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Member since: 2002
Number of posts: 25,704

Journal Archives

Writing environmental ruin, or how to write an obituary for an embattled planet.

Until recently, Princeton University junior Anne Merrill wasn't aware of how time and distance can dampen a person's awareness of the pervasiveness and the toxic endurance of environmental degradation.

As someone who is well-read on environmental topics and active in environmental clubs on campus, Merrill, a comparative literature major, was shocked upon enrolling in the course, "The Literature of Environmental Disaster," to learn about environmental crises of which she'd never heard or realized the scale.

Decades of rapacious oil drilling in the distant Niger River delta that has laid waste to the environment and decimated local cultures with corruption, violence and pollution. A chemical leak in Bhopal, India, in 1984 — long before Merrill was born — caused by an American company's negligence that killed thousands and continues to sicken local populations more than a quarter-century later.

"Before this course, I would have told you that my knowledge of environmental issues was quite broad and, in some areas, deep," Merrill said. "I was unprepared for the number of significant environmental disasters I didn't know of, or had glossed over as having occurred long ago or far away."

It was not news reports of people suffering, or scientific studies on residual pollutants or cancer clusters that brought these events to life for Merrill. It was literature...

Writing environmental ruin, or how to write an obituary for an embattled planet

We need our young people, our best and brightest, to restore what is being lost.

Princeton University President Defends His Immigrants Against the Illegal Ban.

Princeton President Christopher L. Eisgruber issued the following statement to the University community on Sunday, Jan. 29, 2017.

To the Princeton community,

Many of you have written to express concerns about the recent federal executive order barring entry to the United States for refugees and for citizens of seven predominantly Muslim countries. I share those concerns. Since its early days, when the College of New Jersey recruited a transformative president from Scotland, this University has depended on America's ability to attract and engage with talented people from around the world. Princeton today benefits tremendously from the presence of extraordinary individuals of diverse nationalities and faiths, and we will support them vigorously.

The University has taken steps already to assist Princeton students and scholars who are affected by the executive order, including a small number who are currently traveling abroad and face difficulties returning to the United States. Dean of the Faculty Deborah Prentice and Dean of the Graduate School Sanjeev Kulkarni have issued messages providing preliminary information about the order and its consequences. Staff members in the Davis International Center and elsewhere on campus are working around the clock to assess the full impact of the order and to aid and counsel members of our community, including those who are currently outside the United States.

The legal implications of the executive order have been evolving rapidly. My colleagues in the University administration will continue to monitor developments and identify appropriate ways to assist affected individuals. We will update the community as needed to ensure that our students, faculty, and staff know how to obtain information or help.

Princeton will also continue to safeguard personal information about non-citizens as it does for all of its students, faculty, and staff. As I noted in a previous letter to the community, Princeton has policies in place to protect the privacy of every member of the University community. We do not disclose private information about our students, faculty, or staff to law enforcement officers unless we are presented with a valid subpoena or comparably binding requirement...

A Real President Speaks on Immigration

The illegitimate President, who has already violated his oath of office by refusing to defend the constitution, will need to face down many legitimate Presidents of many organizations and countries, all of whom, by vast leaps and bounds, exceed his tiny little bigoted brain by orders of magnitude.

I just realized that I have 648,967 files on my computer, according to my online back up service.

That works out to one file per second over seven and a half days, or 177 files per day for ten years, 89 per day for 20 years.

I guess I'm not as lazy as I think I am.

German Scientists Propose Removing Uranium From Fertilizer.

Uranium was once thought to be a relatively rare element, and at the dawn of the nuclear age, and in the rush to procure it in the 1950's, many low grade ores that are not profitable today were processed to procure the element. Included in these low grade ores was phosphate rock mined in Florida and in other places, ores that are still mined today, not for uranium but for phosphorous, phosphorous being the essential element in fertilizers. Since it is not profitable to remove uranium from phosphate rocks containing it, it is simply left in the fertilizer where it ends up in agricultural fields.

While the levels of uranium in most agricultural fields - particularly those which do not arise from the weathering of granite - uranium is known to be chemotoxic; one of the primary toxilogical target organs are kidneys.

