Sciencemadness Discussion Board - Disposal of Na from a breeder reactor

Disposal of Na from a breeder reactor

Dan Vizine - 19-2-2017 at 08:00

In an unusual twist, I've taken on a consulting role for a company who was awarded a government contract to dispose of steel drums which were used to drain the sodium coolant fluid from an early breeder reactor. The drums were subsequently re-heated and the sodium was poured out. From 2 to 5 pounds of sodium remained in the drum as a "heel". The drums were inerted and stored ~ 50 years ago.

The drums have developed a rust-coated surface. The proposed method of destruction that they plan on is compaction of the drums to a height of 6 or 8 inches, after that I don't have a clue. I have no need to know.

The concerns they'd like me to address include a thermodynamic analysis (easy) of the redox couple (rust & Na), a literature search (I have some limitations), laboratory simulations of potential initiating incidents (the fun part) and a general hazard analysis.

Anybody who has ever looked at Goldschmidt reactions will remember that the fuel metal needs to very active and should possess a high enough bp to not boil away from the reaction site. Thus, sodium is not usually considered for a smooth thermite reaction. But we're not concerned with a smooth reaction, just whether or not one will occur at all.

The thermodynamics say this will be a spontaneous reaction. But whether it actually happens requires empirical data. Yesterday, I decided to try and make a mixture of a stoichiometric amount of sodium and Fe2O3 using molten sodium. The idea was to make a intimate mixture of reactants, similar to Al thermite, without trying to (powder?!) sodium or resort to making sodium sand. The molten sodium was contained in an argon-inerted 2 inch diameter borosilicate test tube at ~ 130 C. The rust was added in portions, swirling vigorously in between additions. The sodium, as I feared, showed little tendency to adhere to the oxide. I allowed the tube to cool until the argon-blanketed mixture started to stiffen ever so slightly. My plan was to then gently mash the reactants together with a porcelain pestle.

Poof! That's all it took. Within a fraction of a second the mixture ignited and went pretty much to completion. Well, at least very little Fe2O3 powder was left. The reaction nuggets were magnetic.

Now that it is obvious that drum compaction, if molten sodium were present, could start a metallothermic reduction. How would molten sodium possibly be present? Interaction with water. I was told that the drums may be wet. But wet how? No info.

The problem is now reduced to something that a few observations could have resolved (if they were made, which they weren't). Is there water? If so, where? On the drum tops? Clinging to the inside drum walls? What does the sodium look like? Still solid? Liquid? In-between?

Does anyone have any experience that may be applicable? Personally, after 50 years, I feel that a boatload of moisture could have diffused in. I'd bet that the top layer of sodium is now concentrated NaOH solution. The sodium layer is only about a half inch deep. I've seen sodium metal that remains protected for decades with a layer of NaOH on top. What condition do you think the sodium would be in? Any real world experiences would be useful. Thanks.

PS. No application of pressure has yet been able to cause ignition. I've tried 12 tons of pressure exerted slowly by a hydraulic press, a jig I built that delivers reproducible 40 joule impacts via a SS rod, and (after 40 joules was not enough), I tried a sledge hammer at full force. Nothing.

[Edited on 2/19/2017 by Dan Vizine]

Sulaiman - 19-2-2017 at 10:19

Well at least all of the Na24 (the nasty one) should have decayed and almost all of the Na22, so no radioactivity problems.

wg48 - 19-2-2017 at 10:22

Well you may want to pad out your report with various analyses but in the final analysis a steel drum with an unknown amount of sodium metal and or sodium hydroxide/ carbonate solution in it cannot be crushed safely to a safe compact. Safe with the meaning used in US or UK industry. The sodium and or caustic solution could be extruded/expelled during the crushing and you could left with a vary nasty compact that may still contain/contaminated with sodium/caustic solution that is leaking. The crushing machine could be contaminated with sodium/caustic and then by water when the next drum is crushed. Then you are still left with the problem of safely transporting and disposal of the compact with perhaps extruded sodium sticking out of it .

