The department of atomic energy has formulated three stage nuclear power development programme consisting of

(1) Pressurized heavy water reactors (PHWRs) using natural uranium.Under the first stage PHWR programme, 14 nuclear power reactor units are in operation with a total capacity of 2720 MWe. An additional capacity of 3960 MWe (6 PHWRS and two light water reactors (LWRs) are under construction to reach a total nuclear power capacity of 6680 MWe by the end of the year 2008.

(2) Fast breeder reactors (FBRs) using plutonium fuel. A beginning has been made on the 2nd stage programme of FBRs by the Indira Gandhi centre for Atomic Research (IGCAR) to construct the first prototype Fast Breeder Reactor (PFBR) of 500 MWe capacity.

(3) Advanced nuclear power reactors using uranium 233 as fuel in thorium-uranium 233.As regards the third stage on Advanced Heavy water Reactor (AHWRs), design demonstration work on utilisation of thorium is in progress at the Bhaba Atomic Research Centre (BARC).

Nuclear Power Status

Some Important Points

• The first commercial nuclear power stations started operation in the 1950s.
• Nuclear energy now provides about 11% of the world's electricity from about 450 power reactors.
• Nuclear is the world's second largest source of low-carbon power (>30% of the total in 2015).
• 50 countries utilise nuclear energy in about 225 research reactors. In addition to research, these reactors are used for the production of medical and industrial isotopes, as well as for training.
• About 60 more reactors are under construction, equivalent to 16% of existing capacity, while an additional 150-160 are planned, equivalent to nearly half of existing capacity.
• In 2016 nuclear plants supplied 2477 TWh of electricity, up from 2441 TWh in 2015. This was the fourth consecutive year that global nuclear generation had risen, with output 130 TWh higher than in 2012.

Sixteen countries depend on nuclear power for at least one-quarter of their electricity. France gets around three-quarters of its electricity from nuclear energy; Hungary, Slovakia and Ukraine get more than half from nuclear, whilst Belgium, Czech Republic, Finland, Sweden, Switzerland and Slovenia get one-third or more. South Korea and Bulgaria normally get more than 30% of their electricity from nuclear, while in the USA, UK, Spain, Romania and Russia about one-fifth of electricity is from nuclear. Japan is used to relying on nuclear power for more than one-quarter of its electricity and is expected to return to somewhere near that level.

According to the World Nuclear Industry Status Report 2017, India is third in the world in the number of nuclear reactors being installed, while China tops the list. India has 22 operable nuclear reactors, with a combined net capacity of 6.2 GWe. In 2017, nuclear generated 3% of the country's electricity.

 The Indian government is committed to growing its nuclear power capacity as part of its massive infrastructure development programme. The government in 2010 set an ambitious target to have 14.6 GWe nuclear capacity online by 2024.  After successful commissioning of Kudankulam units 1 & 2, an agreement was made with Russia in June 2017 for the units 5 & 6 (2 x 1000 MW) with an estimated cost of INR 250 million (3.85 million US$) per MW. Earlier, India had also entered in to an agreement with Russia in October 2016 for the units 3 & 4 (2 x 1000 MW) with an estimated cost of INR 200 million (3.08 million US$) per MW. At the start of 2018 six reactors were under construction in India, with a combined capacity of 4.4 GWe. In March 2018, the  government stated that nuclear capacity would fall well short of its 63 GWe target and that the total nuclear capacity is likely to be about 22.5 GWe by the year 2031.

Benefits of Nuclear Power

• The comparison of the risks of nuclear power generation shows that it is lower or comparable to other forms of power production.
• In addition there are some real benefits of nuclear power production. Fossil fuel substitution results in great environmental benefits. A 1000 MWe coal fired station consumes 3 million tonnes of coal per year producing 7 million tonnes of carbon dioxide, 120 thousand tonnes of sulphur dioxide, 20 thousand tonnes of nitrogen oxide and three quarters of a million tonnes of ash.
• These emissions produce much environmental damage including global warming through the green house effect.
• Similarly for hydel projects large environmental effects and loss of land occurs. For the Kaiga nuclear power plant a land requirement of 0.06 hectare/MWe was required whereas for the hydel projects in Karnataka forest area cleared is 18.6 hectares/MW or a factor 300 times higher.
• Global levels of the main green house gases - carbon dioxide, the chlorofluorocarbons, methane and nitrous oxide are increasing as a result of rising energy demand and industrial expansion. Carbon dioxide from fossil fuel combustion accounts for about 40 percent of the global warming. Hence control of green house gas emissions is essential. In addition to increase of energy production and utilisation efficiency it is essential to substitute fuels like coal by nuclear power.