I have argued here and in many other places around the internet that the uranium already mined, when converted to plutonium is sufficient to provide all the energy needs for humanity for centuries to come, and thus all energy related mining, including uranium mining,, but more importantly the mining of the three dangerous fossil fuels are unnecessary, or would be in a rational world, although clearly we do not live in a rational world.

However I have also argued that there are circumstance in which uranium should be isolated, not because we need it to support the only sustainable form of energy there is, nuclear energy, but because it is wise in some cases to remove it from naturally occurring dilute sources such as water supplies.

A longer version of my argument along these lines, with many scientific references is found here: Sustaining the Wind Part 3 – Is Uranium Exhaustible?

Here is an excerpt referring to phosphate ores that I wrote back then:

In some cases for uranium, a few of which we will examine below, this is the result of anthropomorphic activities associated with mining and processing for the manufacture of nuclear armaments as well as for industrial nuclear power, but in others it a simple fact of geology. Neither can we claim that anthropomorphic sources are solely limited to nuclear armaments and nuclear power: For example, as things stand right now, rather large quantities of uranium are routinely distributed on agricultural fields, owing to the affinity that uranium displays for phosphates.[41] (Historically these phosphate ores were evaluated as potential sources of uranium[42], but higher grade ores were found. Had they been exploited for nuclear fuel purposes, of course, the uranium they contained would not have ended up on agricultural fields, but no matter…)

Here is a link to reference 41 in the text: N. Yamaguchi⁎, A. Kawasaki, I. Iiyama, Sci.Tot.Environ.407, 1383–1390 (2009).

Here is a link to reference 42 in the text: J. Agric. Food Chem., 1953, 1 (4), pp 292–292

Since I have made this argument for some time, I was very pleased to see an article, a "scientific opinion" piece, along the same lines published in the most recent issue of Environmental Science and Technology, one of the world's premier scientific journals devoted to environmental issues.

Here is a link to the open source article: To Extract, or not to Extract Uranium from Phosphate Rock, that is the Question (Environ. Sci. Technol., 2017, 51 (2), pp 753–754)

Since the article is open sourced, and not highly technical, there is no need for me to excerpt much of it; however, I will excerpt the first two paragraphs here for convenience:

Sustainable development is development that meets the needs of the present without compromising the ability of future generations to meet their own needs.(1) The implementation of sustainable development across all human activities also requires responsible extraction of our mineral resources. Raw materials can no longer be extracted based on economic grounds alone, social and environmental aspects must also be equally considered. Consequently, good practice guidelines for mining and processing of mineral resources should aim for minimal environmental impacts, protection of human health, total resource use, and zero waste mines.

Phosphate fertilizers are essential for modern agriculture to support an ever increasing world population. These fertilizers are produced from phosphate rock. It is well-known that phosphate rock contains considerable amounts of accompanying uranium, of which the great majority (80–90%) transfers to the final fertilizer product during mineral processing and is thus dispersed on agricultural soils, leading to the contamination of topsoils as well as ground- and surface waters.

The authors assert that even though the uranium isolated from fertilizers would be more expensive than "conventional" uranium, it should be isolated and utilized in any case, simply to avoid excessive distribution of the element in foods.

By the way, uranium, despite what you may have heard elsewhere, is inexhaustible. It is possible to isolate it at a reasonable cost, albeit at a higher cost than can be sustained today, from seawater, in which there is roughly 4 billion tons. (I discussed the regeneration of uranium to seawater should it be removed in the piece linked above.) An entire recent issue of the important scientific journal Industrial Engineering and Chemistry Research was devoted to dissing this point. (Ind. Eng. Chem. Res. Volume 55, Issue 20 (2016)) It was a pleasure to read.

Germany by the way, has a very stupid official energy program, which is involved with shutting its nuclear plants and replacing them with so called "renewable energy" This has not worked, is not working and will not work to arrest the most serious environmental issue in human history, climate change driven by the accumulation of dangerous fossil fuel wastes, chiefly carbon dioxide, in the planetary atmosphere.

Have a nice weekend.

Spontaneous separation of californium and curium.

The environmental tragedy now commencing in the United States means that future generations will be even more challenged to address severe environmental issues than they would have been had the United States constitution prevented the installation of an insane administration.