I suggest you recommend neutralising sodium or its reaction products and washing out the drum prior crushing it. I just thought the drum could contain hydrogen/air mixture.

Dan Vizine - 19-2-2017 at 10:36

Sulaiman,

Absolutely correct, it has been an awful lot of half-lives.

wg48,

My thoughts exactly. I mentioned that, but they'd rather not for reasons that weren't explained to me. That's the industry standard for this situation. They have other plans for disposal and liquids aren't desirable if they can be avoided.

As the sodium is in a 1/2 " layer and compaction to the desired height leaves ample un-compacted space, extrusion is not a huge concern. When new drums are crushed similarly, the metal does not split or rip. But these drums are 50 years old.

Reading between the lines, maybe there still is a radioactivity concern. Otherwise, a cheaper, easier route would be taken I would guess. I am under the impression that the drum crusher will be consigned to waste also. Contamination of some kind seems inevitable.

Full scale drum crushing tests with new sodium (they bought 300 pounds) are the next phase of their work (once I'm done in 4 weeks).

[Edited on 2/19/2017 by Dan Vizine]

unionised - 19-2-2017 at 11:00

Among the issues I'd worry about would be the possibility of sodium peroxide formation too.

It may sound daft, but I'd start off by making sure that the process started off with a lot of water.
After that you would have hydrogen, scrap steel and dilute caustic.
You would convert an unknown hazard into well documented ones.

Obviously the dunk tank would need to be pretty much "remotely operated"; you certainly can't have anyone near it.

Dan Vizine - 19-2-2017 at 11:39

Hi Unionized,

Thanks for the post.

But here I guess I should reiterate the fact that it seems clear that the normal route of hydrolysis is not desirable.

In fact, to make a a few conclusions based on observations:

1) If some sort of residual radioactivity wasn't present, this entire project wouldn't exist, because otherwise it would just be a routine chemically-contaminated drum operation

2) They just bought 300 pounds of Na for full scale testing of drum compaction. That this process is to meant to proceed with the residual sodium in place is pretty clear. The entire project is written around it.

They have specified that inert gas and application of "asphyxiating silicate based soil cover" are on the table for hazard mitigation.

unionised - 19-2-2017 at 11:57

Fine, but Sulaiman's point still holds- you can't do this on a conventional crushing rig.
You need to assume that, at some point, there will be a sodium fire.

Dan Vizine - 19-2-2017 at 12:33

I think it's fair to say that the possibility of a sodium fire is only real if the drum splits on compacting.

IF the drum stays intact, I think the likely scenario is that, after opening and inerting and as compaction starts, any residual water on the drum head may fall inward. In any rational world, this amount should be fairly small. This is because they have to open to inert with gas and the asphyxiating agent (I think both should be used) and so any standing water would be removed already. The inward-falling water should not be capable of starting a fire under these inert conditions. Aerosols of sodium hydroxide with some oxide and some peroxide wouldn't be surprising.

The full scale drum crushing experiments should suggest an answer as to drum integrity. But, with 50 year old drums, a lot of things are possible. Perhaps the bottoms are fairly rusty and will split. I would like to say the full scale tests would be done on representative drums, but no pictures are available. So, who knows?

Given the uncertainties, a fire or a number of external fires are not impossible.

Given the low caloric output of sodium fires (similar to an equal volume of wood) they are not horrible, but precautions will need to be in place.

The crusher isn't exactly a normal unit in that its lifetime is measured in hundreds of drums, then it will be waste, too.

Thanks for these comments. They are just what I hoped for.

[Edited on 2/19/2017 by Dan Vizine]

phlogiston - 19-2-2017 at 13:22

If the possibility of radioactive contamination is real then a sodium fire may be a more serious concern than it would normally be, as it could disperse radioactive material.

