The Centre has accorded ‘in principle’ approval for the site at Kovvada in Srikakulam district for setting up six light water reactors in cooperation with the USA. A heavy water molecule contains deuterium (Hydrogen-2), which is an isotope of hydrogen that has a neutron in its nucleus in addition to the proton. The hydrogen in light water molecules contains only the proton (and is therefore called protium or Hydrogen-1), according to Quora.com.
The light water reactor is a type of thermal- neutron reactor that utilizes normal water as opposed to heavy water, a form of water that contains a larger amount of the hydrogen isotope deuterium. Normal water that contains the hydrogen-1 isotope called protium. Light water reactors use water as both and a coolant method and a neutron moderator that reduces the speed of fast moving neutrons.
Light water reactors produce heat by controlled nuclear fission. There are several different vital parts of light water reactors that make the generation of nuclear energy possible. The nuclear reactions take place in the nuclear reactor core, where the nuclear fuel components are contained. The core is made of nuclear fuel rods that are pencil thin and are about 3.7m long.
These rods are grouped by the hundreds in bundles called fuel assemblies and are filled with pellets of uranium or uranium oxide... The neutrons that are absorbed by the control rods cannot take part in the chain reaction, however, when the control rods are raised out of the core, more neutrons strike the fissile U-235 (or Pu-239) nuclei in nearby fuel rods, and the chain reaction intensifies as the control rods are out of the way.
All of these components are enclosed in a water-filled steel pressure vessel, called the reactor vessel. The heat generated by controlled nuclear fission turns the water into steam, which drives the power- generating turbines. After the steam flows through the turbines, the steam turns back into water in the condenser. There are two types of light water reactors. In a boiling water reactor, the reactor core heats water, which turns to steam and powers a steam turbine? In a pressurised water reactor, the reactor core heats water, but does not boil it, writes Bobby Zarubin at http://large.stanford.edu/