Search results
Results from the WOW.Com Content Network
Moreover, 239 Pu and 240 Pu cannot be chemically distinguished, so expensive and difficult isotope separation would be necessary to separate them. Weapons-grade plutonium is defined as containing no more than 7% 240 Pu; this is achieved by only exposing 238 U to neutron sources for short periods of time to minimize the 240 Pu produced.
In contrast, the generic civilian Pressurized water reactor, routinely does (typical for 2015 Generation II reactor) 45 GWd/tU of burnup, resulting in the purity of Pu-239 being 50.5%, alongside a Pu-240 content of 25.2%, [5] [6] The remaining portion includes much more of the heat generating Pu-238 and Pu-241 isotopes than are to be found in ...
Plutonium is a chemical element; it has symbol Pu and atomic number 94. It is a silvery-gray actinide metal that tarnishes when exposed to air, and forms a dull coating when oxidized. The element normally exhibits six allotropes and four oxidation states. It reacts with carbon, halogens, nitrogen, silicon, and hydrogen.
239 Pu is virtually nonexistent in nature. It is made by bombarding uranium-238 with neutrons. Uranium-238 is present in quantity in most reactor fuel; hence 239 Pu is continuously made in these reactors. Since 239 Pu can itself be split by neutrons to release energy, 239 Pu provides a portion of the energy generation in a nuclear reactor.
This leads to a class of designs that are optimized for the production of 239 Pu. These breeders are generally built in two parts, a "core" of fuel that is enriched to the point where it can maintain a chain reaction without a moderator, and a "blanket" of 238 U surrounding it that is designed to capture any spare neutrons and create 239 Pu. [1]
One of four example estimates of the plutonium (Pu-239) plume from the 1957 fire at the Rocky Flats nuclear weapons plant. The Rocky Flats Plant, a former United States nuclear weapons production facility located about 15 miles (24 km) northwest of Denver, caused radioactive (primarily plutonium, americium, and uranium) contamination within and outside its boundaries. [1]
On March 18, 2015, Snyder signed an executive order to form the Michigan Agency for Energy with in LARA in 60 days. [7] On January 17, 2013, Governor Snyder ordered that the Office of Financial and Insurance Regulation be transferred out of the department to form a new Michigan Department of Insurance and Financial Services effective March 19 ...
Plutonium-242 (242 Pu or Pu-242) is the second longest-lived isotope of plutonium, with a half-life of 375,000 years. The half-life of 242 Pu is about 15 times that of 239 Pu; so it is one-fifteenth as radioactive, and not one of the larger contributors to nuclear waste radioactivity.