Anyone who lives in Colorado receives a dose of many Fukushima's a year. I have a radon counter in my basement and watch the count ebb and flow with the seasons.
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.
Tritium undergoes beta decay and has a 12 year half life. Beta decay from a sign or your watch can only partially get through your skin (and skin is continuously shed and contains melanin). If you drink (or eat plants/animals in a tritium contaminated foodchain) then you bypass that protective layer and can damage organs that have far less resilience to radiation exposure.
I understood this to be the main concern with regards to harmful radiation. The article states that when HTO is consumed and comes in contact with biological molecules it binds to them and can stay in the body for years. It goes on to state the the negative effects of this may be underestimated.
Right. So put it in an oil tanker, take it someplace with permafrost, pump it out, and let it freeze. A few parts of Hokkaido are cold enough. In a century, it will have decayed enough to be a non-problem.
I don't think I'd want to bank on stable permafrost for a century. And one would probably want to put some care into site selection and construction as seismic hazards got us here to begin with. The residents of Hokkaido might reasonably not be warmly welcoming to this idea. I don't know enough about tritium impact to sublimation rates, but that would presumably be a problem. But point is taken about enclosed and chilled storage for 84-96 years.
I don't fully understand the comment - but I think it's my lack of knowledge here. If I stand next to a sign made with a small amount of tritium I get a small dose of radiation. If I live near a river or ocean that has 0.76 PBq dumped into it, isn't that high concentration going to be a lot worse for me even if I drive past every exit sign in Tokyo? What if I end up growing a Tritium vegetable garden?
> isn't that high concentration going to be a lot worse for me even if I drive past every exit sign in Tokyo
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.)
Er, all it takes is one ingested radioactive particle to damage DNA and spawn cancer. Radioactive particles from Fukushima are showing up in automobile AC filters on the West Coast, and the media hasn't said much about the MOX fuel in Reactor 3 that many experts now theorize could go critical based on the volatile (and largely untested) combination of plutonium and uranium that MOX consists of. And Japanese culture is about the worst possible mindset to deal with this cleanup effort, they are more concerned about saving face and avoiding embarrassment in front of the international community for having made the genius decision to build a bunch of nuclear reactors, some of which are using experimental MOX fuel, on top of the Shionihara Fault. They haven't even located the melted fuel in these reactors yet, and one misstep could easily result in another meltdown or worse yet a critical MOX mushroom cloud that kills millions if not hundreds of millions of humans as the result. Never mind the 850,000 tons of contaminated water they are now simply going to discharge into the ocean.
My old Physics teacher always said to put it on cornflakes. The surface area of all cornflakes in existence (back of the envelope) would result in totally harmless concentrations, undetectable above background. Of course getting the waste evenly distributed over all the cornflakes is another matter, one for the engineers...
Doesn't work that way if you ingest it, right? And obviously not all radiation is equal (alpha, beta, gamma) and even among those they have varying level of energy based on source.
The concern here - if I understand correctly - is that it's ingestion and absorption of a low half live (more energetic) beta emitter.
No, I don't think the distinction between ingestion and external exposure is fredley's point. Indeed, a fixed amount of radiation is much more destructive when ingested.
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.
"Tolerating" might mean experiencing the normal levels of cancer, which is 2nd only to heart disease as a leading cause of death in the US. If we take a given amount of radiation, then, assuming the linear-no-threshold model, spreading that radiation around a giant population does not decrease the number of deaths induced.
James Lovelock (formulator of the Gaia hypothesis) suggested sprinkling radioactive waste through out wilderness areas. This would, in a way, also help preserve these areas because humans would be wary of entering them or building in them.
So oil tankers can apparently carry some 300000 tons. Three or four oil tankers full would then be enough storage space for the onsite water. Couldn't we fill some tankers and have them release the water far away from any fishing grounds?
This was my thought also, although it may not be trivial to just hire an oil tanker to transport radioactive water. Before dilution, there may be a significant risk of contamination to the vessel and crew. You'd probably need a special vessel, specifically designed to handle radioactive fluids. Even if an oil tanker is technically adequate, there's likely some costly certification / approval that would need to be done.
