This MedLibrary.org supplementary page on Plutonium-240 is provided directly from the open source Wikipedia as a service to our readers. Please see the note below on authorship of this content, as well as the Wikipedia usage guidelines. To search for other content from our encyclopedia supplement, please use the form below:
Related Sponsors
| Plutonium-240 | |
|---|---|
| General | |
| Name, symbol | Plutonium-240,240Pu |
| Neutrons | 146 |
| Protons | 94 |
| Nuclide data | |
| Natural abundance | 0 (Artificial) |
| Half-life | 6563 years |
Plutonium-240 (Pu-240) is an isotope of the metal plutonium formed when plutonium-239 captures a neutron. About 62% to 73% of the time when Pu-239 captures a neutron it undergoes fission; the rest of the time it forms Pu-240. The longer a nuclear fuel element remains in a nuclear reactor the greater the relative percentage of Pu-240 in the fuel becomes. For weapons use, the fuel needs to be as low in Pu-240 as possible, usually around 7% of the total plutonium, but this is achieved by reprocessing the fuel after just 90 days of use. Such rapid fuel cycles are highly impractical for civilian power reactors and are normally only carried out with dedicated weapons plutonium production reactors. Spent civilian power reactor fuel typically has under 70% Pu-239 and around 26% Pu-240, the rest being made up of other plutonium isotopes, making it extremely difficult but not impossible to use it for manufacturing nuclear weapons.
240Pu has only about 1/3 as large a neutron absorption cross section as 239Pu, and nearly always becomes plutonium-241 rather than fissioning. In general, isotopes of odd mass number are both more likely to absorb a neutron, and more likely to fission on neutron absorption, than isotopes of even mass number. Thus, even mass isotopes tend to accumulate, especially in a thermal reactor.
See also
External links
| Lighter: Plutonium-239 |
Plutonium-240 is an isotope of Plutonium |
Heavier: Plutonium-241 |
| Decay product of: Plutonium-239 (n) Curium-244 (α) Uranium-240 (EC) Neptunium-240 (β-) |
Decay chain of Plutonium-240 |
Decays to: Americium-240 (β) |
 |
This chemistry article is a stub. You can help Wikipedia by expanding it. |
Wikipedia content modification information:
- This page was last modified on 3 November 2008, at 22:29.
Wikipedia Authorship and Review
Wikipedia content provided here is not reviewed directly by MedLibrary.org. Wikipedia content is authored by an open community of volunteers and is not produced by or in any way affiliated with MedLibrary.org.
Wikipedia Usage Guidelines
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article on "Plutonium-240".
The URL for this specific entry is:
All Wikipedia text is available under the terms of the GNU Free Documentation License. (See Copyrights for details). Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc.