India’s present electricity generation capacity is grossly inadequate to meet needs of the industries as well as of the rural and urban households even for the current population. As a result, the country is witnessing routine load-shedding and a very large number of villages even do not have electricity connections. Moreover, if the country has to achieve a somewhat higher economic growth rate for the rising population, the electricity generation capacity has to increase considerably in the coming years and for this we need to fully exploit all options that are available. The option of hydrocarbon based fuels, which has maximum share in the electricity generation, is known to have adverse effect on the climate and the international community is deeply concerned about it. Also, when the known resources of these fossil fuels get scarce in a not very distant future and the renewable sources alone are not able to fill the deficit, there may be no choice left except to fully exploit the nuclear energy option. In some developed countries, a large fraction of its electricity production is already from nuclear energy. Therefore, a major goal of the Department of Atomic Energy (DAE) in India has been to carry out research and development in this field to develop the required technologies to harness nuclear energy and to install nuclear power stations. While India is vigorously pursuing the nuclear energy programme, nuclear energy has always been a subject of much debate world-wide including India.
Furthermore, rising oil prices and growing environmental concerns over the last decade have led to a reconsideration of sustainable energy fuels. In this context, nuclear power has resurfaced as a keen contender for large-scale energy generation.
India has an installed electricity generation capacity of 274 GW; whereas, it presently requires 1,100 billion kWh of electricity, which is stated to go up to 1,524 billion kWh by 2016-17, 2,118 billion kWh by 2021-22 and 3,880 billion kWh by 2031-32 considering an average GDP growth rate of 8%. As a measure to bridge this gaping hole, India has been investing heavily to augment its nuclear power generation capacity. It has already installed a few nuclear reactors and is in the process of setting up a few more. India initially plans to increase its nuclear electricity generation from present 5,780 MW to 63 GW by 2032, but the target was revised in 2011 to a more realistic 27.5 GW. The Atomic Energy Commission envisages a target of 500 GW of nuclear energy generation by 2060.
In India, there are 22 operating commercial nuclear power reactors with an installed capacity of 6,780 MW. At the end of August 2017 gross generation is 14,380 million units having capacity factor 63% and availability factor 65%. The reactor fleet comprises two Boiling Water Reactors (BWRs) and 18 Pressurised Heavy Water Reactors (PHWRs) including one 100 MW PHWR at Rajasthan which is owned by DAE, Government of India and two 1000 MW VVER reactor KKNPS-1&2, in this, latest addition to the fleet is the unit-2 of Kudankulam Nuclear Power Station, a 1000 MW VVER (Pressurised Water Reactor type), which has started its commercial operation on March 31, 2017. Currently, NPCIL has eight reactors under various stages of construction totaling 6,200 MW capacities.
Several analysts have argued that given India’s limited and low-grade uranium reserves, the development of the nuclear programme beyond 10,000 MWe would imply increasing dependence on uranium imports. However, this viewpoint tends to overlook the logic of India’s three stage nuclear power programme planned by Dr Homi Bhabha, which envisages large-scale utilization of India’s significant thorium reserves. It is in order to tide over the transition from fast breeder reactors to the thorium cycle that India needs uranium. Therefore, unlike the case of coal or oil or gas, where imports appear to be a permanent reality, uranium dependency would be for a limited period of time till India graduates to the thorium cycle. As far as India’s three stage nuclear power generation is concerned, we are just at the beginning of the second stage. India is among the very few countries pursuing this technology.
Potential of Nuclear Power
The challenge for the nuclear community is to assure that nuclear power remains a viable option in meeting the energy requirements of the next century. It could be a major provider of electricity for base load as well as for urban transport in megacities. It can play a role in non-electric applications in district heating, process industries, maritime transport, water desalination, hydrogen production, and for applications in remote areas. It can contribute substantially to security of energy supply and it has the potential to be an almost inexhaustible long-term energy resource through the use of breeder reactors.
However, the current lack of public support could unquestionably constrain the introduction of new plants. It will be necessary to openly discuss the concerns that have limited nuclear power’s acceptance. But discussions of health and environmental impacts along with severe accidents and waste disposal must not be done in isolation as is too frequently the case. As no energy source is risk free, comparative impacts of the various energy systems must be extensively reviewed. Studies of nuclear, fossil, and renewable energy chains show that there are significant issues and impacts inherent in all options.