It sounds like proposing an alternative approach is not part of your job, but how about enclosing the drums in bigger drums that are guaranteed by design to not split open upon compaction? It would prevent a number of the mentioned issues. Mainly, it would remove any uncertainties related to how the old drums will behave.
Also, if you could pierce the old drum after you put it in the new one and apply a vacuum for a while, you may be able to evaporate water that got into the old drum.

unionised - 19-2-2017 at 13:46

I'd agree- the fire isn't a massive problem- just let it burn out.
But the ash is caustic. If the ash is radioactive caustic then you have a big problem- essentially you need to enclose the whole lot and put filtered ventilation in place.

Something like this, but run underwater would be another option
http://www.untha.com/en/applications/metals_a11

OK you get nasty caustic waste water- but whatever you use you will presumably need to wash it down afterwards.
And it's cool to watch anyway :-)

j_sum1 - 19-2-2017 at 14:46

Interesting problem. I am really not sure why they want to crush while keeping the Na in metallic form. It would seem much more sensible to me to convert to an inert salt of some kind or even to let it oxidise in air. I understand the desire to avoid large quantities of liquids but surely there is a feasible method.

What are they going to do with the crushed leaky drums containing both rust and metallic sodium - with presumably some radiation hazard as well? That would seem to me to be more of a hazard than the (semi) intact drums.

Is there any possibility of adding something to the drums before crushing? I am thinking of something like powdered alumina to dilute the contents and lessen the chance of an uncontrolled reaction.

Dan Vizine - 19-2-2017 at 15:02

And then there's the question of what happens inside the compacts once the remaining argon diffuses out and any water settles. This is still a dynamic system in a sense.

The lack of details baffles me. With a little bit of data this analysis could be so much more useful to them. Maybe I'm just a useful component to them having secured the contract, but I get a feeling it runs deeper. If they had data, I'm sure they'd share it. As mentioned earlier, they couldn't supply arguably the single most useful piece of easily collected data, a few pictures. They haven't actually seen the drums! Is that how jobs are put out to bid? Without supplying any data to facilitate that which you want to accomplish?

Mine is not to reason why, I guess.

Again, and I have no evidence this is true, but I believe the goal is to avoid liquids at all costs. Notice that the only suppression agents allowed are a gas and a solid? I think that the planned fate of the compacts may not be compatible with liquid waste.

It may well be that the compactor is situated within an area like a large fume hood. If we assume radioactive dust/spray is in the mix, really, how could it be any other way?

[Edited on 2/19/2017 by Dan Vizine]

Dan Vizine - 20-2-2017 at 06:57

I located an IAEA paper which expanded on the radiological possibilities for the sodium.

As we all seem to be aware, the initially produced Na-24 will have experienced almost 30,000 half-lives in the past 50 years and has long since decayed to magnesium.

Here is where the rest of the concern lies:

There are several sources of radioactivity in bulk Na or NaK from primary circuits:
− Activation of sodium and potassium by neutrons in the reactor core; 22Na and 40K are
the main generated radionuclides;
− Contamination by actinides and fission products due to initial surface contamination of
fresh fuel by fissionable material, fuel cladding failures during operation, or use of
leaking fuel pins. Typical actinide contaminants are Pu, Am, Cm and U isotopes; the
most common fission products are isotopes of caesium. Tritium is also present;
− Contamination by activated corrosion products from fuel cladding and primary circuit
structures, such as 54Mn and 60Co.

Small wonder that this very high purity sodium metal is not suitable for re-use.

PS. Talk about luck!! A reference had this to say about the very barrels in question, and included a picture(!!):

All of the drained sodium barrels located at
the INL’s Materials and Fuels Complex (MFC)
are known to contain less than 5 lbs (2.25 kg) of
residual sodium metal, which is below the 10-lb
threshold above which the barrels would be
regulated under the Resource Conservation
Recovery Act (RCRA) statues. The exact
amount of residual sodium in each barrel is
unknown, however, because the barrels also
contain a mixture of sodium oxides, sodium
hydroxides, and sodium carbonates. Over time,
air and water has leaked into the barrels to react
some of the residual sodium and convert it into
these other materials. Figure 1 shows a
photograph of the inside of one of the 1400 drained
barrels.

and

Additionally, the barrels are considered low
level radioactive waste because of their origin
and measurable radioactive content and must be
disposed according to the waste acceptance
criteria for the Radioactive Waste Management
Complex (RWMC) in southeastern Idaho or
other equivalent facility.

