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Nuclear Waste + the Sun

by SHISHKABOB
Tags: nuclear, waste
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twofish-quant
#19
Jan13-12, 11:25 PM
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Quote Quote by Bobbywhy View Post
I am concerned about the initial phase of this proposal: the launch phase. What would be the risk to us and our environment if the launch vehicle exploded? Seems to me it would be a huge risk of radiation contamination; so great that I would not agree with the idea at all.
Conversely if we had the technology to put 60,000 tons of highly radioactive waste into space with zero probability of failure, then I'm pretty sure we could think of something easier mechanism to deal with this. For example, if we had that level of space technology, we could probably build solar power microwave satellites so that we wouldn't have to worry about nuclear waste at all.

One thing that I wonder about is that I'm wondering if the environment impact of all of those rockets would be worse than than the impact of the radioactive waste.
e^(i Pi)+1=0
#20
Jan14-12, 12:56 AM
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Quote Quote by Vanadium 50 View Post
Where does this "decaying orbit" come from? What is the force causing it to decay?
Sorry, I'm not familiar with orbits. I assumed that under a certain critical velocity an object would just continue spiraling inwards, but I suppose the orbit would just get more eccentric?
Chronos
#21
Jan14-12, 02:44 AM
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It would be colossally stupid to rocket radioactive waste into space, regardless of the destination.
Astronuc
#22
Jan14-12, 09:41 AM
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Quote Quote by SHISHKABOB View Post
okay so I don't want this to be an argument on whether dumping nuclear waste into the sun is feasible or practical or not, as I'm pretty sure it's not

rather I'd like to ask a question that my mom asked me once when I was trying to argue the idea to her. She asked me: "well if you dumped so much radioactive material into the sun, how do you know what will happen if you do that? What if something terrible happens that we could not have predicted?"

My opinion was that the sun is a giant furnace and is already emitting radiation in all sorts of forms and adding a relatively tiny amount of heavy elements to it is not going to have a profound effect on the sun's behavior. She was not convinced, basing her opinion on the fact that I really had no idea what I was talking about, and I really don't.

So, would anything bad happened if we dumped all of our radioactive waste material into the sun? http://ca.answers.yahoo.com/question...5151923AAzOMTF this guy gives an estimate around the middle of his post that there's 60,000 tons of radioactive waste in the world.

if the sun is about 2x10^30 kg, and 60,000 tons is 54.4x10^6 kg, will dumping 2.72e-23% of the sun's mass of radioactive material do anything? What if we had a hell of a lot more nuclear waste, let's say 60 trillion tons, over the course of many years and a big increase in nuclear power plant production, would that much do anything?

What if we dump it all in at once? Will that be different from dumping over a relatively long period of time?

I guess the basic question here is: what happens to nuclear waste if you vaporize it? And then also would it come spraying out of the sun back at us?

EDIT: maybe this should have gone in the nuclear part of the forums, but I was particularly interested in the sun part of the question
Very impractical (as indicated by DH et al), although such limited mass would not affect the sun in any significant matter. Assuming one could get the waste to the surface of the sun, it would more or less stay there, unless it got caught in a CME.

The sun already produces prodigious amounts of radiation in the form of high energy protons, electrons and ions/nuclei. But of course, most nuclei are not radioactive, i.e., they are stable isotopes.

