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Tue Jan 10, 2017, 04:06 AM

A remarkable advance in actinide separations in used nuclear fuel has been discovered.

I'm not shy about offering my opinion, irrespective of public hostility that is very dangerous to the future of humanity, that nuclear energy is the last best environmental approach to producing a sustainable world, given that uranium is inexhaustible, and that when converted to plutonium, the uranium already mined can supply all of humanity's energy needs for centuries to come.

The key to obtaining this plutonium is however, involved in separating it from used nuclear fuel.

Continuous recycling of used nuclear fuel in thermal reactors, however - and I'm not a thermal reactor kind of guy, I'm a fast reactor kind of guy - leads to the accumulation of the minor actinides neptunium (Np), americium (Am), and curium (Cm).

Of these three, two can be oxidized to the +6 oxidation state, (as can uranium (U) and plutonium (Pu)). They are Am and Np. This facilitates their separation from lanthanides (rare earths) that are fission products.

Am and Np are important tools in denaturing plutonium to make it unsuitable for use in nuclear weapons. I discussed this in some detail elsewhere: On Plutonium, Nuclear War, and Nuclear Peace

The stability of the +6 oxidation state is in the following order U > Np > Pu > Am. The oxidation to Am is challenging, but can be accomplished.

Generally using current technology, which is based around the dubious idea of constructing "nuclear waste" dumps, which in my view are completely unnecessary, these separations rely on very old chemistry, solvent extraction, notably in the commercial "Purex" process. Purex processing involves the generation of considerable quantities of chemical waste, in particular because of the instability of extraction agents to high radiation doses. Therefore better processes are advisable, and I've been following these advances for many years.

A very interesting one showed up last year in the literature. Here is a few excerpts from a paper published last year. The reference is Inorg. Chem., 2016, 55 (17), pp 8913–8919 "Group Hexavalent Actinide Separations: A New Approach to Used Nuclear Fuel Recycling"

Some excerpts:

For nuclear power to become a major component in the future of a sustainable energy strategy, several barriers have to be overcome to leverage its inherent carbon-free power generation, which has the possibility of curtailing global greenhouse gas emissions.(1-3) One major barrier is the complexity of implementing the separations involved in the recycle of used fuel to recover the actinides (Ans), maximize energy utilization of the fuel, minimize the waste going to geologic storage, and additionally serve the needs of nonproliferation.(1-3) This will require a technology to recover not only the U and Pu, which are most important in energy generation, but also the minor Ans (MAs, i.e., Np, Am, and Cm), major contributors to the heat load and long-term hazard of geologic storage.(4-8) Currently, the most advantageous technological practices employ solvent extraction as a means to separate U and Pu,(9) yet these technologies haven proven to be challenging to apply to the MAs in a similar manner. This weakness in dealing with the MAs has spawned a large international research effort.(10) Many new technologies are developing in the area of solvent extraction to meet deficiencies; however, the added cost of these advances to separate the MAs is a major limitation and has stifled implementation on a large scale.(11) An innovative solution would be to have a technology achieve a single-step separation for all the Ans, known as a group actinide extraction (GANEX) process.(12, 13)...


Some experimental details of the crystallization, which assumes nitric acid dissolution of the nuclear fuel (which is not necessarily the best approach):

Small batch crystallization experiments with volumes of 1–2 mL were performed with UO2(NO3)2·6H2O as the carrier species. The starting [U(VI)] was 1–2 M, with other An species (Np, Pu, and Am) spiked in at concentrations of 0.12–3.0 mM, and an acidity of 5.7–6.7 N. The An concentrations selected were designed to balance achieving actual U:An ratios seen in used nuclear fuel while ensuring the safety of the experimenter and keeping the radiation exposure ALARA. In experiments that included multiple TRU species, an aliquot of a Pu(VI) solution was first combined with an aliquot of a U(VI) solution, followed by the addition of an aliquot of a Np(VI) solution, and finally addition of an aliquot of Am(III). In the case of Am(VI), the mixture of U(VI), Np(VI), and Pu(VI) was added to the Am(VI) solution, which contained an excess of NaBiO3, as mentioned above.


