Question

Which of the following is a good nuclear fuel?
(A) Uranium-238
(B) Neptumium_239
(C) Thorium_236
(D) Plutonium_239

Answer 1

Hint:Here, you are given four radioactive elements and you are asked to find the better nuclear fuel out of all the four elements. Here, you are supposed to consider the chemical and physical properties or say atomic properties of each element and make them meet the requirements for a better nuclear fuel. The element that will be best meeting the requirements would be a good nuclear fuel.

Complete step by step answer:
Let us have a look at Uranium-238. Uranium-238 is the most common isotope of uranium in nature which constitutes 99.28% of natural uranium. With a probability of about 0.00055%, Uranium-238 decays by spontaneous fission. Uranium-238 is fissionable but not fissile. Fissionable means that an element undergoes fission after capturing a neutron of high or low energy, whereas fissile means that a nuclide which is fissionable can be induced to undergo fission with low energy thermal neutrons.

Basically, it is not sustainable for a nuclear fission chain reaction because neutrons produced by the fission of uranium-238 have lower energies than the original neutrons. Capture of neutrons lead to the formation of Plutonium-239, this is known as fertile isotope. As you can see that uranium-238 contributes in the operation of nuclear reactions and hence is a good nuclear fuel. If you consider the rest radioactive elements, you can easily say that they do not meet the requirements for a good nuclear fuel.

Therefore, Uranium-238 is a good nuclear fuel and thus option A is correct.

Note:We have discussed in detail about Uranium-238, so keep the important stuff in mind. Focus on the two terms used in the discussion, fissionable and fissile, remember that these two terms are different. Fissionable is an element that can undergo fission reaction and fissile is an element that can be made to undergo fission reaction.