[Edited on 2/20/2017 by Dan Vizine]

Magpie - 20-2-2017 at 10:22

I presume that the final crushed drums should be free of elemental sodium and also be chemically unreactive with the atmosphere and any water intrusion. To reach this state I would take off the drum lids and promote the burning of all residual sodium. This should be done in a HEPA protected fume hood, remotely.

Dan Vizine - 20-2-2017 at 12:15

No, Magpie, that isn't it....

The parameters of the disposal are seemingly set. I wasn't asked to comment on a recommended route. I was asked for a risk assessment of the intended method of compacting the drums without any pre-treatment. I can't guess the intention after that, although I'd assume burial. But, it's neither here nor there for my purposes. My task ends with a crushed drum, not on fire.

I think the paper that I found today is the answer I was searching for. There are analyses of 5 or 6 different drums and a picture. The sodium isn't present as aqueous NaOH overlaying a sheet of sodium, it's more lumpy. I haven't read why yet....

But, beyond any doubt, there is a substantial amount of elemental sodium left.

PS. Not trying to be evasive about the paper, but this job came with a confidentiality statement and so I'd rather not identify the exact reactor. The problem as stated could be any LMFBR and, of course, the company name wasn't given.

A couple well-worked-out wet methods exist. They hydrolyze to NaOH, concentrate it to 70% and when it cools it's suitable to bury. A refinement uses carbon dioxide to arrive at the carbonate.

[Edited on 2/20/2017 by Dan Vizine]

j_sum1 - 20-2-2017 at 15:05

Well, I think I share with Magpie and others a general unease that this is not the optimum treatment option. Common sense suggests rendering the material as inert as possible in every sense of the word inert. And leaving the sodium in its elemental form in damaged vessels flies in the face of that.

But, as you say, all this is out of your hands. The question remains open as to whether solid Na will react with iron oxides during the crushing process. Now that you know a bit more about the drums, is it possible to do a mock up with a rusted tin can, a bit of sodium and a hydraulic press?

And dang... I nearly weep for 1400 drums each with a few pounds of elemental sodium being disposed of.

[edit] typo

[Edited on 21-2-2017 by j_sum1]

Texium - 20-2-2017 at 15:27

Quote: Originally posted by j_sum1

I nearly weep for 1400 drums each with a few pounds of elemental sodium being disposed of.

That's pretty much all I've been thinking of as I've been following this thread. I mean, I'd take it, even if it was still slightly radioactive...

wg48 - 20-2-2017 at 18:00

Wow, In total over two tons of hot sodium buried in the ground !!!

I guess at some point hydrogen will be ecaping from the top soil. Could be a big suprise for someone lighting a campfire there one day.

MrHomeScientist - 21-2-2017 at 07:09

Do we know what the purpose of crushing the barrels is? It introduces so many risks and hazards it seems like it's not worth it just to save a little space in storage. Your initial testing certainly seems to indicate that pressing on a mix of sodium and rust is a bad idea.

Very unique problem, Dan. You have a pretty interesting job!

Endo - 21-2-2017 at 07:18

The super-compactor (hydraulic drum crusher) at the INL is located at the Advanced Mixed waste treatment plant (AMWTP) facility. I don't believe that they are currently outfitted to work with inert gas blankets. Typically crushed drums (Pucks) are loaded into 100 gallon drums and bagged with a filtered bag, The drum is lidded and a drum vent is installed into the 3/4 inch bung on top of the drum to prevent the container from building up gas pressure.

I don't see how this waste would ever be legal to ship on a public highway, with the RCRA codes for reactivity and corrosives, as well as the potential for hydrogen/flammable gas generation they would be able to do little except continue to store it onsite albeit with a smaller space footprint.

