For some perspective: I don't have a full breakdown of the release materials on hand, but according to Wikipedia of the 45 PBq you quoted something like 20 PBq of that was Iodine-131 and 5 PBq of Cs-137. That's about 4.3 grams of I-131 and 1.6 kg of Cs-137. In radiological terms that's a LOT if they were concentrated in a small area, not so much when diluted into the entire ocean. Note that estimated releases to the atmosphere were about 10x that IIRC (but don't quote me on exact numbers).

Not to downplay the risks or consequences, people need to decide that for themselves and the dynamics of how this material ends up dispersed in the environment are complicated, but talking in terms of mass helps put things into perspective.

Wiki has a good writeup https://en.wikipedia.org/wiki/Radiation_effects_from_the_Fuk...

Now divide each number by its area.

The ocean constantly churns, mixing these all together, so dividing by the constant area of the world oceans doesn't change this.

This takes decades. The plume was largely concentrated over a few dozen km and couple hundred m deep when it hit california five years later. And actually significant spill would be orders of magnitude worse.

This is also why mass expansion of reprocessing facilities is completely untenable.

Which is why any next-gen nuclear should be doing near-complete fuel consumption. Solid fuel rods aren't going to cut it.

Liquid / molten salts can be reprocessed "online" and the fission products extracted (yeah, handwaves a LOT of chemistry), so you don't get these partially transmuted solid rods.

Even if you have solid rods or solid pebbles doing the primary power, maybe you can have a secondary on-site molten processor to take care of the waste without it shipping.

One of the annoying aspects of arguing with pro-nuclear people is their blind spot for reprocessing/waste. It just gets shrugged/handwaved away, but to the voting public, having a reactor that produces no waste in the traditional solid fuel sense would be a political boon.

The real issue is that nuclear simply isn't price competitive, it barely beats coal. I would like it to be otherwise.

Safe single fluid LFRs are scifi. Two fluid ones have worse reprocessing problems than solid fuel.

It would be nice, but the list of reasons which are sufficient to stop it happening is very long.

I dont think its accurate to equate floating trash and something dissolved in solution. Their behavior is likely to be very different.

Explain the lack of sodium islands.

E: "Cesium dissolves easily in water."[1]

[1] https://www.epa.gov/radiation/radionuclide-basics-cesium-137

This is presumably being downvoted for the unnecessary “gotcha” phrasing, but it is an interesting point of distinction. I have an intuitive guess as to the principles at work, but I don’t really know the actual physics.

> but I don’t really know the actual physics

Vastly oversimplifying: two versus three dimensions.

I don’t think that explains it at all. So garbage floats (more or less), so can be modeled as a 2D plane. But why do patches form? Why isn’t the garbage distributed uniformly across the plane? And why doesn’t that same mechanism apply in 3D?

And factor in decays too!

Is that natural uranium concentrated in rock formations? Because the weapons testing and dumping disperses the material.

I'm genuinely asking

These comparisons—except for Chernobyl—are disingenuous. Nuclear weapons testing has been outlawed and has mostly stopped, natural Uranium and—even more so—Potassium don’t release radiation in nearly the same concentration as Fukushima (or Hanford to that extent). Radiation is dangerous when it concentrates.

Very comparabale! And also sheer luck the main plume went there too..

Or 75mm bananas.