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Sun Dec 8, 2019, 02:08 PM

Continuous On Line Analysis of Constituents of the Radioactive Hanford Tanks.

The paper I'll discuss in this post is this one: Online, Real-Time Analysis of Highly Complex Processing Streams: Quantification of Analytes in Hanford Tank Sample (Bryan et al, Ind. Eng. Chem. Res. 2019, 58, 47, 21194-21200).

Nobel Laureate Glenn Seaborg described the chemical processing in the Manhattan Project to produce plutonium, an element of which he was co-discoverer, as the fastest and greatest chemical scale up in history. The first sample of plutonium he created, which is now displayed in the Smithsonian Institution's History of Science Museum - I've seen it - contained a tiny quantity of plutonium that was invisible; it's existence was recognized by detection of its radioactive decay signal. The nuclear reactions that created it was 238U[d,2n]238Np. The reaction was carried out using the 60 inch cyclotron at UC Berkeley. The neptunium (which was not initially detected) decayed within days to the plutonium isotope, 238Pu, which was characterized by trace chemical procedures in Gilman Hall, room 307, in late February, 1941.

The first human built device to leave our solar system necessarily contains kg quantities of the 238Pu isotope.

As everybody knows, the discovery of plutonium played a huge role in the Manhattan project, and the scale up in which Seaborg played a key role, involved scaling the isolation of plutonium from essentially the atomic scale to multiple kg quantities. This was an industrial process, designed and executed in a completely ad hoc fashion, using materials and substances that had never been seen by anyone previously, possessing properties, notably intense radioactivity, that had never been addressed on an industrial scale.

As someone with considerable experience, albeit largely (but not entirely) indirect, involving the scale up of chemical processes, this is not the way chemical processes are scaled today.

In this process, it was absolutely necessary, given the physics of plutonium at the rate at which it formed to utilize sources of it that were extremely dilute solid solutions of uranium. This procedure therefore necessarily produced significant quantities of by products, many of them highly radioactive. At the time, very few people thought about the long term consequences of handling these by products, now generally described by the public lexicon as "nuclear waste." A far greater concern at that time was that scientists working for Adolf Hitler would develop a nuclear weapons first. In some cases the by products were simply dumped in trenches. Ultimately storage tanks were built. Almost all of this process work was conducted at the Hanford plant in Washington State, the site having been selected because the nuclear reactors that were ultimately built to produce plutonium required significant quantities of cooling water to run.

As everybody knows, the "hot" war, World War II - which started, at least as far as the United States and the former Soviet Union were concerned, as an oil war - became the world's only observed nuclear war, which was followed by a cold war, by the two participants in the war who possessed and produced significant amounts of oil. (There have been many oil wars since 1945, but happily, no more nuclear wars.)

During the cold war, the production of weapons grade plutonium, in Washington State and elsewhere, accelerated to an even larger scale, from kilograms to metric tons. The requirement for the production weapons grade plutonium - tons of which was vaporized in the open atmosphere, and distributed across the planet by the United States, the former Soviet Union, Great Britain, France and China - has always involved the use of dilute solid solutions of the element, and has thus always generated huge quantities of by products. At the Hanford site, 149 single shell tanks were constructed to contain these by products between 1945 and 1964, and after 1964, when it was understood that some of these tanks were leaking by products, many of which were highly radioactive, into the ground. After this was discovered, a new class of tanks were built, double shell tanks, an additional 28 tanks.

During the history of the filling of these tanks, the types of materials in them varied widely, often with marginal record keeping because they were subject to multiple and changeable processes. The initial process for plutonium recovery was called the "Bismuth Phosphate" process, which was followed by the Purex process (still in use in various places around the world), the Urex process, and the Truex process, the "ex" referring to the basic chemical approach in the processes, which is solvent extraction using solvents and extractants produced from the dangerous fossil fuel petroleum, for example, kerosene, and tributyl phosphate. The fuel rods were dissolved in highly corrosive (necessarily corrosive) acids, primarily nitric acid. The nitric acid solutions were neutralized, after extensive processing to isolate plutonium (and in some cases other elements of interest), with sodium hydroxide, enough to keep aluminum from the processes in solution, although in some cases, this aluminum precipitated in a form of the mineral gibbsite.