Conclusions from the paper:

The group An(VI) (U–Am) cocrystallization in nitric acid by a simple adjustment of temperature has been investigated as a new elegant approach for actinide separation in an economical nuclear fuel recycle. Removal of single hexavalent TRUs with UNH was demonstrated to occur in near proportion with a reduction of the system’s temperature, while the lower-valent ions, Am(III) and Pu(IV), were only slightly removed. A group cocrystallization was then achieved with all four An(VI) ions being removed in near proportion to one another. A separation of U(VI), Np(VI), and Pu(VI) from Am(III) was performed with a separation factor of 12–14. It was also seen that, within the crystalline phase, the stability of Am(VI) is significantly increased, showing almost no reduction observed over a period of 13 days, while more than half of the Am(VI) autoreduced to Am(III) in solution in only 10 days. This makes our concept for a single-technology cocrystallization approach much more appealing, as the difficult oxidation may need to be achieved only once to perform multiple recrystallizations and thereby significantly increase the separation factor of the An(VI) species. An effective separation of An(VI) dioxo cations from key fission products was observed, with decontamination factors ranging from 6.5 to 71 in a mildly oxidizing system without Am(VI)


It is interesting that Am (VI) can be separated from Pu (VI), Np (VI) and U (VI) simply be leaving the solution standing for a few weeks, during which time the Am (VI) is reduced to Am (III).

I personally think however that it may not be necessary, or even desirable in many cases, to effect this separation. The presence of Am and Np in nuclear fuels necessarily results in the formation of the heat generating plutonium isotope Pu-238, which is the key to making plutonium unsuitable for use in weapons. It is necessary to do this since as our recent election in this country shows, it is possible for weapons grade plutonium to fall into the hands of psychopathological fools.

Esoteric I know, but interesting.

Have a nice day tomorrow.

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Response to NNadir (Original post)

Tue Jan 10, 2017, 05:33 AM

1. I'm interested in any solution that improves on . . .

Leaving spent fuel rods lying around at individual power stations.

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Response to NNadir (Original post)

Tue Jan 10, 2017, 06:44 AM

2. Nuclear Power is a bad idea for the Human Race

 

Time for all of us to get over it, and not let our thinking be manipulated by the Energy Indu$try, whose
profit$ are threatened by actual progress on alternate energy sources, and
which should be nationalized anyway.

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Response to nikto (Reply #2)

Tue Jan 10, 2017, 07:43 AM

4. Deliberate ignorance is a bad idea for the human race. I have met almost no opponents of...

...nuclear energy who know anything more about it than that they hate it.

They are therefore being Trumpian when they discuss nuclear energy; pontificating on a subject they know nothing about.

If nuclear power had killed in more than half a century of commercial operations as many people as will die in the next two days from air pollution while we waiting insipidly for so called "renewable energy" to displace fossil fuels, people would be burning oil, gas and coal endlessly to spew ignorance all over the internet.

So called "renewable energy" - which sucks resources uselessly and ineffectively - has not worked, is not working, and will not work.

How do I know?

Trends in Atmospheric Carbon Dioxide

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Response to NNadir (Reply #4)

Wed Jan 11, 2017, 02:38 AM

5. I understand your use of "Trumpian" as a slap at pontificating, but lo and behold, in actuality ...

 

Last edited Wed Jan 11, 2017, 04:40 AM - Edit history (3)

In real life,
Trump, ironically it would seem, rather likes his nuke energy:

https://www.bloomberg.com/news/articles/2016-12-09/trump-s-team-is-asking-for-ways-u-s-can-keep-nuclear-alive

http://www.platts.com/news-feature/2017/oil/us-election-2016/trump-nuclear-power-nei-ceo

http://www.foxnews.com/on-air/your-world-cavuto/transcript/trump-we-do-need-nuclear-energy

http://www.fool.com/investing/2016/11/12/what-a-trump-presidency-means-for-nuclear-stocks.aspx



After the Fukushima disaster in Japan in 2011, Trump stated when queried: "I'm in favor of nuclear energy,
very strongly in favor of nuclear energy. If a plane goes down, people keep flying.
If you get into an auto crash, people keep driving."



Let's get real, Doctor NN.

Sounds like Trump is the nuke industry's bro' more than he'd ever be buddies
with any anti-nuke types like me.


Or, is Trump just not being properly "Trumpian" on this issue?

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Response to nikto (Reply #5)

Wed Jan 11, 2017, 06:33 PM

8. This logical fallacy, often comes up in these contexts and obviates the mentality of anti-nukes...

It is called Guilt by Association or sometimes the Association Fallacy.

This calls for, regrettably, an appeal to Godwin's rule.

It happens that the inventors of nuclear energy, many of whom were Nobel Laureate scientists, invented it because they were anti-Nazis.

This is a historical fact, and any educated clear thinking person can, in fact, look it up.

I cannot address people who are uneducated and muddled in their thinking, but again, people not fitting into this class of muddled thinkers can look it up.

