Nuclear Plant -safety
There are four important aspects of safety in a nuclear power plant. To counter any risk from Tsunami and cyclones, the plant is elevated, to a minimum height of 6 metre (pump house) and the auxiliary diesel sets are at a height of 9.3 metre with a redundancy of four times in the diesel generators. Kudankulum plant has installed 154 Hydrogen recombiners across the plant which can absorb any leaked hydrogen and prevent any structural damage.
2. Thermal Hydraulic Safety:-The most advanced safety feature in the Kudankulum plant is the installation of the Passive Heat Removal System (PHRS) which is latest in technology to ensure rapid cooling of the reactor in the event of a reactor problem. The PHRS is a unique steam recirculation system which can continue to cool the plant in the event of the failure of AC power and even when the worst possible scenario of coolant malfunction has occurred, without leaking any radiation in the atmosphere.
Neutronic Safety:-In any nuclear plant the most important cause of failure can be the loss of ability to control the neutrons being generated which is done by a system called control rods. Besides the control rods, the Kudankulum Plant has uniquely implemented the latest technology-The Core Catcher.This is basically an underlying structure with Gadolium oxide which would “catch the neutrons” in the event of a highly unlikely meltdown.
Waste Management:-A popular myth is that nuclear waste is domped into the oceans which kills marine life and contaminates water. This is completely false. Yes, many decades ago, some of the nations used to dump nuclear waste in deep oceans away from habitat but that practice is over now. With the closed loop cycle the waste generated per year from 1000 MW plant is less than 3 percent and that after vitrification would not occupy a space of about 6 cubic metres.
Environmental and Safety issues:- The pollution caused by power generation activities, and the climate change associated with them, are directly or indirectly responsible for about 481,000 deaths every year. Comparatively, in the case of the worst civilian nuclear disaster ever at Chernobyl, the United Nations Scientific Committee on the Effects of Atomic radiation (UNSCEAR) predicted up to 4,000 cancer cases (often curable) due to the accident, besides 57 direct causalities.
Throughout the history of nuclear power generation there have been four major incidents of plant failure-the Kyshtym accident in fuel reprocessing in 1957, the relatively smaller. Three Mile Island meltdown (United States), the much bigger Chernobyl accident (USSR, 1986) and the recent Japanese incident at Fukushima. The first accident was purely due to underdeveloped technology. Even in the case of the Fukushima disaster of 2011, there were extraordinary natural forces in action-The occurrence of four failures in six decades cannot be made out as a case for completely disbanding the technology.
Nuclear fuel of the future:- Thorium is far more abundant, by about four times, than the traditional nuclear fuel, Uranium, and occurs in a far purer form, too. It is believed that the amount of energy contained in the Thorium reserves on earth is more than the combined total energy that is left in petroleum, coal other fossil fuels and Uranium, all put together. India might have the largest reserves of Thorium in the world, with over 650,000 tonnes. In comparison, we have barely 1 percent of the world’s Uranium deposits. Thorium may be able to generate (through Uranium-233 that could be produced form it) eight times the amount of energy per unit mass compared to (natural) Uranium. It produces waste that it relatively less toxic. Being the largest owner of Thorium, the opportunity is for India to vigorously pursue its existing nuclear programmes with a special focus on research and development on the Thorium route as the long term sustainable option.
