Radioactive water at Fukushima Daiichi: What should be done? (2018)
blog.safecast.org
blog.safecast.org
One self luminous exit sign contains about 0.00074 PBq of tritium. The Fukushima stored water contains about 0.76 PBq of tritium, enough for about 1027 signs. I suspect there is far more tritium in the exit signs in Tokyo then there is in the Fukushima water.
https://www.everglow.us/pdf/tritium-exit-sign-fact-sheet-lan...
No, absolutely not. Both are extremely harmless. Zero is zero; neither is more harmful than the other.
Let me put it this way: In both cases, a much bigger threat to you would be walking past the display of bananas at the local supermarket. (And no, you shouldn't be worried about the radiation from THAT either.)
The concern here - if I understand correctly - is that it's ingestion and absorption of a low half live (more energetic) beta emitter.
But regardless, that's not the point I'm disputing. I'm disputing whether "the radiation has been reduced to background levels" necessarily means the negative effect of the radiation has been made negligible. Rather, assuming the linear-no-threshold model, the number of radiation-induced deaths will not decrease.
It worked fine for ships full of chemical weapons in the past, so should be able to work in this case as well. :)
Maybe we've cracked it :)
All the handling involved would also introduce risks, and is probably more cheaply and safely achieved on land.
That said, there's a political aspect to this, and maybe the perception of disposing of the water far away from Fukushima justifies the scientifically unnecessary added complexity.
I bet that this is not even legal, for good reasons
We must stop thinking in the ocean as just a lot of water. This way of thinking is suicidal.
https://phys.org/news/2018-10-chernobyl-life-solar-power.htm...
The article says they aim for up to 100 MWe capacity in the future, which would be nice, yet still illustrates how very powerful nuclear reactors are, with each of the 4 now inactive Chernobyl blocks producing 1000 MWe (and 3x times as much heat!).
1st) Who is this /we/ you speak of?
2nd) Who's tankers are you suggesting /we/ utilize?
3rd) Who is the governing authority here that is in charge of the WE, the VESSELS, and the area of release?
Who's backyard does this take place in?
How much compensation is being offered for these privately owned tankers that will be permanently damaged by the radioactive waste being carried?
Who is paying the wage and medical bills for the crews that are crewing said vessels?
Where does this labor come from in the first place?
Who is safety training these laborers in the proper use of protective gear, proper disposal procedures for contaminated gear, etc...
Finally, where the hell is this highly-contaminated water going to be released and or stored?
Most importantly, who the hell is going to pay for all of what you've suggested?
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I sure as hell am not going to pay for it. TEPCO sure as hell isn't going to pay for it. Japan sure as hell isn't going to pay for it.
SO, I ask again, who's footing the bill for this immensely complex and expensive process?
Water currents would return it to home, or to somebody's home or kitchen. Fishes migrate also.
There's no risk of "water currents causing it to return home". That's not even something that is physically possible.
Water currents move water masses, travel in closed loops and obey the laws of physics. Claiming that is not even physically possible that the same water pass two times by a point is an overstatement. Can be unprobable, but is perfectly possible with enough time.
Water in Fukushima travels to California and Alaska and then returns again to Japan, and then returns to USA in an endless loop. That's how it works. Ask an oceanographer.
Water masses with their own collection of animals and plants are traced far away of their point of origin. Is not a secret at all.
This is what needs to happen, any other action is kicking the can down the road. Another substantial earthquake or time will do the same.
Additionally 60kBq/L is larger compared to other isotopes because of tritium's properties. As long as this isotope is diluted properly there is no possibility of biological aggregation or concentration of this, it is just hydrogen, chemically speaking.
The alternative is to dilute it down so that it's less harmful, but then you have a larger volume, and so containing it is a larger problem. If you dilute it to the point that its volume is the entirety of water on earth, then it's at a safe level (and a fraction of the natural level), and so isn't a containment problem anymore.
Sand will not help the problem; the radioactive component is tritium, which is in the water molecules themselves. The sand will just mix with the water and give you a larger volume that has handling challenges of wet sand and evaporates and sweats radioactive water.
That said, an imperfect distillation may be cheaper, but the quantities of fluid here are still huge.
Meanwhile, it keeps accumulating, because the problem is caused by groundwater leaching into the contaminated reactor area. So at some point, accumulated volume p will probably exceed available storage area q, which seems to be where we are now. So it has to be dumped somewhere.
The solution is almost certainly to dump it at sea, but I don't think they can get away with dumping it right on the coastline, politically.
Maybe they should stack a second row of containers in the second floor then? (hey, we doubled the available space with only steel beams, some concrete and a welder! we can build upwards!, is like magic!)
Every difficult engineering or social problem can be solved by the clever one-line idea of some dude on the internet.
One way is distillation because the boiling point of tritiated water is slightly above that of normal water (101.5°C instead of 100°C), but this seems to be a lot more difficult than distilling alcohol.
Deuterium (not relevant here) has one extra protons, giving two. We write ²H.
Tritium has two extra protons. We write ³H.
Water is ¹H₂O, or (showing the structure) ¹H-O-¹H. (Or ¹H-¹⁶O-¹H, since it's normal oxygen in all this.)
One or both of those normal hydrogen atoms can be replaced with tritium: ³H-O-¹H or (rarely) ³H-O-³H.
Chemically, both ¹H-O-¹H, ³H-O-¹H, ³H-O-³H, or for that matter ²H-O-¹H or any other combination are essentially identical. Any chemical process you might think to do on normal water will have the same result on tritium-water.
To separate them, you must use physical properties: tritium-water is slightly heavier. This is how different isotopes of uranium are isolated — centrifuging to separate the heavier and lighter molecules — but it's likely to be extremely costly at the quantity being discussed.
Is the radioactivity low enough?
Radioactivity is super easy to detect even at harmless levels. Sunburn is a far (probably a million times? More?) bigger concern with similar effects (radiation burns possibly leading to cancer), yet people still go outside.
The whole Fukushima aftermath is a good example of the Mike Tyson Principal: Everyones got a plan till they get punched in the face. There were plans how to prevent this kind of mess until it actually happened.
People grossly overestimate how much radiation there is, not to mention how dangerous it is. Bananas are much more radioactive than fish from the pacific, regardless of when or where caught. :)