Authoritative comparative assessments illustrate the potential of nuclear power to mitigate energy-related health and environmental damage-it can be shown to be one of the most environmentally acceptable means of generating electricity. If external factors such as the societal costs of climate change, environmental damage, and health effects were included in all analyses, a clear nuclear advantage would arise over fossil fuels and the economic competitiveness of nuclear power in a radically changing financial environment would escalate.
If a significant contribution from nuclear power is to take place by the middle of the next century, a large amount of new generating capacity would be required averaging as high as 20 new units annually. There are a number of issues relevant to the fuel cycle and the type of reactor desired that must be dealt with now, in order to provide the best conditions for an increased nuclear role. They included those brought about by slowdown in nuclear power growth and large amounts of plutonium expected to be recovered from dismantled nuclear warheads. In an increasingly competitive and international global energy market, a number of key factors will affect not only the energy choice but also the extent and manner in which different energy sources are discussed below. These includes optimal use of available resources, reduction of overall costs, minimizing environmental impacts, convincing demonstration of safety and meeting national and global policy needs.
For nuclear energy, these factors will determine the future fuel cycle and reactor strategies. Obtaining public acceptance has not been included as a key factor; it is in reality a vital one for nuclear energy. It will be necessary to communicate the real benefits of nuclear power to the public and policy makers in an open and credible manner.
- a) Maximizing Resource Utilization
Known and likely resources of uranium should assure a sufficient nuclear fuel supply in the short and medium term even with reactors operating primarily on once-through cycles with disposal of spent fuel. However, as uranium demand increases and reserves are decreased to meet the requirements of increased nuclear capacity, there will be economic pressure for the optimal use of uranium in a manner that utilizes its total potential energy content per unit quantity of ore. A variety of means is available to accomplish this during the enrichment process and at the operational stage. Over the longer term, recycling of generated fissionable material in thermal reactors and introduction of fast breeder reactors will be necessary. Thorium could also be a valuable energy resource in the longer term.
- b) Uranium Fuel Cycle
Isotopic separation technology enables lowering the U-235 content in the enrichment process waste tailings. This results in extraction of more of the original 0.7% fraction of this fissionable isotope existing in the natural uranium ore that consists primarily of non-fissionable U-238. At the operational stage, higher fuel burn-up cycles will utilize more of the U-235 contained in the enriched uranium fuel elements – concurrently reducing the amount of spent fuel relative to the energy produced. However, reprocessing of spent fuel instead of disposal would allow the recycling of generated plutonium through mixed oxide fuel in thermal reactors as well as in fast breeder reactors and also make available uranium with its fissionable isotopes that are contained in spent fuel. Reprocessing would significantly increase the energy potential of today’s uranium resources – theoretically by a factor of around 70-and also substantially reduce the quantity of troublesome long-lived radioactive elements in the remaining waste. By far, recycling provides the best use of available uranium resources. The current policy of interim spent fuel storage before ultimate disposal preserves the potential for future reprocessing to extract fissionable material, particularly plutonium.
- c) Thorium Fuel Cycle
Although uranium is likely to remain the main natural resource for nuclear power systems, in the longer term the use of fertile thorium as a feed material is possible. While uranium contains a fissionable isotope, thorium does not. It must be enriched with either fissionable U-235 or plutonium to start the fuel cycle. The U-233 that is subsequently generated in the reactor from thorium conversion is fissionable. The thorium fuel cycle, with its lower operating fuel temperatures, has advantages in the physical performance of fuel elements and also with respect to the characteristics of the core physics. The existence of indigenous thorium in a number of countries that have limited uranium deposits would make this an attractive option. Thorium-based fuel cycles have been developed in a number of countries. The thorium fuel cycle can be used in all types of current systems-light and heavy water as well as high temperature gas and fast reactors without requiring significant changes in the reactor design or safety concepts. However, present knowledge of the extent of thorium resources in the world is poor even though extensive deposits with high grade ore have been found. Extraction of thorium from ores is a somewhat difficult process, and its economics are not established. There are also difficulties of separation of the produced U-233 from the spent fuel. But the remaining waste is significantly easier to deal with than the waste from the current uranium based fuel cycle without reprocessing.
- d) Maximizing Economic Benefits
As fuel costs are relatively low, reduction of overall costs by decreasing development, siting, construction, operation, and initial financing expenses is essential to the overall economic viability of nuclear energy. Removing the uncertainties and variability in licensing requirements, particularly, before commissioning, would allow for more predictable investment and financial strategies.
