Fuel reserves and research capability
According to a report issued by the
IAEA, India has limited uranium reserves, consisting of approximately 54,636 tonnes of “reasonably assured resources”, 25,245 tonnes of “estimated additional resources”, 15,488 tonnes of “undiscovered conventional resources, and 17,000 tonnes of “speculative resources”. According to
NPCIL, these reserves are only sufficient to generate about 10 GWe for about 40 years.
[23] In July 2011, it was reported that a four-year-long mining survey done at
Tummalapalle mine in
Kadapa district near
Hyderabad had yielded confirmed reserve figure of 49,000 tonnes with a potential that it could rise to 150,000 tonnes.
[24] This was a rise from an earlier estimate of 15,000 tonnes for that area.
[25]
Although India has only around 1–2% of the global
uranium reserves,
thorium reserves are bigger; around 12–33% of global reserves, according to IAEA and US Geological Survey.
[26][27][28][29] Several in-depth independent studies put Indian thorium reserves at 30% of the total world thorium reserves.
[3][4][5][6]
As per official estimates shared in the country's Parliament in August 2011, the country can obtain 846,477 tonnes of thorium from 963,000 tonnes of ThO2, which in turn can be obtained from 10.7 million tonnes of
monazite occurring in beaches and river sands in association with other heavy metals. Indian monazite contains about 9–10% ThO2.
[2] The 846,477 tonne figure compares with the earlier estimates for India, made by IAEA and US Geological Survey of 319,000 tonnes and 290,000 to 650,000 tonnes respectively. The 800,000 tonne figure is given by other sources as well.
[30]
It was further clarified in the country’s Parliament on 21 March 2012 that, “Out of nearly 100 deposits of the heavy minerals, at present only 17 deposits containing about 4 million tonnes of monazite have been identified as exploitable. Mineable reserves are ~70% of identified exploitable resources. Therefore, about 225,000 tonnes of thorium metal is available for nuclear power programme.”
[31]
India is generally considered as the leader of thorium based research in the world.
[32][10] It is also by far the most committed nation as far as the use of thorium fuel is concerned, and no other country has done as much neutron physics work on thorium.
[33] The country published about twice the number of papers on thorium as its nearest competitors during each of the years from 2002 to 2006.
[7] Bhabha Atomic Research Centre (BARC) had the highest number of publications in the thorium area, across all research institutions in the world during the period 1982-2004. During this same period, India ranks an overall second behind the United States in the research output on Thorium.
[34] Analysis shows that majority of the authors involved in thorium research publications appear to be from India.
[35] According to
Siegfried Hecker, a former director (1986–1997) of the
Los Alamos National Laboratory in the
U.S., "India has the most technically ambitious and innovative nuclear energy programme in the world. The extent and functionality of its nuclear experimental facilities are matched only by those in
Russia and are far ahead of what is left in the US."
[10]
Stage I – pressurised heavy water reactor
In the first stage of the programme,
natural uranium fuelled
pressurised heavy water reactors (PHWR) produce electricity while generating
plutonium-239 as by-product. PHWRs was a natural choice for implementing the first stage because it had the most efficient reactor design in terms of uranium utilisation, and the existing Indian infrastructure in the 1960s allowed for quick adoption of the PHWR technology.
[36] India correctly calculated that it would be easier to create heavy water production facilities (required for PHWRs) than uranium enrichment facilities (required for LWRs).
[37] Natural uranium contains only 0.7% of the fissile isotope
uranium-235. Most of the remaining 99.3% is
uranium-238 which is not fissile but can be converted in a reactor to the fissile isotope plutonium-239. Heavy water (
deuterium oxide, D 2O) is used as
moderator and
coolant.
[38]
Indian uranium reserves are capable of generating a total power capacity of 420 GWe-years, but in order to ensure that existing plants get a lifetime supply of uranium, it becomes necessary to limit the number of PHWRs fueled exclusively by indigenous uranium reserves. US analysts calculate this limit as being slightly over 13 GW in capacity.
[39] Several other sources estimate that the known reserves of natural uranium in the country permit only about 10 GW of capacity to be built through indigenously fueled PHWRs.
[40][41][42][43] The three-stage programme explicitly incorporates this limit as the upper cut off of the first stage, beyond which PHWRs are not planned to be built.
[44]
Almost the entire existing base of Indian nuclear power (4780 MW) is composed of
first stage PHWRs, with the exception of the two
Boiling Water Reactor (BWR) units at Tarapur.
[45][46] The installed capacity of
Kaiga station is now 880 MW, making it the third largest after
Tarapur (1400 MW) and
Rawatbhata (1180 MW).
[46] The remaining three power stations at
Kakrapar,
[47] Kalpakkam[48] and
Narora[49] all have 2 units of 220 MW, thus contributing 440 MW each to the grid. The 2 units of 700 MWe each (PHWRs) that are under construction at both
Kakrapar[47][50] and
Rawatbhata,
[51] and the one planned for Banswara
[52] would also come under the first stage of the programme, totalling a further addition of
4200 MW. These additions will bring the total power capacity from the first stage PHWRs to near the total planned capacity of 10 GW called for by the three-stage power programme.
