Here in the Kurzgesagt labs we test very important ideas to see what happens when you blow things up
or play with black holes. Many of you suggested that we look into an idea that sounds reasonable:
Shooting nuclear waste into space. It is one of those concepts that seems like an
easy fix for one of the main problems with nuclear energy. But it turns out this idea
is not just bad but horribly bad and it gets worse the longer you think about it.
Why is that?
What is nuclear waste?
Nuclear waste is a fuzzy term and comes in categories which
vary from country to country. But in general there are three broad levels:
90% is low level nuclear waste – tools, gloves or
trash used at a nuclear facility that could be weakly contaminated,
with some short lived radioactivity. This stuff is generally safe for normal disposal.
7% is intermediate level nuclear waste – mostly materials that have been in close proximity to a
reactor core long enough to become dangerously radioactive. With proper handling it is either
safely buried or melted down and mixed into glass or concrete and stored deep underground.
So 97% of nuclear waste is similar to toxic byproducts from other industries. Not great,
not terrible – we can handle it. The remaining 3% is where our problems begin.
High level nuclear waste is very concentrated spent fuel taken out of a reactor core. Formerly
uranium, it is now made of various dangerous and often highly radioactive elements. As a bonus it
is also incredibly hot and not easy to handle at all. This is what we want to shoot into space.
All in all, around 440 active nuclear reactors create about 11,000 tonnes of high level nuclear
waste each year. Since 1954, we have accumulated 400,000 tonnes of dangerous radioactive waste.
Most countries are dealing with it by not dealing with it and kicking the can towards the future.
Great! So let’s launch it into space! According to scientists space is big and nobody lives there,
so it seems perfect for yeeting away this mess. There are a few tiny problems though.
Problem 1: Stuff Ain't Cheap
Even though spaceflight is getting more affordable, it’s still extremely
expensive. Just to get something into low earth orbit costs on average about $4,000 per kilogram.
Putting that into perspective, it costs about $1600 to mine, separate, and fabricate one
kilogram of nuclear fuel, so launching waste into space has suddenly made nuclear fuel for reactors
way more expensive and greatly increased the cost of the electricity they produce.
To launch one reactor’s worth of nuclear waste would cost at least $100 million per year.
To deal with all the 440 operational nuclear power plants’ high level nuclear waste, would cost
some $44 billion per year for space launch before packaging, transport and security costs are added.
Ok let us pretend we don’t care. Currently we could not shoot all the nuclear waste
into space even if we wanted to. There just aren’t enough rockets.
In 2021, we saw a record 135 launches into space. If we repurposed each of those rockets and filled
them all with nuclear waste, the total amount that could be lifted into a Low Earth Orbit,
which is the closest orbit above the atmosphere, is nearly 800 tonnes.
We’d need at least 14 times more rockets to handle just today’s nuclear waste,
let alone get rid of the hundreds of thousands of tonnes in temporary storage. We would need
to create entire new space industries to keep up with the demand for giant,
toxic space trash trucks. And it gets worse!
Problem 2: Space is hard
We only made the calculation for low earth orbit, where we send most of our rockets and satellites.
Littering the space around earth with thousands of casks of spent nuclear fuel would be a nightmare
for space junk management and satellite collision avoidance. Worse still, at this altitude there
still is a little bit of atmosphere causing a tiny bit of drag, so we might have nuclear
waste raining down from space within just a few years. Experts would call this a huge problem.
Clearly, we have to launch our waste farther. If we wanted to send it to, perhaps, the moon,
we either need way more rockets or we need to build much bigger ones. Making it even more
expensive. A single Saturn V, the rocket used by the Apollo program, which cost about $1.5
billion adjusted for inflation per launch, could get about 43.5 tonnes from the earth to the moon.
So we would need about 260 Saturn V rocket launches every year. And of course, using the
moon as target practice for nuclear-waste tipped rockets kind of makes a huge mess.
So maybe don’t aim for anything – space is empty, do we really need a target?
Shooting waste in any random direction is, you guessed it, also a bad idea. Orbits are
loops which means they have a tendency to come back to where they started. Put enough in the
sky in random directions, and you'll get one back eventually. So we would want to launch our nuclear
waste deep into space, which means we need EVEN bigger rockets that would be even more expensive.
Not that we would be completely safe then. Earth might run into these interplanetary caskets at
some time in the far future and experience a pretty meteor shower made from radioactive dust.
Ok. But how about we shoot it into the sun?!
Ironically, the sun is pretty hard to hit.
While the sun has very strong gravity, everything on earth is moving with respect to the sun,
including the rockets that we launch, meaning a rocket would have to ‘cancel
out’ all the orbital motion it has around the sun so it can stop orbiting and fall in.
Because of this it is actually easier to launch a rocket entirely out of the solar
system than it is to launch it into the sun. But to do either of these
things we need even bigger rockets, probably the biggest we’ve ever built.
Urgh. Nothing works.
The thing is: It still gets much worse.
Problem 3: Rockets go Brrrrrrrr
Rocket engineering has taken huge steps since the Apollo era.
We have made them relatively safe. We’ve mostly replaced the toxic explosive cancer
fuels of the past decades with much saner mixes of liquid oxygen and hydrogen or
kerosene. The newest designs even land themselves so that they can be reused.
And yet, Out of the 146 launches in 2021, there were 11 failures. Which means that a sizable
number of our rockets carrying high level radioactive waste would be exploding on the
launch pad or in the worst case: disassembling at high altitude or crashing from hypersonic speeds.
Each failure would be at least equivalent to a mini-Chernobyl – but instead of being
contained under a slab of concrete, spread throughout the atmosphere.
Radioactive particles could make their way to far away places by riding on the winds.
Most would fall in the ocean but some would land on the inhabited parts of the world.
They could cover farmlands and get concentrated into our food, or enter our water supply. Which
is, well, bad. Imagine regular large scale nuclear disasters happening. People would not be happy.
Conclusion and Opinion Part
Nuclear waste is scary. But the fear of it and horrible ideas like shooting
it into space reveals how bad we are at understanding risk. Because the largest
amounts of radioactive elements like uranium and radon are actually released by coal. Burning
millions of tonnes of coal each year leaves ash as a waste product, that includes about
36,000 tonnes of radioactive materials. Less radioactive than high level nuclear waste,
but there is also a lot more of it and it is handled way less carefully.
Some of this ash is caught by filters, but most is simply pushed back into leaky mines, shoved
into piles exposed to the wind or poured into ponds that regularly spill into rivers and lakes.
Living within 1.6 km of an ash pile increases your cancer risk up to
2000 times over the acceptable limit. And this is on top of other toxic chemicals like heavy metals,
and of course their massive CO2 emissions. And yet, while nuclear energy is flawed and its
current form may only be a transitory technology, nuclear power plants are a harder sell than coal.
Nuclear waste and the lack of willingness to deal with it are a real issue. It's not insurmountable
though. There are good methods to handle it, like burying it deep underground or reprocessing some
of it into new fuel. But however we ultimately deal with this issue we hope one thing is clear:
shooting nuclear waste into space is one of the worst ideas ever.
Researching this crazy thing, conducting all of these important tests and of course,
creating this video, took us around 2,000 hours – which is insane for a YouTube video.
And we couldn’t do it without you!
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