How is plutonium-238 formed?
Where and how is Pu-238 produced? Pu-238 is formed by irradiating in a nuclear reactor the Neptunium-237 isotope obtained in the reprocessing of irradiated nuclear fuel. As it is a manufactured isotope, its greatest limitation is its difficulty to produce a sufficient amount.
Is plutonium-238 man made?
Plutonium is considered a man-made element, although scientists have found trace amounts of naturally occurring plutonium produced under highly unusual geologic circumstances. The most common radioisotopes. For example, uranium has thirty-seven different isotopes, including uranium-235 and uranium-238.
Where is plutonium-238 found?
Plutonium generally isn’t found in nature. Trace elements of plutonium are found in naturally occurring uranium ores. Here, it is formed in a way similar to neptunium: by irradiation of natural uranium with neutrons followed by beta decay. Primarily, however, plutonium is a byproduct of the nuclear power industry.
How much does plutonium-238 cost?
Not surprisingly, plutonium-238 is expensive to make – very expensive. One pound of plutonium-238 costs about $4 million to make. And that does not include the upfront investment needed to reestablish production of plutonium-238 in the United States, which is expected to cost as much as $150 million or more.
Where does 238 Pu in plutonium come from?
Pure 238 Pu for radioisotope thermoelectric generators that power some spacecraft is produced by neutron capture on neptunium-237 but plutonium from spent nuclear fuel can contain as much as a few percent 238 Pu, originating from 237 Np, alpha decay of 242 Cm, or (n,2n) reactions.
How is plutonium 238 prepared in a nuclear reactor?
Pure plutonium-238 is prepared by neutron irradiation of neptunium-237, one of the minor actinides that can be recovered from spent nuclear fuel during reprocessing, or by the neutron irradiation of americium in a reactor.
What is the density of plutonium at room temperature?
Plutonium-238 is a very powerful alpha emitter; as alpha particles are easily blocked, this makes the plutonium-238 isotope suitable for usage in radioisotope thermoelectric generators (RTGs) and radioisotope heater units. The density of plutonium-238 at room temperature is about 19.8 g/cc.
What is the half life of plutonium 241?
Plutonium-241 is fissile, but also beta decays with a half-life of 14 years to americium-241. Plutonium-242 is not fissile, not very fertile (requiring 3 more neutron captures to become fissile), has a low neutron capture cross section, and a longer half-life than any of the lighter isotopes.