India has vast deposits (about 50 per cent of the world) of thorium which can yield up to 200,000 GWe/year of electrical energy easily meeting her energy requirements of the new century.
Nuclear Power Minerals:
Uranium occurs as disseminations and impregnations in Archaean crystalline schists and Pre- Cambrian metamorphosed slates and phyllites in Bihar and some parts of the Himalayas.
It also occurs in pegmatites; but a more reliable and substantial source of uranium lies in the deposits of monazite sands both beach and alluvial. Compounds of this highly strategic metal of increasing value as atomic fuel in nuclear power reactors are found in India associated principally with crystalline, igneous and metamorphic rocks.
Here uranium mineralization is associated with sulphidic copper and oxidized iron, rather than with gold, lead, zinc or vanadium ores. The uranium ores of India belong to three categories:
(1) Pegmatitic Pitchblende and complex niobates, tantalates and titanates of uranium, e.g. samarskite, fergusonite, brannerite, etc.
(2) Uranium compounds impregnating rocks that have been involved in orogenic movements giving rise to larger shear and thrust-planes, e.g. along the Singhbhum Copper Belt in Bihar and the tightly compressed rocks of the Aravalli synclinorium in Rajasthan.
(3) Monazite occurring in large beach-sand deposits on the east and the west coasts of India and in some places in Bihar carries a small fraction from 0.2 to 0.4 per cent of uranium oxide.
The need for the development of nuclear energy in India arises from the country’s meagre power resources in the fossil fuels (only 0.6% of oil and gas and 6% of coal reserves of the world) and hydro electricity with numerous social and environmental problems and long gestation period.
The main source of this rare heavy metal, a likely future substitute for uranium in atomic energy reactors, is monazite, which contains up to 10 per cent of thoria and 0.3 per cent of urania; other minerals carrying thorium is thorianite (ThO2-70 per cent with uranothorianite).
The resources of India in thorium, the ‘fertile’ fission metal and the potential atomic fuel of the near future, are of considerable magnitude.The very rare mineral thorianite (ThO2-70 per cent), which is found in the crystalline rocks of Sri Lanka in commercial quantity, is found as a rare constituent of some Kerala ilmenite sands.
Besides its use in a number of valuable metallurgical alloys mentioned under ‘Beryl’ elsewhere, beryllium oxide is of use as a ‘moderator’ in nuclear reactors for atomic power generation. The reserves of beryl in India being considerable, it will be able to meet all indigenous demands for atomic as well as metallurgical uses.
This light metal has sprung into strategic prominence in experiments on the production of atomic energy through thermonuclear fusion of light elements. The former mineral is fairly widespread in the mica belt of Bihar, Madhya Pradesh and Rajastfian, the reserves of which are ample for future requirements.
A deposit of lithium-mica, lepidolite, has been found in the Bastar region of Madhya Pradesh- Orissa in the form of boulders of lepidolite aggregating a few hundred tonnes. It is capable of supporting a small industry for the manufacture of lithium salts rather than for the extraction of lithium metal.
India possesses large resources of this rare metal in the mineral zircon (Zr02-65 per cent) which forms about 6 per cent of the well-known ilmenite beach sands of the Indian coasts, particularly the Kerala coast. Zircon sand contains baddeleyite, another zirconium mineral. Zircon concentrates also occur in the alluvial soil in Ranchi and Hazaribagh districts of Bihar.
Not occurring free in nature, this greyish metal is extracted from the mineral zircon, which is silicate of zirconium. Zirconium is alloyed with iron, silicon, tungsten, etc. It is also used for removing oxides and nitrides from steel and in making flash lamps of various kinds. Zirconia, the oxide of zirconium, is used as a refractory in abrasive, in enamels, etc.
Pure zirconium possesses some valuable properties; resistance to heat and corrosion and complete inability to capture thermal neutrons. It has, therefore, attained prominence lately as a structural and cladding material in atomic reactors. Crytolite is a radioactive variety, containing a small percentage of U308. An exportable surplus of zircon exists in India (total reserves: 10,160,000 tonnes).
Ilmenite is the chief ore. Reserves of ilmenite (TjO2—50-60 per cent) are computed at nearly 152 million tonnes. Though these reserves are large, they are by no means inexhaustible at the rate of depletion that was prevalent in the years previous to World War II.
Kerala State has started manufacture of titanium paints locally on a small scale. Titanium, ‘the metal of the future’, possesses some extraordinary properties for use in industry and commerce as well as for defence purposes.
India’s Nuclear Power Programme:
Nuclear power has played an important role in the power development in all the developed countries and it forms over 17% of the total installed power capacity in the world. About 30-40% of the power development in the Asia-Pacific region is of nuclear type.
