Radioacive element (7)

I believe the answer is:

uranium

(Other definitions for uranium that I've seen before include "Radioactive element of atomic number 92" , "Radioactive metallic element" , "Radioactive element used for nuclear energy" , "Mineral used in nuclear reactors" , "Chemical element, source of nuclear energy" .)

I've seen this clue in The Guardian.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.