(Chemical symbol: U). A heavy, metallic element occurring in nature, obtained from its ores as the fissionable isotope U-235. Finely divided uranium powder is pyrophoric and care must be exercised to prevent fires. Atomic number, 92; atomic weight, A measure of the relative ease of application of a 238.07; melting point 1132°C(2070°F).Uranium is welding filler metal to make a sound weld.
Used principally in nuclear applications and research.