To meet the long term energy needs of the country, a three-stage nuclear power programme was formulated in 1954. The programme aimed at using natural resources of uranium and thorium available in the country for power generation as below:
Stage I: 10,000 MW through natural uranium fuelled pressured heavy water reactors;
Stage II: Fast breeder reactors with plutonium as fuel and thorium as blanket for breeding U-233; and
Stage III: Breeder reactors using U-233 as fuel aid thorium as blanket.
Nuclear power production began in India with the commissioning in 1969, of the Tarapur Atomic Power Station (TAPS 420 MW) at Tarapur in Maharashtra. This station had two boiling water reactors (BWRs) and it was set up with US help on a turnkey basis. The US discontinued its cooperation in 1974. The Nuclear Power Board with the support of Indian industries successfully developed the required technology and the plant is operating successfully.
As is obvious from the distribution of the nuclear power stations, the greatest advantage of this source of power is that it may be located anywhere and thus the areas away from localised sources of fossil fuel may benefit. It is also very economical. A unit of electricity at Tarapur and Kalpakkam costs 40 to 58 paise compared with 60 to 90 paise per unit from the thermal plants in the respective regions. However, the cost from new nuclear power plants is gradually rising, At Narora it costs 118 paise.
NPCIL is responsible for design construction commissioning and operation of nuclear power reactors. Including RAPS-1 of 100 MW which is owned by the government) and 6 reactors under construction with capacity of 4800MW. The total generation in the calendar year 2011 was 32405 million units (MU). NPCIL is presently operating 20 nuclear power reactors with an installed capacity of 4780 MW.
Tarapur Power Station:
For putting up India’s first power stations, the Tarapur site, near Mumbai in western India was chosen in 1958 after a comprehensive survey of a number of possible sites all over the country. Two boiling water reactors (BWR) of 200 MW each were purchased from USA in 1964 as a turn key project, but with maximum participation of Indian personnel in all stages of design, construction, testing and training operations.
The station went into commercial operation in late 1969. However, since 1970 the enriched uranium fuel elements for the station are being fabricated in India based on imported hexafluoride.
As the Tarapur reactors are amongst earlier BWRs, several modification have been progressively carried out based on operational experience to ease operation and maintenance of equipment, reduce personnel radiation exposures, minimise radioactive discharges to the environment and improved reliability and overall performance of the station.
In 1960 it was decided that first stage natural uranium reactors would be of the heavy water type. These reactors would enable the maximum utilisation of the country’s limited uranium reserves. By 1962 it was decided that the second atomic power station would be located near Kota in the State of Rajasthan and that the two 220 MW reactors would be based on the Canadian design which at that time was considered as proven.
Canada was responsible for the design and supply of major equipment for the first unit while India took up the responsibility for construction and installation activities. Right from the start of this project, efforts were made to manufacture as many components as possible in India.
Thus the Rajasthan station opened up opportunities for many Indian industries to enter the nuclear power field and develop sophisticated technologies indigenously. Some of the nuclear equipment manufactured in the country for the second unit include the reactor vessel (calandria), end shields, dump tank, shield tank, steam generators, fuelling machines, sealing and shield plugs, etc.
Kalpakkam Power Station:
The third power station near Chennai consists of two units of 235 MW each. Though these reactors are similar to the Rajasthan units, several design modifications have been introduced for reasons of economy and due to special conditions at the site.
Some of the modified features include pre-stressed concrete reactor containment building, stainless steel end shields, submarine tunnel for drawing cooling water from the sea and an indoor switchyard. The Madras station marks the coming of age of the Indian atomic energy programme, as full responsibility for the execution of the project, including design, construction, commissioning the operation rests with Indian engineers and scientists.
Narora Power Station:
The Fourth is the 2?235 MW reactors at Narora in Uttar Pradesh. The first unit of the country’s fifth twin unit PHWR station set up at Kakrapar has just attained critically.
Kaiga Power Station:
Work has been initiated recently by the newly formed Nuclear Power Corporation at a new site, Kaiga in Karnataka. The plant has been in operation since 2000 and is operated by Nuclear Power Corporation of India. It has four units with one still under construction. All of the four are small sized CANDU plants of 220 MW.
Kakrapar Atomic Power Station:
It has in Gujarat near Surat and consists of two 220 MW pressurized water reactors with heavy water as Moderator (PHWR). KAPS went critical as 3 September 1992 and began commercial electricity production in September 1985. In Jan. 2003, the CANDU Owners Group (COG) distinguished KAPS -1 as the world-wide best PHWR of its class.
Project under Construction:
Kudankulam Nuclear Power- 1 and 2 Rajasthan Atomic power Project – 7 and 8.
A nuclear reactor that produces the same kind of fissile material as it burns, as called the breeder reactor. Breeder reactors while using plutonium as fuel can produce more Pu-239 than it consumes by converting non-fissionable U-238 that predominates- in natural uranium ore.
