Which fuel is used for nuclear energy in planets?

Correct option is A

The correct answer is option (a) Natural uranium.

Explanation

The primary fuel used for nuclear energy, both on Earth and in other planets (like those with active geological processes or potential for future space exploration), is natural uranium. Natural uranium contains mostly U-238, a stable isotope, with a very small amount of U-235, which is fissile and capable of sustaining a nuclear chain reaction.

In stars, including the Sun, nuclear energy is generated primarily through nuclear fusion (not fission) using hydrogen isotopes, but on planets, fission is more commonly associated with nuclear energy sources, and natural uranium is typically the material used in nuclear reactors.

Information Booster

• Natural uranium is found in the Earth's crust and consists mostly of U-238 (around 99.3%), with only about 0.7% being U-235.

• U-235 is the isotope responsible for sustaining nuclear fission reactions in reactors, while U-238 is often used in breeding reactors or can be converted into plutonium-239, which is also fissile.

• In nuclear reactors, U-235 is enriched from natural uranium to increase the proportion of this fissile isotope, but natural uranium is still the primary starting material.

Additional Knowledge

Explaining the other options:

1. U238: U-238 is the isotope that makes up most of natural uranium, but it is not itself directly used for energy production in the same way U-235 is. U-238 is used in reactors that breed plutonium, but it is not the fuel in the same way U-235 is.

2. U236: U-236 is typically produced in reactors from U-235 and is not a naturally occurring isotope. It is not used directly as a fuel in planetary systems.

3. Related: This option is too vague to be applicable in this context.