Nuclear Power Plants Indian Prospective

NUCLEAR POWER PLANTS FROM INDIAN PERSPECTIVE

“The discovery of nuclear chain reactions need not bring about the destruction of mankind any more than did the discovery of matches. We only must do everything in our power to safeguard against its abuse.” - Albert Einstein

CHAPTER I

INTRODUCTION AND METHODOLOGY

Introduction

1. Energy is the prime mover of growth and is vital for the sustenance of modern economy. As a result, future economic growth crucially depends upon the long-term availability of energy from sources that are affordable, accessible and environmentally friendly, India being no exception. One can therefore safely say that energy sector holds the key to the accelerated economic growth of India.

2. India today ranks sixth in the world in total energy consumption and is although rich in coal and renewable energy sources like solar, wind and hydro, has very small hydrocarbon reserves. India therefore is a net importer of energy and more than 25% of her primary energy needs are met through imports[i]. The domestic energy production pattern is such that coal and oil account for 54% and 34% respectively with natural gas, hydro and nuclear contributing to the balance. Despite this there exists a large gap between the electricity demand and supply with peak national capacity deficit estimated at about 29%. To overcome this problem all available sources of energy, including nuclear power, must be optimally developed and deployed.

Why Nuclear Power

3. The electricity generation in India is dominated by coal-fired thermal plants to the extent of 72%[ii], primarily due to the low cost of generation and abundance of coal deposits. With time, the depletion of oil, natural gas and coal reserves would push the price of these fossil fuels up. This scenario would make the other sources of power generation like nuclear power a cheaper option. Therefore, it is necessary to have diversity in the installed capacity to include all conventional as well as non-conventional sources of energy.

4. While economics is an important consideration for harnessing any energy source, Dr. Bhabha 's remark made four decades ago about economics of power generation sums it up nicely. He said 'No power is costlier than no power ' meaning lack of power could impose a severe economic penalty. The case for a higher priority to nuclear power, despite its higher cost in certain cases, is thus impressive and deserves very serious considerations. 5. Another important factor to be considered is environment. Progressively, the need for non-polluting sources of energy, like nuclear power, would be felt not only for supporting economic growth but also for basic needs such as availability of clean air and water. In fact, the day is not far off when we would need to view nuclear energy as not just a source of electricity but a primary energy source which could assure our sustainable future.

India’s Nuclear Power Programme

6. Realizing the importance of developing nuclear power, the forefathers of Indian nuclear power programme guided it towards complete independence in the nuclear fuel cycle. This involves all processes starting from extraction of ore, through energy production, till final disposal of waste products. The necessity for this arose since India was not accepted as a nuclear weapon state, having acquired the nuclear weapons capability after 1970 and has not signed the discriminating NPT. As a result, India 's nuclear power program proceeded largely without fuel or technological assistance from other countries. Its power reactors to the mid 1990s had some of the world 's lowest capacity factors, reflecting the technical difficulties of the country 's isolation, but with continued improvements and R&D effort, it rose impressively from 60% in 1995 to 85% in 2001-02[iii].

7. Sanctions notwithstanding, today India 's nuclear energy self-sufficiency extends from uranium exploration and mining through fuel fabrication, heavy water production, reactor design and construction, to reprocessing and waste management3. It is also developing technology to utilise its abundant resources of thorium as a nuclear fuel. However the isolation did affect the Indian nuclear power programe in some ways. The nation could not benefit from some of the new and improved commercially available NPP. Hence the share of nuclear power in the countries total electricity production has been just about 3% of the total capacity. All this is however likely to change.

8. With changing geo-political equations and India’s emerging economic and technological power, several new areas of international cooperation, including nuclear power, are opening up to it. This holds a promise for the new generation Nuclear Power Plant (NPP) designs as well as uranium fuel for them being made available to India. In light of the various options that may possibly be made available to India, let’s look at the path and technology the nation needs to adopt to make good her energy security needs while retaining retain her strategic options open.

METHODOLOGY

Statement of the Problem

9. This paper seeks of identify the technology and path that the Indian NPP should pursue to fulfil the nation’s growing energy needs without compromising on its strategic requirements.

Justification of the Study

10. As part of a nation’s energy security needs, it is necessary for it to have majority of its need to be met through internal resources, lest it becomes vulnerable to international blackmail. From a long-term perspective, India has rather limited options in this regard. The existing reserves of coal in India would be inadequate to meet an enhanced rate of energy consumption for its entire population for more than a few decades. Therefore in order to meet the large energy needs for industries and urban centers, one of the sustainable energy resource available to India, and indeed to the entire world in a longer-term time frame, is nuclear energy. Here too, India is in a rather unique situation.

11. India has the world 's second-largest reserves of thorium, over 30 percent, but just about 0.7 percent of the world 's uranium. Uranium is the only naturally occurring fissile element that can be directly used in a NPP to produce energy through nuclear fission. Thorium on the other hand needs a longer approach. To generate nuclear energy from thorium, it is necessary to first generate energy from uranium, then a by-product of that process is used with thorium in a reactor, which then releases more energy.

12. This implies that a NPP based on thorium needs uranium reactors and fuel processing to precede it. India thus needs uranium fuelled NPPs to produce the by-product which can then run its thorium cycle to generate energy. India therefore should have at least a minimum number of uranium reactors to ensure that it can run the required number of thorium reactors. This is not possible in the short term due to various reasons including international embargo against India in the field of nuclear energy. However, change is inevitable.

13. The winds of change are coming about because despite having an active and large nuclear programme that is outside the NPT, India is strongly commitment to preventing the proliferation of weapons of mass destruction. This has made the world to realize that as a responsible state with advanced nuclear technology, India should acquire the same benefits and advantages as other such states.

14. This sentiment has also been aided by clarity provided by the Indian nuclear doctrine. The doctrine stipulates that India’s nuclear weapons, as part of a large military force, are to be placed under democratic civilian command and control. It further states the principle of no-first-use and to build a minimum credible deterrence to enable this. This maturity in thought and application, along with an exceptional nuclear safety and security record and an impeccable non-proliferation stance, has made nations take an increased interest in building long-term strategic partnerships with India.

15. The other important factor that is driving this increased willingness, or should one say, the eagerness, to cooperate in nuclear field is economics. India’s rapid economic growth has opened up new vistas for trade and has made India an attractive destination. For instance, with the opening up of nuclear cooperation with India, the opportunities that present themselves include an estimated import of some six to 12 reactors by India to start with. This translates into about $32 billion of business[iv], generating not only revenue but also significant amount of employment internationally. It is also true that moving the nuclear boulder out of the way would throw up a whole lot of other business opportunities like in space, science, military hardware or other high-tech items, which were earlier banned as these came under the "dual-use technologies" denied to India.

