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.