plutonium-239
(redirected from Pu 239)plutonium-239
[plü′tō·nē·əm ¦tü‚thər·dē′nīn] (nuclear physics)
A synthetic isotope chemically similar to uranium and neptunium; atomic number 94; made by bombardment of uranium-238 with slow neutrons in a nuclear reactor; used as nuclear reactor fuel and an ingredient for nuclear weapons.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.