Good luck!

Dan Vizine - 21-2-2017 at 12:52

Quote: Originally posted by MrHomeScientist

Do we know what the purpose of crushing the barrels is? It introduces so many risks and hazards it seems like it's not worth it just to save a little space in storage. Your initial testing certainly seems to indicate that pressing on a mix of sodium and rust is a bad idea.

Very unique problem, Dan. You have a pretty interesting job!

I wondered the same thing. And then I found out it was 77,000 gals of sodium in 1,400 drums packed 80 to a cargo container. That's 18 cargo containers. It would seem that that could be reduced to 5.

It doesn't seem reasonable that it could be buried like that.

I don't mean to sound like this is normal work for me. It just came out of the blue, probably once in a lifetime.

I also got confirmation that the radioactivity is very low. If it weren't reactive, it could be buried in Idaho as radioactive non-hazardous waste.

[Edited on 2/21/2017 by Dan Vizine]

wg48 - 21-2-2017 at 14:55

77,000 gallons of warm (radioactive) sodium is considered “none hazardous" ... That’s a definition I have not come across before.

A lot more than a few pounds per barrel then.

Its not that long ago they would have opened the barrels and dumped them at sea. I think we (EU and US) don't do that anymore.

Texium - 21-2-2017 at 20:15

With the rising acidity of the world's oceans, it probably wouldn't hurt

j_sum1 - 21-2-2017 at 21:16

Here is how it used to be done. But apparently we now just crush and bury. I wonder if it is a significant improvement.
https://www.youtube.com/watch?v=HY7mTCMvpEM

Fulmen - 22-2-2017 at 05:27

I think the risks of a redox ( Goldschmidt) reaction between Na and iron oxide are quite real. I worked at a magnesium plant once, and we handled a fair bit of scrap for recycling. We had at least one explosion/fire from this during unloading. Our makeshift test was to collect a sample of dust and drop a glowing nut into it.

froot - 22-2-2017 at 09:43

Dan I would imagine this risk assessment will have a discouraging feel about it.
There are too many unknowns to confidently say that the method described will proceed without any challenges.
No sane person would approve of this horrible idea.

I understand that this is outside of your scope but for the sake of discussion my suggestion would be to seal the sodium with wax first. A wax with a melting point lower than that of sodium.
Say there is up to 2 inches of sodium in a barrel.
Add 2 inches of molten wax to capture any loose material on the sodium surface by spraying it in to wet all the loose material and help prevent it from floating. . When that's cooled add another 2 inches of clean wax and let that cool.
Now you have a solid layer of around 6 inches. Cut the barrel into 2 pieces just above the wax layer and crush the top piece as flat as possible, you should be able to get it thinner than 2 inches.
That would come to a total of less than 8 inches per barrel and no fires.

This would eliminate the possibility of barrels splitting at the sodium during crushing.

Questions are, could molten wax trigger any reactions?
How much potentially reactive material is stuck to the walls of the barrels?

unionised - 22-2-2017 at 13:42

I wondered how long it would be before that vid surfaced.
I can't see this process getting to completion without a violent redox reaction.
Not every time- bust sooner or later.

It reduces the bulk- and I guess that makes it easier / cheaper to dig the hole.
But eventually the ground will sink + compact the barrels- well out of the range of any humans.

Dan Vizine - 22-2-2017 at 14:52

Quote: Originally posted by wg48

77,000 gallons of warm (radioactive) sodium is considered “none hazardous" ... That’s a definition I have not come across before.

A lot more than a few pounds per barrel then.

Its not that long ago they would have opened the barrels and dumped them at sea. I think we (EU and US) don't do that anymore.

I say "was" because that was the original amount. The primary loop was 77,000 gallons which required 1400 drums. The sodium was melted and poured out. These drums are what's left. The sodium was hydrolyzed to give enormous multi ton blocks of 70% NaOH and buried. I THINK the goal here may simply be to turn 18 cargo containers into 5 since a well worked out method exists for total clean-up. It uses moist CO2 followed by water.

