[chemicalLindsay]

you know how nuclear power plants once finished with there radioactive fuel rods they bury them somewhere really deep underground in lead containers.I wonder if they could bombard the used up radioactive fuel rods with radiation (beta.alpha and/or Gamma) in order to make the nucleus of the atom even more unstable ,Thus release more radiation which would hopefully decrease the half life of the element.This would then hopefully make the element decay alot more  rapidly ,thus release more radioactive particle and be more radioactive but make it become stable in an alot shorter time period.(note this is an idea that is almost definetaly wrong so dont try it or think it is right).

[hmx9123]

I've always thought that the way we disposed of nuclear waste was stupid.  Why can't we harness the energy that is there or figure out a way to use the waste?  I'm sure some bean counter figured out that even though it's expensive to bury the waste, it'd be more expensive to develop a way of using it, but still.  It seems like such a waste to me.  Maybe 50 years down the road we'll be digging up our radioactive waste in order to harness its power.

As for your question, I think that it is quite possible and may decrease the half life of the isotopes produced.  The problems are:
a. we aren't willing to pay to do the research to figure out what would happen b. it may create more of a mess than we had to start with
c. it may create isotopes with greater half lives.

You should do some reading on a nuclear experiment gone awry.  Look up 'radioactive boy scout' on google.  I'm not sure if the story is urban legend or not, because some of it sounds fishy to me, but it is an interesting story.

[jdurg]

The "radioactive boy scout" story is true.  Kind of scary really, but true.  As for the original question, the problem is with money and what the uranium winds up turning into.  In order to turn the waste into nuclides with short half-lives, you'd have to throw them in a particle accelerator which isn't cheap to run.  The amount of money spent on the attempted disposal of the waste would be far, far, far more than you could ever possibly earn from the fuel itself.  If you just bombard uranium-235 with radiation, you may very well wind up turning it into plutonium.  Plutonium has a much longer half-life than uranium and is much, much, much more fissionable.  Plutonium is horribly nasty stuff that is both chemically and radiologically lethal.  The idea of turning our spent uranium fuel into fissonable plutonium fuel was once researched, but envirnomentalists and activist groups prevented it from ever becoming widespread.  If you want to know more about it, just do a search for breeder reactors on google.  (Breeder reactors convert fissionable uranium into fissionable plutonium).  The only problem is that once you're done with the plutonium, you have spent plutonium waste which is even more nasty to cleanup than spent uranium waste.

[Corvettaholic]

Considering the future of the petroleum market, maybe converting spent uranium into fissionable plutonium isn't such a bad idea. I assume the US Gov't has looked into blasting radioactive waste into the sun, seems like a decent idea to me. But aren't there treaties involving radioactive material in space?

[hmx9123]

Well, the other problem with using breeder reactors is that your plutonium is close to or by itself weapons grade, from what I understand.  So if some idiots get a hold of your waste, you're in trouble.  Also, like you said, you've got plutonium waste after using it in a reactor.  Crazy.

I've heard of the idea of sending it into the sun before, but I was talking with a friend the other day and discussing that; there's an odd problem to that, which is that perhaps one day we'll need that material, and if we've effectively destroyed it, we're in trouble.  Right now we have a tremendous amount of natural resources in landfills.  Imagine if we took it all and sent it to space, never to return.  We'd effectively be throwing away resources that we have on this plante, no matter how 'unusable' a form they were currently in.  Sooner or later, we'll probably have to start some serious recycling if we want to keep this planet hospitable to human life.

[jdurg]

Well, there is no such thing as "non-weapons grade plutonium."  All isotopes of plutonium that I know of, and which are formed in a breeder reactor, are fissionable.  That is what makes plutonium so nasty.  It dishes out neutrons like there's no tomorrow, and it is horribly poisonous chemically.  It has to be the most lethal element on the periodic table in terms of chemical lethalness and radiological lethalness.  It's kind of funny because I was watching Back To The Future today on TV, and when I was a kid it never really bothered me that they just cavalierly carted around plutonium.  But now that I've grown up and learned about the stuff, the way they handled the Pu and how they moved it around would have exposed them to lethal amounts of radiation.  In the body, plutonium mimics calcium in every manner.  As a result, it builds up in your bones and stays there emitting neutrons at high rates.  This leads to cancer of every form imaginable forming.  That is why plutonium in the hands of a terrorist is a horribly frightening idea.  Even if they don't have a nuclear blast, which is difficult not to do when you have plutonium, spreading Pu over a wide area is just intensely scary.  

Another problem with having plutonium around is an accidental meltdown.  It doesn't take a helluva lot of plutonium to reach a critical mass.  In breeder reactors over in the former U.S.S.R., they have had "incidents" where too much generated plutonium was stored in one area and the Pu went critical.  It would have been a whole lot worse if the plutonium was stored in too close of a proximity to itself.  (There was enough separation between the fuel to prevent a chain reaction explosion).  Instead, the pile just went critical and started heating up and outputting radiation at an alarming rate.  While people did get very sick and die from it, there was no nuclear explosion.  There's just too much danger when you're dealing with Pu that you don't have to deal with working with Uranium.  (If someone gave me a rod of pure elemental uranium, I'd hold it for a second before throwing it back in a lead container.  If someone offered to let me hold a rod of plutonium, I'd say no without hesitation).

[Donaldson Tan]

Arent the Japanese were successful harnessing power from the Breeder Reactors?

[chemicalLindsay]

The problem or danger with sending all of our radioactive wastes to the sun is also that the rocket containing all of the wastes could blow up and consequently spread all of the radioactive materials all over the continent it came from which would be very scary and dangerous as jdurg has already mentioned.But my main point is that we could make the planet a safer place if we just figured out how we could dispose of them safely.Also I would like to take back what I said.Getting the radioactive fuel rod to emmit beta radiation would probably be what would cause it to become plutonium which is very dangerous.

[Scratch-]

I just recently read about this in my physics book, it said that reactors work by slowing down neutrons emitted from the reactors core (like the boy scouts foil wrapped radium) so that they are more likely to hit the small amounts of U-235 (fissionable) mixed in the U-238 (non-fissionable). Does this sound right? It also said that breeder reactors produce fissionable (plutonium) material from non-fissionable (U-238) material and a small amount of fissionable (U-235) material.

[jdurg]

Well, all isotopes of plutonium that are normally generated are fissionable.  (As far as I am aware).  That is what makes Pu such a good nuclear fuel.  Unlike uranium, you don't need to purify plutonium in order to have enough of a fissionable isotope to create a "nuclear mass."  That's also what makes plutonium so dangerous.  Give someone 40 kg of uranium, and they'd have a helluva time making a bomb out of it since only the U-235 isotope, which occurs in very small quantities, is fissionable.  Give them 40 kg of plutonium, however, and they don't have to do anything to make it into a critical mass.  They already have multiple critical masses right there.  That is why governments generally don't get all flustured if someone has ten pounds of uranium metal on them.  Sure they'll watch closely and might talk to them about it, but they won't throw them in jail.  If someone has that same ten pounds but in plutonium, well, not only would they probably be receiving a lethal dose of radiation, but the government would seize it immediately and lock them up for some time.