Clean Energy Options and Nuclear Safety

It is well established that there is a direct relationship between energy consumption and human development index. In India, our per capita consumption of electricity is almost one-fourth of the world average. Thus to achieve our long cherished goal of becoming a Developed nation we need to move forward for strengthening the energy infrastructure at a much higher pace while simultaneously addressing environmental issues.

The growing appetite for energy in recent times has been constrained by a rapidly diminishing conventional sources such as Oil and Coal. Globally, nearly 70% of electricity is generated from fossil fuels and so it is in India, too. As a result, electricity accounts for about 40% of global energy-related Green House Gas emissions. And these emissions are expected to grow to 58% by 2030. According to GHG Emission 2007 Report of Ministry of Environment & Forests, India ranks 5th in aggregate GHG emissions in the world, behind USA, China, EU and Russia. However, the emissions of USA and China are almost 4 times that of India. Scientists believe that a temperature rise above 2-2.5 degrees due to the increasing GHG emissions risks serious consequences. The Inter-governmental Panel on Climate Change (IPCC) has predicted that with rising temperatures, the frequency of heat waves, droughts, and heavy rainfall events will only increase. This, in turn, will adversely affect agriculture, forests, water resources, industry and also human health and settlements.

Presently, of the total installed electricity generation capacity of just over 1.9 lakh Mega Watts in India, about 56% is met by Coal, 10% by Gas & Oil, 21% Hydro, 11% by Renewable Sources and less than 3% by Nuclear energy. In order to emerge as a global super power and strive for a sustained growth of above 9 percent through 2031, we may need to attain growth of primary energy supply by 3 to 4 times and electricity supply by 5 to 7 times of present consumption. However, energy security concerns will also be significant as over 90% liquid fossil fuel and up to 45% of coal requirements would need to be imported.

One of the major challenges is to provide a large proportion of our country`s population with access to energy sources which are clean, convenient & affordable. Renewable sources including Solar, Wind, Biomass, etc. and Nuclear Energy which are clean & green energy options, have vast potential in meeting national demand and addressing the growing concerns about depleting oil reserves and harmful effects of Green House Gas emissions. The challenge before us is to make the renewable energy and nuclear energy technologies sustainable, convenient, efficient, safe and affordable.

We are blessed with a significant renewable energy resource base. Estimates indicate that a potential of over 200 Giga Watts (GW) electric power capacity exists from Wind Energy. Solar Energy has the potential to generate around 50 Mega Watts per square km. of area. Small hydro and Biomass could further augment the capacity by 40 GW.

India today stands among the top 5 countries of the world in terms of renewable energy capacity. We have an installed base of over 23 GW, which is over 11% of total power generation capacity and contributes over 6 per cent to the electricity mix. National Action Plan on Climate Change mandates increasing share of renewable power in the electricity mix to 15% by the year 2020. While the impact of renewable energy from the perspectives of energy security & environmental sustainability is well appreciated, what is often overlooked is its capacity to usher in energy access for the most disadvantaged people. However, most renewable energy sources including wind and solar power are variable and may not always be available for dispatch when needed.

The integrated energy policy of the country recognizes that nuclear energy is capable of providing long-term energy security and is based upon judicious utilization of the nuclear resource profile of the country. We now have 20 nuclear power reactors in the country with an installed capacity of 4780 MW of electricity.

As the major source of electricity generation in the country at present is Coal, the role of nuclear power is to supplement the base load generation from coal fired power plants at locations away from coalmines and, in the long term, to utilize the abundant Thorium resources to generate electricity of over 650,000 Tonnes which is more than one-fourth of the total deposit of Thorium in the world. Comparatively we have barely 1% of the world Uranium deposits which is currently being put to effective use. It is also estimated that Thorium can generate (through uranium-233 producible from it) 8 times the amount of energy per unit mass compared to (natural) Uranium.

