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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 reasonable. In the US, it would take just one facility to deal with all 99 reactor waste streams.
I don't think we need to spend money and energy to transmute it by theses questionable laser schemes. Accelerator driven transmutation of waste was shown the dustbin a few decades ago, hopefully this will have the same fate. Please don't ruin our valuable trash.
And no one ever talks about how we’ll handle solar waste. Has it changed and is no longer a problem going forward? Last I looked into it a few years back it was shaping up to be a very serious and toxic problem. They were very difficult to recycle, and full of lead, cadmium, and other nasty things. Something needs to be done with them but everyone was pretending they’re completely clean and safe.
My introduction to this was when I went to work for a solar manufacturer and had to take blood tests to measure cadmium levels.
I mention this all the time to coworkers who blindly believe solar is a perfect technology. It is really, really bad - especially the old stuff with all these REE's and extremely low efficiency. I am pretty upset that California now REQUIRES solar for new construction. It really feels we should have waited for the efficiency/cleanliness/recycling to mature a lot before that.
I get 27.300 results for "solar waste" on google. 88.000.000 for "solar waste management". Literally "no one ever"...
Spent fuel is only a part of it though. There is also tubes, piping, tools... Basically, components that are used for maintenance and are now effectively useless.
> 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?
Don't even centralize it all in one facility, just store it on-site.
> Please don't ruin our valuable trash.
How valuable could it possibly be? I challenge you to calculate the net present value on all of that nuclear waste.
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
I wonder what our attitude towards landfills would be if they were described the same way that nuclear waste storage facilities are.
> no country can claim to have a comprehensive solution for dealing with its toxic waste.
> more than 60 years after getting into nuclear energy, [France] still has no definitive way to cope with it.
Sentences like these imply that there's dangerous waste just sitting sitting around while officials scratch their heads about what to do.
We do have comprehensive solutions. We build giant concrete wells and just put the waste there, problem solved.
This solution seems to be accepted as reasonable for garbage via landfills, but for nuclear waste its somehow treated as a workaround until we find some other magical way to get rid of it.
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?” "
Or we could just use that valuable fuel and put it into nuclear reactors to make energy and other useful stuff. But that seem to be a totally crazy idea.
Reprocessing is its own nightmare and, I think, only France tries to do it. All of these processes (the "uranium cycle") are terribly polluting in their waste outputs and dangerous places for the people who have to work there and live near them.
France's power is cheap by European standard [0]. So there isn't an economic issue.
Going by order-of-magnitude of input materials, if it is an environmental nightmare it is still going to be better than the mining process for raw materials going in to solar panels and whatever else. AFAIK they all use rare earths that get mined in China and refined with some horrible process. Pure volumes of solar panels suggest the incidental environmental damage will be worse from, eg, trampled grass and land disturbed.
So it isn't an environmental or an economic nightmare relative to the alternatives. In what sense is it a nightmare? It seems to be working for France.
[0] https://ec.europa.eu/eurostat/statistics-explained/index.php...
It's like the US doesn't already have a number of remote areas like Hanford, Oak Ridge, Idaho Falls, the Savannah River Site, Rocky Flats, etc. that are already set up (and somewhat contaminated already) for handling this sort of material and process. In reality it's a political nightmare, not a pollution one.
What nightmare? Reprocessing is a net cleanup compared with letting the waste sit. I have some nuclear engineering background and honestly I don’t know what you’re referring to.
The UK still has a site too but yes there's only a handful globally. The former site at Dounreay in Scotland used to leak particles on a regular basis which were all kinds of bad news for anything living that came into contact with them or perhaps one kind of bad news: horrible death.
This is wrong. There are many ways of reprocessing and many are far better then the limited once used so far. Its just that we haven't advanced in terms of nuclear technology in the last 40 years.
We will never solve any of these problems if we don't embrace nuclear technology.
Doesn't that need more energy than you generated out of the material in the first place?
I wonder how much this processes would consume and further reduce the effective yield.
Energy from other sources, such as renewals could be used. The disposal could be scheduled when those are generated in excess.
> 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...
I also wonder about that. If it transmutes into the natural decay products, energy must come out, and, depending on the size of that laser/proton gun, we could (although I think that’s highly unlikely) even be talking about a way to make small nuclear bombs.
