With enormous momentum behind the nuclear deal, it is now probably unstoppable in US as huge business is linked with it. So far, India has sailed the deal through troubled waters meticulously but the real task starts at home, where plans to implement massive nuclear power programme may face some daunting obstacles.
India requires two types of technology for its nuclear energy programme i) natural uranium for its Pressurised Heavy Water Reactor (PHWR) programme, and ii) import of Light Water Reactors (LWR) and fuel for these imported reactors. The Nuclear Power Corporation of India Ltd. (NPCIL) deals with nuclear power generation in India. During three years of negotiation on the nuclear deal, the NPCIL has got clearance for 4 massive nuclear parks, which are going to generate 45,000 MW of power, equal to one-third of our total installed capacity. The sites selected for these parks are at Patisonapur in Orissa, Haripur in West Bengal, Kowadi in Andhra Pradesh and Mithirvirdi in Gujarat. These sites have been given clearance for soil quality, flood risk, seismic activities and all other geo-morphological features essential for a nuclear power plant.
The nuclear energy programme may face the following hurdles in future: i) the acquisition of the land for the proposed nuclear power plants. ii) The need of water source for the cooling purpose of the plant iii).Safe disposal of the waste to the satisfaction of the nearby inhabitants.
We daily listen to the news of dharnas and agitations being organised by the farmers and villagers under the banners of various political parties.
Our government will have to come out with a legal framework under which it can acquire land for public purpose, giving commensurate compensation to the displaced people and assurance of jobs.
Most of the nuclear power plants need water for cooling in two ways i ) to transfer heat from the reactor core to the steam turbines, and ii) to remove and dump the surplus heat from this steam circuit. The amount of cooling required in any steam-cycle power plant of a given size depends upon its thermal efficiency. It does matter whether it is fuelled by coal, gas or uranium. However, currently operating nuclear plants often do have lower thermal efficiency than coal counterparts of similar age, therefore, require more water for cooling. When the availability of cooling water is limited, cooling does not need to be a constraint on new generating capacity as other alternative cooling options are available at slightly higher cost.
The bigger the temperature difference between the internal heat source and the external environment, the more efficient is the process in achieving mechanical work. Hence, the desirability is to a high temperature internally and a low temperature environmentally. In a coal-fired or conventionally gas-fired plant it is possible to run the internal boilers at higher temperatures than those with finely-engineered nuclear fuel assemblies as it may cause damage to the core. This reduces the thermal efficiency of the nuclear power plants and leads to increase in consumption of water. This consideration gives rise to desirably installing the power plants alongside very cold water.
Fresh water, the elixir of life, is a valuable resource in most parts of the world. At places, where it is scarce, then, water for drinking and irrigation purposes will have to be diverted for cooling of the reactor core. This act is going to invite the anger of public of the region where the plant is installed. Such incidents have already been witnessed in some cases. Two Russian nuclear power plants each of 1000 MW are under installation at Koodankulam in Tamil Nadu. These plants were initially proposed to get water for cooling of the reactor from the nearby Pechiparai dam but because of vociferous protests from the villagers not to allow a single drop of water, the NPCIL is weighing the options of using sea water. The sea water requires desalination prior its use as coolant in the plant. This process will enhance the production cost of electricity.
Lastly, the nuclear power plants are linked with risk of radiation leakage from the nuclear wastes. The wastes from the nuclear power plant are categorised as high, medium or low-level wastes by the amount of radiation that they emit. These wastes come from a number of sources which include:
i) Low-level waste (LLW): It comprises paper, rags, tools, and clothing, filters etc. having small amounts of mostly short-lived radioactivity. It is not dangerous to handle, but must be disposed of more carefully than normal garbage. During the lifetime of a nuclear power plant, 90 per cent of the total volume of radioactive waste generated is low-level wastes and it contains only about 1 per cent of the total radioactivity
ii) Intermediate-level waste (ILW): It contains higher radioactivity levels then LLW, and need shielding during handling. These wastes arise from dismantled internal structures of the reactor core, which become radioactive after prolonged operation. A small part of this waste remains radioactive for years, so short -lived intermediate - level waste can often be disposed of with LLW. Disposal of ILW is underground, in specially constructed repositories not necessarily very deep.
iii) High-level waste (HLW): There are two types of high level waste (HLW) i.e. fission products and transuranics separated from the spent fuel and the spent fuel elements. Both types of HLW must be treated prior to disposal. After reprocessing, it is incorporated into solid blocks of borosilicate glass. This process is known as vitrification.
For direct disposal, used fuel assemblies require encapsulation in containers made, for example, of stainless steel or copper. There is a cooling period of about 50 years between removal from the reactor and disposal as the level of radioactivity and heat from the used fuel fall rapidly in the first few years and then slow down to about one thousandth of the level at discharge by 40 years. Thus, long term storage facilities are required at one central place i.e. at the reactor site.
In spite of all the precautions put in order, there can be cases of leakage of radiation. The NGOs claim that the risk of nuclear radiation and contamination can spread over an area of 100 square kilometres. The villagers nearby a power plant have the apprehensions of radiation leakage. Due to these apprehensions, the government is not able to mine uranium from the mines in Andhra Pradesh and Meghalaya as the villagers are protesting against the mining in this region. So, the installation of power plants may face the hurdles discussed in the article. Hence, it becomes the duty of one and all to understand the energy needs of our country and come together to get its benefits with overcoming the obstacles.
The writer is from the Dept of Chemistry and Physics, CCS, HAU, Hisar
