The radioactive stuff in it is the water. This is super-heavy-water, formed with tritium instead of "normal" hydrogen. It's already been filtered to remove all

The radioactive stuff in it is the water. This is super-heavy-water, formed with tritium instead of "normal" hydrogen. It's already been filtered to remove all other (radioactive) contaminants. There is no cost effective way to filter out the heavy water from regular water at the scale required though.