Physico-chemical properties of Chernobyl "Elephant's Foot" Lava.

[NNadir]

I'm on a couple of technical news feeds at my job and an article in one of them caught my eye since I am interested in all things involving nuclear energy. The news item is here: Innovative Material Could Help Clean Up Chernobyl and Fukushima.

Whenever one reads a press release about science with the word could in the title, one's "critical thinking required" alarm should light up and start buzzing loudly. I would argue that 95% of the time, or perhaps more, when this happens one should expect to read a distortion, wild inflation, or overly optimistic or overly pessimistic interpretation of a laboratory finding that has little to do with what actually happened in the laboratory.

I am an old man. For my entire adult life, I have been reading how so called "renewable energy" could power the entire world, "by 1995," "by 2000," "by 2010," "by 2015," "by 2020..." and so on.

Reality:

Here is a table of sources of energy taken from the data found in the International Energy Agency’s 2017, 2018, and 2019 Editions of the World Energy Outlook published annually:



A table of changes:



Sources:

2019 Edition of the World Energy Outlook Table 1.1 Page 38] (I have converted MTOE in the original table to the SI unit exajoules in this text.)

IEA 2017 World Energy Outlook, Table 2.2 page 79

Sometimes, I'd guess maybe 10% to 15% of the time, one is inspired to actually look at the original source article - if, in fact, one has been published - to find out what is actually being stated by the scientists who did the work, without added journalistic or marketing spin.

In the case of the above cited news article, here is the actual paper to which the news item actually refers:

Synthesis, characterization and corrosion behaviour of simulant Chernobyl nuclear meltdown materials. (Hyatt, et al, npj Materials Degradation volume 4, Article number: 3 (2020))

It is open sourced; anyone can read it.

It does contain the following statement in the abstract:

Use of these simulant materials allowed further analysis of the thermal characteristics of LFCM and the corrosion kinetics, giving results that are in good agreement with the limited available literature on real samples. It should, therefore, be possible to use these new simulant materials to support decommissioning operations of nuclear reactors post-accident.

"LFCM" is defined above in the abstract as "Lava-like fuel containing materials."

The event at Chernobyl was, and always will be, the worst case for nuclear reactor technology. All the money spent to "clean up" Chernobyl will save very few lives, because 34 years later, very few lives are now at serious risk.

Recently elsewhere in this space I wrote this in response to a comment:

Chernobyl was 34 years ago. The immediate death toll was 31 people; over the long term, perhaps a few thousand people will ultimately have their lives shortened significantly.

Let's say that the death toll of air pollution averaged, over the last 34 years, five million people per year, a lower rate than what is currently understood.

That works out to 170,000,000 deaths from air pollution in the 34 years since Chernobyl.

Of course, the fact that we don't pay attention to one, and microexamine the other makes no difference in the actual numbers.

And then there's climate change. Do you grasp how serious, how much death and destruction will be involved in comparison to Chernobyl?

Here are some things that have killed more people than 60 years of nuclear operations: Automobiles, aircraft, fatty foods, water, house fires...

Do we routinely assume that cars, aircraft, fatty foods, water and houses are "too dangerous?" Do we say any of these things should be phased out? (For the record, I do believe that cars should be phased out, but that's just me.)

I'm a scientist. I am trained to think critically. In general this means rejecting journalistic impressions, which are often geared at making people not think critically but rather in emotive and/or sensationalist terms.

Look at politics. "But her emails..."

I look at journalism about nuclear energy in exactly the same way, "...but her emails..."

We could save more lives that we propose to spend to "clean up Chernobyl and Fukushima" to some absurd standard of safety if we spent the same amount of money to stop destroying the planetary atmosphere. That's my could statement.

Nuclear energy, overall, saves lives by preventing dangerous fossil fuel waste, including but limited to air pollution, from killing people, which it does continuously, with and without accidents occurring, that is, during normal operations.

Reality.