Other points to consider in such a plan - 1) the cost of launching material (~$10,000/kg) from the earth to orbit, the first step before transporting from LEO to GEO to elsewhere in the solar system, and 2) the radiation pressure on any material object as it approaches the sun. In the former, compare the energy required to dispose of the waste to the energy derived from the waste. For the latter, determine if the waste could actually be deposited in the sun.
Chronos
#23
Jan14-12, 11:52 PM
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It would make far more sense to dig a deep hole in a remote desert and dump the stuff in there - oh, that has already been proposed. Launching radioactive waste into space is not only expensive, but, illogical. One errant launch could contaminate an entire hemisphere. What are the odds of that happening - far too high for my comfort level.
SHISHKABOB
#24
Jan15-12, 12:24 AM
P: 614
well, like I said, it was more a question of what would happen if the sun got a dose of radioactive material, not so much the practicality of eliminating nuclear waste via launching it into space
Astronuc
#25
Jan15-12, 06:10 AM
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Quote Quote by SHISHKABOB View Post
if the sun is about 2x10^30 kg, and 60,000 tons is 54.4x10^6 kg, will dumping 2.72e-23% of the sun's mass of radioactive material do anything? What if we had a hell of a lot more nuclear waste, let's say 60 trillion tons, over the course of many years and a big increase in nuclear power plant production, would that much do anything?
2.72e-23% of fission products and transuranics would have no significant effect, and neither would 1 e-14%. The fusion process already produces gamma and beta (positron) radiation.

http://csep10.phys.utk.edu/astr162/l...y/ppchain.html
http://csep10.phys.utk.edu/astr162/lect/energy/cno.html

Locally, there would be a reduction in pp-fusion, or CNO-fusion, and there would be a change in emission spectrum based on the range of Z-values, but the additional lines would be rather weak compared to H, He lines.
D H
#26
Jan15-12, 07:23 AM
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Quote Quote by Chronos View Post
It would make far more sense to dig a deep hole in a remote desert and dump the stuff in there - oh, that has already been proposed. Launching radioactive waste into space is not only expensive, but, illogical. One errant launch could contaminate an entire hemisphere. What are the odds of that happening - far too high for my comfort level.
Rocket technology isn't all that reliable. Odds of a failure are somewhere between 1/50 to 1/200. With thousands of launches needed to get 60,000 tons of material into space, there's a near certainty that several failures will occur. Dumping nuclear waste into space just isn't logical.
qraal
#27
Jan22-12, 05:34 AM
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Quote Quote by SHISHKABOB View Post
okay so I don't want this to be an argument on whether dumping nuclear waste into the sun is feasible or practical or not, as I'm pretty sure it's not

rather I'd like to ask a question that my mom asked me once when I was trying to argue the idea to her. She asked me: "well if you dumped so much radioactive material into the sun, how do you know what will happen if you do that? What if something terrible happens that we could not have predicted?"

My opinion was that the sun is a giant furnace and is already emitting radiation in all sorts of forms and adding a relatively tiny amount of heavy elements to it is not going to have a profound effect on the sun's behavior. She was not convinced, basing her opinion on the fact that I really had no idea what I was talking about, and I really don't.

So, would anything bad happened if we dumped all of our radioactive waste material into the sun? http://ca.answers.yahoo.com/question...5151923AAzOMTF this guy gives an estimate around the middle of his post that there's 60,000 tons of radioactive waste in the world.

if the sun is about 2x10^30 kg, and 60,000 tons is 54.4x10^6 kg, will dumping 2.72e-23% of the sun's mass of radioactive material do anything? What if we had a hell of a lot more nuclear waste, let's say 60 trillion tons, over the course of many years and a big increase in nuclear power plant production, would that much do anything?

What if we dump it all in at once? Will that be different from dumping over a relatively long period of time?

I guess the basic question here is: what happens to nuclear waste if you vaporize it? And then also would it come spraying out of the sun back at us?

EDIT: maybe this should have gone in the nuclear part of the forums, but I was particularly interested in the sun part of the question
The Earth and Sun are made of roughly the same stuff, but Earth lost most of the hydrogen/helium that makes up most of the Sun. Heavier elements make up about 2% of the Sun, the equivalent of about 7,000 times the mass of the Earth. That's a lot of heavy stuff to dilute a tiny, tiny fraction of the Earth's uranium in.

