Plutonium-239 has a half-life of 25,000 years, meaning it takes that long to lose half of its radioactive potency. Uranium-235 has a half-life of 700 million years.

Captured: The molecular structure of plutonium dioxide-239 Devoted fans can wait hours on the red carpet to get their favourite movie star's autograph, but that's nothing compared to acquiring the ...

The half-life of plutonium-239 is 24,000 years, so if it escaped in smoke from a burning reactor and contaminated soil downwind, it would remain hazardous for tens of thousands of years.

After 50 years of searching, physicists have spotted the fingerprint of radioactive plutonium, revealing the secrets of this complex molecule behind nuclear weapons.

It's also the second oldest known man-made plutonium 239, said Jon Schwantes, a PNNL senior research scientist who led the investigation. The oldest is held in the Smithsonian.

There was one other possibility, a research reactor that produced plutonium 239 in the 1940s. The X-10 reactor in Oak Ridge, Tenn., was a prototype for reactors later built at Hanford.

Plutonium-239 found inside a broken, rusty safe has been shown to be of historic significance: dating from December 1944 it is the very first weapons-grade plutonium refined at the site, or ...

Plutonium-239 is primarily used for weapon production, while another isotope, Plutonium-240, isn’t particularly useful in the creation of nuclear weapons, according to Steve Nesbit, ...

Nuclear weapons use plutonium-239, but NASA depends on something quite different: plutonium-238. A marshmallow-sized pellet of plutonium-238, encased in metal, gives off a lot of heat.

Idaho State University has been fined after it lost track of a small amount of plutonium 239, a substance used to make nuclear weapons. University Officials say the sample, missing since 2003 ...

As it was said (and sang) in 1979, plutonium is forever…with thousands of years of radioactivity from nuclear fission (especially plutonium 239). Jeff Bezos—proving again that he is not ...