Fast Breeder Reactors:
Under the second stage of India’s nuclear programme, fast breeder reactors will be used for power generation. For the development of such reactors the Indira Gandhi Centre for Atomic Research (IGCAR) was set up in 1971. The Centre has successfully built a East Breeder Test Reactor using indigenously developed mixed uranium-plutonium carbide fuel core.
Thorium Based Reactors:
Thorium will be used as fuel or power generation in the third stage of the Indian nuclear power programme. Utilisation of throium in the research reactors and power reactors for the production of uranium-233, a nuclear fuel has been established along with the facilities for its separation from irradiated thorium research radiography.
The neutron source reactor ‘Kamini’, which uses uranium-233 obtained from irradiated thorium, attained full power level of 30 kwt. It will be used for neutron radiography irradiated fuel.
The reactor has been set up by the BARC at Kalpakkam. Thorium fuel bundles have also been successfully used in the Kakrapara Atomic Power Station for flux flatting. Design of an advanced stage heavy water reactor for utilisation of thorium is making good progress at the BARC.
Heavy Water Production:
Since the pressurised heavy water reactors (PHWRs) generating nuclear power, use heavy water as a moderator and coolant, a small plant using electrolysis (of water technology was set up at Nangal (Punjab) in 1961. Since then, seven more large units have been installed at Baroda and Hazira in Gujarat, Kota in Rajasthan, Manuguro in Andhra Pradesh, Talcher in Orissa, Thai in Maharashtra and Tuticorin in Tamil Nadu.
The designing, construction and operation of the heavy water plants based on ammonia-hydrogen exchange and indigenously developed water-hydrogen sulphide exchange process, is vested with the Heavy Water Board.
Besides meeting the home demand for heavy water fully, the DAE has begun exporting it, commencing with the first consignment to South Korea. A Heavy Water Reconcentration facility set up in 1962, upgrades the used, degraded heavy water from research reactors. Nineteen such units are in operation in the country presently.
Atomic Minerals Mining:
The Atomic Minerals Division (AMD) of the Department of Atomic Energy has been the sole agency engaged in the exploration and mining of uranium in the country for the last 50 years.
It has discovered reserves of 78,000 tonnes of uranium oxide and it has mines at Jaduguda, Bhatin and Narwapahar in Bihar, which are operated by the Uranium Corporation of India Ltd (UCIL), a subsidiary of the DAE. Uranium ore has also been discovered by the AMD at Domiasiat (Meghalaya) and Lambapur-Yellapur and Lummalapalla (Andhra Pradesh).
The UCIL had started operations with only’ one underground mine and a processing mill at Jaduguda (Bihar). It has opened two more mines at Bhatin and Narwapahar. Another mine will be opened at Domiasiat. The UCIL also runs two recovery plants at Rakha and Mosabani (Bihar) to recover uranium from copper tailings from the Hindustan Copper Complex Plant.
The Indian Rare Earths (IRE), another public sector undertaking of DAE, has been engaged since 1950, in mining and processing of mineral sands containing thorium and rare earth minerals.
The company has three mineral sands separation plants at Manavalakurichi (Kerala), Chavara and Chatrapur (Orissa), which produce ilmenite, rutile, monazite, zircon and garnet.
A rare earth’s plant at Alwaye (Kerala) produces rare earths chlorides. The IRE manages the thorium mills at Trombay. Placer deposits are commercially exploited by the IRE which supplies thorium ores to the throium plant at Trombay and Zircon for production of zircaloy components.
Nuclear Power Policy of India:
The Nuclear Power Corporation of India was established in 1989 to realise the target of generating 9000 MW of electricity. For this purpose three Nuclear Reactor Centres have been established. These are as follows:
(i) Accelerated exploitation of domestic conventional energy resources;
(ii) Intensification of exploration to achieve indigenous production of oil and gas;
(iii) Management of demand of oil and other forms of energy;
(iv) Energy conservation and management:
(v) Optimization and utilisation of existing capability in the country;
(vi) Development and exploitation of renewable sources of energy to meet energy requirements of rural communities;
(vii) Intensification of resources and development activities in new and renewable energy resources; and
(viii) Organisation of training for personnel engaged at various level in the energy sector.
It is not only the use of fossil fuels that pollutes our surroundings; even the use of nuclear energy gives rise to pollutants and hence, pollutes our environment. In fact, the pollution caused by the use of nuclear energy from fission process is much more damaging than the pollution caused by burning fossil fuels. The fuels like U-235 are active substances, which keep on emitting some nuclear reactions all the time.
The dangerous nuclear radiations can enter into the environment by leakage from nuclear reactors where fission of U-235 is going on. These nuclear radiations can damage and cause irreparable damage to cells and in some cases even lead to death.