The insanity exists however, and those of us who can in the United States should not abandon our pursuit of knowledge, however much science may be threatened by the anti-intellectual bent of the mob that has seized control of the United States in defiance of Democracy.

If we have learned nothing in the last two decades about addressing climate change, it is that so called "renewable energy" cannot stabilize the atmosphere. This is demonstrated by the incontrovertible fact that the expenditure of trillion dollar sums on this failed technology has had no effect whatsoever on the unrelenting increase in climate change forcing gases.

We're at 406,14 ppm this week, 3.52 ppm higher than last year.

Although we have left a great mess for all future generations, one thing that they may not appreciate is that we have left them is sufficient fully isolated uranium to provide for all of the world's energy demands for many generations to come, as well as technology that can make access to uranium inexhaustible beyond several centuries, with rather less than dire environmental impact. A relatively small amount of uranium is capable of eliminating all the world's energy mines, all of the coal fields, all of the gas fields, fracked and traditional, and all of the world's oil fields.

For the overwhelming bulk of this uranium to be utilized, it will need to be converted to plutonium, utilizing, among other things, existing plutonium inventories (including weapons grade plutonium which must be denatured and rendered impossible to use in nuclear weapons.)

Right now, and for the immediate forseeable future, most of the world's nuclear reactors utilize the thermal neutron spectrum which is many ways undesirable, but it's what we have for now, at least until the fine upcoming generation of nuclear, chemical, and materials science engineers can apply their intellects to change this state of affairs, as we must hope they will.

Continuously recycled plutonium in a thermal cycle, according to one reference, (Ref: Nuclear Reactor Physics, William E. Stacy, Wiley and Sons 2001. pg.234) will consist of an isotopic mixture having roughly 8.17% [sup]238[/sup]Pu, 45.10% [sup]239[/sup]Pu,
20.54% [sup]240[/sup]Pu, 18.57%, [sup]241[/sup]Pu, and 7.62% [sup]242[/sup]Pu. These figures show - they are probably only valid as a first approximation - that plutonium can be readily transformed into a form totally unsuitable for weapons use, owing to the heat load associated with [sup]238[/sup]Pu and [sup]241[/sup]Pu which decays in situ to [sup]241[/sup]Am.

However the transuranium isotope distribution will not be limited to plutonium in this state of affairs (which is less sustainable than fast spectrum fission reactors, which can supply all human energy needs indefinitely.) Among the transuranium elements, working from the same reference, only 51% will be represented by plutonium. Roughly 5% will be neptunium, 9% will be americium, 34% will be curium, with smaller amounts being represented by californium and berkelium.

As I noted earlier in a post here, the accessibility of high oxidation states makes the separation of plutonium, neptunium, and americium from traditional used nuclear fuels, almost all of which are based on oxides of the actinides. Neptunium and americium are the key to generating [sup]238[/sup]Pu to eliminate the value of plutonium for weapons diversion.

In the case of americium, however, an intermediate in the production of [sup]238[/sup]Pu is [sup]242[/sup]Cm. The other curium isotopes will also be present, and what's more, inevitably, this curium will also be contaminated with californium. Because of californium's high rate of neutron production, it is desirable to separate it from other elements both to utilize this spontaneous flux, and to simplify the handling of curium for the recovery of its heat.

Neither californium nor curium however exhibit stable higher oxidation states. This means that while they are easily separated from the lower actinides, they are more challenging to separate from one another; in general (especially since in general only small amounts are produced today), one must resort to procedures like chromatography.

All of this is why I read with interest today a paper detailing a spontaneous separation of curium and californium.

The paper is here: Inorg. Chem., 2015, 54 (23), pp 11399–11404 "Spontaneous Partitioning of Californium from Curium: Curious Cases from the Crystallization of Curium Coordination Complexes"

Some text from the paper:

Curium plays a central role in actinide chemistry in that it is isoelectronic with gadolinium, and both trivalent ions possess half-filled f7 shells. This allows curium(III) compounds and complexes to be used as benchmarks for comparisons with gadolinium and other lanthanide analogues as well as with both earlier and later actinides.(1) Given the spherical symmetry of the f[sup]7[/sup] configuration and the general perception that both 4f and 5f orbitals are nonbonding, one might expect that gadolinium(III) would be an excellent analogue of curium(III) if the difference in their ionic radii is excluded. In fact, the electronic characteristics of curium(III) diverge from those of gadolinium(III) in a number of respects...

