Best Answer

Fissile elements are those in which the nucleus will fission or split, thus releasing energy. The two which are involved in nuclear reactors are uranium 235 and plutonium 239. Uranium is the only naturally occurring one, plutonium is created when uranium 238 is irradiated in a reactor, and when chemically separated and purified it can be used together with uranium for further supplies of nuclear fuel.

When a uranium 235 nucleus captures a neutron, it splits into two other nuclei, of lower atomic number (the fission products) and also releases another 2 or 3 neutrons, plus a lot of energy. By adjusting the balance between allowing neutrons to find U235 nuclei, and absorbing them in other material in the reactor, the reactor can be adjusted to just continue at a steady neutron flux level and hence a steady power level.

User Avatar

Wiki User

15y ago
This answer is:
User Avatar

Add your answer:

Earn +20 pts
Q: What are fissile elements and what makes them fissile elements?
Write your answer...
Still have questions?
magnify glass
Related questions

Which property makes elements such as uranium and plutonium useful for nuclear energy?

This characteristics is the possibility to be fissile when bombarded with neutrons and to maintain a chain reaction.

What are in atomic bombs?

Fissile and/or fusible elements, chemical explosives to start the reaction, electronics to handle arming/disarming/firing, etc.

What uranium nucleus is fissile?

The isotopes 233U and 235U are fissile with thermal neutrons and the isotope 238U is fissile with fast neutrons.

What is nuclear breeding?

This means the breeding of fissile material from non-fissile. Thus for example Pu239 results from irradiating U238 which is not fissile. Thorium can also be used to breed fissile uranium.

Why are only uranium and plutonium used in nuclear reactors?

Because these are the only two elements (isotopes: Uranium 235, plutonium 239 and plutonium 241, fissile with thermal neutrons) that have fissile isotopes which can sustain a chain reaction in conjunction with a moderator, that is in a so called thermal reactor like PWR or BWR. Uranium 238 is fissile with fast neutrons though it will not sustain a chain reaction by itself, and would only be a significant source of power in a fast reactor. In a thermal reactor it captures neutrons and forms Pu-239 which then does add to the reactor's fissile fuel. Some other transuranic elements have fissile isotopes but they are not used as it is much easier and cheaper to use uranium produced from uranium ore. Also thorium can be used in nuclear reactors as a fertile isotope.

Why was uranium used for nuclear war?

Its one of only 2 elements that have fissile isotopes, the other is plutonium which must be manufactured from uranium in reactors.

What does it mean when the isotope is fissile?

"Fissile" means "capable of undergoing fission."

What are the same between uranium and plutonium?

Both are chemical elements, solid, metals, radioactive, having fissile isotopes, chemically reactive, toxic etc.

Similarties between uranium-235 and plutonium-239 in nuclear reactors?

Uranium 235 and Plutonium 239 are fissile elements, fissionable with thermal neutrons.

What does it means if an isotope is fissile?

Fissile isotopes are isotopes of an element that can be split through fission

Why were breeder reactors developed?

Breeder reactors were developed to allow use of non-fissile or fertile fuel, such as uranium-238 and thorium-232, instead of fissile fuel, such as uranium-235 and plutonium-239. They do have fissile fuel in them, but they use its neutron flux to convert the non-fissile (fertile) fuel into fissile form, extending the lifespan of the core.

What is fissile fuel in a atomic bomb?

possible fissile isotopes usable as fuel:uranium-235plutonium-239uranium-233