- e) Development, Capital Costs
The high costs associated with new design development will likely result in less expensive evolutionary improvement of today’s reactor systems rather than the more expensive introduction of revolutionary new designs and technologies. Governmental development funding has substantially decreased over the years and as with all mature technologies, the source of funding will shift entirely to the private sector.
The need to reduce high initial capital costs will encourage economies in siting and construction. It will lead to multi-unit sites at existing locations that will also maximize infrastructure investments. There will be more emphasis on plants with standardized systems and components as successfully employed in France. Plant size and unit power levels will be matched to regional needs and the choice of suppliers will be based on long-term economics rather than on short-term advantages.
In the operational area, reduction in costs will require high availability and load factors brought about by high quality systems, long core fuel cycle periods, short shutdown times and the ability to rapidly return to power. There will be a continued evolution of separate organizations providing various plant and fuel cycle services, particularly, on a regional basis.
- f) Licensing
Some of the high capital costs of new facilities and extended construction periods are related to the uncertainties and demands in licensing requirements. Uncertain waste management and decommissioning requirements and costs deter investments. These factors may lead to a rationalization of the licensing process leading to more certainty in regulation and a concurrent decrease in the time from site selection to operation. Waste and decommissioning requirements based on comparative assessments of other industrial practices may lead to a more practical approach to radioactive material without compromising safety.
- g) Financing
Innovative and novel investment strategies will be needed to meet evolving and changing investment goals. The large initial capital investments required for nuclear power projects could be easier to raise in the framework of multinational funding arrangements. Build, operate and transfer arrangements may be used in developing countries that allow for adequate returns on non-domestic investments before shifting ownership. Incremental investment strategies through modular energy systems would also decrease initial financing needs.
- h) Maximizing Environmental Benefits
Although nuclear energy has distinct advantages over today’s fossil burning systems-in terms of fuel consumed, pollutants emitted and waste produced-further reducing environmental concerns can have a major influence on public attitudes. As the overall health and environmental impact of the nuclear fuel cycle is small, attention will be directed at improved techniques to deal with radioactive waste. This would support global sustainable development goals and at the same time increase competitiveness with other energy sources that will be required to adequately deal with their waste. Reactor systems and fuel cycles can be adjusted to minimize waste production. Design requirements to decrease waste quantities and volume reduction techniques such as ultra-compaction will be employed. Advanced technologies to contain and immobilize high-level waste are under development. But, of most significance, programmes are currently in place to demonstrate the adequacy of deep underground disposal of high-level waste. The construction and operation of a geologic repository in the next decade could allay public concerns over the safety as well as cost of disposal. If deemed necessary, the long-lived isotopes (actinides) that are radioactive for many thousands of years can be transmuted in actinide burning reactors. The necessary technology exists for these reactors and their associated chemical separation plants. Thorium fuel cycle results in less long-lived isotopes and lower disposal requirements.
- i) Maximizing Reactor Safety
With more than 442 reactors operating for more than 20 years on average, nuclear power generally has an excellent safety record. Three accidents-Three Mile Island in 1979, Chernobyl in 1986 and Fukushima in 2011, demonstrated that a very severe nuclear accident has a potential to cause national and regional radioactive contamination. Although safety and environmental impacts are becoming a key issue for all energy sources, many in the general public perceive nuclear power as particularly and intrinsically unsafe. The safety concerns coupled with the associated regulatory requirements will, in the near term, continue to exert a strong influence on nuclear power development. In order to reduce the magnitude of real and perceived accidents, a number of approaches will be used in new facilities.
Extraordinarily effective barriers will reduce the likelihood of significant off-site radiological accident consequences to an extremely low level to eliminate the need for emergency action plans. Enhancing the integrity of the reactor vessel and reactor systems will also decrease the likelihood of onsite consequences. International collaboration will provide reactor and system designs that incorporate globally accepted safety and engineering standards. It will contribute to assuring safety worldwide and encourage country-of-origin licensing as an acceptable basis for national licensing of imported reactors. Plant designs and processes are more intrinsically safe by incorporating passive safety features rather than active protection systems. High temperature gas-cooled reactors that employ ceramic graphite fuel can limit the potential for the release of radioactive material and may emerge as a viable option. Continued development of a strong global nuclear safety culture brought about by international collaborative efforts aimed at strengthening safety worldwide would contribute to public awareness of the strong international commitment to assuring safety. A wide range of international agreements, non-binding safety standards and international review and advisory services already exists in what is now distinctly seen as an international nuclear safety regime.