The early tanks were designed to accommodate solutions that were subject to continuous boiling, since the side products were not only radiologically hot, but also thermally hot. Once it was recognized the tanks were leaking, it was decided to reduce the heat load in them by removing the cesium from the tanks, using another set of processes that were also somewhat ad hoc. I wrote about the processing involved elsewhere in this space: 16 Years of (Radioactive) Cesium Recovery Processing at Hanford's B Plant. As I noted in that post, the process utilized to remove the cesium was recognized, after the fact, as having created a theoretical risk of a massive chemical explosion owing to a potential for a chemical reaction between ferricyanide and nitrate. It was happily discovered however that the radiation in the tanks had destroyed the cyanide and rendered any risks nil.

This outcome, by the way, suggests why so called "nuclear waste" has largely unappreciated value, since it has the demonstrated value of destroying high risk chemicals, some of which are far more intractable than cyanide and are features of far larger quantities of wastes than are present at Hanford, specifically electronic and the very frightening (at least to people paying attention) agricultural waste nitrous oxide.

Unlike nitrous oxide, the "nuclear waste" tanks, and the Hanford site in general, has garnered a huge amount of interest and concern, particularly from a set of people, anti-nukes, who I personally regard as intellectual and moral cripples. I, as anyone who has ever read the tripe I write here - which is not necessarily designed to be informative as it is to drive my autodidactic exercises - knows, am a rather rabid advocate of the rapid scale up of nuclear energy, which I regard as the only practically available tool to save humanity from its most intractable wastes, the most dangerous form of waste being dangerous fossil fuel waste. Combustion wastes, including the combustion wastes associated with "renewable" biofuels kill, as I often point out, kills about 19,000 people per day. These wastes are most commonly called "air pollution." Another 1200 people die per day from diarrhea associated with untreated fecal waste. As an advocate of the rapid expansion of nuclear energy, people who oppose my admittedly less than uniformly admired stance, are always directing my attention here to the Hanford reservation, about which they know less than I do, since they are a uniformly uneducated bunch when it comes to nuclear issues, and simply hate stuff about which they know nothing. The Hanford tanks are not risk free. It is very possible that materials leaching from them will someday result in death or injury for some people, but the number of "at risk" people is vanishingly small when compared to the observed and on going death toll of people killed by other wastes, in particular, combustion wastes associated with dangerous fossil fuel and "renewable" biomass combustion. I therefore morally and intellectually reject the notion that we should spend hundreds of billions of dollars to save a few lives that may be lost from Hanford leaching when we are unwilling to spend a comparable amount of money to clean up the planetary atmosphere which are in the process of destroying.

The moral idiots making this case, that Hanford is a dire emergency requiring the abandonment of nuclear power, while the death toll of air pollution, climate change from dangerous fossil fuels and, for that matter, fecal waste, is not, simply make me angry and upset.

Thank God DU has an ignore function. I have a very low tolerance for deliberate ignorance.

Despite this objection of mine, huge amounts of money are being spent to "clean up" Hanford utilizing an arbitrary risk to cost ratio that would never be applied to dangerous fossil fuels, since the application of such a ratio to dangerous fossil fuels would make them immediately unaffordable, and we believe we can't live without our consumer stuff that dangerous fossil fuels power. The silver lining on this cloud of selective attention is that the money being spent is producing some very good science, science that will have value in many fields, including the field of the recovery and utilization (ideally) of radioactive materials.

That brings me to the paper referenced at the outset.