The Fukushima accident has shaken given rise to safety concerns in respect of nuclear power plants when exposed to an external event of a very high magnitude. We are now facing a new challenge to restore this confidence even though there has been no casualty due to radiation exposure though the loss of life in Japan exceeded 20,000 due to earthquake and tsunami. Following the Fukushima tragedy, which falls in seismic zone 4 and 5, Government of India has mooted a comprehensive review of the safety standards of all our nuclear power installations which are as such located in Zone 2 expect the one at Narora which is in zone 3. The results of the safety reviews that were mandated by the Government have been made public and several recommendations have already been implemented. A roadmap has been prepared for implementing rest of the recommendations. It has also been decided to invite missions of International Atomic Energy Agency (IAEA) namely Operational Safety Review Team (OSART) and Integrated Regulatory Review Service (IRRS) for peer review of safety of our nuclear power plants and of the regulatory system respectively. A Bill to confer statutory status to the regulatory authority has also been introduced in the Parliament.

In India, a systematic approach using well-defined principles is followed in the design of nuclear power plants. While making provisions for the required safety features, Nuclear Power Plants are constructed in accordance with the highest quality standards. Commissioning of the systems is carried out to test and demonstrate adequacy of each system and the plant as a whole by actual performance tests to meet the design intent before commencing the operation of the plant. Operation of the plant is carried out as per defined and approved procedures in the technical specifications that are thoroughly reviewed and approved by Atomic Energy Regulatory Board. The regulatory framework in India is indeed robust. All these measures are for ensuring safe operation of the plants, safety of occupational workers, members of public and protection of environment. With sound design, trained and experienced operating staff and safety conscious approach to operation, the possibility of any accident is remote. However, to meet any unlikely situation of an accident, well thought-out formal emergency preparedness plans are in place.

All nuclear power plant sites in our country are self-sufficient in the management of radioactive waste. Adequate facilities have been provided for handling, treatment, storage and disposal of nuclear wastes generated at these sites. Management of radioactive wastes is carried out in conformity with regulatory guidelines based on internationally accepted principles.

Undoubtedly, for transition to a highly efficient economy, utilizing renewable & nuclear energy is essential. Shifting to a sustainable energy system based on such options will require replacing a complex, entrenched energy system with innovative policy instruments. Various kinds of fiscal incentives, capital subsidies, generation based incentives; preferential tariffs, etc. are some of the measures. India has already put a cess of Rs.50 per tonne of coal consumption and from the proceeds has created a National Clean Energy Fund to support clean energy development.

Research and development in nuclear & renewable energy is another major area of action. Larger scale applications of new energy systems would depend on how rapidly the costs decline and efficiencies increase. It, in a way, leads to creation of national energy innovation system that involves prominent research and academic institutions as well as industry.

Types of Reactors

A variety of reactor types, characterized by the type of fuel, moderator, and coolant used, have been built throughout the world for the production of electric power.

Based on moderators

• Light water reactor (LWR): These power reactors use nuclear fuel in the form of uranium oxide isotopically enriched to about 3 percent uranium-235. The moderator and coolant are highly purified ordinary water. A reactor of this type is called a light water reactor (LWR).
• Pressurized water reactor (PWR): In the pressurized water reactor (PWR), a version of the LWR system, the water coolant operates at a pressure of about 150 atmospheres.
• Boiling Water Reactor (BWR): In boiling water reactor (BWR), a second type of LWR, the water coolant is permitted to boil within the core, by operating at somewhat lower the boiling pressure. As in the PWR, the condenser cooling water has a separate source, such as a lake or river.
• Advanced Heavy Water Reactor (AHWR):The proposed design of the AHWR is that of a heavy-water-moderated nuclear power reactor that will be the next generation of the PHWR type. It is being developed at Bhabha Atomic Research Centre (BARC), in Mumbai, India and aims to meet the objectives of using thorium fuel cycles for commercial power generation. The AHWR is a vertical pressure tube type reactor cooled by boiling light water under natural circulation. A unique feature of this design is a large tank of water on top of the primary containment vessel, called the gravity-driven water pool (GDWP).

