Hi I'm back and found more bullshit for you:
Despite the US Atomic Energy Commision (AEC) having known since 1955 from its disastrous nuclear weapons testing in the Marshall Islands that radioactive material does not dissipate but moves in scattered pockets and streams in sea water,17
I checked out citation 17 and found this, http://www.ips-dc.org/nuclear_tuna_and_nprs_trivialization/, which indeed quotes from an AEC memo dated 1955. Since the author of this work is too lazy to find a more recent source for this claim, I figured I might check to see what's out there. Here's a study I found:
Model simulations on the long-term dispersal of 137Cs released into the Pacific Ocean off Fukushima (2012)
The charts on page 6 of the study are the money shots. You can see how quickly it dissipates. After one year of the accident, almost none of the ocean has a concentration of Cesium-137 greater than 1 in 1000 relative to the original concentration in the immediate vicinity of the plant at the time of the accident. The areas that do have a higher concentration barely register above that 1 in 1000 threshold. By 2.5 years after the accident, no patch of the ocean has a concentration greater than 1 in 1000 and most affected areas are below 1 in 10,000. After 10 years, most of the ocean has a relative concentration between 1 in 10,000 to 100,000.
The quoted AEC memo is only accurate on a timescale of about 0 to 6 months, if you check out the maps at the top of page 6.
Another important issue omitted by this citation (and the original discussion itself is that the biological half-life of cesium (the isotope doesn't matter, it's just chemistry) is a mere 70 days. They want to scare you with the idea that Cesium-137 takes 30 years for half of it to decay away (which isn't scary at all: longer half-lives mean less intense radioactivity compared to shorter ones), and leave you to assume that it remains inside your body the entire time. That is patently false. Your body confuses cesium for potassium, which is why it takes cesium up if you ingest it. By the same token your body also flushes cesium out like potassium, at a rate of about half of the cesium every 70 days.
A long radiative half-life + a short biological half-life = low dose.
At the same time, general confusion prevails concerning the effects of radioactive materials, how they spread and how to protect against them.
This is just patent bullshit. Radiation protection as a discipline is more than a century old, having originated since before the splitting of the atom.