Actually the "general perception" of 5f is not really valid, but no matter.

A little more on uses for curium:

Curium(III) is perhaps the most luminescent of all 5f-element ions and emits characteristic orange light centered near 600 nm.(7) This property is extraordinarily useful in a wide variety of applications that range from solution complexation studies to the environmental behavior of trivalent actinides to biological probes to understanding energy-transfer processes in f-block materials.(7) Changes in the coordination of curium(III) can cause substantial shifts in the photoluminescence peak position and spectral shape.(7) In contrast, gadolinium(III) compounds, while capable of emitting at visible wavelengths, have low quantum yields even when antennas are utilized for energy transfer and are often used as nonemitting hosts in europium(III)- and terbium(III)-doped materials.(8)

Some remarks on separations:

The separation of middle-to-late actinides from one another has been a key challenge for decades in the development of the chemistry of these elements, their use as targets for the production of super heavy elements (i.e., transactinides), and advanced nuclear fuel cycles for separating lanthanides from actinides. Studies of the stability constants of trivalent lanthanides and actinides with α-hydroxyisobutyrate show that a monotonic trend exists with lanthanides.(14) However, with diethylenetriamine-N,N,N′,N″,N″-pentaacetic acid, this trend is not preserved; curium binds more weakly, and californium more strongly, than expected.(14, 15) These early studies were already suggestive of a change in chemistry occurring at californium that continues through mendelevium.(14, 15)

We recently communicated a few features of the curium(III) tris-chelate, 2,6-pyridinedicarboxylate (dipicolinic acid, DPA) complex, Cm(HDPA)3, as a part of a comprehensive study that compared middle actinides with californium.(16-18) Herein, we substantially expand on our analysis of this complex as well as elucidate the structure and properties of the bis-chelate complex [Cm(HDPA)(H2DPA)(H2O)[sub]2[/sub]Cl][sup]+[/sup].

They ran some crystallizations and to their surprise found that the crystallization process lead to the separation of tiny amounts of californium complexes from curium complexes.

The collection of photoluminescence spectra from groups of crystals revealed that the colorless crystals of DPA that cocrystallize with the bis-chelate luminesce green, as shown in Figure 4. Collection of this luminescence spectrum showed that the green luminescence is superimposable with that of Cf(HDPA)[sub]3[/sub], including the fine vibronic structure (see the Supporting Information).(16) Single-crystal X-ray diffraction studies demonstrate that these crystals are ostensibly just DPA. However, it must be kept in mind that crystal structures are averages of the total composition of the crystal and are largely insensitive to trace doping.(31) However, they are clearly doped with low levels of Cf(HDPA)[sub]3[/sub], . Dissolution of the crystals followed by energy-resolved liquid scintillation counting of californium in the crystals reveals doping levels of 37(5) ppm. The error on this number represents the deviation in the dopant levels between crystals and supports essentially constant doping levels from crystal to crystal. Crystals were also cut and broken, and the lack of significant variation in the photoluminescence intensity of the interior versus exterior of the crystals reveals a relatively uniform distribution of californium throughout the samples. This level also indicates that californium is concentrated within the DPA crystals because the californium levels in typical 248Cm samples are ∼1 ppm (or less).

Here's the picture of the crystals:

Esoteric, I know, but cool. They'll need to know these sort of things in the future if they wish to save themselves from what our irresponsibility has done.

Enjoy the coming week.

My personal favorite protest picture today: Antarctica.

CNN's photos of protests around the world.

We have one running on every damned continent.

We may have a large subset of sexist racists in the USA who have managed to subvert the will of the majority, but it's very, very, very, very clear that humanity is not going to stand aside while the United States is pillaged by thugs.

The orange thug may find his 1930's style "America First" fascism may lead to severe economic sanctions, a pariah status, and a vast retreat by his Quisling collaborators.

We'll be watching horror movies to avoid listening to the Trump crap. What about you?

We figure that the scariest horror movie can't equate to the horror in the White House, a zombie with a paint on off color tan and a comb over that glows in the dark.

What you gonna do?

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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