16. Increased cooperation would also possibly enable India to have access to several new and more efficient reactor designs and also fuel for them. Some of these designs may suit Indian needs while some may not. Some of the possibilities may be good as a stepping stone for thorium exploitation while some other may suit us to fill the gaps in energy generation capacity. However each ‘carrot’ may have a ‘stick’ also attached to it. The international cooperation in this field may translate into some nations wanting to increase international control on our nuclear assets and impose curbs on our strategic nuclear weapons capability. Therefore, in light of several possible options, it would be prudent on India’s part to choose her path carefully and preserve her strategic interests while making the most use of the new technology and cooperation that the world is offering.

Scope

17. The issue of nuclear power deals with three separate, and individually vital, topics. First is that weather we need nuclear energy in the first place or the other sources of energy, including the renewable sources of energy would be able to fulfil the energy needs of the world. Second is to identify the technology and path the nuclear power program must pursue to meet the requirements while at the same time keeping the possible hazards under manageable limits. The third topic is that of nuclear weapons program which has assumed significance since several nations have been covertly trying to acquire this capability under the disguise of developing nuclear energy.

18. For the purpose of this study, it is accepted that the nation needs to diversify her energy options and nuclear power being an important constituent, needs to be enhanced for India’s growth and development. Also, since the nuclear weapon capability of the nation has been well established, this topic is also not commented upon. Thus this study has been primarily restricted to the second topic with only passing mentions of the nuclear weapon proliferation issues where deemed necessary.

Method of Data Collection

19. The source of most of the information has been books and articles from the library. Articles and studies put up on the internet, newspaper and magazine have also been referred to. In addition a lecture by Dr Srikumar Banerjee, Dir BARC on India’s nuclear power doctrine at the DSSC on 21 Jan 2007 has also been made use of. A bibliography of sources is appended at the end of the paper.

Organisation of the Paper

20. The presentation of topics is as follows. Chapter II gives the basics of nuclear power generation. The chapter includes the basic types of nuclear power plants and their characteristics in brief. Chapter III elaborates upon the energy extraction from uranium and how it can be enhanced. It covers aspects of thermal reactors, breeder reactors as well as fuel processing. Chapter IV deals with thorium as fuel and how is energy extracted from it. Chapter V deals with the economics, safety and other uses of nuclear power plants. In all these chapters, the implications for India are also mentioned to draw inferences concurrently so that the reason for adoption of certain technologies over other is made amply clear. Chapter VI concludes by suggesting the types of nuclear power plants that India must develop to meet her critical requirement of thorium utilisation.

CHAPTER II

BASICS OF NUCLEAR POWER GENERATION

INTRODUCTION

1. In order to understand the pros and cons of different NPPs and their characteristics, it is necessary to first get acquainted with the basics of nuclear energy. Therefore in this chapter we will look at energy generation in a reactor through nuclear fission. The elaboration will be confined to explaining the basic principles that underlie in the generation of useful energy from uranium and the technical problems that arise in doing it. Concurrently, the influence of the current and futuristic technology options would be considered from Indian point of view. So let’s start by understanding nuclear reactions.

NUCLEAR REACTIONS

2. If we overcome the repulsive force between two nuclei and get them close enough, they can interact with one another through the strong nuclear force and reactions between the nuclei i.e. ‘nuclear reaction’ can occur. There are two types of nuclear reactions, viz. fission and fusion reaction. Fusion reaction is a process in which two light nuclei combine to form a single heavier nucleus while in a fission reaction a heavy nucleus, like uranium, is bombarded with a neutron with sufficient energy which splits the heavy nucleus into two smaller nuclei. Both types of reaction are accompanied by the release of large amounts of energy which can be harnessed usefully.

Fission Reaction of Uranium Atom

4. To understand how uranium can undergo fission reaction, lets first understand the complex uranium atom. Uranium (simply known as U) is the heaviest naturally occurring element with 92 protons in its nuclei and either 143 neutrons (U-235), 146 neutrons (U-238) or 142 neutrons (U-234). Pure uranium consists of 99.28% of the isotope U-238, about 0.71% of the isotope U-235, and a trace of U-234 which can be ignored.

5. When a nucleus of U-235 is hit by a neutron it is likely to undergo the following fission reaction:

U-235 + n = Xe-134 + Sr-100 + 2n + Heat

The by-products of this reaction (Xe-13 and Sr-100) could be any of some 20 possible pairs and this type of reaction is not confined to uranium alone but also takes place in other fissile atoms as well. The two new neutrons generated enable this type of reaction to propagate itself. The newly-released neutrons can hit the nuclei of the other U-235 atoms present and cause them to split. These in turn would give off more neutrons which split even more U-235 atoms and so on throughout the mass of the metal. As a result a self-propagating chain reaction will be started. But this process is taking place in fissile material only. Lets us now see at to what happen to the other atoms also present in the reactor.

Fissile and Fertile Materials

6. Atoms which can readily undergo fission by neutrons, like U-235, are called fissile materials while those atoms, like U-238 which can be converted into fissile material are called fertile materials. To elaborate, when a U-238 atom is bombarded with a neutron, it absorbs it and becomes U-239. This is unstable in nature and gives off a β-particle[v] from its nucleus and becomes an atom of a new element, neptunium-239. This new atom is also unstable and throws off yet another β-particle to become plutonium-239 (Pu-239). This Pu-239, like U-235, undergoes fission by neutrons and is a fissile material. Therefore U-238 can yield a fissile atom and is called a fertile material. Another fertile material which occurs in nature is thorium (Th-232, 90 protons and 142 neutrons). Absorption of a neutron changes Th-232 to Th-233, which gives off a β-particle and becomes protoactinium-233. This gives off another β-particle and becomes U-233. This new isotope is also fissile.

7. Both the fertile materials, U-238 and Th-232, occur in large quantities in the earth 's crust, but nature provides only one of the fissile materials, U-235, which is therefore the starting point of all atomic power.

8. The fission reaction is initiated and controlled in a nuclear reactor and the energy released in the form of heat is put to work by boiling water to generate steam which in turn is used to drive turbines and produce electricity. This energy can also be used in a variety of ways like in chemical processes, industrial and domestic heating and water desalination etc.

Implications for India

9. The possible conversion of fertile Th-232 into usable fertile U-233 opens the way for the nation to utilise its vast reserves of thorium for electricity generation.

NUCLEAR REACTORS

10. Newly born neutrons in fission reaction travel at great speed and can cause fission if they hit a fissile nucleus, but the chances of scoring a hit are fairly small due to the small percentage of fissile atoms in the total quantity of fuel present. Therefore a fission chain reaction will not start unless there are either a large number of fissile nuclei present in each unit volume of fuel or the speed of the neutrons is reduced to enable collision with the fissile atoms despite their lesser concentration. The two types of reactors which use these very different approaches are the fast reactors and thermal reactors.

11. Fast Reactor. Newly born fast neutrons move at around 10,000 miles a second[vi] and are most likely to miss the fissile atoms present in un-enriched uranium fuel (0.71% U-235). Therefore to ensure that sufficient number of fission reactions occur, the fuel is enriched to have a larger number of fissile atoms per unit volume. In short, a reactor that depends on fast neutrons would require fuel with higher concentration of fissile material, which could either be U-235, Pu-239, or U-233. Such a reactor is called a fast reactor.