Also, will the end result still be energy positive? Even if the transmutation doesn’t add energy to the nucleus, that can be problematic, as that laser will need to be powered.
And of course, there’s the question of ‘aim’: can we really target individual atoms well enough to ‘hit’ them exactly once? (this might be fairly easy if the process requires specific energies that the radioactive atoms, once ‘hit’ no longer are sensitive to)
Well, other atoms?
Depending where you start from and how do it. Here is an example: http://www.ipodphysics.com/resources/trans90.jpg
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.
Radioactive materials are dangerous because their subatomic makeup is unstable, meaning they emit dangerous particles as the atom degrades from the inside. So it would seem that, in order to fix that, you'd have to re-populate the innards of the atom with enough protons to make it stable again.
It's worth noting that transmutation is definitely possible. The alchemists of old would be thrilled to know that we can, in fact, make gold from base metals (in a nuclear reactor). The problem with that is that the cost of doing so is worth more than the gold could be sold for.
is there a way to zap plastic waste in minutes ?
Yes - you can burn it for energy, which is already done in many countries. With good enough filters it's the best solution to plastic waste that we have.
There are multiple ways. Grinding it up and then using a plasma furnace to break down the molecules is a proven way to reduce a waste stream to component elements.
tl;dr - scientist proposes solution to the nuclear waste problem: alchemy. With lasers.
This is another of many "silver bullet" proposals to reverse the environmental damage caused by Western civilization. Most of they won't work and will have unintended consequences. As always, prevention is the best cure.
Maybe so, but can you please not post unsubstantive comments to HN, especially about grand divisive topics? It leads to much less specific and much less interesting discussion.
This is about nuclear waste that came from power plants that massively helped the amount of greenhouse gases we emit (cause the alternatives were fossil fuelled plants) so I’m not sure what you mean exactly
Everything we do is about trade-offs. Solar panels have toxic chemicals, too (Cadmium compounds, Hexaflouroethane, Lead [1]). Wind involves rare-earth metals like Neodymium which are produced in mines that resemble toxic war zones in far-flung regions of China [2]. None of us will ever exist on this earth without leaving fingerprints. It's not about 'zero' it's about 'better' one step at a time. Defeatism and refusing to accept anything short of perfection is a good way to get nowhere.
For reference 1 ton of Thorium produces as much electricity as 200 tons of Uranium or 3.5 megatons of coal -- which would you rather use?
[1] https://sciencing.com/toxic-chemicals-solar-panels-18393.htm...
[2] https://www.dailymail.co.uk/news/article-1241872/EXCLUSIVE-I...
[3] https://en.wikipedia.org/wiki/Thorium-based_nuclear_power
Only by Western civilization? China is the largest polluter; India is third. The West may not be blameless, but it is not solely the fault thereof.
What is your better idea, now that the time for prevention has passed?
here you go
https://www.youtube.com/watch?v=1R5G5hTC7pc
next quest
“A radionuclide is an atom that has excess nuclear energy, making it unstable.”
This seemed like a vague definition, didn’t sit well with my memory of high school chemistry and physics. Turns out it’s the first sentence on Wikipedia:
https://en.m.wikipedia.org/wiki/Radionuclide
Someone at Bloomberg got a little lazy.
It's accurate and not really vague at all, it's just not highschool level physics. I'll try to explain it in layman terms.
Imagine that you have a bunch of free particles that are not connected to each other in any way, and are far enough from each other that any interaction between them (such as electromagnetic fields) is negligible. Ignoring their own masses, the energy of the system is zero. Now imagine these same particles, bound together into a single atom.
Obviously, for the atom to be stable, you don't want it to be able to fall apart on a whim. You want a system where you have to input a lot of energy for the atom to fall apart. But as we just said, the state where the constituent particles are separate is the default, zero-energy state. Therefore, a stable state where you have to add energy to reach the default free state must actually have negative energy! To be specific, the binding energy is negative while the energy related to the mass of the particles, i.e. e=mc2, is positive. The atom is actually lighter than the sum of its parts!
