What is Plutonium
Plutonium is a transuranic chemical element with atomic number 94 which means there are 94 protons and 94 electrons in the atomic structure. The chemical symbol for plutonium is Pu. It is a man-made isotope and is created from uranium in nuclear reactors. Therefore we can find this element in irradiated nuclear fuel or as a fissile material in nuclear weapons. In fact, scientists have found trace amounts of naturally-occurring plutonium. Four isotopes (238Pu, 239Pu, 240Pu and 244Pu) can be found in the nature.
- Trace amounts of 239Pu originate in radiative capture of neutron on 238U. Free neutrons come from a spontaneous fission reaction of 238U.
- Trace amounts of 244Pu originate in its relatively long half-life of about 80 million years.
- The isotope 240Pu is in a decay chain of the isotope 244Pu. These nuclei are present in the unalterable proportions of the radioactive equilibrium between 244Pu and 240Pu.
- Extremely small amounts of 238Pu originate in extremely rare double negative beta decay of naturally-occurring isotope 238U.