12. Thermal Reactor. Fissile nuclei are much more likely to undergo fission if the neutron is travelling comparatively slowly (about 1 mile a second)6. The fast moving neutrons are slowed down to the required speed by allowing them to collide with the atoms of some light material called a moderator. With each collision, these fast neutrons lose energy until finally they are moving quite slowly. They are then in thermal equilibrium with the moderator atoms and are described as thermal neutrons and such a reactor a thermal reactor. The choice of moderator depends upon its neutron absorption properties and the concentration of fissile material present in the fuel. Some of the options are[vii]:

a) Deuterium, constituting the heavy water absorbs neutrons the least and can be used in reactors using natural uranium as fuel.

b) If light water is used, then since hydrogen’s affinity to neutrons is greater, some enrichment of fuel is necessary.

c) Other moderators like beryllium, helium, graphite etc. all have their peculiar design and enrichment necessities.

13. Out of all these options, the reactor using pressurised heavy water as moderator (PHWR) is the best option given its design and safety features. These reactors can also be refuelled during operation and needs no complete shut down for refuelling, thereby providing enhanced average utilisation.

Implications for India

14. In case India wants to use unenriched uranium as fuel, then it needs to adopt PHWR design. If minor enrichment of uranium is possible, the light water reactor design is feasible and if we have even higher enrichment capability, then fast reactors can be used for power generation.

Complete Nuclear Power Plant

15. A complete NPP is illustrated diagrammatically in Fig 2.3. At the core of the reactor is the nuclear fuel in bundles. In a reactor since the number of free neutrons is closely controlled to keep the rate of reaction constant, excess neutrons are removed by inserting control rods into the reactor. These rods are also located in the core along with suitable moderator. The heat of fission is transferred using coolant, which may be a liquid or a gas, and heat exchangers. The transferred heat is then usefully employed. Round this ensemble of fuel, moderator, control rods, and coolant is a thermal shield, usually made of steel, to reduce the amount of heat radiated outwards. This entire assembly is thereafter surrounded with a concrete shield to prevent the escape of damaging radiations.

Heat Released from Nuclear Reaction

16. The primary advantage of nuclear energy is the outstanding difference in release of heat as compared to fossil fuels. Fission of a single atom of uranium yields energy equal to 200 MeV (million electron volts) in comparison to only 4eV in the oxidation of one carbon atom[viii]. Therefore, on equal weight basis the total energy from the nuclear fission of 1 tonne of uranium is about as much as that produced from 2.5 million tonnes of coal combustion. To reemphasise with an example, a pound of uranium (roughly an inch cube), which would sit easily on the palm of a child 's hand, would provide as much heat as two trainloads (thirty wagons each) of coal[ix]. The only impediment in this example is that we do not know as yet how to burn uranium completely.

Duration of Fuel in a Reactor

17. In the nuclear reactor the fission reaction produces several types of fission products as well as fresh isotopes, some of which are fissile while some absorb neutrons strongly (they are called nuclear poisons). Poisons tend to put the reaction off while the newly bred fissile atoms keep it going. This nuclear deterioration of fuel restricts the length of time for which it can be left in a reactor because the poisons adversly affects the reactivity of the reactor. This time can be extended to some extent by fuel enrichment. Apart from nuclear deterioration, the repeated heating and cooling of the fuel metal causes damage to the fuel assembly and is the present limiting factor to the length of time for which fuel can be left in a reactor.

Thermal Efficiency of Reactor

18. The thermal efficiency of a reactor is governed by the second law of thermodynamics consequently; higher the temperature of the core, higher is the thermal efficiency. For instance, if due to structural limitations the maximum temperature of core is restricted to 500o C which translates into 400oC of coolant temperature, the thermal efficiency is just 30%. On the other hand if the reactor can be run at the core temperature of 750oC resulting in 650oC coolant temperature, the thermal efficiency rises to 40%. Therefore it is better to have reactor designs that run at a higher core temperature than the lower one but this high temperature poses several design problems which have to be overcome.

Summary

19. Fission reaction takes place only in fissile atoms and U-235 is the only naturally occurring fissile material in nature. However, fresh fissile material can be generated or bred in a reactor using fertile atoms like U-238 or Th-232. This process of extracting energy and breeding of fissile material takes place in a reactor. These reactors could be either fast or thermal reactors. These reactors have their peculiar fuel requirements and the output of fissile material varies. All reactors however try and harness the outstanding heat released from the fission reaction to their advantage. How successful they are and what can be done to enhance the energy extraction from the nuclear fuel is discussed in the next chapter.

CHAPTER III

ENERGY EXTRACTION FROM URANIUM

Introduction

1. The simplest way to use natural uranium would be to put it into a reactor and leave it there until it either ceased to maintain a chain reaction or was in danger of failing mechanically, it would then be removed and replaced with fresh fuel. The limiting factors of mechanical deterioration could be increased by metallurgical or engineering methods while the limit on fuel life set by nuclear deterioration could also be altered to some extent by the design of the reactor. The range of possible variation however is not very large with natural uranium but this can be altered with enriched fuel. Let us now see the various ways of energy extraction from uranium and what can be done to enhance it.

Once Through Cycle

2. As mentioned, in a “once through cycle” of natural uranium, the fuel is put into a reactor until it either ceased to maintain a chain reaction or is in danger of failing mechanically. The fuel would then be discarded and replaced with fresh fuel. Such a method is very wasteful of resources, let’s see how. 3. In a reactor, the energy is obtained from fission of U-235 and Pu-239 which gets generated concurrently. In a typical reactor using natural uranium as fuel, only about 0·3% to uranium is burnt or used before the fuel has to be changed[x]. Consequently the spent fuel contains a lot of useful material. For example, after producing energy at a rate of 3,000 MWd(H) the spent fuel would contain about 0.4% of unburnt U-235, 0.3% of Pu-239 and 99% of U-238, as well as 0.3% of fission products. Thus in a once through cycle, the fuel is discarded after only 0.3% of it has been used. Let’s see how this percentage can be improved9.

Increasing the Energy Output from Natural Uranium

4. One way to increase the output of energy from natural uranium in a single pass is to irradiate it for longer durations. This can be done by reducing wastage of neutrons through leakage and absorption. One more way is to use enriched fuel. A small increase in the concentration of the fissile isotope, from 0·71 per cent to, say, 0·8 or 1·0 per cent gives the reactor designer greater freedom and allows a large increase in burn-up. Enrichments up to several times the concentration of natural uranium have been considered. Uranium can be enriched by either gaseous diffusion method or by centrifuge technology. Pu-239 or U-233 can also be added to increase the fissile content of the fuel. These can be sourced by chemical treatment of spent fuel. This increases the total burn-up to about 1% of fuel[xi].

Further Enhancement of Energy Output from Uranium

5. Despite the higher amount of fuel burnt with higher irradiation, the spent fuel still contains 99% of fissile (Pu-239 & U-235) and fertile (U-238) material. So let’s see what can be done to burn all of the fuel, or at least a really large fraction of it.

