NASA Chief Scientist Jim Greene asks:
Can we go (to the Moon) and drink the water?
The source of the water in this case would be ice deposits to be found in permanently shaded areas on the Moon.
Is there any speculation on how radioactive water on the Moon might be? There are cosmic rays and energetic particles from the Sun and probably some flux of neutrons as well. These can induce reactions that can result in the production of radioactive isotopes of hydrogen and oxygen, and there may even be radioactive or heavy isotopes from the solar wind as well.
Screenshot from NASA's Gravity Assist Podcast Goes to the Moon