A single nuclear reactor can produce as much heat as 40 million, 100 watt lamps.
What's inside of nuclear reactor? Well inside of nuclear reactor is a uranium fuel which is sealed inside rods. The rods are arranged in groups called fuel elements.
A liquid(water or a molten metal) or a gas flows around the rods to cool them. Special control rods, made up of a substance which absorbs neutrons, can be raised or lowered, these rods stops the chain reaction. As an extra precaution against neutrons escaping, the elements are surrounded by a moderator. The moderator deflects neutrons back into the reaction to contain the dangerous radioactivity produced by the chain reaction, the reactor assembly is shielded by thick walls of steel or concrete.
