[Krasniy Yastreb]

Another article I dug up.

Giant laser transmutes nuclear waste

16:19 14 August 03

NewScientist.com news service

A giant laser has cut the lifetime of a speck of radioactive waste from millions of years to just minutes. The feat raises hopes that a solution to nuclear power's biggest drawback - its waste - might one day be possible.

"It is not going to solve the waste problem completely, but it reduces toxicity by a factor of 100. That's an attractive proposition," says Ken Ledingham, at the University of Strathclyde in Glasgow, who led the British and German research team.

The transmutation was performed using the Vulcan laser, which is the size of a small hotel and housed at the Rutherford Appleton Laboratory in Oxfordshire. About a million atoms of iodine-129 were transformed into iodine-128. The half-life of iodine-129 is 15.7 million years, meaning it remains radioactive for an extremely long time. In contrast, the half-life of iodine-128 is just 25 minutes.

Iodine-129 is one of the many radioactive isotopes created when uranium is burnt in a reactor. Currently they all have to be discharged, stored or disposed of by the nuclear industry.


Million billion watts

The Vulcan laser can produce short pulses of enormous power - a million billion watts. Pulses were fired at a small lump of gold, which produced enough gamma radiation to knock out single neutrons from iodine-129, converting it to iodine-128. The results of the experiment will be published by the Journal of Physics D: Applied Physics.

Ledingham says that the same technique could be applied to other radioactive wastes like technetium-99, strontium-90 and isotopes of caesium. But a different process would be required for other long-lived wastes like plutonium and americium.

Nuclear waste can also be transmuted by reactors or particle accelerators. For laser transmutation to challenge these methods, Ledingham says that suitable "tabletop" lasers will have to be developed, which could take 30 years.

But all the approaches use vast amounts of energy. At present, the Vulcan laser would have to be fired 1017 times at the original 46-gram block of iodine-129 to transmute all of the atoms. "You would need to build a number of power stations to transmute the waste from another power station," warns Karl Krushelnick, a laser physicist at Imperial College in London and part of the team.


Reprocessing required

Even if this major problem could be overcome, other obstacles could block the laser technology from entering commercial use. According to Ian McKinley from the Swiss nuclear waste company, Nagra, the approach assumes that reactor spent fuel will be reprocessed, which separates the waste. But reprocessing is "extremely expensive and increasingly unpopular", he says.

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.

"It's a nice idea," McKinley told New Scientist, "but I wouldn't buy shares in a company selling this process quite yet."


Written by Rob Edwards

Could a refined version of this method remove some of the danger from nuclear power?

[Noumenon]

For some reason many people oppose the transition from traditional methods of generating power to nuclear power...this is a knee jerk reaction that makes no sense. Even before this laser, nuclear power was cleaner and more efficient than other methods. Now with this new invention there is no reason to oppose nuclear power, except stupidity. Everyone, including environmentalists, should embrace nuclear power, but they don't. We need to get the word out and educate people about the benifits of this form of energy. It could also prevent blackouts such as the ones in California a couple years ago (probably not the recent one though).

[Yeddi]

I think the reasons why people oppose it is because of Three Mile Island and Chernobal. And the tonnes apon tonnes of radioactive material that has to be stored for thousands of years unless this laser can be used.

You say that it's efficient, does that account for the money needed to store the radioactive wastes and protect the public?

I can see that Nuclear power must be adopted, or fusion, as fossil fuels and such will disappear and solar and the rest just don't supply enough.

[Krasniy Yastreb]

I still hold hopes for cold fusion. If only the damn 'hot' fusion people and oil companies stopped lobbying to have it supressed...

And that's an interesting point about accidents Yeddi. No laser could have prevented the Chernobyl reactor exploding and covering Europe with a radioactive miasma, so they'll have to find a solution to that aswell I guess.