Bangalore: The Kaiga nuclear plant consisting of four reactors comes under seismic zone three which ordinarily means a moderate damage risk zone. There are five seismic zones in India and zone five is the one with severest risk and high damage risk zone. Zone four is also classified as high damage risk zone, zone two is low damage risk and zone one is very low damage risk. Kaiga officials told TOI that so far quakes have not occurred in the immediate area of the plant. The only one close to Kaiga was in Koyna in 1971 that measured 5.7in magnitude. According to Kaiga senior official H M Bhatt, Kaiga can withstand a quake of intensity more than 6. The Kaiga plant, officials said, has an emergency generator system as back-up if power shuts down as well as an emergency cooling system. Any reactor in an emergency needs to be cooled to restrain heat generated by meltdown involving nuclear fuel and fuel rods that eventually causes an explosion and release of radioactive material. Power systems play a crucial role in ensuring the cooling system works and that