Dan Vizine - 22-2-2017 at 15:13

Quote: Originally posted by froot

Dan I would imagine this risk assessment will have a discouraging feel about it.
There are too many unknowns to confidently say that the method described will proceed without any challenges.
No sane person would approve of this horrible idea.

I understand that this is outside of your scope but for the sake of discussion my suggestion would be to seal the sodium with wax first. A wax with a melting point lower than that of sodium.
Say there is up to 2 inches of sodium in a barrel.
Add 2 inches of molten wax to capture any loose material on the sodium surface by spraying it in to wet all the loose material and help prevent it from floating. . When that's cooled add another 2 inches of clean wax and let that cool.
Now you have a solid layer of around 6 inches. Cut the barrel into 2 pieces just above the wax layer and crush the top piece as flat as possible, you should be able to get it thinner than 2 inches.
That would come to a total of less than 8 inches per barrel and no fires.

This would eliminate the possibility of barrels splitting at the sodium during crushing.

Questions are, could molten wax trigger any reactions?
How much potentially reactive material is stuck to the walls of the barrels?

Your opening was spot on. Or was a few days ago. Since then I came across a photo of a representative drum from this lot. The chunks are sodium oxide/hydroxide/carbonate around a metallic core. There are pieces on the sides of the barrel. They look loosely adhering but you can't say for sure. In my mind the real question is, when one of the lumps crushes, will that drive any hydroxide (and moisture of hydration) into fresh metal and cause a fire? I see fire, not a raging thermite reaction, as the actual danger. Fire will release radioactive smoke. A thermite reaction would burn out very quickly and not destroy the drum wall. There just isn't enough rust. But, it WOULD start the other available sodium burning.

Wax can pull away from walls when the crushing starts. Otherwise, no, it doesn't react with sodium. I favored mineral oil, but it's liquid and not acceptable.

I have a series of good tests dreamed up and I've made a few test jigs. This weekend should be productive.

Dan Vizine - 22-2-2017 at 15:23

Quote: Originally posted by j_sum1

Here is how it used to be done. But apparently we now just crush and bury. I wonder if it is a significant improvement.
https://www.youtube.com/watch?v=HY7mTCMvpEM

Burial was my uninformed guess way back when. Now, I am pretty sure that anything with elemental sodium in it just isn't able to be buried as radioactive non-hazardous waste. This can only be about space-saving. They just want to avoid fire while crushing. Ultimate disposal will be at a future date.

j_sum1 - 22-2-2017 at 16:18

Ok. Here's an idea.

The sodium remaining is obviously in excess to the rust and the water. That which is there could potentially cause ignition but after that the limiting reagent is atmospheric oxygen.

If the crushing could be done in a closed cylinder then air will be expelled and even if a reaction occurs it will quickly die out.

Say, a cylinder that the drums fit in reasonably snugly and a ram that is near to sealed against the wall of the cylinder. Add some temperature measurement to the set-up so that you have information on when/if a reaction occurs. Crush slowly allowing air to escape. Monitor the temperature. Remove ram and empty the cylinder when cool. You should be able to get a nice puck without an uncontrolled fire.

Dan Vizine - 23-2-2017 at 06:51

Quote: Originally posted by unionised

I wondered how long it would be before that vid surfaced.
I can't see this process getting to completion without a violent redox reaction.
Not every time- bust sooner or later.

It reduces the bulk- and I guess that makes it easier / cheaper to dig the hole.
But eventually the ground will sink + compact the barrels- well out of the range of any humans.

As many things in life are, this is the provenance of statutes and rules, not common sense.

From my tests so far, unless the sodium is molten, no amount of crushing, compacting in a hydraulic press, or impact (up to and including a hand sledge hammer swung with all my strength) will ignite the redox reaction. In my present view, prevent the sodium from burning or melting and we'll get no thermite type reaction. Many more tests to follow, though.

Dan Vizine - 23-2-2017 at 07:00

Quote: Originally posted by j_sum1

Ok. Here's an idea.