6. There are broadly three steps that could be taken towards this goal. The first is to prolong reactivity by getting rid of the neutron-absorbing fission products. The second is to put the unburnt fissile atoms back into the reactor. The third is to convert a really large proportion of U-238 into Pu-239. Let’s see these steps in a little greater detail.

Removing the Neutron-Absorbing Fission Products

7. As the fuel rods undergo fission reaction, the nuclear poisons build up in them and slow down the rate of reaction, ultimately putting a limit for the duration for which the fuel can be left in the reactor. Removing these ashes from the rods would help a little, but as these are locked up in solid uranium metal, these rods itself have to be changed periodically and the poisons extracted by elaborate chemical treatment. Use of fuel in liquid form, which is circulated in the reactor, can facilitate continuous removal of these poisons, however highly corrosive nature of the molten fuel poses difficulties which are being overcome with continuing research work.

Putting the Unburnt Fissile Atoms Back

8. The spent fuel contains a large amount of un-burnt fissile material which needs to be utilised instead of being discarded with the spent fuel. The process of doing this is what is meant by putting unburnt fissile material back. Let’s see how it increases the fuel utilisation.

9. It can be mathematically shown that if the conversion factor of the reactor is C (burning one atom of fissile material resulting in the formation of C atoms of plutonium) then one can burn 1 / (1-C) times the fissile content of the fuel fed to the reactor. For example if the reactor has a conversion factor of 0.8, then 1 / (1-C) would equal 5. Therefore, if the feed was of natural uranium, with 0.71 per cent U-235, one might expect to burn a total of 5 x 0·71 or 3·55 per cent of the fuel. It must however be borne in mind that this is not possible simply by leaving the uranium until 3·55 per cent had been burnt, but it might be done by removing the uranium, when forced to do so by deterioration, separating from it the Pu, and putting the Pu back into the reactor with some fresh natural uranium[xii].

10. Two aspects emerge clearly out of this. Firstly, at the expense of the fissile material already present in the fuel, fresh one is bred along with the energy production. However, and this is important to note that, the amount of fresh fissile material bred and extractable is about 70 – 80% of the fissile material originally present. For example, one tonne of natural uranium as fuel would contain 7.1 Kg of U-235. After the fission in a thermal reactor, the spent fuel would contain at best 4.9 to 5.6 Kg of Pu-239 in it which can be extracted. Hence after the energy extraction, there is lesser amount of fissile material available than what went into the reactor. Secondly, it all the plutonium were fed back, the burn-up would be increased to 3·55% of fuel. However, due to losses through chemical processes and differing nuclear properties of various fission products, this utilisation reduces to about 2% which is still worth striving to attain.

Breeding

11. The third of the three steps towards full utilization of nuclear fuel is the conversion of a really large proportion of fertile atoms U-238 and Th-232 into fissile atoms Pu-239 and U-233 respectively. To take this step we need a reactor in which the conversion ratio is greater than one. From such a reactor, at the end of a period of operation, it would be possible to extract more fissile material than what had been supplied to it. Therefore any process by which more fissile material is produced than is consumed is popularly called breeding. The amount of new fuel produced, in relation to that consumed is defined by the gain of the process.

12. In a breeder reactor, catering for self sustenance and wastage, a neutron yield of greater than 2·15 is needed for breeding. In a reactor with thermal neutrons, U-233 yields an average of 2·28 neutrons per fission and offers a hope of breeding, while with fast neutrons, Pu-239 is the best fuel with a neutron yield of 2·6. So it seems that the best way to breed would be to use a fast reactor with plutonium as fuel and U-238 as fertile material. Also a thermal reactor using U-233 / Th-232 cycle may be capable of breeding or at least of self-sustaining operation. 13. In a breeder reactor, both the fuel and the fertile material have to be processed chemically from time to time to remove fission products and to extract the newly-bred fissile material. After this processing both have to be fabricated again into fuel elements. These processes cost money and cause some loss of fissile material. The effects of this are firstly, the net positive gain is smaller than the gain indicated by the conversion ratio of the reactor and secondly the loss of fissile material makes it possible to achieve a burn-up of only about half the total uranium. The rate at which newly-bred fuel accumulates in a advanced breeder reactor is although not very high and, when allowance is made for processing losses, it may take more than five years for the amount of fresh fuel formed to equal the amount invested in the reactor.

Fast Breeder Reactors

14. Breeder reactors using fast neutrons are called Fast Breeder Reactor (FBR). As the neutrons yield from the fission of Pu-239 by fast neutrons is 2.6, a reactor using Pu-239 in the fuel ought to have a high conversion factor and hence a greater utilization of nuclear fuel than any other. This has been a primary reason for developing fast reactors. These reactors are characterized by the small size of their cores, high enrichment of the fuel, extremely high heat rating, remarkably good neutron economy and liquid metal coolant.

Comparison between the Three Processes

15. A comparison between the three processes is made for easy comprehension. Suppose a NPP has a generating capacity of 6,000 MW(E) and delivers power at this rate throughout the year. For a single pass process only about 0.6% of fission products are used. The fuel reprocessing may increase the utilisation to about 3%. The greatest utilisation would come from breeder reactors from where the utilisation could be as high as 60 – 70% of total fuel.

Implications for India

16. Pressurised Heavy Water Reactor (PHWR). ‘Natural uranium’ can be used in thermal reactors with heavy water as moderator. Since India does not have the technology to enrich natural uranium, these PHWR becomes suitable and provide freedom from imported uranium for light water reactors. The safety record of these reactors has also been good. PHWR therefore offer the best utilization of country’s limited uranium resources and since they provide a high plutonium yield which can be used in breeder reactors, it becomes the first choice in the country’s nuclear power programme.

17. Fast Breeder Reactor. Since India has very limited uranium resources, the advantage of FBR in its ability to utilise about 50% resources stand out the most. As compared to the once through cycle, it amounts to some 50 times more energy extraction[xiii]. Fast reactors also burn, in situ, higher actinides and thus minimize the waste problem. This also opens a way of utilizing the energy potential of thorium which is abundant in India.

18. There is a common misconception that fast breeders breeds fast. They only use fast neutrons while breeding rather slowly. For faster growth of FBR capacity, shorter doubling time would be needed, towards which research is already on.

19. Light Water Reactors. These reactors need enriched fuel which has to be imported. However the high burn up rates results in greater fuel utilisation, higher temperatures and thus better thermal efficiency and also greater yield of Pu-239 from its spent fuel. Therefore with imported enriched uranium this becomes a good option to scale up the current energy generation capacity while at the same time if Pu-239 extraction is permitted from its spent fuel, then to scale up the FBR capacity as well.

20. Since India has meagre reserves of natural uranium, even if we develop the uranium enrichment capability, the total quantum of indigenous uranium extractable will be the limiting factor. For example, to enrich one tonne of natural uranium to contain 1.5% of U-235, more than one tonne of depleted uranium would be generated which would not participate in energy generation at all. Thus the only answer to light water reactors is imported uranium.

