My guess is there will be a rise in cancer cases in Japan in the coming years/decades.
What kind of radiation is it to start with? Because that affects how long it lasts for.
Whatever type of radiation the 2 nuclear bombs were when they dropped in 1945 didn't seem to last long as both Hiroshima and Nagosaki seemed to have both recovered quite well. It must be safe there if all those people live in these 2 cities today.
But yeah i have no idea how a nuclear disaster affects the water
Xbox One, PS4 and Switch (+ Many Retro Consoles)
'When the people are being beaten with a stick, they are not much happier if it is called the people's stick'- Mikhail Bakunin
Prediction: Switch will sell better than Wii U Lifetime Sales by Jan 1st 2018