Giant Laser Transmutes Nuclear Waste

paulnuyu writes "NewScientist is reporting that scientists have transmuted nuclear waste with the Vulcan Glass Laser, cutting iodine-129's half-life from 15.7 million years down to just 25 minutes (as iodine-128). The advance is remarkable, but not practical: the laser would need power from a number of power plants to transmute the waste produced from just one nuclear plant."

Comments

Re:Beowolf

[deglr6328]

my submission for this story was way more informative "2003-08-20 17:11:37 Using Ultrahigh Power Lasers to "Burn" Rad (science,science) (rejected)" damnit!

anyway a beowulf cluster of vulcan lasers will probably look something like what's being built at the University of Rochester right now called Omega EP. Which will be nearly 10 times as powerfull as Vulcan. :-)

Re:Not a good way to dispose of neuclar waste.

[confused one]

First, learn to spell nuclear.

Then read the article -- they said this was an impracticle idea, just shows it can be done.

To answer your second question, not necessarily. If you put the iodine-129 target into a container surrounded by water, for example, the released neutrons would either interact with one of the nuclei to form an isotope with a similarly short half-life, or decay into a hydrogen atom (neutrons have a very short half-life themselves, quickly decaying into a proton and electron).

Re:Not a good way to dispose of neuclar waste.

[sraak]

at the end of the story is this:
"He also points out that dramatic reductions in the half-lives of isotopes inevitably lead to huge immediate increases in the levels of radiation being emitted per second. Initial missions from iodine-128 would be hundreds of billions of times higher than from iodine-129, causing handling problems for nuclear operators."

you are right. if you cut down the radiation time, you multiply the intensity of the radiation...
i do not want to be anywhere near when they start processing nuclear waste with lasers, practical or not.

Re:That's going the wrong way!

[bluGill]

One, people don't understand.

Two: science understands. Something with a halflife of a few days isn't a problem, it is gone before it sits around long. Something with a half life of thousands of years can still be radioactive enough to be very dangerious, but because of the long halflife it will be very dangerious for years. Once you get into millions of years for a halflife, it isn't very dangerious, but thousands of years turns out to still be dangerious.

Note, I'm talking total half life until it decays either into something stable. If something has a halflife of 10e-16 seconds, but decays into something with a halflife of 10,000 years, it is still dangerious in quanity.

Re:A more interesting problem than iodine ..

[Anonymous Coward]

I'm sorry, but your post contains many technical inaccuracies. Here they are, with brief commentary, in no particular order.

1. Japan has only one fast breeder reactor, Monju... an experimental design.
2. All of the recently constructed reactors in Japan are Light Water Reactors, either pressurized (PWR) or boiling (BWR).
3. ALL reactors fueled with uranium produce plutonium... and since the plutonium is in the core, some of it gets burned (and destroyed) by fission, contributing to the energy released by the fuel.
4. If we have excess plutonium available, we can use it to make fuel for reactors... it will be mixed with uranium dioxide to make mixed oxide fuel (MOX).
5. The difference betweeen a breeder and a non-breeder is the conversion ratio attainable. In non-breeders, the value is less than 1. In breeders, the value is greater than 1. A value of exactly 1 implies that for every atom of fuel fissioned, one new atom of fuel is created by transmutation of fertile material (i.e., U-238).
6. The ONLY reason to build a breeder with high conversion ratio is to produce excess plutonium for use in non-breeders.
7. Breeding is possible in light water reactors. This was demonstrated at Shippingport, PA. The conversion ratio is not high, but it is definitely greater than 1.
8. ALL reactors, whether breeder or non-breeder, produce wastes, including iodine.
9. The feature that distinguishes nuclear power is the energy density of the fuel, and the corresponding small volume of waste relative to amount of energy generated.
10. All spent fuel is not waste. Typically, about 95% of nuclear waste is just U-238... which just happens to be a fertile material perfect for creating plutonium in a breeder reactor.
11. A closed nuclear fuel cycle, in which breeder and non-breeder reactors are used and fuel reprocessing is allowed, achieves the highest possible utilization of fuel.
12. The closed fuel cycle is the holy grail of nuclear power. Even so, there would be waste products to eliminate.
13. Another method proposed for elimination of such waste is accelerator transmutation.
14. ANY method of reducing the toxicity of this waste is a welcome addition to the technological toolbox.

In summary... we know what to do with the plutonium (burn it as fuel). All reactors produce iodine, cesium, barium, krypton, xenon, lanthanum, etc. The volume of these waste products is small, but any method that can reduce the toxicity is desirable.