Plutonium-242
| General | |
|---|---|
| Symbol | 242Pu |
| Names | plutonium-242 |
| Protons (Z) | 94 |
| Neutrons (N) | 148 |
| Nuclide data | |
| Half-life (t1/2) | 375000 years |
| Isotope mass | 242.059 Da |
| Decay products | 238U |
| Decay modes | |
| Decay mode | Decay energy (MeV) |
| Isotopes of plutonium Complete table of nuclides | |
Plutonium-242 (242Pu or Pu-242) is the second longest-lived isotope of plutonium, with a half-life of 375,000 years. The half-life of 242Pu is about 15 times that of 239Pu; so it is one-fifteenth as radioactive, and not one of the larger contributors to nuclear waste radioactivity. 242Pu's gamma ray emissions are also weaker than those of the other isotopes.
It is not fissile (but it is fissionable by fast neutrons), and its neutron capture cross section is low.