The fact that the Nobel quality scientists who developed nuclear energy were anti-Nazi does not imply that people who oppose nuclear energy are therefore Nazis.

My personal opinion is that they are ignorant as sin in general, but I would not accuse them of being Nazis. Being a Nazi has nothing to do with nuclear energy.

If Donald Trump announces that filling one's lungs with water will result in death, this does not prove that filling one's lungs with water is good for you.

My personal opinion is that Trump is a coal freak, something he's said many times. No one who is for coal can also be for nuclear energy. My energy opinions entirely derive from my opposition to all dangerous fossil fuels.

I've heard this fallacy many times in this space, almost always being offered by anti-nukes, and nothing, nothing at all, obviates the quality of their thinking than their repeated use of it.

Thanks for demonstrating whence you come.

Have a nice evening.


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Response to NNadir (Reply #8)

Thu Jan 12, 2017, 01:35 AM

9. No need to be testy----I still think you're going to like Trump's Nuke policy A LOT

 

You will likely have more empirical reason than I, or most people, to be happy about
Trump's administration, due at least to their strongly pro-nuke policies, if nothing else.

It's silly calling it, "guilt-by-association", when all points noted in the articles relate to actual policy stands
and are likely to have real-world results (i.e. more nuke plants in America).



From all you have said about your beliefs on the subject,
sounds like a win for you.




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Response to nikto (Reply #9)

Thu Jan 12, 2017, 02:20 AM

11. Whatever. I happen to think you're pretty clueless, but I already made that clear. Trump will...

Last edited Thu Jan 12, 2017, 10:02 PM - Edit history (1)

...decimate science, and that, my friend, seems like a win for you, since you obviously have a very cartoonish view of science, and probably, if my experience of anti-nukes is consistent, have never opened a science book in your life.

Your crude, and frankly rather silly - the sort of trash talk one often hears from the withered minds of anti-nukes - to imply that to endorse nuclear energy is to support racist fools with a level of thought that is anti-nukish in its intellectual sophistication (or lack thereof) is duly noted, and again, consistent with what we often see and hear from antinukes.

These are afterall, people who whine about Fukushima while seven million people per year die from air pollution without offering a whimper for the real dead.

The first nuclear reactor to be constructed from scratch in over thirty years - too little to late - was pushed through by Mr. Obama's first Secretary of Energy, Steven Chu.

Steven Chu Criticizes Clean Power Plan For Neglecting Nuclear

Now, if I were at the level of an idiot anti-nuke, I could utilize a specious logical fallacy, that went like this: "Anti-nukes must hate Obama because his admisitration moved nuclear power forward."

But I won't.

Unlike the scientifically illiterate antinukes I encounter, I take care in the integrity of my arguments.

Using nuclear power is not preferable to destroying the planet with dangerous fossil fuel waste, this while we wait for the failed "renewable nirvana" that never comes, because Steven Chu likes it. It's better because, well, it's better.

Not a single reactor will be built by Trump, and almost everything Trump says is a lie, and only fools are unaware of that. His contempt for scientists and engineers is almost as clear as yours.

Have a nice day.

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Response to NNadir (Reply #11)

Fri Jan 13, 2017, 07:33 AM

12. Doesn't it feel good to get that off your chest?

 

Venting is good for the soul.




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Response to nikto (Reply #12)

Fri Jan 13, 2017, 12:20 PM

13. It's not off my chest.

I'm glad you're amused - and rather unsurprised that you are - but there's a lot on the chest of humanity, and because of stupidity and ignorance, and unjustified paranoia many people die unnecessarily from lung and other air pollution related diseases.

I personally don't find that very funny, which is why I have made as much effort as I have to confront the awful people who have brought this result on humanity.

The pictured plant, by the way, saved human lives. There should have been thousands of such plants, but regrettably, fear and ignorance won. We, those of us alive today will never again see carbon dioxide levels below 400 ppm in our lifetime.

Congratulations.

Have a wonderful giggly weekend.

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Response to NNadir (Original post)

Tue Jan 10, 2017, 07:15 AM

3. Am not qualified to make a judgement but

I'll pass this on to a nuclear physicist who is. No, sincere, not sarcastic, i must add.

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Response to Duppers (Reply #3)

Thu Jan 12, 2017, 01:35 AM

10. Hi!

 

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Response to NNadir (Original post)

Wed Jan 11, 2017, 02:56 AM

6. Actually, I can think of a practical nuclear-energy to ask of someone with expertise

 

According to the top article in the link just below (dated last week), it is still unknown how deep
the 3 cores at Fukushima have melted down/penetrated into the earth beneath the domes:

https://nuclear-news.net/category/2-world/asia/japan-asia/fukushima-2016/

They apparently have no idea of the current core depth (unless inside-info is being suppressed).

