Answer:

In a nuclear power station, the commonly used fuel for producing heat is uranium. Uranium is a naturally occurring element that is found in small amounts in the earth's crust. It is a highly radioactive and dense metal that can be used as a fuel in nuclear reactors.

How is uranium used as a fuel in a nuclear power station?
- Nuclear Fission: The process of nuclear fission is used to generate heat in a nuclear power station. In this process, the nucleus of a uranium atom is split into two smaller nuclei, releasing a large amount of energy in the form of heat.
- Controlled Chain Reaction: The fission process is initiated by bombarding a uranium atom with a neutron. This causes the uranium atom to become unstable and split into two smaller nuclei, along with the release of additional neutrons. These newly released neutrons can then go on to collide with other uranium atoms, causing a chain reaction.
- Heat Generation: As the chain reaction continues, a large number of uranium atoms are split, releasing a significant amount of heat. This heat is used to generate steam, which in turn drives turbines to produce electricity.
- Cooling System: To prevent overheating, a cooling system is used to remove the excess heat produced during the fission process. This typically involves circulating water or a liquid coolant through the reactor core to absorb the heat and transfer it to a separate system where the heat is used to generate steam.

Advantages of using uranium as a fuel:
- Abundance: Uranium is relatively abundant in the earth's crust, making it a viable option for long-term energy production.
- High Energy Density: Uranium has a very high energy density, meaning that a small amount of uranium can produce a large amount of energy.
- Low Greenhouse Gas Emissions: Nuclear power generated from uranium does not produce greenhouse gas emissions, making it a cleaner alternative to fossil fuel power plants.

Conclusion:
Uranium is commonly used as a fuel in nuclear power stations due to its ability to undergo nuclear fission, which releases a large amount of heat. This heat is then used to generate steam and produce electricity. Uranium is an abundant and energy-dense fuel source, making it a viable option for long-term and cleaner energy production.