You need a high intensity neutron flux to make water radioactive, which spent fuel doesn't provide. The kinds of radiation you find in a cooling pond won't acti

You need a high intensity neutron flux to make water radioactive, which spent fuel doesn't provide. The kinds of radiation you find in a cooling pond won't activate water, so all you have to worry about is stuff potentially dissolving into it. Here's a paper on how water gets activated when it cools a nuclear core (which does have massive numbers of neutrons zipping around): https://doi.org/10.1016/j.pnucene.2019.103042 https://doi.org/10.1016/j.pnucene.2019.103042