Because of the ad hoc nature of the processes to which the contents of the Hanford tanks were subject, the nature of their contents is highly variable and in some cases, unknown. The paper is about the contents Hanford Tank AP-105, a single shell tank from the 1960's that has been leaking for some time. However to see how variable the contents of the tanks can be, here is a graphic from a government report, PNNL-18054 WTP-RPT-167, Rev 0, describing variability in a set of Hanford tanks not including AP-105:

In order to reduce costs, improve safety and quality in any industrial process, real time analysis of the process is to be preferred to what the authors called "grab sample collection and offline analysis. To wit, from the introduction of the paper:

Online monitoring of chemical processes is a growing field with the potential to impact manufacturing, field detection, and fundamental research studies.(1−5) This approach allows for unprecedented, in situ characterizations of chemical systems. A variety of analytical techniques have been employed, ranging from ultrasonics to mass spectrometry.(6,7) However, optical spectroscopy offers a pathway with the greatest potential for providing chemical information including concentration, oxidation state, and speciation.(8−11) The primary strength of optical spectroscopy is the ability to provide significant amounts of characterization data for many chemical species, which leads to the primary challenge associated with this technique. In complex systems with multiple chemical species, the measured optical signals will be proportionally complex. The resulting spectral overlap, matrix effects, ionic strength effects, or signal interferences can inhibit accurate or timely response.(12,13)

This is strongly evident when monitoring the complex streams of the Hanford waste site, the largest superfund cleanup site in the United States.(14,15) With millions of gallons of radioactive waste needing to be remediated and moved to environmentally secured locations, current processing schemes rely heavily on sample collection and off-line analysis to ensure the correct management of materials. Grab sample collection and off-line analysis, however, are time consuming, costly, and have the potential to expose personnel to hazardous conditions.(13,16−19) Most importantly for processing timelines, waiting on grab sample analysis can force a batch-processing approach with extended periods of wait time between processing steps.(20) The Hanford site would benefit from the application of online monitoring by realizing faster (real-time) characterization of process streams while substantially reducing the need to expose personnel to hazardous conditions in the collection of grab samples.

Optical spectroscopy, and particularly Raman spectroscopy, is useful in the analysis of Hanford tank wastes. A majority of tank components are Raman-active with unique fingerprints that can be used to identify and quantify target analytes.(20)
The primary analytical challenge lies in accurately quantifying target analytes within the Hanford tank matrix. Hanford tanks contain a wide range of chemical species, with limited precharacterization to inform and aid in signal analysis.

Raman spectroscopy was discovered in the late 1920's by C.V. Raman, the first Asian to win the Nobel Prize. At the time of his discovery, during the British Raj, when the British regarded themselves as superior to Indians with absolutely no justification, Raman spectroscopy involved extremely hard work, with a single experiment taking many days to perform. The technique involves exciting a molecule with intense monochromatic light, and observing weak emissions radiating at wavelengths differing from the monochromatic light. The development of lasers and CCD detection devices has made it possible to develop commercial instruments that can run experiments in seconds rather than days. Since the emissions involve vibrational and rotational changes in molecules, raman signatures can only be obtained for multi-atomic molecules and not for atoms or ions that are not bonded to another atom or ion.

Here, from the paper, is a description of the contents of the components of Tank AP105.

The equipment:

Spectra were collected using a Raman spectrometer from Spectra Solutions Inc. and associated Spectra Soft software (version 1.3). Instrumentation consisted of a thermoelectric-cooled charge-coupled device detector and 671 nm diode laser. Collection times of 1 s were utilized, where every five spectra were collected and averaged into one spectrum for modeling and online monitoring applications. No spectral data processing other than data collection was performed using the Raman instrumental software.
A specialized flow cell, consisting of a machined holder to maintain the Raman probe alignment into a quartz flow cell, was used to interrogate both stationary and flowing samples. Flow loops were maintained with a QVG50 variable speed piston pump (Fluid Metering, Inc.) capable of pumping fluids at rates from 0 to 35.6 mL/min as set by a controller module. Flow rate calibration curves can be seen in the Supporting Information.

The experiments take 1 second.

The following graphics demonstrate the result of the Raman real time spectroscopy experiments performed on simulated and real Hanford tank contents:

The caption:

Figure 1. Spectra of pure components anticipated in tanks focused on the fingerprint range (top), overlapping NO3 and CO32 bands (middle), and the water band (bottom).

The caption:

Figure 2. Parity plots for NO3 (top) and CrO42 (bottom) showing results for both the training set (gray circles) and validation set (other markers).

The caption:

Figure 3. Spectral response of the multicomponent sample (top) and the concentrations over the course of the run (bottom).