Heavy Water Production

Heavy Water Board produces heavy water which is used in the pressurized heavy water reactors as moderator and coolant. Heavy Water (D20) production facilities in India : Tal (Maharashtra), Hazira (Gujarat), Kota (Rajasthan), Tuticorin (Tamil Nadu), Nangal (Punjab), Talcher (Orissa), Baroda (Gujarat).

Three Generation of Reactors

• First generation reactors: designed to have capacity of 250 mw/day established at Rawatbhata, Narora, and Kalpakkam Kaiga. Use natural Uranium as fuel, D₂0 as coolant and moderator. All are PHWR and produce Plutonium as by product.
• Second generation reactors : 500 mw; First at Tarapore in Maharashtra, Breeder Reactor, Pu as fuel, will convert Thorium into U-233 uses liquid Na as Coolant.
• Third generation reactors: Capacity of 1000 mw, U-233 as fuel (Thorium will be converted into U-233). So it will be Thorium Cycle reactors. Light water as coolant and moderators.

Canadian deuterium-uranium reactor (CANDU)

In the initial period of nuclear power development in the early 1950s, enriched uranium was available only in the United States and the Union of Soviet Socialist Republics (USSR). The nuclear power programs in Canada, France, and Great Britain therefore centered about natural uranium reactors, in which ordinary water cannot be used as the moderator because it absorbs too many neutrons. This limitation led Canadian engineers to develop a reactor cooled and moderated by deuterium oxide (D2O), or heavy water. The 20-reactor Canadian deuterium-uranium reactor (CANDU) system has operated satisfactorily, and similar plants have been built in India, Argentina, and elsewhere.

Propulsion Reactors

Nuclear power plants similar to the PWR are used for the propulsion plants of large surface naval vessels such as the aircraft carriers. The United States, Great Britain, Russia, and France all have nuclear-powered submarines with such power plants. India has joined the club with its nuclear powered submarine INS Arihant.

Research Reactors

Research Reactors are experimental reactors used for research to develop nuclear sub-system and designing commercial power reactors and further uses of radio-isotopes. At present eight research reactors are functional.BARC’s reactor programme provides for meeting the growing demand of radioisotopes, and to provide facilities for basic and applied research, development of advanced reactors and associated technologies. The research reactors DHRUVA, CIRUS and APSARA at Trombay have been used for the production of radioisotopes besides their use in basic and applied research, irradiation testing of fuels & materials, and training. The KAMINI reactor utilised for irradiation, activation analysis of samples and neutron radiography of specimens.

Various reactors include

• APSARA:  Operational in 1957, First reactor in Asia, First reactor of India, First indigenous reactor; capacity of 1 MW; Its commissioning started India’s nuclear Programme situated at Trombay.
• CIRUS: Commissioned in 1960, at Trombay with Canadian assistance capacity of 40 MW; used for isotope production, material testing and conducting engineering experiment. Important facility for isotope production.
• ZERLINA: Zero Energy Reactor, built in 1961 indigenously, situated at Trombay, capacity 100 MW; decommissioned in 1984.
• PURNIMA – I: Commissioned in 1984, Plutonium fuelled reactor at Trombay, capacity 100 MW.
• PURNIMA – II: Modified version of PURNIMA – I by BARC at Trombay in 1990; uses U-233 fuel in solution form from Thorium; capacity 100 MW.
• KAMINI: Kalpakkam Mini Reactor; jointly by BARC and Indira Gandhi Research Centre (IGRC) Kalpakkam, Commissioned in 1993 (became critical 1996), Capacity of 30 MW; uses U-233 as fuel (produced by PURNIMA – II); only reactor in world using U-233 as fuel; its 3^rd generation reactor (use vast reserves of Thorium). KAMINI his further lead to designing of AHWR. It used light water as Coolant and moderator. Kamini is source of neutrons for radiography.
• DHRUVA: Largest research reactor at Trombay by BARC in 1985; capacity 100 MW; used natural Uranium as fuel D₂0 (heavy water) as coolant and moderator; used for research in advanced nuclear physics and for isotope production. Largest facility to produce isotopes like I-131, I-125, Cr -51 for medical uses.
• FBTR (Fast Breeder Test Reactor) :First reactor of 2nd generation of Nuclear Power Programme; commissioned in 1985; built by Indira Gandhi Atomic Research Centre at Kalpakkam based on the design of Rhapsodic Reactor of France; Capacity 42 MW,; built to convert Thorium to U -233; First reactor in the world to use Uranium- Plutonium-Carbide fuel; uses liquid sodium as coolant. Its development has led to designing of PFBTR at Kalpakkam. IAEA has certified its design; construction started in Jan 2003 and Commissioned in 2006-07.

