The various isotopes also have different principal decay modes. The isotopes present in commercial or military plutonium are plutonium, , and Table 2 shows a summary of the radiological properties of five plutonium isotopes. The isotopes of plutonium that are relevant to the nuclear and commercial industries decay by the emission of alpha particles, beta particles, or spontaneous fission. Gamma radiation , which is penetrating electromagnetic radiation, is often associated with alpha and beta decays.
Various sources give slightly different figures for half-lives and energies. Table 3 describes the chemical properties of plutonium in air. These properties are important because they affect the safety of storage and of operation during processing of plutonium.
The oxidation of plutonium represents a health hazard since the resulting stable compound, plutonium dioxide is in particulate form that can be easily inhaled. It tends to stay in the lungs for long periods, and is also transported to other parts of the body. Ingestion of plutonium is considerably less dangerous since very little is absorbed while the rest passes through the digestive system. Plutonium combines with oxygen, carbon, and fluorine to form compounds which are used in the nuclear industry, either directly or as intermediates.
Table 4 shows some important plutonium compounds. Plutonium metal is insoluble in nitric acid and plutonium is slightly soluble in hot, concentrated nitric acid. However, when plutonium dioxide and uranium dioxide form a solid mixture, as in spent fuel from nuclear reactors, then the solubility of plutonium dioxide in nitric acid is enhanced due to the fact that uranium dioxide is soluble in nitric acid.
This property is used when reprocessing irradiated nuclear fuels. The subsequent absorption of a neutron by plutonium results in the formation of plutonium Absorption of another neutron by plutonium yields plutonium The higher isotopes are formed in the same way. Since plutonium is the first in a string of plutonium isotopes created from uranium in a reactor, the longer a sample of uranium is irradiated, the greater the percentage of heavier isotopes.
This energy could result in an explosion large enough to destroy a city or fuel a nuclear reactor. The first atomic bomb used in war had a uranium core and was dropped on Hiroshima, Japan on August 6, The second atomic bomb used had a plutonium core and was nicknamed " Fat Man " because of its round shape. Publication of the discovery and the naming of the new element plutonium was delayed until a year after the end of World War II.
Seaborg originally considered the name "plutium", but later thought that it did not sound as good as "plutonium. Later, during the Cold-War era, large stockpiles of weapons-grade plutonium were built up by both the Soviet Union and the United States. Each year about 20 tons of plutonium is still produced as a by-product of the nuclear power industry. As of it was estimated that the plutonium stockpile was about tons, world-wide. Since the end of the Cold War these stockpiles have become a focus of nuclear proliferation concerns.
In , the United States and the Russian Federation mutually agreed to each dispose of 34 tons of weapon grade plutonium before the end of by converting it to a mixed uranium-plutonium oxide MOX fuel to be used in commercial nuclear power reactors. Today plutonium remains an important component of nuclear weapons, and the United States maintains plutonium-related capabilities in support of national defense and global nuclear deterrence.
Pu for civilian nuclear power plants provides energy for many nations. Plutonium continues to be vital to space exploration pushing the limits beyond which manned space exploration is possible and satisfying our quest for knowledge. Twenty-three radioactive isotopes of plutonium have been characterized from mass numbers to Nine of these exhibit metastable states , though these all have half-lives less than one second.
The longest-lived isotopes are plutonium, with a half-life of All of the remaining radioactive isotopes have half-lives less than 7, years. By far of greatest importance is the isotope Pu produced in extensive quantities in nuclear reactors from natural uranium:.
Plutonium with a half-life of Both Pu and Pu have many practical applications as discussed below. Plutonium is unique among the elements in its physicochemical complexities by virtue of its position at a transitional location in the periodic table where the 5 f electrons are at the border between delocalized not associated with a single atom and localized associated with a single atom behavior and it is considered one of the most complex of the elements.
Plutonium also sits near the juncture where the actinide series transitions from main d -block element chemistry to rare earth like behavior as a result of the actinide contraction.
Because of its defense and commercial importance, plutonium is one of the most intensely investigated of elements. Plutonium metal has a bright silvery appearance at first and takes on a dull gray, yellow or olive green tarnish when oxidized in air.
A relatively large piece of plutonium is warm to the touch because of the energy given off by alpha decay. Larger pieces will produce enough heat to boil water. The metal readily dissolves in concentrated mineral acids. Uranium absorbs neutrons emitted by the fission of uranium; uranium is formed, which emits a beta particle and decays to neptunium; the neptunium emits another beta particle, becoming plutonium Once begun, the reaction proceeds spontaneously until the uranium fuel rods in the reactor are converted to a certain uranium-plutonium mixture.
The rods are dissolved in acid and the plutonium separated by chemical means, especially by solvent extraction. Plutonium is important for its use in nuclear weapons and nuclear reactors.
Plutonium has been used to power scientific equipment in lunar exploration and implanted heart pacemakers see pacemaker, artificial. Plutonium is an extremely dangerous poison; it collects in the bones and interferes with the production of white blood cells. Plutonium is found naturally in very small quantities in association with uranium ores. Of the test, Oppenheimer said, "We knew the world would not be the same.
A few people laughed, a few people cried. Most people were silent. I remembered the line from the Hindu scripture, the Bhagavad-Gita. Vishnu is trying to persuade the Prince that he should do his duty and to impress him takes on his multi-armed form and says, 'Now I am become Death, the destroyer of worlds.
The explosion had the energy equivalent of approximately 20, tons of TNT. The first war-use atomic bomb dropped on Hiroshima, Japan, on August 6, That atomic bomb, dubbed "Little Boy," had a uranium core, though. The second bomb, dropped on Nagasaki, Japan, in August 9, , had a plutonium core. Freshly prepared plutonium metal has a silvery bright color but takes on a dull gray, yellow, or olive green tarnish when oxidized in air. The metal quickly dissolves in concentrated mineral acids.
A large piece of plutonium feels warm to the touch because of the energy given off by alpha decay; larger pieces can produce enough heat to boil water. At room temperature alpha-form plutonium the most common form is as hard and brittle as cast iron. It can be alloyed with other metals to form the room-temperature stabilized delta form, which is soft and ductile. Unlike most metals, plutonium is not a good conductor of heat or electricity. It has a low melting point and an unusually high boiling point.
Plutonium can form alloys and intermediate compounds with most other metals, and compounds with a variety of other elements.
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