From the above data from the IEA, despite all the hoopla about solar and wind energy saving the world, all the cheering, all the "could power 100% of world energy by 'year such and such'", after an "investment" of trillions of dollars devoted to wind and solar every decade, coal has been the fastest growing source of energy on this planet in the 21st century.

Again, it's open sourced; you can read all about the "LFCM simulant" in the original paper, if you're interested. I found looking through the references in the paper to be interesting, since the references refer to some of the real "Chernobyl Lava" that has been recovered from the reactor.

The real Chernobyl lava is interesting though. I could not access some of the papers through Google Scholar, but I was able to download reference 17, which is not, I believe, open sourced. Here it is:

Physico-chemical properties of Chernobyl lava and their destruction products (Andrey A. Shiryaev, et al. Progress in Nuclear Energy 92 (2016) 1040-118)

It contains this text:

Bulk lava samples were manually detached under harsh conditions in 1990 by Mr. Vladimir Zirlin of the V.G. Khlopin Radium Institute (St. Petersburg, Russia) from two different types of lava. Small samples described in the current paper represent pieces of much larger specimens (several tens cm3): the fragments of black lava (Sample I, approx. 3 _ 1.5 _ 1.5 mm in size, Fig. 1A, B, and Sample II ca. 4.5 _ 2 _ 2 mm in size, Fig. 1C, D) were collected from the lava stream “Elephant foot”, level þ6.0 m (Borovoi et al., 1991a; Burakov et al., 1997a); and the fragment of brown lava (Sample III, 3 _ 2 mm, Fig. 1E, F) was collected from the steam-discharge corridor at level þ6.0 m (Borovoi et al., 1991b; Pazukhin et al., 2003). The fragments were mounted in 1991 into acrylic resin and manually polished in a glove box. For the polishing SiC powder with grain sizes (decreasing during the process) 28/14, 10/5 and 3/ 1 mm were used; final polishing was performed on dense paper with diamond paste (1/0). After the polishing the samples were stored at laboratory till 2015. This process provided mirror-like finish with virtual absence of a damaged layer as confirmed by successful EBSD analyses of steel droplets (see below). Despite pronounced radiation damage of the resin at the contact with the lava after 24 years of storage, the surface of LFCM remains mirrorlike.

Here is a picture of the "elephant's foot:"



The person in this picture was of course, in great danger; it may be "Mr. Vladimir Zirlin of the V.G. Khlopin Radium Institute" referenced in the text above. The grainy nature of the picture is almost certainly connected to radiation exposure of the film during the trek to take the photograph. If this is Mr. Zirlin, he was still publishing papers as late as 2012.

Development of New Generation of Durable Radio-luminescence Emitters based on Actinide-doped Crystals (Zirlin et al., Procedia Chemistry Volume 7, 2012, Pages 654-659).

He seems to have lived at least 22 years after taking the picture, and, in fact, was still working 22 years after taking the picture. It would hardly be surprising however, if his life has been significantly shortened by the act of taking the picture than if he had not taken the picture, and bravely carried the samples out of the reactor for analysis, whereupon they were sealed in an acrylic resin.

Anyway, let me return to the interesting Progress in Nuclear Energy paper. It begins with a description similar to those one can read in many places both in the general and the scientific literature, with more or less detail. These descriptions are very popular and wide spread in both the professional and general news, as people are far more interested what's going on in Chernobyl since 1986 than they are in the 170,000,000 deaths from air pollution since 1986 that I postulated above.

