Search results
Results From The WOW.Com Content Network
Gamma radiation of modest energies, in the low tens of MeV, can induce fission in traditionally fissile elements such as the actinides thorium, uranium, [3] plutonium, and neptunium. [4] Experiments have been conducted with much higher energy gamma rays, finding that the photofission cross section varies little within ranges in the low GeV ...
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 has a half-life of 24,110 years. [1]
The demon core (like the core used in the bombing of Nagasaki) was, when assembled, a solid 6.2-kilogram (14 lb) sphere measuring 8.9 centimeters (3.5 in) in diameter.. It consisted of three parts made of plutonium-gallium: two hemispheres and an anti-jet ring, designed to keep neutron flux from "jetting" out of the joined surface between the hemispheres during implosi
Fission product yields by mass for thermal neutron fission of U-235 and Pu-239 (the two typical of current nuclear power reactors) and U-233 (used in the thorium cycle). This page discusses each of the main elements in the mixture of fission products produced by nuclear fission of the common nuclear fuels uranium and plutonium.
Trace amounts of plutonium-238, plutonium-239, plutonium-240, and plutonium-244 can be found in nature. Small traces of plutonium-239, a few parts per trillion , and its decay products are naturally found in some concentrated ores of uranium, [ 54 ] such as the natural nuclear fission reactor in Oklo , Gabon . [ 55 ]
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.
Decay chain of 240 Pu. Plutonium-240 (240 Pu or Pu-240) is an isotope of plutonium formed when plutonium-239 captures a neutron.The detection of its spontaneous fission led to its discovery in 1944 at Los Alamos and had important consequences for the Manhattan Project.
Nuclear fission separates or splits heavier atoms to form lighter atoms. Nuclear fusion combines lighter atoms to form heavier atoms. Both reactions generate roughly a million times more energy than comparable chemical reactions, making nuclear bombs a million times more powerful than non-nuclear bombs, which a French patent claimed in May 1939.