Koodankulam Nuclear Power Plant in Tamil Nadu went Critical

The Koodankulam nuclear power plant in Tamil Nadu on 13 July 2013 went critical. The plant will start full-fledged power generation in a month. With the dilution of boric acid in primary coolant water, the neutron multiplication process is being done in reactor core.

The nuclear reactor was loaded with 163 enriched fuel assemblies containing 80 tons of Uranium Oxide in October 2012. The nuclear reactor power will be increased in stages to attain full capacity of 1000 MW. At the first stage the nuclear plant will be synchronized to the southern grid with 400 MW in a month.

The power generation will be increased to 50 per cent, 75 per cent 90 per cent and finally 100 per cent in phases. With the commissioning of Koodankulam Nuclear Power plant, the nuclear power generation will rise to 5780 MW in the country.
Kudankulam Nuclear Power Plant is located in the Tirunelveli district of the southern Indian state of Tamil Nadu.

What is a Nuclear Reactor?
A nuclear reactor is a device to initiate and control a sustained nuclear chain reaction. Nuclear reactors are used at nuclear power plants for generating electricity. A reactor consists of an assembly of nuclear fuel (a reactor core), surrounded by a neutron moderator such as regular water, heavy water, graphite, or zirconium hydride and control rods that control the rate of the reaction. Most nuclear reactors use a chain reaction to induce a controlled rate of nuclear fission in fissile material, releasing both energy and free neutrons.

When it is said to be critical?
In a nuclear reactor, the neutron number at any instant is a function of the rate of neutron production (due to fission processes) and the rate of neutron losses (via non-fission absorption mechanisms and leakage from the system). When a reactor’s neutron population remains steady from one generation to the next (creating as many new neutrons as are lost), the fission chain reaction is self-sustaining and the reactor's condition is referred to as critical. When the reactor’s neutron production exceeds losses, characterized by increasing power level, it is considered supercritical, and when losses occur, it is considered subcritical and shows decreasing power.