Pu or Pu-239) is an isotope of plutonium. Plutonium-239 is the primary fissile isotope used for the production of nuclear weapons, although uranium-235 is also used for that purpose. Plutonium-239 is also one of the three main isotopes demonstrated usable as fuel in thermal spectrum nuclear reactors, along with uranium-235 and uranium-233.

Plutonium 239, 239Pu, is a fissile isotope, which means 239 Pu can undergo a fission reaction after absorbing a thermal neutron. Moreover, 239 Pu also meets the alternative requirement that the amount (~2.88 per one fission by thermal neutron) of neutrons produced by fission of 239 Pu is sufficient to sustain a nuclear fission chain reaction.

Se-79, half-life of 327k years, is one of the long-lived fission products. Given the stability of its next lighter and heavier isotopes and the high cross section those isotopes exhibit for various neutron reactions, it is likely that the relatively low yield is due to Se-79 being destroyed in the reactor to an appreciable extent. Se.

Plutonium-240 has a high rate of spontaneous fission, raising the background neutron radiation of plutonium. Plutonium is graded by proportion of 240 Pu: weapons grade (<7%), fuel grade (7–19%) and reactor grade (>19%). Lower grades are less suited for bombs and thermal reactors but can fuel fast reactors.

Plutonium-239 and plutonium-241 are fissile materials. This means that they can be split by both slow (ideally zero-energy) and fast neutrons into two new nuclei (with the concomitant release of energy) and more neutrons.

Plutonium-239 is a highly fissionable material, making it ideal for constructing an atomic bomb. However, Manhattan Project physicists discovered a problem with plutonium fuel. When plutonium-239 absorbs another neutron it becomes the isotope plutonium-240, which undergoes spontaneous fission.

Plutonium-239 decays through spontaneous fission while emitting alpha particles. While undergoing decomposition, Plutonium-239 releases energy close to 5.245 MeV. Some radioactive materials can undergo decomposition by more than one method.

Fission of plutonium-239 or uranium-235 produces over 100 radioisotopes with half-lives varying from fractions of a second to millions of years. Other radioisotopes are produced by neutron absorption in the fuel or surrounding materials (these are termed activation products).

fissile material, in nuclear physics, any species of atomic nucleus that can undergo the fission reaction. The principal fissile materials are uranium-235 (0.7 percent of naturally occurring uranium), plutonium-239, and uranium-233, the last two being artificially produced from the fertile materials uranium-238 and thorium-232, respectively.

The FRAM isotopic analysis software has the capability for verifying isotopic composition with accuracy requisite for performing these blending operations. Another capability of FRAM allows the quantification, relative to plutonium, of the concentration of fission products in the mixture or …