All countries having nuclear power reactors use uranium as nuclear fuel.
The same reason as the other countries that have nuclear power plans. Firstly to show off power. The other reason : Fear. Not even for energy generation, nuclear capability is justified due to the high risk that nuclear power plants represent.
There are currently (year 2013) 31 countries having nuclear power reactors. The rest are not having nuclear power.
In the US, and in many other countries, anyone who uses electricity
32 countries in the world are using nuclear electric power.
Because it is there.
The United States uses more nuclear power than any other country, around 20 percent of the power in the United States is created via nuclear power. Other countries that use nuclear power include France, Russia, and Japan. These countries all create more energy via nuclear power percentage wise, however none create nearly as many total Kilowatt hours as the United States.
Why should India be any different to other countries?
France is the world largest generator of nuclear power by percentage.
You don't need nuclear power, energy can be generated using other methods, fossil fuels, hydro-electric etc. However nuclear power does reduce a countries reliance on fossil fuel, which can be particularly important for countries with few fossil fuel reserves of their own. Nuclear power stations do not release CO2 into the atmosphere so do not directly contribute to global warming. Many countries are looking at an investment in nuclear power to help meet CO2 emissions targets. Nuclear power stations are also required to make plutonium for nuclear weapons. Plutonium does not occur naturally and can only be made from uranium in nuclear reactors. Any country with a nuclear weapons program will have a civilian nuclear power industry for this reason.
France produces about 80% of its electricity by nuclear plants, but this is an exception in Europe, most countries with nuclear plants have about 20%, as in the USA. Not sure about Japan, but nuclear appeals there I think because they have little fossil fuels in the country. See www.world-nuclear.org for a more detailed survey.
All of them that have nuclear power... that happen when your the first to do something...