An atom that doesn't have negative binding energy, i.e. has "excess energy", has nothing binding the constituent particles together, since they have more than enough energy to go run free on their own. Therefore it is unstable. Elements with a small enough binding energy, small enough that random fluctuations can overcome it and make the atoms fall apart, are what we call radioactive elements.
Your periodic reminder that - despite the propaganda campaign run by nuclear advocates to make it seem like being anti-nuclear is to be anti-science - nuclear power remains massively expensive and even less safe than people think.
Here's the most comprehensive peer-reviewed survey around:
We summarize the results of a recent statistical analysis of 216 nuclear energy accidents and incidents (events). The dataset is twice as large as the previous best available. We employ cost in US dollars as a severity measure to facilitate the comparison of different types and sizes of events, a method more complete and consistent that the industry-standard approach. Despite significant reforms following past disasters, we estimate that, with 388 reactors in operation, there is a 50% chance that a Fukushima event (or more costly) occurs every 60–150 years. We also find that the average cost of events per year is around the cost of the construction of a new plant. This dire outlook necessitates post-Fukushima reforms that will truly minimize extreme nuclear power risks. Nuclear power accidents are decreasing in frequency, but increasing in severity.
https://www.sciencedirect.com/science/article/pii/S221462961...
The problem is that people who are anti-nuclear are often also anti-coal and anti-fossil-fuel and anti-everything-that-actually-sustains-current-human-level-of-development.
For those people, it has to be "clean renewables", with the speculation being that technology will fix all the issues with it. That ignores that maybe technology can also fix the issues with nuclear - and more readily so.
How many Fukushimas will we (society) accept every 150 years in order to stop climate change? That's really the only question that matters.
Kind of agree. There's been 4 catasrpohpic reactor meltdowns and there are ~400 reactors. That's a 1% failure rate. That's really bad. That's the status quo, which does not mandate continued low safety and lack of economic advantage. That's why there is R&D. Today what you say is true - great. Tomorrow, who knows. High energy density and human ingenuity could make genIV a reality.
> Mourou and Tajima want to create a high-speed laser-driven accelerator to produce a beam of protons that can penetrate atoms.
Is it only me who is reminded of Iron Man 2 and the new element created by that hacked together accelerator in Tony Stark's basement?
As for the topic of the article: I would really find it interesting how much "bandwidth" (=kg/day) such a setup has and what the energy requirements are. If the process consumes more than half the energy that the fission process generated, is it still profitable then? Also, what are the byproducts? I can't really believe that this leaves stable lead and other things only behind.
Nuclear energy has its advocates—it spews little by way of emissions and is produced relatively cheaply.
Nuclear is anything but cheap. It's a net negative energy source, meaning the the electricity costs more to produce than it can be sold for. This is why the industry requires massive subsidies to stay alive. (If I recall correctly, the last round of subsidy in the US was over $50 billion.)
Nuclear power also requires massive amounts of carbon, as the uranium fuel must be mined and extensively processed before it is useful. The mining and milling process is horribly polluting and has ruined the land and water in many places on Earth.
Now, having said that, I certainly hope this guy can come up with a way to transmute radioactive elements with lasers. That would be terrific. But I'm doubtful.
A big problem with nuclear is expense. The figures from France are misleading because the state and the power companies are deeply entangled financially. A clearer view is possible in the UK because they have market system, and subsidies tend to be more transparent. The message from the UK is that nuclear power is not financially viable, and no nuclear power stations would be built without government subsidy. The subsidy required is far greater than that required by renewables. See https://www.theguardian.com/uk-news/2017/nov/22/hinkley-poin...
Got a source? I'd read the EROI of nuclear is quite high.
This is true not of nuclear energy in general but -- if what you're saying is true -- of the Uranium cycle commonly in use today. To my knowledge, it was originally selected because it can support production of weapons-grade Plutonium. I'd wager, at the time, the power generation (and economics) was more of a side-effect.
I'm personally more interested in seeing Thorium reactors re-visited, as Thorium is much more prevalent in the earth, can't be used to produce weapons-grade Plutonium, is much safer, more stable, yields fissile products with much shorter half-lives, and so on. That's not to say there aren't challenges but I think this would be something worth investing in. [1]
[1] https://en.wikipedia.org/wiki/Thorium-based_nuclear_power