Is there any way to get a ballpark estimate on something like this?

It is an ongoing issue of practical concern for all those
who are conscious of nuclear energy as a factor in our lives, one way or another.

Just askin'.

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Response to nikto (Reply #6)

Wed Jan 11, 2017, 06:09 AM

7. I am very conscious of nuclear energy as a factor in our lives.

I've spent more than thirty years in the primary scientific literature reading all about it, and have many thousands of scientific papers in my files on the subject.

Nuclear energy saves lives, and frankly, I suspect that more people have died from the air pollution that resulted from running computers to complain (or worry) about Fukushima than have actually died from radiation.

Seven million people die each year from air pollution. ( Lancet 2012, 380, 2224–60: For air pollution mortality figures see Table 3, page 2238 and the text on page 2240)

This means that every seven or eight years, more people die from air pollution than died from all of the genocide, bombing, combat, and deprivation associated with World War II.

I generally know what kind of question I'm being asked when someone says "'They' don't know...." Who exactly are "they?" Do you, or the authors of the website know everything everyone anywhere knows about the reactor cores at Fukushima?

In 1988, two years after Chernobyl (about which I'm often asked) 167 oil workers were instantly vaporized on the Alpha Piper oil platform. Piper Alpha A similar event in the Gulf of Mexico, Deepwater Horizon, spread million ton quantities of carcinogenic petroleum over huge areas of the Gulf. Is there a "they" who know how to keep the benzene from the disaster from killing people?

In fact, pumping gasoline at a gas station involves exposures to carcinogens, as anyone can see if one pumps gas in California, where the Proposition "so and so" requires the true statement that "California" knows that gasoline, in particular the copious amounts of benzene in it, is a carcinogen. People generally ignore these signs, but they don't ignore the bogeyman "Fukushima" even though in comparison to petroleum, all of the nuclear accidents associated with more than half a century of commercial nuclear operations are, frankly, trivial.

The website to which you have linked is an anti-nuclear website designed to utilize specious scare tactics. The point of these web-based scare tactic websites is claim that nuclear energy is not perfect, and not without risk, which of course, it isn't. However nuclear energy need not be perfect and without risk to be vastly superior to everything else. It only needs to be vastly superior to everything else, which it is.

I began my nuclear energy research when Chernobyl blew up. I was an idiotic nuclear opponent at the time, but I justify my ignorance at that time by noting that previous to Chernobyl there was no experimental evidence of what the worst case for the destruction of a nuclear plant was. Because I was "concerned" about nuclear energy, and only relied on pop literature produced by say, the morons at "The Union of Concerned Scientists" (of which I was member at the time, even though my membership required me to provide no information proving that I was, in fact, a scientist) I expected millions of deaths from Chernobyl.

In the last 30 years, I must have read tens of thousands of pages of information about Chernobyl and Fukushima. You can do the same thing I did. To do this, I simply dragged my ass to university libraries, found out at each library to which I went about their policies for "guest users" and where necessary, paid the fees, and um, read all about many highly technical issues concerning nuclear energy, changing many of my ideas about many of the particulars of the technology, but coming to the conclusion that overall, this is the only technology that has a shot of saving humanity from itself.

I am not in a position where I feel obligated to answer your question in any detail about what "they" know about the status of the core of the Fukushima reactors. Twenty five thousand people died in the Sendai earthquake that also destroyed the reactors. They were killed by buildings, cars, drowning, etc because they lived in a coastal city at low elevation. In 2004, roughly a quarter of a million people, mostly in Indonesia, died in roughly the same way as the overwhelming number of people who died from the Sendai earthquake. Almost no one died from radiation at Fukushima. How come we don't have the same level of concern as we have for the reactors for, um, coastal cities?

Were the Japanese Engineers Who Built Fukushima Incompetent?

I know that the most serious energy disaster before humanity is climate change, followed by the toxicology associated with the combustion of dangerous fossil fuels and biomass, followed by the toxicology of dangerous fossil fuel mining. To my mind, based on decades of autodidactic self education, I've concluded that nuclear energy is the last, best hope for humanity. Nuclear energy is not risk free, but it's risks are trivial compared to everything else.

Sorry, but I'm not going to dignify your question with an answer.

Have a very nice day tomorrow.

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Response to NNadir (Original post)

Sat Jan 21, 2017, 01:07 PM

14. LOL!!!!!!11111

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