21. High Temperature Reactors. Today there is significant interest in high temperature reactor design due to its high thermodynamic yield and its application in various chemical and other industrial uses. In such systems, Helium is normally used as cooling fluid. There is another important utility of high temperature reactor and that is in hydrogen generation where the heat is used to crack water directly to generate hydrogen which is a viable fuel.

22. Spent Fuel Reprocessing. In all the processes except the once through cycle, spent fuel reprocessing becomes essential. Therefore the complete mastery of the closed fuel cycle including reprocessing of fuel is a central requirement of Indian Nuclear Power Programme.

Summary

23. To summarise, we saw the process of fission reaction and the various types of reactors. We also saw the advantages and the disadvantages of various systems from Indian point of view. In reality, these systems are not rivals in the nuclear field but as alternatives which may suit one situation today and a different situation tomorrow. It is therefore necessary not to disregard any option but to keep the options open while perusing own strategic and energy requirements in mind. Till now we have primarily focused our attention on uranium exploitation. In the next chapter we would look at the other fertile material available in abundance in India and how it can be used for power generation as well.

CHAPTER IV

THORIUM UTILIZATION

Introduction

1. India has the world 's second-largest reserves of thorium, over 30%, but just about 0.7% of the world 's uranium. As a result, it makes better economic sense to exploit energy from an abundant and cheap resource, like thorium, than one that has to be imported. Therefore, almost from the beginning of Indian nuclear power program, some effort has always been expended towards developing the technology of thorium utilisation.

2. In the previous chapter we saw some characteristics of uranium as fuel. The reactors which were described with uranium as fuel can also be used with thorium, enriched with fissile material like U-233 or Pu-239, as fuel albeit with minor modifications if needed. In this chapter shall first look at the characteristics of thorium as fuel and the pros and cons of its use, followed by the reactors in which it can be used. Thereafter some modern concepts of reactor designs would also be mentioned.

Thorium Exploitation

3. Thorium occurs principally in monazite sands, from which it is extracted by methods similar to those used for uranium. Unlike uranium, thorium does not need enrichment as the natural metal consists entirely of the desired fertile isotope, Th-232 which needs to be converted into fissile U-233 before use. This conversion is achieved in a fast breeder reactor

4. In a FBR, the core has Pu-239 and uranium and a blanket of Th-232 around it. These Th-232 atoms absorb excess neutrons and get transmuted into U-233. This U-233 is thereafter chemically separated and used in the U-233 / Th-232 cycle. However, it would take time to build up a stock of U-233 big enough to fuel any considerable number of reactors hence there is a time limit to scalability.

5. Another approach is to put Pu-239 as seed material along with Th-232 in the thermal reactor core. The excess neutrons produced from Pu-239 are used to convert Th-232 into U-233. Once the reaction stabilises, i.e. enough U-233 have been converted, it should be possible to make the reaction self sustaining[xiv] with thorium alone since the neutron yield with U-233 is an average 2.28. In this manner, it should be possible to burn 30 to 50 per cent of thorium if the chemical processes turn out to be cheap and has low losses. This type of reactor is also called “Advanced Heavy Water Reactor”.

Advantages and disadvantages of Thorium as Fuel

6. Th-232 / U-233 cycle has a good ratio of neutron yield to neutron absorbed thus making it a good fuel in any reactor type. The physical (thermal) characteristics of thorium are also good resulting in lesser strain on the fuel clad therefore it can sustain high burn-up rates. The fuel deterioration is also slower allowing the fuel to reside in the reactor for longer periods of operation[xv]. These properties remain valid even at high temperatures; hence thorium is also recommended for high temperature reactors. In thorium based fuel, there is effective consumption of external fissile material like U-235 or Pu-239 added initially; therefore it can be used to dispose off excess fissile material as well. This system also generates less long-lived wastes thereby reducing the volume of spent fuel.

7. One disadvantage of thorium is the relatively long half life (27 days) of the intermediate product Pa-233. This result in reactivity surge after reactor shutdown due to U-233 production, and must be factored in during reactor operation[xvi]. The other disadvantage is the higher technological challenges present in the reprocessing and recycling of bred U-233 due to strong gamma radiating by products. The need to separate U-233 from the fuel also makes reprocessing an integral part of a sustainable thorium fuel cycle.

Thorium Fuelled Advanced Reactors

8. As mentioned, owing to its good neutron economy, thorium is a good fuel in any reactor type. Consequently, there are several concepts for advanced reactors based on thorium fuel cycles which include[xvii]:

a) Light Water Reactors with fuel based on plutonium oxide (PuO2), thorium oxide (ThO2) and/or uranium oxide (UO2) particles arranged in fuel rods. Thorium

b) High-Temperature Gas-cooled Reactors. The use of helium as a coolant at high temperature results in almost 50% thermal efficiency. These reactors are of two kinds:

i) Pebble-Bed Modular reactor (PBMR) which can potentially use thorium in its fuel pebbles. Thorium

ii) The Gas Turbine-Modular Helium Reactor (GT-MHR) whose core can accommodate a wide range of fuel options, including HEU/Th, U-233/Th and Pu/Th.

c) Molten salt reactor.

d) Advanced Heavy Water Reactor (AHWR).
Use of Thorium in Accelerator Driven Systems (ADS)

9. In an ADS system[xviii], high-energy protons, on colliding with a target element such as lead, tungsten etc. cause detachment of a large number of neutrons from these nuclides in a process known as ‘spallation’. These neutrons can provide the required population to sustain a self-terminating fission chain in an otherwise sub-critical blanket (an arrangement similar to a nuclear reactor with not enough fuel to make it critical). Both uranium as well as thorium is suitable as fuel for this system. Such a system, called ‘Accelerator Driven System’, can be used to produce several times more electrical energy than that required for operating the accelerator. This system can be used either for power generation or destruction of actinides resulting from the U/Pu fuel cycle. The use of thorium instead of uranium means that less actinide are produced in the ADS itself.

Summary

10. Thorium, though it possesses a number of superior physical and nuclear characteristics than uranium, is not fissile. Thus, even with much greater abundance as compared to uranium, has lagged far behind uranium. With growing needs of energy in today’s world, uranium alone cannot fully meet the aspirations and compulsions of the entire world, hence the renewed interest in thorium exploitation.

11. With the modest uranium reserves, and growing economy, India’s large growth in nuclear power capacity can be realised only through efficient utilisation of fertile materials like thorium and U-238. A closed nuclear fuel cycle, which involves reprocessing and recycle of fissile materials, is thus inevitable for us. Thus thorium utilisation for large scale energy production is critical for the India’s future energy security.

12. Towards this all avenues of energy production with thorium must be exploited. India has already developed and tested the technologies needed to extract energy from Thorium, but large scale execution has not yet been possible, mainly because of limited availability of Plutonium. Therefore thorium fuelled advanced reactors like light water reactor, advanced thorium breeder reactor, Compact High Temperature Reactor and ADS etc. needs to be developed for thorium exploitation.