The safety record of Indian nuclear plants is no exception and experience gained in overcoming the consequences of a few incidents has helped confirm validity of the safety features. Though these safety standards are excellent, there is a need to further improve them to obviate the need for public evacuation after a severe accident, which contributes to the negative public mind-set about nuclear energy.
Important safety issues are radiation effects, radiation waste management, decommissioning and accident risks in reactors. These have been adequately addressed and improvements continue. The radiation doses to operating personnel and the public during normal operation are well within limits prescribed by the Atomic Energy Regulatory Board. Nowhere in the world have the effects of radiation been noticeable in normal operation of nuclear facilities.
Radiation waste is isolated from the biosphere while the gases from fossil plants are entering the atmosphere. India developed the technology for radiation waste management well in time and new breakthroughs are not required. Further developments are expected in the technology of partitioning and actinide burning which will considerably reduce the storage time.
- j) Safety Features of the Indian Thorium Advanced Heavy Water Reactor Design
The Indian thorium fuelled Advanced Heavy Water reactor has been designed with safety as top priority. It has several innovative and passive safety features that would effectively shut down the reactor in the event of any foreseeable accident. Along with the conventional active shutdown capabilities such as scramming or flooding the reactor with coolant, the reactor also has several passive shutdown systems that will automatically activate in the event of a hot shutdown, prolonged shutdown, or loss of coolant accident. During normal operation, coolant is circulated by natural convection instead of pumps, so a loss of power will not cause a loss of coolant. If a loss of coolant accident did happen, the rising temperature would cause the automatic release of a reactor poison into the system, which would kill the reaction. If this system were to fail, and the temperature continued to rise, the large gravity driven water pool at the top of the reactor building would automatically start flooding the bottom the reactor cavity, effectively submersing the whole reactor core. If the reaction rate continues to increase, there is enough coolant to keep there is enough coolant to keep the reaction in check for 72 hours, more than enough time for the operator to step in and manually shut down the reactor.
- k) Satisfying Key Policy Needs
Energy independence along with non-proliferation concerns and excess military plutonium are high on the list of policy factors at the national and international level that strongly influence the nuclear option. In a political world, energy independence through security of energy supply and a balanced mix of energy sources are of paramount national interests. With nuclear power, security of supply concerns are lessened as adequate strategic inventories can be relatively easily established with low financial costs. Today’s global energy mix has an almost 90% fossil component. Clearly, where indigenous fossil fuel resources are lacking, nuclear energy can contribute substantially to the energy mix in India.
The overall safety is much better than it was 10 years ago, but we still have vulnerabilities in safety, as well as in security. In the nuclear domain, the role of governments goes beyond setting national energy goals. Nuclear energy, if produced safely, offers promise. The requirement hence is to fast-track civilian nuclear expansion while maintaining the highest standards of nuclear safety and security. Today’s world has to carefully make the right choices to assure the future generations of a brighter and secure tomorrow.
Conclusion
Nuclear power is likely to remain a major part of India’s energy plan. Though it has had some success, notably, the development of some expertise over most steps in the nuclear fuel chain, India’s atomic energy program has not achieved any of its promises. The most important failure has been that after more than 60 years, nuclear power constitutes only less than three percent of the nation’s electricity generation capacity. To some extent, this has been a result of international sanctions imposed on India after its nuclear weapon tests. An important lesson from this experience is that while export controls and other trade restrictions might not cause a nuclear program to completely shut down, sanctions may slow its growth. The limited amount of nuclear electricity generated has been at a relatively high cost. The DAE’s reactor construction costs have not dropped over the years and, despite their claims of improved construction practices, show little evidence of learning. The operational efficiencies of reactors have improved over the decades, however. The agency in charge of regulating safety at nuclear facilities comes under the administrative control of the AEC, and is therefore not truly independent. The effects of the NSG waiver remain uncertain.
India is blessed with aplenty of sunshine and a nearly inexhaustible resource of Thorium. Our future depends on how efficiently these two resources are utilised. With India’s entry into international nuclear cooperation, the opportunity for a rapid growth in the installed capacity helps in accumulating fissile inventory at a faster pace. In the meantime, several enabling indigenous technologies have been developed for thorium utilization. Focused developments in solar and Thorium energy can lead to a stage when India do not have to look onwards for meeting its energy demands for several centuries, in harmony with environment. We should not protect the environment; we should create a world where the environment doesn’t need protection. Thus, a long term energy security and a clean environment for the country can be achieved.
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