Comment by freudian123 | Hacker News Reader

Comment by freudian123 | Hacker News Reader

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I did some back of the napkin math, USA generates about 2000 tons of nuclear waste a year[1] and it costs DOE half a billion dollars to store it[2].

Instead as you said we could yeet it all into space with like 20 starship launches, taking the $100/kg price tag it would cost us 2 million dollars to send it to space. Starship electronics should be radiation hardened so the unique payload shouldn't affect it much. The only risk is starship blowing up during launch. That would be a bummer.

There's already a paper discussing this[3].

I love the last line in the paper

'Both the technology and the need exist. What does not yet exist is the will and support of the engineering and political communities'

Mind you this came out in 1992, we have far better technology now.

[1]https://www.scientificamerican.com/article/nuclear-waste-let.... [2]https://earth.stanford.edu/news/steep-costs-nuclear-waste-us... [3]https://space.nss.org/wp-content/uploads/Space-Manufacturing...

I imagine the risk of the rocket blowing up right after launch and scattering radioactive waste all over Texas would make this a non-starter.

If Starship flies as much and is as safe as SpaceX predicts, they will have enough data to show empirically that Starships launches have an expected risk below 0.1% (i.e., it won't rely on theoretical models). That 0.1% isn't nothing, but it could easily be acceptable if the nuclear waste disposal Starship flight is launched from a sea platform (which is currently a planned Starship capability) in the middle of the Pacific. For instance, it's already been well argued that dilution of radioactive waste in the oceans could also provide a good disposal option, leading to a worldwide increase in background radiation that is much smaller than the baseline levels.

(There are a lot of important details here, including (1) the disputed argument that some isotopes might be preferentially concentrated by some organisms to high levels in any dilution scenario and (2) that an explosion of Starship in the Pacific would not dilute the radioactive waste as uniformly as a dedicated waste dilution program. My comment is just trying to point out that this could plausibly be acceptably safe and more careful analysis would be needed to check.)

Could we not put it in a thick lead box which is designed to survive explosions?

Why don't they just make the whole plane out of the same material as the black box?

Thicker box = more weight = $$$. Plus is anything really resistant to thousands of tons of rocket fuel?

Sure, more weight but at the bargain price of $100/kg

Could it be resilient enough? I have no idea. I'm a programmer.

We already make containers that can tolerate being pummeled head on by freight trains without leaking, so I imagine that we could definitely engineer something similar for space travel.

Isn't Uranium as sturdy as any material you'd pick to encase it in?

Your math seems off, 1 ton is 1000kg, but your point still stands at $200 million plus the overhead of containment and transport to starship. This is far more economical that I expected.

But also this is the price to orbit. As the escape velocity is 1.5x higher we can probably assume the same or a greater increase in cost. Maybe you could just justify a really high orbit? It would take a long time for it to build up.

The main risk is taking off, you'd want something well protected and capable of surviving starship blowing up at any point during ascent, including returning safely to earth and impacting. You'd probably want to (unusually) launch over land - perhaps Alaska/Canada, to make retrieval easier should it fail before reaching orbit.

Once it's in a low orbit, the extra shielding isn't needed as much as it's not going to fall back to earth quickly, so boosting from there to a high orbit would reduce the mass needed to be transported.

In theory you could maybe do it for say $4b/yr all in.

How many orbital solar collectors could you use to concentrate energy and beam the equivalent energy currently produced by nuclear plants to a desert based collector?

Yeah, I didn't even consider this. But at what point does orbital solar energy start to make sense?

I wonder what the $/kg before we can just send up solar panels that last 100+ years and provide continuous microwave beams of clean energy to ground stations.

But once it's launched it's a lot of potential energy lost for ever, no?

Isn't there part of this spent fuel that could be used as fuel again? I'm thinking MOX on steroids.

Weren't surgenerators supposed to 'recycle' and reduce drastically the amount if 'final waste'? Weren't next-gen fission plants supposed to take in even higher rates of spent fuel?

I believe France has the types of reactors you are talking about in use - from what I remember they still do end up producing some waste though.

I feel like we should probably save the stuff just in case we end up needing it eventually in the future. Could be some aliens out there that love the stuff!

Oh yeah, there'll always be waste but reducing it by orders of magnitude is the best waste management bet I can think of. Less mining in sketchy places too. 'my waste is my energy independence strategy' :-)

Perhaps life on Earth was a long-con destined for us to throw our nuclear fuel out into the stars for easy harvesting

I wonder if lining a spaceship in nuclear waste might actually end up blocking interstellar radiation (assuming the nuclear waste is not also irradiating you). That stuff is pretty dense right?

I imagine that building a breeder reactor could be cheaper per kilogram of nuclear waste it burns, while also generating energy instead of spending it.

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