13. The future developments in reactor technology must also cater for critical factors of scale, safety, cost construction time and efficiency. The overriding factor would however remain the efficient exploitation of uranium resources and development of thorium based reactors.

CHAPTER V

ECONOMICS, SAFETY AND OTHER USES OF NUCLEAR POWER PLANTS

Introduction

1. Till now we have seen the various types of NPP for large scale power generation. We also saw the fuel suitability or combinations for them. There are several other factors that must be kept in mind while selecting the power plants like the economics, safety factors and other uses for which they may be needed or employed. This chapter would look at those factors, starting from the economics of scale, installation and running. This would be followed by a brief look at the safety aspects necessary for these reactors and finally we would look at the other uses of nuclear power that the nation would like them to perform.

Economy of Scale

2. In attempting to obtain maximum performance per unit of cost, it is always advantageous to build plants with higher power output. This is the principle of "economies of scale." It thus costs substantially less to build and operate a 1,200 MW plant than two 600 MW plants of the same basic design[xix]. But big is not always beautiful because:

a) Safety. If safety is the primary goal, it is much easier to ensure that adequate cooling will be available if there is only half as much heat to dissipate.

b) Construction Time. The time required for construction can be a very important ingredient in determining costs, and it obviously takes longer to construct a larger plant. Also since smaller plants have fewer pumps and valves and less piping, they require fewer welds, which reduce the time needed for constructing them.

c) Mass Fabrication. As compared to a larger reactor, many more parts of a smaller reactor can be produced and assembled in a factory, thus improving their quality assurance and standardisation while at the same time reducing cost.

d) Simplicity. A smaller plant favours simplicity over complexity providing larger margins for safety and cost saving in bigger plants.

Implications for India

3. The above factors point towards an optimum size of reactor so that the cost, safety and manufacturing ease is taken care of. A reactor with too small a power output, like the 220 MW PHWR, as well as very large power output augers unfavourably from cost point of view. Thus PHWR of about 700 MW capacities meets most these criteria. There are some exceptions to this, like the power plant needed for propulsion has to be small in size to fit in the vehicle, or certain specific designs which are more efficient in small modular configuration, like the pebble bed reactor and needs a large number to be assembled for greater aggregate power.

4. During nuclear reactor development the effort should therefore be for reduction in capital and running cost by design standardisation, robustness in design, simplicity in operation and good power output at higher burn-up

Economics of Nuclear Power Plants

5. In countries like India where the natural resources are not so abundant, no coal, no oil, no gas leaves no choice! However, planners today do recognise the importance of economics, and nuclear power must be cost-effective to be deployed in larger scale.

6. While calculating the cost of power, like in all power technologies, there are fixed costs and operating costs, and their inherent uncertainties. Such calculations also depend on the assumptions. Fixed costs depend significantly on the chosen design/technology. And to some extent, operating costs also depend on this. In an analysis by the UBS Investment Research in 2005, the project costs (fixed cost) for state of the art LWRs based on imported designs and foreign collaboration has been made. As per this the European estimates are approximately 1,680 $/kW[xx]. This price could reduce with scale. Suppliers for new design plants indicate overnight construction costs as low as $1,100/ kW.

7. Nuclear power is capital intensive. However the corollary of the high capital costs is low operating costs, especially for fuel. An estimate puts energy cost from an AP-1000 reactor at 3.2 to 3.6 cents per kW. Other designs like the Canadian ACR, or the European EPR, or even the Japanese ABWR are also very cost competitive. In the future, while fossil fuel prices will increase rapidly, even if nuclear fuel prices rose similarly, the impact on net power costs would be much lesser (about half or lower) compared to gas based power plants.

Funding of New Power Plants

8. As and when the imports of NPP open up, the very high fixed cost can possibly be met only with international collaboration in construction and financing. Because of the absence of large markets for nuclear power in the US, LWR manufacturers will be more than interested in selling such power plants to India, if necessary even with attractive financial packages. The best model may therefore be for the foreign partner, perhaps in collaboration with an Indian power corporation, to undertake to build the power plant, supply fuel, and produce power, which Indian power utilities can buy at reasonable rates. Several additional agreements such as on accident liability, fuel supply, disposal, and possible spent fuel reprocessing will all have to be negotiated between the vendor countries and India.

9. In a scenario of disruption in uranium fuel supplies the power generation at these nuclear plants would be halted, but since the share of nuclear power, even in the most optimistic scenario, may not rise to more than 10-15 per cent of all the electricity produced, the effect of the denial, though unsettling, would not be catastrophic.

Impact of Imported Reactors on Indigenous R and D

10. The imported reactors, instead of stifling our R&D effort would give it a boost. The import of LWR would enable the Indian scientists to now focus all their energies and resources on building more PHWR, improving fast breeder reactors and exploring new avenues for thorium utilisation. While some solutions may not turn out to be feasible or optimal, new fuel cycles and sources are going to be very relevant in the future when the world runs out of cheap fossil fuel and even the uranium resources come under pressure.
Safety aspects

11. The underlying safety consideration of NPP is the exposure of people to radiation over and above that which they normally receive from the natural background. Towards this better monitoring and control systems are being developed and installed. The new reactor designs also lay very high emphasis on meeting the internationally accepted safety criteria. Therefore today’s nuclear power plants are much safer than some of the earlier designs. A testimony to this statement is the Japanese nuclear power programme, despite its high population density. Though there were some minor accidents or leaks but Japan continues to build new improved plants.

Implication for India

12. To ensure safety against natural calamities, in India and all over the world, the nuclear power plants are designed to withstand the maximum potential earthquake that can occur at the site. The site selection criteria includes, disqualification of sites having high seismic potential beyond stipulated limits[xxi]. This approach was proven in case of the 2001 Bhuj earthquake, when Kakrapar Atomic Power Station (KAPS), near Surat kept operating safely during and after the earthquake and continued to supply power; whereas large part of the Gujarat State was severely affected. The devastating Tsunami on the East coast on India also caused little damage to the MAPS atomic plant located on the sea shore close to Chennai. In addition, manmade events like hazard from aircraft crashes, explosions, and toxic gas releases from industrial activities are also adequately addressed in the plant siting and design.

Other Uses of Nuclear Power

13. Apart from large scale electricity generation, nuclear power has several other applications as well. Some of the applications are potentially equally important. These range from the use of nuclear power for propulsion, to the generation of electric power on a small scale, to the production of heat in industrial and chemical processes, and to providing large sources of radiation for industry to name a few.

14. Small NPP are needed to power ships where the non-dependence on air for power generation (submarine application) and very small volume of fuel requirements (large military aircraft carriers) make these attractive options. These small power plants can also be used in localities far from ports, like North India, and in remote parts of the country where there is little industrial development, especially if they lacked indigenous fuel resources. In regions like Ladakh and Kashmir which remain cut off from the rest of the country for extended periods in winters, small NPP can effectively provide electricity without the need for large movement of fuel. The security of such plants near hostile border however needs to be evaluated.

