Table of Contents
Are U-235 and U-238 both uranium?
U-235 is the main fissile isotope of uranium. Natural uranium contains 0.7% of the U-235 isotope. Uranium-235 and U-238 are chemically identical, but differ in their physical properties, notably their mass. The nucleus of the U-235 atom contains 92 protons and 143 neutrons, giving an atomic mass of 235 units.
What is the difference between uranium-235 and plutonium-239?
Plutonium-239 is more frequently used in nuclear weapons than uranium-235, as it is easier to obtain in a quantity of critical mass. Both plutonium-239 and uranium-235 are obtained from Natural uranium, which primarily consists of uranium-238 but contains traces of other isotopes of uranium such as uranium-235.
Is uranium and plutonium the same?
On the Periodic Table plutonium is two spots above uranium – uranium has an atomic number of 92 (that is, it has 92 protons) and plutonium is at 94. To make Pu-239, the nuclide used in nuclear weapons, it’s a fairly simple process. Natural uranium is over 99% U-238, which doesn’t fission all that well.
What are the critical masses for U-235 and Pu-239?
The critical mass of a bare sphere of uranium-235 at normal density is approximately 47 kg (104 pounds); for plutonium-239, critical mass is approximately 10 kg (22 pounds).
What is U-239 in what ways is it different from U-238?
In what ways is it different from U-238? U-239 is an isotope of uranium. It has one more neutron in the nucleus than U-238.
Which statement is correct for U 235 and U-238?
U-238 has 4 more neutrons than U-234 and three more neutrons than U-235. U-238 is more stable thus being more abundant naturally. U-235 is used as fuel in nuclear reactors and/or weapons.
How does U-238 become Pu-239?
By capturing a neutron, uranium-238 becomes uranium-239 that rapidly changes by beta radiation into neptunium-239. This neptunium is transformed then by beta radiation, after 3 days on average, into a new nucleus: plutonium-239. This radionuclide is fissile, like uranium-235.
What’s more powerful uranium or plutonium?
Plutonium-239, the isotope found in the spent MOX fuel, is much more radioactive than the depleted Uranium-238 in the fuel. Plutonium emits alpha radiation, a highly ionizing form of radiation, rather than beta or gamma radiation. When alpha-emitters get inside cells, on the other hand, they are extremely hazardous.
What is supercritical plutonium?
When a fission-type nuclear bomb explodes, what’s actually happening is that the uranium or plutonium fuel is going supercritical. This essentially means that there are enough fissioned (split) atoms pumping out enough neutrons to keep a chain reaction going.
What are the characteristics that describes fission fusion and both?
Both fission and fusion are nuclear reactions that produce energy, but the processes are very different. Fission is the splitting of a heavy, unstable nucleus into two lighter nuclei, and fusion is the process where two light nuclei combine together releasing vast amounts of energy.
How does U-238 become Pu 239?
Is it possible to make a nuclear weapon with 239 Pu?
Lower proportions of 239 Pu would make a reliable weapon design difficult or impossible; this is due to the spontaneous fission (and thus neutron production) of the undesirable 240 Pu. ^ “Physical, Nuclear]
Which is more dangerous plutonium 239 or uranium 235?
Plutonium-239 emits alpha particles to become uranium-235. As an alpha emitter, plutonium-239 is not particularly dangerous as an external radiation source, but if it is ingested or breathed in as dust it is very dangerous and carcinogenic.
What happens to the nucleus of U-239 when it fissions?
The new nucleus may decay into a different nuclide. In this example, U-239 becomes Np-239 after emission of a beta particle (electron). But in certain cases the initial capture is rapidly followed by the fission of the new nucleus.