Here is the introduction:

The accident at the 4th Unit of Chernobyl Nuclear Power Plant (ChNPP) on 26 April 1986 led to destruction of the reactor core and release of an enormous amount of solid and gaseous radioactive products to the environment due to explosion and subsequent fire. Independent approaches based on 137Cs and 90Sr fractionation and structural peculiarities of dispersed fuel and corium particles showed that transient (few seconds or less) temperatures immediately prior to the explosion event reached at least 2200e2600 _C leading to reactions between the UO2 fuel and zircaloy cladding (Burakov et al., 1997a, 2003; Kashparov et al., 1996; Kashparov et al., 1997). The explosion epicenter was presumably localized in a relatively small volume of the reactor core (Abagyan et al., 1991; Adamov et al., 1988; Kashparov et al., 1997). Though the estimates vary, the amount of fuel dispersed to dust (both inside and outside the reactor building) and expelled from the reactor shaft is estimated as ~4e6% from the total amount of 190 metric tons of uranium (Arutyunyan et al., 2010; Information…, 1986; Lebedev et al., 1992).

In the RBMK reactors the reactor basement plate is a cylinder 14.5 m in diameter and 2 m in height, filled with serpentinite with bottom and top steel lids interconnected by stiffening ribs and water tubes. During the explosion a 100-110_ sector of the basement plate was pushed approx. 4 m down, merging the reactor shaft with a former sub-reactor room 305/2 (e.g., Arutyunyan et al., 2010). The amount of nuclear fuel in the room 305/2 is estimated at 65-80 tons of UO2 (Borovoi et al.,1998). Before and shortly after the explosion the fuel reacted with zircaloy and later with construction materials (sand, concrete, serpentinite, steel), leading to the formation of so-called lava-like fuel-containing materials (LFCM) or Chernobyl “lava” (Burakov et al., 1994, 1997a,b; Ushakov et al., 1997). Several days after the accident considerable fraction of the initial lava pool spread into other rooms of the reactor building (Burakov et al., 1997a), forming vertical and horizontal flows which solidified into a highly radioactive glassy material with inclusions of high-uranium zircon crystals (Zr1-xUx)SiO4, particles of molten stainless steel, uranium oxide dendrites and grains, and particles of Zr-U-O phases (solid solutions in the system of UO2-ZrO2). Several varieties of the lava are known (e.g., Anderson et al., 1993; Borovoi et al., 1990, 1991a, 1991b; Burakov et al., 1994, 1997a,b; Pazukhin, 1994; Pazukhin et al., 2006; Savonenkov et al., 1991; Trotabas et al., 1993): 1) brown lava; 2) black lava, and 3) much less abundant and less studied polychromatic lava. On the lower levels of the reactor building the flow of brown lava entered water in the bubbler tank forming pumice-like material (Borovoi et al., 1991a; Trotabas et al., 1993). Controversy still exists about the total amount of uranium in all “lava” streams in comparison with initial fuel inventory. Estimates vary from 9-13% (Kiselev and Checherov, 2001) to >80% (Arutyunyan et al., 2010) of total amount of the ChNPP fuel; the rest is believed to remain in inaccessible premises of the reactor, possibly as fuel rods fragments.

Since 1986, and 1990, when the lava samples were first collected at Chernobyl, there have been huge advances in analytical chemistry, and the purpose of the paper is to utilize these lava samples using this new technology:

We report here new results on present (as of 2014e2015) state of lava samples and aerosols collected inside the “Shelter” building, complementing our recent investigation of radioactivity distribution in the lava samples (Vlasova et al., 2015). Most of the analytical techniques employed by us are applied to the lava samples for the first time and obtained results are important to derive consistent model of the lava and to resolve some of existing controversies.

In addition, some new samples were acquired:

2.2. Aerosol particles

Aerosol particles were collected in 2010-2014 at the distance of 20-30 cm from the lava heap in room 012/7 (level 0.0 m, the first floor of the Bubbler tank (Borovoi et al., 1991a)) using a pack of three Petryanov filters with different particulate retention sizes mounted on the nose of the air blower Н810 RadeCo operating for 2 h at a pump rate 100 dm3/min. Daily variations of the air temperature in this room are negligible, annual variations are within 4С -9С in winter and 13-С in summer). Chemical and radionuclide (e.g., 137Cs/241Am) composition of the particles collected is consistent with composition of the heap (Pazukhin et al., 2003; Ogorodnikov et al., 2013).

