absorption from the different spectrum).