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Zapping Nuclear Waste in Minutes Is Nobel Winner’s Holy Grail Quest

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Re: Zapping Nuclear Waste in Minutes Is Nobel Winner’s Holy Grail Quest

#121
post #95

Earlier quoted context omitted.

I think the best option would be to accelerate the decay. That should be relatively easy (i.e. has a net energy output) and massively reduces the radioactivity.

Accelerating the decay would increase the radioactivity, at least until you've reached something with a long half-life.

Yes, but short-term high-radioactivity material is easy to do with, as is the super-long term low radioactivity material. The problem is the stuff in the middle which has a long enough half life that it's hard to store safely for that long but enough radioactivity to be dangerous. So if you can turn that stuff into either of the previous two catagories it's a win.

Re: Zapping Nuclear Waste in Minutes Is Nobel Winner’s Holy Grail Quest

#122
They had me at Cedric Villani

"For Cedric Villani, a French lawmaker and the winner of the Fields Medal—the Nobel Prize equivalent for mathematics—that’s no reason to give up. “What Mourou is really after is the accelerator that the laser creates,” he said. “It’s far-off, but why not?” "

Re: Zapping Nuclear Waste in Minutes Is Nobel Winner’s Holy Grail Quest

#123

> The idea is to transmute this nuclear waste into new forms of atoms which don’t have the problem of radioactivity. What you have to do is to change the makeup of the nucleus. Ok, but what exactly is it transmuting the atom to?

Let's take an example.

Here's the list of the 7 long-lived fission products [1]. The nastiest appears to be Caesium-135 [2]. If you zap this with a proton it becomes Barium-136, which is a stable element (the half-life is so long that it cannot be estimated; probably it is in the trillions of years).

[1] https://en.wikipedia.org/wiki/Long-lived_fission_product#The...

[2] https://en.wikipedia.org/wiki/Isotopes_of_caesium#Caesium-13...

Re: Zapping Nuclear Waste in Minutes Is Nobel Winner’s Holy Grail Quest

#124
post #90

Earlier quoted context omitted.

> Spent nuclear fuel, sometimes called waste, is actually a resource that next generation reactors will be able to tap That's just hope. How convenient not having to deal with the mess! To me, it sounds like a religion. The same argument could be applied to rising CO2 levels. Just let future generations figure it out. What could go wrong?

I think there are important differences. We know that wastes has energy (otherwise they would not radiate), there are stored in a well specified area. Unfortunately nuclear energy had a very bad PR for past 50 years, as a result nobody wanted to do any searcher in areas related to it). It seems that it is slightly better now, environmental organizations at least are not trying to occupy nuclear reactors, unfortunatel…

> nuclear energy had a very bad PR for past 50 years

There is not a positive way to tell people that will be forced to quit their homes, workplaces and properties when nuclear problems eventually arose but hide information or lie systematically about it does not help, neither does the "see no evil/ what could happen?/ but nobody died / your cancer is not my fault" permanent defensive stance deployed again and again.

Nuclear energy sector worked hard to earn the current mistrust

Re: Zapping Nuclear Waste in Minutes Is Nobel Winner’s Holy Grail Quest

#125
post #34

Earlier quoted context omitted.

And, as far as deaths go, you can't get numbers for something you didn't count. No real accounting has ever been made of the number of people who got cancer and/or died from nuclear activities, starting with the activities at the Hanford Site on through atmospheric testing and today's nightmares like Fukushima. The nuclear industry regularly uses this technique of "nothing to see here" to hide the fact that all nucle…

> No real accounting has ever been made of the number of people who got cancer and/or died from nuclear activities, First of all, nuclear weaponry waste from WW2 and the Cold War are wholly unrelated to activities of civilian nuclear power. While the material is similar in nature, you do not need to melt commercial waste down into radioactive vats of acid to extract pure weapons-grade plutonium in order to make low-c…

This persuaded me to look her up. Wow ...

https://www.theguardian.com/commentisfree/2011/apr/05/anti-n...

Re: Zapping Nuclear Waste in Minutes Is Nobel Winner’s Holy Grail Quest

#126
post #70

Earlier quoted context omitted.