If all the radioactive waste dropped into the Sun and was sprayed back out at the Earth, how wide an area would it spread out over? At 6 atoms of solar wind per cc, streaming out of the Sun at 400 km/s that 60,000 tons (assume its atomic mass is 238) will spread out over a circular area about 9 million kilometres across if it all came flying back out at once. Diluted over such an area, with Earth a tiny fraction, the rise in radioactivity of the planet would be barely noticed, let alone hazardous.
Ryan_m_b
#28
Jan22-12, 06:23 AM
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Quote Quote by Chronos View Post
It would make far more sense to dig a deep hole in a remote desert and dump the stuff in there - oh, that has already been proposed. Launching radioactive waste into space is not only expensive, but, illogical. One errant launch could contaminate an entire hemisphere. What are the odds of that happening - far too high for my comfort level.
+1.0 To this. Whenever I hear a proposal that involves launching something into space to achieve the goal I always think about whether or not those billions of dollars could be better spent doing the job on Earth. At the cost of developing a system of fail-safe rockets capable of transporting kilotonnes of material we could just build deep vaults.
qraal
#29
Jan22-12, 06:50 AM
P: 775
With the right gravity assist from Jupiter a payload can be dropped into the Sun for a much, much lower fuel bill than doing a direct mission. But as most of the "waste" is potential fuel for future reactor designs the idea of dumping it is stupid. Likewise indefinite burial.
osxraider
#30
Dec3-12, 02:09 AM
P: 26
hello everyone,

I've been reading through the thread as a search got me here and of course, I love PF!

Anyway, I have a problem to solve and so I thought I'd tried a revive this thread!

Here is the problem statement:

A nuclear waste disposal spacecraft is to be sent from Earth in order to carry radioactive waste either out of the solar system or into the Sun. Which alternative is cheaper in terms of delta v requirements ? The lesser delta v, the cheaper!

Remember that planetary fly-bys are allowed which means Venus and Mercury for this specific problem going to Sun. We will assume that whenever the spacecraft reaches Venus's sun orbit, venus will be there and the same for mercury. In case we are dumping outside the Solar System, we need to consider all planets beyond Earth. These should be used to minimize the required delta v.

Further, both trajectories lie in the elliptic.

Can people get me started off on how to go about designing the orbits and then figuring out which one is ultimately cheaper?

I will also need to use STK to design the orbits!

I'm sure now you understand why I came upon this thread! I would be very appreciative of any guidance! Thanks!
Bobbywhy
#31
Dec3-12, 02:51 AM
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[QUOTE=osxraider;4182443]

Further, both trajectories lie in the elliptic. QUOTE]

Did you mean "ecliptic"?

http://en.wikipedia.org/wiki/Ecliptic
osxraider
#32
Dec3-12, 03:33 AM
P: 26
hello Bobby,

sorry, I meant all trajectories are elliptical.
D H
#33
Dec3-12, 04:53 AM
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For those who wish to help oxraider, please do so in this thread: http://www.physicsforums.com/showthread.php?t=656422.
ImaLooser
#34
Dec4-12, 04:32 AM
P: 570
Quote Quote by mathman View Post
I haven't done any quantitative analysis, but I suspect if the entire earth was dumped into the sun nit much would happen.
Dumping all of the planets in there would not have any significant effect, I think. I have read that a small black hole passing through the Sun would not have all that much of an effect.
tfr000
#35
Jan20-13, 08:11 AM
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P: 127
re: "decaying orbit"
It can be done - just design the orbit so that the perihelion dips into the outer atmosphere (whatever it's called) of the Sun. With each pass, it loses a little v due to drag, until it finally crashes and burns.
Of course, the difference in delta-v to get from that orbit to a directly-intersecting one is minor, so there's not really any point.
Tango Whiskey
#36
Feb4-13, 01:56 AM
P: 1
To think that dumping all of the waste on the planet would cause any disruption at all would be like saying that dumping a bucket full of iodine in the ocean would turn it orange. The volume is absolutely non-existent in scale.


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