2.3. Spontaneously detached individual sub-millimeter particles

These chips were collected in 2013-2014 on the planar cuvette placed for 6 months on the floor 0.50 m in front of a lava heap in room 012/7 (see chapter 2.2). These particles are of particular interest, since their detachment from the lava accumulation appears to be spontaneous. The particular lava agglomeration is mechanically heterogeneous: the internal part is highly porous (pumice-like or granulated, see Fig. 1G, H) since it was formed when hot brown lava stream entered in contact with water in the Bubbler tank, whereas the outer shell is glassy due to rapid quenching (Borovoi et al., 1991a; Pazukhin et al., 2003). The glassy shell was partly broken by researchers. The exact origin of the studied particles e the heaps’ shell or interior or even destruction of eventual pieces of pumice observed in this room is unclear.

There is reference in the excerpts above to several isotopes of interest in connection with the Chernobyl event, specifically, 137Cs and 90Sr. These two elements, cesium and strontium, and in fact their salts and/or oxides, are highly volatile at the temperatures described during the Chernobyl meltdown, and it is well known that they were widely distributed across Europe in detectable amounts. (It should also be noted that being radioactive, they can be detected as extremely low levels, not all of which represent a severe health risk.)

I have long been following with interest the behavior of environmental loads of Cs-137 in particular, since its volatility suggests some interesting possibilities in nuclear reactor engineering that may be of use when future generations if and when they find the where-with-all and resources to clean up the dangerous fossil fuel disaster that we have left for them, in deep contempt for their lives, something that will only be possible using nuclear technology, given the high energy to mass ratio of nuclear fuels.

For example, before being banned from Daily Kos for telling the truth, the truth being that opposing nuclear energy is akin to murder, I wrote this somewhat sardonic piece in 2010: Post-Chernobyl Radionuclide Distributions in an Austrian Cow. At that time, in 2010, 45.6% of all the Cs-137 released by the Chernobyl accident had decayed to non-radioactive Ba-137. As of this writing, about 54.3% has decayed, 45.7% remains.

Neither Austria nor the rest of Europe has been depopulated by eating cows containing Cs-137 since 1986. (Cows all around the contained Cs-137 well before 1986 from open air nuclear weapons testing. In fact, about 17.7% of the Cs-137 released by the 1945 Trinity nuclear weapons test in 1945 is still radioactive. It seems to be inevitable that New Mexican cows have detectable Cs-137 in them.) Eating cows, by the way, is generally bad for you. More people have died from fatty foods since 1986 than have died from Chernobyl, way more people, hundreds of millions of people in fact. Chernobyl or not, no one ever proposes banning cows because eating them is "too dangerous."

Anyway. Anyway. Anyway.

Here are some tables on the elemental composition of the Chernobyl lava:







A few elements listed here have long lived radioactive isotopes that may be detectable in the samples: They are zirconium (Zr-93 as a fission product and from radioactive induction in Zr-92 in structural materials), iron (Fe-60 from radioactive induction of short lived Fe-59, in turn from the induction of Fe-58) and, of course, uranium, which has been radioactive since the formation of the Earth, and which would have been radioactive whether or not it had ever been in the core of the Chernobyl Unit 4 reactor.

The specific activity - the number of radioactive decays per gram - of none of these elements is particularly high; in every case they are way lower than the specific activity of cesium-137.

Here are some pictures of radioactive lava:





The caption:

Fig. 1. Optical and SEM images of Chernobyl lava samples. AeD e black lava (Samples I and II), E, F e brown lava (Sample III); G, H e granulated brown lava from room 012/7 (see text). A, C, E, G, H e optical photographs; B, D, F e BSE mode. Note significant radiation damage in surrounding acrylic resin.

