"Radiation" has become a dangerous word from some 70 years of Hollywood storylines.

https://www.bbc.co.uk/news/world-asia-66094479

But it varies widely - for example the solar radiation that provides 99+% of the energy to run the industrialized nations, produce our food, fiber, and forest products, etc. is essential to every human activity and existential to every human.

OTOH, pretty much even the most ignorant US citizens know that nuclear reactors produce dangerous radiation, so this news story may seem like some kind of international conspiracy.

Let me calm your fears.

Everything that passes through or near to a reactor core becomes radioactive, but the elements differ wildly in their toxicity, strength and lifetime. Water has to pass through the core to keep it from overheating and melting into the rock underneath or exploding into the sky like Chernobyl. The cooling water pathways were corrupted by the tsunami and ensuing steam explosions, so the water passing through picks up radioactive contaminants.

These are then separated from the water chemically, so none of the dozens of toxic radio-isotopes are in the huge and expanding number of storage tanks, which will in the not too distant future be too numerous to house on the controlled reactor site.

BUT, there is a very small amount of relatively benign radiation remaining IN THE WATER. Tritium is a radio-isotope of Hydrogen, chemically IDENTICAL, so it can't be separated from the non-radioactive Hydrogen in the water.

Since the site sits on the sea, the obvious answer is to mix the barely radioactive cooling water with sea water until it is almost impossible to measure, and adds less radiation to the water flowing out of the nuclear site than the background radation that is present in all ocean water.

The radiation emitted by Tritium is a very low energy electron, and there are no known cases of radiation poisoning or cancer from the normal small amount of Tritium that is present in the world. These electrons are so weak they are stopped by 1/4" of air, and by the outer dead layer of human skin.

So, listen to the scientists.

This is a safe plan, there is no evil corporate of government behind it.