Whats your point exactly? Earthquakes and other natural disasters will continue to happen. Until catastrophic failure can be eliminated or the scope of the damage can be reduced, nuclear power will not be considered safe. Saying "ok that happened but it won't happen again" is simply not acceptable.

Sure, but people saying they don't want nuclear power in Germany "because of Fukishima" is absurd. No power plant is Germany is at a risk of tsunami or a major earthquake. Should Japan be building nuclear power plants in areas which are at risk of both? Probably not. Should that be stopping countries like Germany fro building them? Also not. The same standard doesn't have to apply everywhere.

Yeah, and they did not expect the earth quake in case of "Fukishima" to become that big either, but than again it did. There are unknown unknowns.

Re: Zapping Nuclear Waste in Minutes Is Nobel Winner’s Holy Grail Quest

#127
post #90

Spent nuclear fuel, sometimes called waste, is actually a resource that next generation reactors will be able to tap - both for energy and uncommon element feedstock. Just like shale used to be "garbage" until the tech to make it useful was developed, spent fuel will be seen as waste until we can make it useful. Letting this very manageable amount of waste sit in repositories until we get our shit together is utterly…

> Spent nuclear fuel, sometimes called waste, is actually a resource that next generation reactors will be able to tap That's just hope. How convenient not having to deal with the mess! To me, it sounds like a religion. The same argument could be applied to rising CO2 levels. Just let future generations figure it out. What could go wrong?

It's more than hope, it's engineering. Future generations don't need to figure anything out, because the last two generations already did.

The Integral Fast Reactor was a reality in 1994, including a reprocessing scheme and inherent safety, when congress cut its funding. It's not my favorite reactor. My favorite, the molten chloride fast reactor, was theoretically investigated in 1972, including its potential for transmutation of actinides (excellent), I-129, Tc-99 (both good) and even Sr-90 and Cs-137 (both rather pointless).

What could go wrong and in fact did go wrong is politics. That's what prevents the practical investigations.

Re: Zapping Nuclear Waste in Minutes Is Nobel Winner’s Holy Grail Quest

#128
post #74

Earlier quoted context omitted.

How would one transport the waste across the country? I imagine there are some security issues with that too.

Very easily these days [1] Its been done since days of nuclear plants. And no - there are no security issues, since as the name indicates, its a “waste”; you can’t make a bomb out of it and spreading it would not be as efficient as some type of gas that you would have easier access to. I imagine actually officials would love just to give away that nuclear waste to ISIS, preferrably deliver it to them for further hand…

> there are no security issues, since as the name indicates its a “waste”; you can’t make a bomb out of it

Without applying a lot of imagination, I can think out about some non trivial security issues in the idea of adding deplected uranium waste to a bomb as shrapnel. Definitely a bomb can be made with this stuff.

Re: Zapping Nuclear Waste in Minutes Is Nobel Winner’s Holy Grail Quest

#129
A ridiculous idea.

The article doesn't go into technical details, but it appears this boils down to a compact proton accelerator. Those protons could be smashed into heavy metal atoms, which will release high energy neutrons. Those neutrons could in turn be used to irradiate nuclear waste, transmuting it.

The first problem with that idea is that stable atoms would be transmuted, too. So unless the waste is separated chemically (aka reprocessed), irradiating it with neutrons tends to make matters worse. In some cases, notable cesium, isotopic separation seems necessary. But if you assume reprocessing, you might as well stuff the components to be irradiated into a reactor, where the actinides act as fuel and some waste products will transmute away.

The second problem is the ridiculously low efficiency of such an accelerator system. Carlo Rubbia has been talking about the concept (ADS, Accelerator Driven System, also called Energy Amplifier) for something like 20 years, and even he only envisions supplying comparatively few neutrons to a subcritical reactor. But a barely subcritical reactor isn't all that different from a critical reactor, except you can turn it off by turning off the accelerator instead of by moving a control rod.

In short, this is another guy with a solution (the accelerator) looking for a suitable problem.

(For the record, continuous recycling of actinides is a good idea that turns "the waste problem" from an unsolvable million-year problem into a manageable 500 year problem. Transmutation of iodine and technetium may be a good idea, too, because these are the only long term radionuclides that would leach into water.)

Edit: names are difficult

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