By the way, in the first week of April 1986, the concentration of the dangerous fossil fuel waste carbon dioxide in the planetary atmosphere was 349.79 ppm. (The week ending April 6, 1986 from the data at the Mauna Loa CO2 observatory.) In the first week of April 2019, the same figure was 413.13 ppm. Unlike the world wide levels of Cs-137 since the much discussed Fukushima event, the levels of the dangerous fossil fuel waste are going up, not down. Since April 6, 1986, using the figures reported at the Mauna Loa observatory this morning, for the week of February 9, 2020, the concentration of this dangerous fossil fuel waste in the planetary atmosphere has risen by 64.61 ppm.

Unless you are Mr. Zirlin or a colleague involved in the same kind of work, the probability that you will die as a result of Chernobyl is roughly comparable to the probability that you will win the Powerball lottery. The probability that you will die from air pollution, or a car accident, or the effects of eating cows - if you do eat them - is five or six orders of magnitude higher.

Maybe you couldn't care less; maybe you think Chernobyl is the worst thing that ever happened. I disagree. There are, in my mind, hundreds of thousands of things that were worse. For me, since I'm in the unusual position of actually giving a shit about future generations, climate change is much, much, much worse. With respect to nuclear reactors, Chernobyl and Fukushima type events are easily engineered away, just as we engineer away aircraft failures, which by the way, have killed way more people than nuclear reactors have in the last 60 years.

I hope you're having a pleasant Sunday morning.

[dewsgirl]

1. I thought the photographer that took the photos of the elephants foot

died? I read Midnight in Chernobyl, back when the mini series came out great book.

[NNadir]

2. That could be true. I do not know the identity of the person in the photograph...

...or the person who took the photograph, assuming that a 2nd person was there and an automatic camera was not used.

The referenced paper however, refers to "Mr. Vladimir Zirlin of the V.G. Khlopin Radium Institute" who is reported to have carried samples of the "elephant's foot" material. He was still alive in 2012.

It is interesting how many popular books and mini-series came out about Chernobyl. I've been through a few of them, although I feel that the focus on Chernobyl is, as stated, a "...but her emails..." statement. Probably my favorite popular book on the topic is Wormwood Forest, which was written by Mary Mycio, a Ukranian-American journalist. Unlike most journalists she did not macerate the reporting; she took nuclear advocates like myself and anti-nukes to task equally. One doesn't see much "fair and balanced" reporting like that anymore. It is very, very, very rare, especially on topics involving science.

When I was a kid, a pathologist in the hospital where I worked, would let young people on the staff attend autopsies on the weekend, I guess to inspire us to become physicians. I recall one autopsy where he dissected a lung carcinoma to show us the carbon particles inside it. I asked him if the deceased person was a smoker, and - I will never forget this - he said, "No, smoker's lungs look much worse. This man was a teacher in New York City." (This took place in the 1970's.) I did not pursue a career directly involved in medicine, but, again, I have never forgotten that pathologist's remark. In retrospect, I think it changed my life.

It would be interesting if people made mini-series called "Midnight in Lung Tissue," but that's not going to happen. We focus on the extreme at the expense of understanding the routine, which is tragic, since we are rapidly destroying the planetary atmosphere.

It is likely to my thinking that somewhere between 150,000,000 and 200,000,000 human beings have died from air pollution since Chernobyl.

If we do nothing more about the destroyed reactor at Chernobyl, the death toll from the event will be vanishingly small when compared to the death toll of the normal use of dangerous fossil fuels.

That's a fact. Facts matter.

Climate change will affect every human being who comes after us; in fact every living thing that comes after us.

It is a crime against the future that we think Chernobyl important and climate change as something that we could do something about if we get around it to it.

Thanks for your comment.

[stopdiggin]

3. total agreement

I hope a younger generation is listening (and survives with enough resources and social stability to implement what they've learned)

My own generation just completely jumped the track on this. A absolute triumph of (self-inflicted) misinformation.

[NNadir]

4. My sons tell me that among the groups with whom they travel, most everyone agrees on this point.

They of course, are facing the consequences of climate change.

They have to clean up our mess.