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 get what you're saying, but I also can't help but chuckle at the fact that you're practically quoting the old "We'll just tow it until it's beyond the environment" skit.
I wondered that myself. I think the problem is that they first need to dilute it considerably before releasing it. If they do that before loading it onto the ship it might take too many journeys to empty the tanks. If they do it onboard the ship the you've got a ship full of radioactive water sailing about. I'm not sure how hazardous the water is but you might struggle to find people willing to sail on it.
Tritium is quite weakly radioactive. It is effectively shielded by a few millimeters of air. As long as the crew doesn't drink the cargo they should be pretty save.
Maybe just get an older tanker and sink it over the destination ? If you make holes big enough in the process it should take care of both dilution & the contaminated vessel.
It worked fine for ships full of chemical weapons in the past, so should be able to work in this case as well. :)
The same release from a vessel in open water is less likely to damage an ecosystem than release from the shoreline. That said, if it's diluted enough and released over a long enough period of time, it's unlikely to make much difference.
That brings up a good point. There are a few nuclear zones that no one lives in right (Chernobyl came to mind after watching that hbo show)? Why don’t we at-least get some value out of of these sad situations and convert one to a nuclear disposal site?
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!).
Life beings migrate. What situation would you prefer: radioactive water waiting safely in a tank in fukushima for 24 years to save your family from cancer, or Chernobyl's birds soaked in Fukushima's water, pooping and molting in your backyard to save TEPCO some money and allow them to circumvent their responsabilities?
That's not how it works. It's dilute enough it's safe to just dump it on the coast already; dumping it at sea would just be a big PR production to make it appear even safer.
There's no risk of "water currents causing it to return home". That's not even something that is physically possible.
> 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.
"Under the scenarios being discussed, the water would be diluted to 60,000 Bq/L before being released to the ocean. This number alone seems alarming, but is the concentration level that has been legally allowed to be released from Japanese nuclear power plants and reprocessing facilities such as Tokaimura for decades."
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.
Quick question / thought, why not run it through beds of sand that take some of the radiation and bury that sand somewhere? Eventually as you run the water through the sand long enough it should become less and less irradiated right?
The problem is that you have a large volume of radioactive fluid. The radioactivity is "low-level" but still poses a danger to health and life. If you store it somewhere, you have to be sure it will stay there. Additionally, if it turns out you stored it somewhere silly, you'd want to be able to get it back.
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.
You don’t need to dilute it to the entire volume of the earth’s supply to make it safe. Remember, we build granite countertops and eat nuts and go outside in the sunshine, all of which have large amounts of natural radiation.
I’m guessing if there were a way to filter out the tritium they probably already would have. The article states that they already removed other isotopes from the water, but not the tritium. This leads me to believe there is something particularly tricky about separating it from water. Hopefully someone with some knowledge can weigh in here as I am curious as well.
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.
The difficulty of filtering out tritium from water is that tritium oxide is water and not some solution or colloid. Tritium is an isotope of hydrogen and reacts with oxygen to water, namely tritiated water.
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.
Which is a good point, but "half life" doesn't mean "all gone". It'll take some x cycles to get it down to some safe level y. So the water needs stored until then, if it's not being released somewhere.
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.
> at some point, accumulated volume p will probably exceed available storage area q
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!)
Tritium can be refined, and is done for various applications (radiolabelling; nuclear weapons; nuclear fusion). However it's expensive, as is reflected by its cost of about $30k per gram. It'd be even more expensive to refine from a dilute solution.
That said, an imperfect distillation may be cheaper, but the quantities of fluid here are still huge.
I'm far more worried about what happens when the next tsunami strikes. Getting rid of tons of contaminated water sounds important, or the sea will come and take it in one go.
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.
Or lack of sun is also unhealthy by the you can't win for nothing principal.
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.
There's probably a number of reasons not to eat fish caught in the Pacific ocean, but nothing to do with Fukushima was ever one of them.
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. :)
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...