The caption:

Figure 4. Raman spectral response (top) over the course of the flow test and resulting chemometric measurements (open circles) of NO3 (middle) and CrO42 (bottom) to known values (black dashed lines).

The caption:

Figure 5. Spectra of real AP-105 at multiple flow rates and resulting chemometric results from flow test.

An important feature of the instrument must be the radiation resistance of the components.

Irradiation Experiments

A Raman probe and two different samples of a quartz window material (sample cuvettes) were exposed to γ dose from a cobalt-60 source. These materials were irradiated stepwise, increasing by a decade each irradiation, from 1 104 rad to a cumulative dose of 1.7 108 rad. Between each irradiation step, the spectra of the AP-105 tank simulant were acquired using irradiated and nonirradiated micro-Raman and 1 cm cuvettes.

The results:

The caption:

Figure 6. Picture of the window material before and after complete irradiation (top), spectra of AP-105 simulant as a function of dose (middle), and resulting NO3 measurements across the dose steps (bottom).

The table of analytical results.

The R2 values are, in some cases, a little lower than what we would accept in the pharmaceutical industry, but almost certainly sufficient for this type of analysis.

The paper's conclusion:

Raman spectroscopy is a robust and highly applicable tool that can be applied to the online monitoring of complex and hazardous processing streams. Subsequent analysis of spectra utilizing chemometric analysis allows for highly accurate, real-time quantification of target analytes. Raman spectroscopy and chemometric analysis were successfully utilized to accurately identify and quantify nine critical components of real tank waste from Hanford tank AP-105: a radioactive sample that has more than 10 components in a high ionic strength environment. Furthermore, the Raman probes and subsequent analysis demonstrated highly robust capabilities to perform accurately after receiving over 1 10^8 rad of γ dose. Overall, Raman-spectroscopy-based online monitoring is a powerful route to characterize processing streams that present challenges such as chemical complexity and hazardous or damaging environments.

Interesting, I think.

I trust you're having a wonderful Sunday and that if you will be celebrating the upcoming holidays, that your preparations are going well.

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Reply Continuous On Line Analysis of Constituents of the Radioactive Hanford Tanks. (Original post)
NNadir Dec 8 OP
SonofDonald Dec 8 #1
NNadir Dec 8 #2
SonofDonald Dec 10 #3
NNadir Dec 10 #4

Response to NNadir (Original post)

Sun Dec 8, 2019, 02:41 PM

1. You sure can put it out there

I read enough already to make me even more worried.

Hanford is a hole into which they throw billions of dollars.

And that isn't anywhere near being remediated.


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Response to SonofDonald (Reply #1)

Sun Dec 8, 2019, 04:26 PM

2. The atmosphere, by contrast, is a waste dump that...

...actually kills people.

As long as people care more for stuff like Hanford more than stuff that kills people, the word "SHIT" will have little meaning.

Let us know when Hanford has killed as many people as will die in the next 20 minutes from dangerous fossil fuel waste.

It is idiotic and frankly immoral to spend hundreds of billions of dollars to focus on Hanford when we won't spend 500 dollars to install a septic system in an area where more people will die from fecal waste than will ever die from Hanford leachates.

We live in a world where scientifically illiterate journalists have trained us in A Pavlovian fashion to insist that the only thing requiring remediation is radioactive materials. If nothing were done at Hanford the results would not be as dire as the death toll from air pollution will be this week. Let me know about your plan to remediate the atmosphere to the same standard you apply to Hanford. We have destroyed the planet's future with the bad thinking of selective attention.

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Response to NNadir (Reply #2)

Tue Dec 10, 2019, 12:18 PM

3. You seem angry

Happy Holidays!

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Response to SonofDonald (Reply #3)

Tue Dec 10, 2019, 06:44 PM

4. Well, you know what they say...

..."If you're not angry, you're not paying attention."

I am paying attention.

There is really no limit to how angry I am about climate change in particular, and the destruction of the environment in general. I will die, soon enough, seething at what my generation has done to all future generations.

It didn't have to be this way. The fact that people are more concerned about Hanford than they are about stuff that actually kills people is a big, big, big, big part of the reason it is this way.

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