To earn this Clue, you must complete Mission 0: Agent Training.
The scene first starts with a radar screen with yellow planes and bombs and the Bermuda Triangle. A chunk of uranium appears on the radar. It starts beeping with the green circles, and the word URANIUM appears, along with the radar's green line.
Uranium is number 92 on the Periodic Table of the Elements. It is highly radioactive. Uranium is used as the main ingredient in a nuclear bomb.