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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.
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 ...
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.
Pu, and eventually fissile 239 Pu and heavier isotopes of plutonium. The 237 Np can be removed and stored as waste or retained and transmuted to plutonium, where more of it fissions, while the remainder becomes 242 Pu, then americium and curium, which in turn can be removed as waste or returned to reactors for further transmutation and fission.
Neptunium-239 has 146 neutrons and a half-life of 2.356 days. It is produced via β − decay of the short-lived uranium-239 , and undergoes another β − decay to plutonium-239 . This is the primary route for making plutonium, as 239 U can be made by neutron capture in uranium-238 .
The isotope 240 Pu has about the same thermal neutron capture cross section as 239 Pu (289.5 ± 1.4 vs. 269.3 ± 2.9 barns), [6] [7] but only a tiny thermal neutron fission cross section (0.064 barns). When the isotope 240 Pu captures a neutron, it is about 4500 times more likely to become plutonium-241 than to fission.