Breeder Reactors

• The special features of a fast breeder reactor is that the nuclear fission of plutomium caused by fast neutrons, releases more number of neutrons in the fission process, than in uranium 235 in the thermal reactors.
• Further the additional neutrons released, combined with the fact that absorption of fast electrons is less in coolant and structural materials, produce more fuel than is consumed in the generation of electricity, increasing the fissile materials quantity, resulting in increased installed capacity of FBR itself.
• For example 0.6% of natural uranium utilised in electricity energy production in PHWR, increases to over 75% in FBR.
• Hence the nuclear energy resource through FBR in the world [2000 million tonnes of oil equivalent (mtoe)] would be much larger than the combined energy resource of coal (517 mtoe), oil (138 mtoe) and gas (126 mtoe), identified in the whole world so far.
• As far as India is considered, the normal energy resources are oil (2btce), gas (2btce), Hydro (84 Gwe), coal (200 bt), uranium (180 btce in FBR), thorium (920 btce in FBR).
• As such coal and nuclear are the only two large resources available for energy generation India. Therefore Fast Breeder Reactor (FBR) provides a long term energy security to the country.

India Developing Thorium Based Fast Breeder Nuclear Reactor

• Fast Thorium Breeder Reactor (FTBR) is being developed by V. Jagannathan and his team at the Bhabha Atomic Research Centre (BARC) in Mumbai
• A paper was submitted to the International Conference on Emerging Nuclear Energy Systems (ICENES) held June 9-14, 2008 in Istanbul.
• Power reactors of today mostly use a fissile fuel called uranium-235 (U-235), whose 'fission' releases energy and some 'spare' neutrons that maintain the chain reaction. But only seven out of 1,000 atoms of naturally occurring uranium are of this type. The rest are 'fertile', meaning they cannot fission but can be converted into fissionable plutonium by neutrons released by U-235.
• Thorium, which occurs naturally, is another 'fertile' element that can be turned by neutrons into U-233, another uranium isotope. U-233 is the only other known fissionable material.
• It is also called the 'third fuel'. Thorium is three times more abundant in the earth's crust than uranium but was never inducted into reactors because - unlike uranium - it has no fissionable atoms to start the chain reaction.
• According to the scientists, their FTBR design exploits the fact that U-233 is a better fissile material than plutonium.
• Secondly, they were able to maximise the breeding by putting the fertile materials inside the core rather than as a 'blanket' surrounding the core as done traditionally. 'At present, there are no internal fertile blankets or fissile breeding zones in power reactors operating in the world,' the paper claims.
• Thorium-based fuels are yet to be commercialized. France is also studying a concept of 'molten salt reactor' where the fuel is in liquid form, while the US is considering a gas-cooled reactor using thorium.
• The handful of fast breeder reactors (FBRs) in the world today - including the one India is building in Kalpakkam near Chennai - use plutonium as fuel.
• The India-US civilian nuclear deal is expected to enable India import uranium and reprocess spent fuel to recover plutonium for its FBRs.
• But the FTBR still needs an initial inventory of plutonium to kick-start the thorium cycle and eventually to generate electricity.
• The conditional go ahead to reprocessing under the ages of National reprocessing Facility as a part of Indo-Us nuclear deal needs to be operationalised soon.
• 'The US and Russia have piles of plutonium from dismantled nuclear weapons India should be allowed to borrow this plutonium needed to start our breeders.

Significant progress was made in the developments of fuel for Prototype Fast Breeder Reactor (PFBR). This included fabrication and characterization of mixed uranium-plutonium oxide fuel pellets of different compositions. After the successful demonstration of Sol-gel microsphere pelletisation technique for production of good quality high-density pellets suitable for PHWR fuel, a large-scale uranium-oxide microspheres preparation was undertaken at Trombay.

