A debate over breeder reactors

Print edition : December 05, 1998

Criticism of India's fast breeder reactor programme by two academics, including a former Scientific Adviser to the Defence Minister, triggers a spirited response from the nuclear energy establishment.

QUESTIONS raised by two academics regarding the "technology" and "viability" of India's Fast Breeder Reactor (FBR) programme have been countered by scientists and engineers of the Department of Atomic Energy (DAE), the exchange adding to the heat of the ongoing debate in the country on the nuclear question in the wake of Pokhran-II.

In an article entitled "India's nuclear breeders: technology, viability and options", published in Current Science (pages 549 to 558, Volume 75, No.6 of September 25, 1998), Rahul Tongia and V.S. Arunachalam advised the DAE to abandon the FBR programme because, according to them, it was not a viable option for India. Instead, they recommended that India build a series of Pressurised Heavy Water Reactors (PHWRs) and Light Water Reactors (LWRs) using indigenous and imported uranium. Their conclusion follows an examination of the "technical viability" of India's nuclear power programme based on "indigenous materials and technology", and "specifically, the role of breeder reactors for extending the domestic uranium supplies."

Current Science, which started publication in 1932, is brought out by the Current Science Association in collaboration with the Indian Academy of Sciences, Bangalore. Tongia and Arunachalam are with the Department of Engineering and Public Policy at Carnegie-Mellon University in Pittsburgh, Pennsylvania. Arunachalam was formerly Scientific Adviser to the Defence Minister of India.

Fast Breeder Reactors, which use plutonium, are called so because they have no moderator (heavy water or light water) and breed more fuel than they consume.

In the article, Tongia and Arunachalam said: "Our study shows breeding is unlikely to occur at anywhere near the rates envisioned, leading to a very slow growth of fast breeder reactors (in India). In addition, domestic uranium reserves restrict the growth of Pressurised Heavy Water Reactors, which are likely to be the main contributors to nuclear capacity in the short term. The thorium-uranium 233 cycle in fast breeders does not appear attractive, and for the uranium 238-plutonium cycle, only metallic fuel offers hope of a relatively fast doubling and reprocessing time. To increase the share of nuclear power in the coming decades, India should consider the construction of a number of large thermal reactors based on indigenous and imported uranium and also the design, development and validation of reactors that operate with thorium-plutonium fuels."

The views expressed by Tongia and Arunachalam have been challenged by top scientists and engineers of the DAE, especially those at the Indira Gandhi Centre for Atomic Research (IGCAR), Kalpakkam, about 70 km from Chennai. The IGCAR has been entrusted with the development of the FBR programme.

Top IGCAR scientists questioned the three fundamental assumptions that the article by Tongia and Arunachalam is premised on: 1. The speed with which India could build PHWRs, and their plant load factor (PLF) in the past, on the basis of which Tongia and Arunachalam have made projections for the future; 2. That enough plutonium would not be reprocessed from PHWRs to fuel the FBRs; and 3. That FBRs to be built in India would have a long doubling time (the time taken by an FBR to breed enough plutonium so that one more FBR can be set up) and that India should use metallic fuel instead of oxide fuel in its near-term breeder reactors. They also question the validity of the recommendation that "India should consider entering into long-term agreements with other countries, with appropriate policy innovations, for importing uranium."

DR. HOMI J. BHABHA, the founder of India's nuclear power programme, envisaged a three-stage approach to nuclear electricity generation. In the first stage, PHWRs would use natural uranium as fuel and heavy water as moderator and coolant. PHWRs generate electricity at the Rajasthan Atomic Power Station (RAPS) in Rawatbhatta, the Madras Atomic Power Station (MAPS) at Kalpakkam, the Narora Atomic Power Station (NAPS) in Uttar Pradesh and the Kakrapar Atomic Power Station (KAPS) in Gujarat.

When natural uranium is used as fuel in PHWRs, plutonium 239 is a byproduct. The aim of reprocessing is to separate plutonimum 239 and the left-over uranium from the fission products. Plutonium 239 and initially the left-over uranium, and subsequently thorium kept in blanket form, will fuel fast breeder reactors, which will form the second stage of India's nuclear electricity programme. A step towards this was taken when the Fast Breeder Test Reactor (FBTR) of 13 MWe capacity at Kalpakkam, which uses uranium-plutonium carbide fuel, attained criticality in 1985. A milestone was reached on July 11, 1997, when electricity from the FBTR flowed into the Tamil Nadu grid.

The IGCAR is now working on a Prototype Fast Breeder Reactor (PFBR), with 500 MWe capacity. The design is in an advanced stage and construction will start in the year 2001.

Thorium used in FBRs gets converted into uranium 233, a fissile material. In the third stage, breeder reactors will use uranium 233 as fuel and thorium in blanket form to generate electricity. A small step towards the third-stage programme was taken when the KAMINI experimental reactor at Kalpakkam attained criticality in October 1996, using uranium 233 and thorium.

Bhabha envisaged this three-stage programme because natural uranium reserves in India were limited, whereas there were vast reserves of thorium. Since breeders breed more uranium 233 than they consume, it is estimated that 5,00,000 MWe (500 GWe; 1 gigawatt is 1,000 megawatt) of electricity can be generated from the third stage for at least four centuries.