15. Industry needs energy in three forms: mechanical, to drive its machines; electrical, for electrochemical processes (though some is converted to mechanical energy); and thermal, to warm its buildings, dry its products, and accelerate its chemical processes like in steel making. Another group of processes that operate at temperatures from 500 to 1000°C includes the carbonization and gasification of coal, for the production of fuel gas, smokeless solid fuel, tar, and oils that may be separated into petroleum and fuel oil.

16. Industrial uses of radiation include its application for medical sterilization and sterilization of food without cooking it. In industrial chemical processes, radiation can be applied most economically to trigger reactions that will then go on by themselves. Another application is to grafting on the surface of a polymer a second, different, polymer and vulcanization of rubber to name a few.

17. Heat from high temperature reactors can be used to produce hydrogen more directly without first having to generate electricity. Nuclear heat can also be used for desalination of brackish or sea water.

Summary

18. The high capital cost of NPP is well offset by the low operating costs, especially for fuel. Therefore research must also focus on developing NPP which have better cost, safety and simplicity features. The low cost of operation and extremely compact fuel augers well for deployment of NPP in remort parts of the country. These reactors must also incorporate adequate safety features to avert any catastrophic disaster. Apart from large scale electricity generation, the nuclear power has a large number of other applications as well. These must be further developed in order to reduce our dependence on fossil fuel and also reduce the polluting gasses.

CHAPTER VI

CONCLUSION

Introduction

1. India is a country occupying 2% of the world 's land mass and currently generating about 2% of the global electricity, mostly using low grade coal of which it has about 5% of the world’s reserves. India has, however a share of 16% in the world 's population. To achieve a modestly high level of economic growth in India, the domestic generation capacity needs to be increased several folds. With the depleting coal and oil resources, limited hydro power and with growing global concerns of green house gases generated by fossil fuel fired stations, India has no option but to use nuclear and other non-conventional resources for meeting her future power requirements.

2. India being a non signatory of NPT does not enjoy international cooperation in the field of nuclear energy. This may change in the future with the changing geo-political equations and growing economic clout of India. In the case of availability of imported technology and uranium, we must optimally utilize our own natural resources while making up the deficiencies in our capability with foreign help.

3. India has very limited uranium reserves but has almost one third of the world’s thorium reserves. Therefore thorium utilization has to be at the centre of our nuclear power programme. But to utilize thorium we need fissile material. Therefore the study points towards the following path that we must adopt to fulfill our critical need of thorium utilization.

Power Generation from Thorium

4. As we saw, thorium can be used as fuel when used with either U-235, U-233 or with Pu-239, all of which are the fissile materials. With this cycle, once the reaction stabilizes, there is no need for fresh fissile material as the Th-232 gets converted into U-233 at adequate rate to keep the reaction self-sustaining. Let us now summarize at the ways to source these fissile materials one by one.

Sourcing U-235

5. U-235 is present in natural uranium at a concentration of 0.7%. This can be extracted from the natural uranium and used with thorium. However there are three issues involved. Firstly, India does not have enough resources of natural uranium to extract this isotope at sufficient levels. Secondly, the nation does not have the knowhow of uranium enrichment and lastly, due to the meager uranium reserves, the waste of depleted uranium cannot be accepted. Thus utilizing U-235 as fissile material is ruled out, unless imported uranium is made available to us.

Sourcing U-233

6. U-233 is created when Th-232 absorbs a neutron in either a thermal reactor or a breeder reactor. In the thermal reactor, apart from energy generation, the rate of generation of U-233 is just sufficient to sustain the reaction without the need for further seed, once the reaction stabilizes. Thus U-233 generated cannot be spared for any significant capacity up gradation. This is not the case in FBR. In a FBR, along with the energy generation, fissile material is generated which is in excess of the self sustaining requirement and can be spared for fuelling new reactors. For breeding U-233, Th-232 is put in the blanket around the core of the reactor. However there is a catch here. For running of a FBR, first of all we need Pu-239 as seed. Therefore, for generation of U-233 in a FBR, first Pu-239 has to be generated.

Sourcing Pu-239

7. Pu-239 is created in most efficiently in thermal reactors with natural uranium as fuel if heavy water is used as moderator. For this the spent fuel has to be chemically reprocessed and the Pu-239 separated from it, either to be used again in the PHWR, FBR or AHWR to utilize thorium directly. However with our current reasonably assured resources of uranium, we can grow our PHWR programme up to a level of only 10,000 MWe of installed capacity that too for a few decades. This would provide Pu-239 at a very slow rate, and our FBR scaling would continue to be low through the next few decades.

8. The other source of Pu-239 is through low enriched uranium light water reactors. These reactors need imported uranium because firstly, India does not have the technology of uranium enrichment and secondly, we do not have enough uranium reserves. The reprocessing of this spent fuel would give us the additional source of Pu-239. Since the burn-up rates of these reactors are high, the amount of Pu-239 generated is also high, and so is the electricity generation. Therefore India must insist on the right for the spent fuel reprocessing if we import such reactors and fuel.

9. Once the FBR capacity based on Pu-239 has been successfully established, it will be necessary to have FBRs of short doubling time (12–15 years) to be able to further grow the FBR capacity in tune with the growth of the national electricity base. Here a long-term nuclear cooperation with Russia could also give India access to that country 's breeder technology and lessons from its proven experience including the BN-600 and higher capacity BN-800 reactor designs.

ADS

10. Apart from needing fissile material for energy extraction from thorium, new technologies like the ADS must be developed. These would provide faster scalability and good safety measures even against proliferation.

Suggested Nuclear Power Plant Options

11. Nuclear power needs to be harnessed for meeting India’s power requirements, and it is apparent that the other fuels are unlikely to provide the desired growth rate. It would not be correct to claim that nuclear power is the panacea to India’s energy challenges, rather, to suggest that nuclear power is a worthwhile option to pursue. India stands to benefit from imported nuclear fuels and reactors to significantly augment its indigenous capabilities. While nuclear plants are capital intensive, operating costs are relatively low, and in an increasingly fossil fuel constrained world, the fuel costs are not likely to escalate as fast as the fossil fuels. Therefore our nuclear power programme must have the following nuclear power plants options:

a) Pressurised Heavy Water Reactors to use indigenous natural uranium and then process the spent fuel and extract Pu-239 from it.

b) Imported Light Water Reactors with their enriched fuel and the right to reprocess its fuel and keep the Pu-239 extracted. This would be short term requirements as firstly, this would fulfil the immediate power need of the country by expanding the installed power base and secondly to generate Pu-239 for use in thorium cycle.

c) Fast Breeder Reactors to convert a large portion of fertile material into fissile material so that it can be used for thorium exploitation. We may like to use the vast experience and expertise of Russia in furtherance of our FBR programme.

d) Thorium usage could be through reactors using Th-232 / U-233 cycle or alternatively, in thermal reactors using Pu-239 / Th-232 as initial seed and then running it on Th-232 / U-233 cycle. Any other reactor design which ultimately helps us to enhance our thorium exploitation must also be researched and adopted. This would ensure that energy from thorium is available to us in significant quantity for several centuries.

