"Tons of radioactive water" is a silly measurement. The water itself isn't radioactive, it has radioactive material mixed in with it. If you quadrupled the amount of water, you would have 4 million tons of radioactive water but it'd be the same amount of radioactivity, just more diluted.
It's even sillier because "radioactive water" isn't a measurement of the amount of radiation or a description of the decay process that reduces the danger over time
