Why can't nuclear waste be launched into the sun?

Question

My understanding is that nuclear waste is relatively small in volume, yet storage is problematic. If companies like SpaceX succeed, and the price of launching cargo into space falls by another order of magnitude or two, is is either possible or feasible to launch the waste out of Earth's orbit, either into deep space or at the sun?I can think of a few reasons this might be risky or impossible: 1. The risk of launching nuclear waste is too high, given the possibility of a failed launch spreading the waste in our atmosphere. 2. Even with an order of magnitude decrease in launch prices, it is still prohibitively expensive. 3. For engineering reasons, it's nearly impossible to launch a rocket at the sun. If nuclear rockets or reactors are built in space, would this be a possible way of handling nuclear waste from reactors already in space?

nabla9 · Accepted Answer

Very popular question.The short answer is: Counterintuitively it would take less energy to launch a spacecraft to another star than our own sunAs for why not into the space in general:Risk of rockets failing. Lancing probes with small nuclear batteries is controversial. Think about launching tens of tons of nuclear waste. Almost 100,000 tonnes of nuclear waste is produced per year. That's clearly too much to launch.If we would use SpaceX Falcon Heavy to launch only the highly radioactive waste )12,000 tons per year) for $2,500 per kg. It would cost $30 billion per year and 240 Falcon Heavy launches per year. Some of them will fall down, explode etc. and that must be dealt with.----https://www.popularmechanics.com/space/rockets/a21896/why-we...https://www.forbes.com/sites/startswithabang/2019/09/20/this...https://www.universetoday.com/133317/can-we-launch-nuclear-w...https://astronomy.com/news/2016/07/heres-why-we-cant-just-ro...

db48x · Answer

Not only is the Sun the most expensive place in the solar system to deliver cargo to, it's also a really stupid idea to throw away nuclear waste. What we call waste today is really just fuel that we have extracted about 2% of the available energy from. The other 98% of the energy is still in there, waiting for us to decide to use it. The only reason we don't use that energy is that we didn't build reactors that can use it, and these days it's basically impossible to build new reactors. Too much politics, too many rules, too much NIMBY.

sxp · Answer

You should play https://www.kerbalspaceprogram.com/ to learn the mathematics of orbital dynamics required to launch something into the sun. It's really hard which is why many of our solar system probes need to bounce off other planets (aka "gravity assist") to get close to the sun.
The math might change once we get a space elevator and a solar sail since it would be cheaper to get things into orbit and then parachute them into the sun.
Another idea would be to bury it into a really deep hole (https://en.wikipedia.org/wiki/Deep_borehole_disposal) or a part of the tectonic plates that would quickly take it into the Earth's core (https://en.wikipedia.org/wiki/Ocean_floor_disposal).

scribu · Answer

"For a spacecraft to launch toward the sun, it must accelerate to nearly match the Earth’s velocity—in the opposite direction."
Source: https://www.theatlantic.com/science/archive/2018/08/parker-s...
> If nuclear rockets or reactors are built in space, would this be a possible way of handling nuclear waste from reactors already in space?
If you're not already falling towards the Sun, it must mean you're in some sort of orbit around it. So you'd still need to cancel that out.

notaspecialist · Answer

We should hoard that like the gem it is. Higher atomic-complex material that is not common like hydrogen can be useful for the future when we learn how to artificially increase the neutron count in a stable method.

ALittleLight · Answer

Storing nuclear waste isn't really a problem, we have a lot of ground to bury it in, and, as you say, it's relatively small. One way to think about it is that the nuclear fuel is all buried in the ground before we use it, so burying the waste (or using it in a different reactor) seems perfectly reasonable.

hindsightbias · Answer

Finding the most expensive solution to a problem sometimes works for DoD or NASA. But nuclear just isnt sexy enough.

logotype · Answer

Why not the other way around? Drill into the earths core and simply dump it there.

simonblack · Answer

I once suggested that we put it into orbit, probably around the Sun. That meant it was far enough away not be harmful, but close enough that when conditions were right, it could be recycled into usable resources.

alkonaut · Answer

Yes, all of the above.2 and 3 are almost the same thing with &ldquo;difficult&rdquo; and &ldquo;expensive&rdquo; being closely related.

happy_path · Answer

Side question, and what about sending nuclear waste to a volcano?

known · Answer

May be possible in the longer run when we have appropriate cost-benefit-analysis

chovyfu · Answer

or our trash. always wondered this. its probably cost prohibitive is the general answer.