12. The international cooperation on nuclear energy should be viewed as a golden opportunity for India to increase its power generation base using nuclear energy and also as recognition for its outstanding nuclear non-proliferation practices. This will also free the Indian scientists to focus on the development of advanced fuel cycle reactors based on thorium and plutonium that may yield a large payoff. Once there is greater pressure on uranium resources, fast reactor technology is also going to become critical. If India perseveres in these areas, she may then end up as a pioneer in plutonium and thorium technologies that may meet its growing power if needs not in the immediate decades, but definitely a few decades later. India will then turn out to be global leader in these technologies. An embargoed nation, long denied its due, would rise to become the global resource for these technologies.

BIBLIOGRAPHY

1. David Hart. Nuclear Power in India. New Delhi, 1983. 2. Kenneth Jay. Nuclear Power Today and Tomorrow. London, 1960. 3. Dhirendrs Sharma. India’s Nuclear Estate. New Delhi, 1983. 4. SD Thomas. The Realities of Nuclear Power. Cambridge, 1988. 5. Ian Blair. Taming the Atom. Bristol, 1983. 6. Dr Srikumar Banerjee, Director BARC, Lecture on Indian Nuclear Doctrine at DSSC, Wellington, on 21 Jan 07. 7. B R Bergelson, A S Gerasimov And G V Tikhomirov, Operation of CANDU power reactor in thorium self-sufficient fuel cycle. Pramana, Indian Academy of Sciences Vol. 68, No. 2, February 2007 8. Safety Criteria for Siting a Nuclear Plant. STUK, Guide, 11 Jul 2000. 9. RK Sinha and A Kakodkar. Indian Programme related to Innovative Nuclear Reactor Technology. 13th annual conference-2002, Oct 2002. 10. R Chidambaram and RK Sinha. Importance of Closing the Nuclear Fuel Cycle. Nuclear Energy, 2006. 11. A Bharadwaj, R Tongia, VS Arunachalam. Whither Nuclear Power, Economic and Political Weekly, Mar 2005. 12. Larry Parkar and Mark Holt, Nuclear Power: outlook for New US Reactors. CRS Report for Congress, 09 Mar 2007. 13. IAEA booklet on Generic Safety Issues for Nuclear Power Plants with PHWR. Jun 2007. 14. Raj Chengappa. Why US wants the Deal, India Today, 19 Nov 07. 15. V Raghuraman and Sajal Ghosh. Indo-US Energy Cooperation – Indian Perspective. Confederation of Indian Industries, India. Mar 2003 16. Nuclear Power in India. Briefing Paper 45, Australian Uranium Association, Sep 07. 17. Need of Nuclear Power. Nuclear Fuel Complex, department of Nuclear Energy, Govt of India 18. Raj Chengappa. Why US Wants the Deal India Today Nov 19 2007 19. Wilson PD. 1996,The Nuclear Fuel Cycle, OUP, Nuclear power Reactors, Oct 2005, p 3 20. Placid Rodriguez and SM Lee, Who is afraid of breeders, Indira Gandhi Centre for Atomic Research, Kalpakkam. 21. http://www.wikepedia.com 22. http://www.howstuffworks.com

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[i] V Raghuraman and Sajal Ghosh. Indo – US Cooperation in Energy – Indian Perspective: Mar 2003, pp 4,5
[ii] Need of Nuclear Power. Nuclear Fuel Complex. http://www.nfc.gov.in/html-nuclear.htm accessed on 11 Aug 07
[iii] Nuclear Power in India. Briefing Paper 45, Australian Uranium Association, Sep 07. http://www.uic.com.au/nip45.htm. accessed on 15 Sep 07
[iv] Raj Chengappa. Why US Wants the Deal. India Today, Nov 19 2007, pp 36,37
[v] A Beta-particle is akin to an electron, having negligible mass and a negative charge of one unit. A nucleus losing a beta-particle gains one positive charge or atomic number without any change in its mass number, and becomes a different element.
[vi] Kenneth Jay. Nuclear Power Today and Tomorrow pp 8-17
[vii] Wilson PD. 1996,The Nuclear Fuel Cycle, OUP, Nuclear power Reactors, Oct 2005, p 3
[viii] Dr Srikumar Banerjee, Director BARC, Lecture on Indian Nuclear Doctrine, DSSC, Wellington, 21 Jan 07
[ix] Kenneth Jay. Op. cit., pp 32 - 40
[x] Kenneth Jay. Nuclear Power Today and Tomorrow pp 33 - 35
[xi] R Chidambaram and RK Sinha, Nuclear Journal, Importance of closing Nuclear fuel cycle, p 2
[xii] Kenneth Jay. Op. cit., p 36
[xiii] Placid Rodriguez and SM Lee, Who is afraid of breeders, http://www.ias.ac.in/currsci/nov251998/articles13.htm accessed on 21 Jul 07
[xiv] BR Bergelson, AS Gerasimov and GV Tikhomirov, Operation of CANDU power reactor in Thorium Self Sufficient fuel cycle, Feb 2007, pp 1-3
[xv] India, Department of Atomic Energy: Shaping the Third Stage of Indian Nuclear Power: pp 4-8
[xvi] Michel Lung, presentation at the seminar at the Joint Research Center (JRC), Ispra, Italy, July 1996 http://npc.sarov.ru/english/digest/142004/appendix9.html sourced on 07 Nov 07.
[xvii] UIC Briefing Paper # 67, Thorium, Sep 2007, http://www.uic.com.au/nip67.htm, sourced on 30 Dec 07
[xviii] RK Sinha and Anil Kakodkar, Indian Programme related to Innovative Nuclear reactor Technology, Oct 2002, pp 6-8, http://www.indian-nuclear-society.org.in/conf/2002/2.pdf sourced on 07 Feb 08
[xix] The Next Generation of Nuclear Plants, ,-. 9 : F G îÝÈ·¥?~iT?Ý2http://www.indian-nuclear-society.org.in/conf/2002/2.pdf, sourced on 30 Dec 07.
[xx] http://web.mit.edu/nuclearpower/pdf/nuclearpower-ch1-3.pdf
[xxi] Safety Criteria for siting a Nuclear Power Plant, Guide, 11 Jul 2000, pp 3-6

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[pic] [pic]

Fig 2.1: Nuclear Fission Reaction Fig 2.1: Nuclear Chain Reaction

[pic]

Fig 2.3: Nuclear Reactor

Bibliography: 1. David Hart. Nuclear Power in India. New Delhi, 1983. 2. Kenneth Jay. Nuclear Power Today and Tomorrow. London, 1960. 3. Dhirendrs Sharma. India’s Nuclear Estate. New Delhi, 1983. 4. SD Thomas. The Realities of Nuclear Power. Cambridge, 1988. 5. Ian Blair. Taming the Atom. Bristol, 1983. 10. R Chidambaram and RK Sinha. Importance of Closing the Nuclear Fuel Cycle. Nuclear Energy, 2006. 19. Wilson PD. 1996,The Nuclear Fuel Cycle, OUP, Nuclear power Reactors, Oct 2005, p 3 20