[44][45]
Capital costs of PHWRs is in the range of Rs. 6 to 7 crore ($1.2 to $1.4 million) per MW,
[53] coupled with a designed plant life of 40 years. Time required for construction has improved over time and is now at about 5 years. Tariffs of the operating plants are in the range of Rs. 1.75 to 2.80 per unit, depending on the life of the reactor.
[54] In the year 2007–08 the average tariff was Rs.2.28. The tariffs of new plants to be set up, both indigenous and imported, are expected to be about Rs. 2.50 in the year 2015 (at 2007 prices).
[55]
Stage II – fast breeder reactor
In the second stage,
fast breeder reactors (FBRs) would use a
mixed oxide (MOX) fuel made from
plutonium-239, recovered by reprocessing spent fuel from the first stage, and natural uranium. In FBRs, plutonium-239 undergoes fission to produce energy, while the uranium-238 present in the mixed oxide fuel transmutes to additional plutonium-239. Thus, the Stage II FBRs are designed to "breed" more fuel than they consume. Once the inventory of plutonium-239 is built up thorium can be introduced as a blanket material in the reactor and transmuted to
uranium-233 for use in the third stage.
[13]
The surplus plutonium bred in each fast reactor can be used to set up more such reactors, and thus grow the Indian civil nuclear power capacity till the point where the third stage reactors using thorium as fuel can be brought online, which is forecasted as being possible once 50 GW of nuclear power capacity has been achieved.
[56][57][58] The uranium in the first stage PHWRs that yield 29 EJ of energy in the once-through fuel cycle, can be made to yield between 65 and 128 times more energy through multiple cycles in fast breeder reactors.
[59]
The design of the country's first fast breeder, called
Prototype Fast Breeder Reactor (PFBR), was done by
Indira Gandhi Centre for Atomic Research (IGCAR).
Bharatiya Nabhikiya Vidyut Nigam Ltd (Bhavini), a public sector company under the
Department of Atomic Energy (DAE), has been given the responsibility to build the fast breeder reactors in India.
[42][56] The construction of this
PFBR at
Kalpakkam was due to be completed in 2012.
[60][61] It is not yet complete. A start date in 2015 has been suggested.
[56]
In addition, the country proposes to undertake the construction of four FBRs as part of the 12th Five Year Plan spanning 2012–17, thus targeting 2500 MW from the five reactors.
[62][63] One of these five reactors is planned to be operated with metallic fuel instead of oxide fuel, since the design will have the flexibility to accept metallic fuel, although the reference design is for oxide fuel.
[64] Indian government has already allotted Rs.250 crore for pre-project activities for two more 500 MW units, although the location is yet to be finalised.
[56]
Doubling time
Doubling time refers to the time required to extract as output, double the amount of fissile fuel, which was fed as input into the breeder reactors.
[a] This metric is critical for understanding the time durations that are unavoidable while transitioning from the second stage to the third stage of Bhabha’s plan, because building up a sufficiently large fissile stock is essential to the large deployment of the third stage. In Bhabha's 1958 papers on role of thorium, he pictured a doubling time of 5–6 years for breeding U-233 in the Th–U233 cycle. This estimate has now been revised to 70 years due to technical difficulties that were unforeseen at the time. Despite such setbacks, according to publications done by DAE scientists, the doubling time of fissile material in the
fast breeder reactors can be brought down to about 10 years by choosing appropriate technologies with short doubling time.
[17]
Type U238–Pu cycle Th–U233 cycle
oxide 17.8 108
carbide-Lee 10 50
metal 8.5 75.1
carbide 10.2 70
Another report prepared for
U.S. Department of Energy suggests a doubling time of 22 years for oxide fuel, 13 years for carbide fuel and 10 years for metal fuel.
[65]
Stage III – thorium based reactors
See also:
Thorium fuel cycle
A sample of
thorium
A Stage III reactor or an Advanced nuclear power system involves a self-sustaining series of
thorium-232-
uranium-233 fuelled reactors. This would be a
thermal breeder reactor, which in principle can be refueled – after its initial fuel charge – using only naturally occurring thorium. According to the three-stage programme, Indian nuclear energy could grow to about 10 GW through PHWRs fueled by domestic uranium, and the growth above that would have to come from FBRs till about 50GW.
http://en.wikipedia.org/wiki/India's_three-stage_nuclear_power_programme#cite_note-67 The third stage is to be deployed only after this capacity has been achieved.[57]
According to replies given in Q&A in the Indian Parliament on two separate occasions, 19 August 2010 and 21 March 2012, large scale thorium deployment is only to be expected “3 – 4 decades after the commercial operation of fast breeder reactors with short doubling time”.[66][31] Full exploitation of India’s domestic thorium reserves will likely not occur until after the year 2050.[67]
India's three-stage nuclear power programme - Wikipedia, the free encyclopedia