Fabrication

The Nuclear Fuel Complex (NFC), Hyderabad meets the fuel and zircaloy requirements of all the nuclear power reactors in the country. In addition, NFC manufactures stainless steel tubes for other industrial applications.

Fuel Reprocessing

The Fuel Reprocessing Plants at Trombay, Tarapur and Kalpakkam for the separation of uranium-233 from thorium rods irradiated at CIRUS and DHRUVA reactors approached completion and revamping of PREFRE Plant at Tarapur continued.

IGCAR’s Lead Mini Cell (LMC), a demonstration facility for reprocessing of FBTR fuel on laboratory scale, reached advanced stage of completion.

Waste Management

In nuclear reactors a number of radioactive waste products are produced as the fuel is used up. Prominent among them are plutonium, strontium, cesium and barium which are produced by fission of uranium and neutron irradiation.There are two types of nuclear wastes

• High-level waste which will be radioactive for thousands of years. High level waste is sealed in concrete and steel tanks and stored deep underground. High level waste is also now being converted to glass. This involves dissolving the spent fuel in acid, converting it into a glassy form, enclosing it in metal containers, and burying it underground. But scientists have not yet found out how to make the rubbish completely safe.
• Low-level waste which is less radioactive. When the fuel elements are first removed from the reactor, they are allowed to cool long enough for the radioactivity of the fission products to decay to acceptable levels, a process usually involving their immersion in water for a month or so. The waste is then sent to nuclear reprocessing plants where useful uranium and plutonium are separated for reuse.Some low-level waste is pumped straight into the sea.

Waste Management Facilities at Tarapur, Trombay and Kalpakkam.A major milestone of the radioactive waste management programme was the inauguration of country’s first Solid Storage Surveillance Facility (S3F) at Tarapur. Solid Storage Surveillance is an important stage prior to the disposal of higher level wastes in deep geological repository. India is the fourth nation in the world to have such a hi-tech facility.

At the Waste Immobilization Project, Trombay an indigenously designed and manufactured for immobilization of highly active radioactive wastes in glass matrix was successfully commissioned.

• The construction of the other WI plants at Trombay and Kalpakkam also made good progress.
• Arrangements For Safety Of Nuclear Plants  And Mining
• Currently, every nuclear power plant is inspected once in a year.
• Monitoring of radiological safety of the workers at all nuclear power plants
• Continuously measuring of concentration of radioactivity in environment through samples.
• continuous review of reports by Atomic Energy Regulatory Board (AERB).
• Directorate of Regulatory Inspection and Enforcement (DRI&E) with effect from January 1, 1994 to augment the inspection and related activities at atomic power plants
• At Trombay, safety related technology development is done for augmentation of Facility for Accident Scenarios
• The radiological safety support to various nuclear power plants and other fuel cycle facilities by BARC.
• The DAE have drawn up comprehensive Emergency Preparedness and Response Plans to handle postulated emergency scenarios like Plant and Site Emergencies.
• UCIL has put in place measures necessary for radiological safety and the radiation levels.

Thorium deposits in India

• By itself is not a fuel but it turns into U-233 an excellent nuclear fuel; extracted from Monazite sand along the coast of Kerala, Tamil Nadu, Andhra Pradesh, Orissa. One of the largest deposits of 3.6 lakh/tones; considered to be of high grade.
• Noteworthy uranium occurrences were located by ground radiometric surveys in parts of West Khasi Hills district (Meghalaya); Solan and Sirmour districts (Himachal Pradesh) and Cuddapah district (Andhra Pradesh).
• Other identified potential areas are parts of Bhima basin (Karnataka) and Vindhyan basin (Uttar Pradesh and Bihar), along the coastal tracts of Andhra Pradesh and Kerala.

Uranium deposits in India

• Meghalaya: Domiasiat in West Khasi Hill District and Wahkyn.
• Andhra Pradesh: Nalgonda, Guntur, Cuddapah, Chittoor.
• Gujarat :    Garunal in Panchmahals District.
• Rajasthan: Putholi in Chittorgarh district.
• Karnataka: Gogi in Gulbarga district.