The sodium remaining is obviously in excess to the rust and the water. That which is there could potentially cause ignition but after that the limiting reagent is atmospheric oxygen.

If the crushing could be done in a closed cylinder then air will be expelled and even if a reaction occurs it will quickly die out.

Say, a cylinder that the drums fit in reasonably snugly and a ram that is near to sealed against the wall of the cylinder. Add some temperature measurement to the set-up so that you have information on when/if a reaction occurs. Crush slowly allowing air to escape. Monitor the temperature. Remove ram and empty the cylinder when cool. You should be able to get a nice puck without an uncontrolled fire.

We're starting to converge on thinking. Remember, though, thermite doesn't need oxygen. That is not a big deal (probably) because I think that unless the sodium gets to the mp, crushing won't initiate the reaction. I doubt if crushing gets the metal anywhere near hot enough to melt the sodium. In fact, I'd be willing to bet that crushing leads to no more than a handful of degrees of temp rise. The planned full scale test will confirm or deny this.

Has anybody here used a drum crusher before? Ever felt a just-compacted drum?

wg48 - 23-2-2017 at 13:21

Dan: I have not seen a drum compacted but I would expect there to be hot spots perhaps as the surfaces of the metal slides over each other. The problem is how many drums do you have to compact to be confident there will not be hot spot or spark that can ignite the thermite or sodium and what if there is sodium peroxide in the drum.

Ideally you need a set up such that any fire, leakage, minor explosion does not endanger personnel, damage the equipment or spread to the other drums.

[Edited on 23-2-2017 by wg48]

j_sum1 - 23-2-2017 at 21:13

My point is that both iron oxide and atmospheric oxygen will be limiting reactants in a snug cylinder. If a reaction does begin you can simply wait for it to die off and cool down. You might get a temporary sodium fire but there is no need to panic. Sparks, thermite, localised hot-spots and melting need not cause problems. That leaves reaction with water present which might be a bit less predictable -- potentially explosive and certainly releasing gas and a bit of heat. Mitigating against that possibility is the main reason for crushing slowly I think. It means there is some time for H2 to escape and heat to dissipate. And if there is a coulombic explosion the vessel is not tightly compacted at the time.

I reiterate, this is not the way I would do it, but the most feasible practice I see within the constraints given.

j_sum1 - 10-3-2017 at 01:48

Any updates Dan?

Sulaiman - 10-3-2017 at 02:31

Sodium metal can be extruded by a small hand tool to form sodium wire,
when the barrels are crushed I would expect any remaining unreacted sodium to be squeezed out of the bulk material.
Possibly a problem, possibly a coarse separation method ?

Dan Vizine - 12-3-2017 at 13:55

Since I last reported, much has been clarified to me. All of the odd restrictions now make utter sense. The goal isn't just to save space, it's permanent sequestration in a very stable form. Probably one of the best sequestration techniques of all. Wish I could say more, more but the last sentence really has a strong indication contained in it.

I took some interesting pictures during the preparation of this report, one of the pictures below shows a 20 J impact on a Na on rust smear. Barely did anything, but some ignition seen. 40 J was another story. Results similar to the ~25 J/sq. cm accepted value for aluminum on steel

Another question was answered. How much moisture can soil contain and still act as a slow, controlled sodium oxidant? At a certain level, it works beautifully. The attached picture was taken during trials to determine the allowable moisture level to act as an asphyxiant. The picture shows that 10% sure isn't it.

Dan Vizine - 12-3-2017 at 14:05

Quote: Originally posted by Sulaiman

Sodium metal can be extruded by a small hand tool to form sodium wire,
when the barrels are crushed I would expect any remaining unreacted sodium to be squeezed out of the bulk material.
Possibly a problem, possibly a coarse separation method ?

A report from the mid-80's indicates that the sodium exists as irregular rocky-looking masses of average size 1 - 4 inches. No liquid is seen in a random sampling of 6 drums. The lumps are a nugget of sodium, coated with a layer of solid sodium hydroxide monohydrate. This is coated with hard, crusty carbonate hydrates. I can't really reveal the method that was devised, but I think we've adequately addressed this.

j_sum1 - 12-3-2017 at 14:12

All very mysterious. I wish you were able to reveal more.
But you are sounding a lot more confident about the whole process, which is a good thing.

Dan Vizine - 17-5-2017 at 09:26

Hello Again,

* WORK OPPORTUNITY *

The results of the last Na work helped secure the desired government contract and that project is proceeding.

There is a new contract and this is an opportunity for someone here (hopefully) to become involved.

The subject is something called MOMS. This acronym stands for...well, I'm writing it now...
"The process called metal oxide mitigation of sodium, commonly referred to as MOMS, is really a specialized variation of the same type of metallothermic reaction of which thermite is an example. However, because of the relative free energies of the products and reactants, MOMS is a gentle, easily controlled method of reacting sodium to form highly stable products. While initially designed to react sodium with a silica-based substrate, the chemistry applies to other group 1 metals, particularly potassium."

The silica-based substrate is soil. We have a precise breakdown of its makeup, not surprisingly it's two thirds silica with a helping of hematite. And a bunch of other things.

We're going to be looking at the reactions that I have tentatively worked out:

10 M + Fe2O3 + 6 SiO2 --> 5 M2SiO3 + 2 Fe + Si (M = Na, K)

and

4 M + 3 SiO2 --> 2 M2SiO3 + Si (M = Na, K)

What my contact requested is:

In addition to this we are interested in undertaking some computer modeling to simulate the thermodynamics and reaction chemistry (multiphase transition). We are seeking some expertise in use of software like Star-CCM+, ANSYS Fluent, COMSOL, or other similar programs. Do you have access and capabilities in this area or could you make recommendation?

So, if you are such a person, please contact me. I can put you in touch with them and this could be a good opportunity. It seems as though this company is going to be involved in this sort of project in an ongoing fashion. A well-received piece of work could lead to you getting other pieces.

This is a world-class company, and if you aren't the person they are looking for you won't be able to fake it. This is clearly a job for either a grad student, professor or working or retired professional. Hopefully you are that person and you and I will end up working together.

Please note that they hope you have some sort of access to one of the software packages, in addition to simply knowing how to use it. They won't be supplying any software. Compensation is very generous.

In this case we're going to be looking at ways of disposing of radioactive NaK and radioactive LiH via a modified MOMS.

See: Geomelt, but this will be in a container.

Dan

[Edited on 5/17/2017 by Dan Vizine]

MrHomeScientist - 17-5-2017 at 09:55

Quote: Originally posted by Dan Vizine

Please note that they hope you can access the software, and not simply use it.

Surely they don't expect people to have personal copies of those software packages? I use COMSOL at work and that's a $20,000 piece of software.

Dan Vizine - 17-5-2017 at 10:07

No, I think that was implicit in the statement. He just said access it.

Dan Vizine - 22-5-2017 at 07:46

OK, Thanks guys. I see a quite a few people at least gave it a glance, and I appreciate it.

Dan

PS. The expiration date on this is indeterminate. The contract is still in the bidding phase, anyway. So, if someone eventually sees this and wants to reply, please do. It's not necessarily too late until I post otherwise.

[Edited on 5/22/2017 by Dan Vizine]

Dan Vizine - 22-5-2017 at 12:25

Quote: Originally posted by MrHomeScientist

Quote: Originally posted by Dan Vizine

Please note that they hope you can access the software, and not simply use it.

Surely they don't expect people to have personal copies of those software packages? I use COMSOL at work and that's a $20,000 piece of software.

Whew! I just obtained a copy of COMSOL 5.1. After installing for an hour, it works. I guess. It's hard to say, really . Even after an afternoon of YouTube videos, it's difficult to even know where to begin. Well, that isn't my problem, thankfully.

[Edited on 5/23/2017 by Dan Vizine]