TOP IGCAR officials object to the harsh tone of the article and the advice it offered. Dr. Placid Rodriguez, Director, IGCAR, and Dr. S.M. Lee, Director, Safety Research, Health Physics, Information Services, Instrumentation and Electronics Group (SHINE), IGCAR, sent in a rejoinder to the article. In the rejoinder, they point to Tongia's and Arunachalam's recommendation that India enter into long-term agreements with other countries for importing uranium after going in for "appropriate policy innovations". Significantly, there are restrictions imposed by the Nuclear Suppliers Group on the supply of nuclear materials to India. Rodriguez and Lee said: "The advice is clear. The appropriate policy innovations should be those that satisfy the Nuclear Suppliers Group to remove the restrictions."

Frontline met Rodriguez, Lee, S.B. Bhoje, Director, Reactor Group, IGCAR, and other scientists of the DAE to get their views on the article.

According to Lee, electricity consumption in India is 400 KW hr (units) per person a year, as against 2,700 units in Singapore, 5,000 units in Europe, and 10,000 units in the United States. Consumption in India is expected to go up, and about 400 GWe to 500 GWe would have to be generated between 2025 and 2050. Lee said that this requirement could not be met by coal, hydel, solar and wind energy alone, and the three-stage nuclear electricity programme could play a crucial role in this.

According to Lee, the country could generate 15 GWe for 30 years by using 60,000 tonnes of uranium available in the PHWRs. But it needed about 400 GWe to 500 GWe. This is where the IGCAR came into the picture, Lee said.

LEE said that the IGCAR had made several scenario studies and concluded that "with our nuclear resources, we can generate 400 GWe to 500 GWe of nuclear power for at least four centuries." To reach this target, four steps were required: 1. PHWRs should be set up fast enough to generate 15 GWe; 2. FBRs, which will use plutonium reprocessed from PHWRs, should be installed to generate an additional 25 GWe; 3. Short-doubling-time FBRs of advanced technology, which use plutonium and depleted uranium, should grow quickly to generate 350 GWe; and 4. This capacity could grow to between 400 GWe and 500 GWe and be maintained at that level for four centuries using uranium 233 and thorium.

But Tongia and Arunachalam argued that enough plutonium would not be reprocessed from PHWRs because the latter would not be built quickly enough and because their PLF would be low. As a result, the construction of breeders would be delayed, given the doubling time for Indian reactors. Their primary source for data on breeding is the 1980 International Nuclear Fuel Cycle Evaluation (INFCE) report, compiled with international collaboration.

Tongia and Arunachalam said: "In Bhabha's 1958 papers on using thorium, he pictured a doubling time of only 5-6 years for uranium 233 in the thorium-uranium 233 cycle. INFCE projects this to be at least 70 years." Bhabha had assumed that Liquid Metal Fuel Reactors would be commissioned, but these were not built owing to "technical difficulties".

V.S. Arunachalam, former Scientific Adviser to the Defence Minister.-P.V. SIVAKUMAR

Tongia and Arunachalam added that publications by DAE scientists, especially Raja Ramanna, former Chairman of the Atomic Energy Commission, and Lee, "suggest an optimistic picture for the growth of fissile material through breeding..." (The reference is to a paper written by Ramanna and Lee in Pramana (a journal of physics), 1986, 27, pages 129-137.) While calculating doubling times, DAE scientists "have used futuristic reactor performance scenarios, and yet-to-be-built reactor designs..," Tongia and Arunachalam said.

Tongia and Arunachalam, who modelled PHWR growth as a source of plutonium, said that the limit to PHWR growth was set by domestic uranium availability, which varied between 30,000 and 90,000 tonnes in the model. In their analysis, Tongia and Arunachalam "assumed a 40-year life for PHWRs in India and an average PLF varying between 40 and 75 per cent". Elsewhere, they said, "On average, Indian lifetime PLFs have been more modest for PHWRs, averaging between 30 and 60 per cent." In their reckoning, "PLF is the most important parameter in determining the doubling time" of breeders fuelled by plutonium-uranium 238.

Tongia and Arunachalam argued that "the growth of fissile material through breeding would not be as rapid as desired to allow an increase in nuclear power capacity in the near future... Even with... 70 per cent PLF, the share of nuclear power will continue to remain low...."

They added: "Under the current policy scenario, the share of nuclear power will remain very low for the coming five or more decades. The limits on domestic uranium supplies, as well as construction constraints, will restrict PHWR growth... breeding will be very slow, especially based on oxide fuel currently planned. Even the fastest breeding cycle... will allow only a limited share for nuclear power in the coming decades... The assumptions made by (the) DAE are overly optimistic and... unrealisable."

They argued that "the limits on construction due to licensing delays, capital availability and its high cost, infrastructure requirements and environmental concerns are very real. Multilateral funding for nuclear power is unavailable, and the Indian Government is currently funding only two teams working on twin reactors. Without increasing the number of teams... the installed base will plateau as older units are decommissioned. Reducing the construction time does not alter the outlook much, and there is a limit to how many reactors can be constructed simultaneously..."

On the fuel option, they said that "only metallic fuel coupled with dry processing appears to be an attractive fuel option. However, this technology has still not developed fully, let alone found commercial use." However, they said, even metallic fuel would not be adequate to produce fissile material rapidly enough to increase the percentage of nuclear power.

Tongia and Arunachalam concluded: "The Indian nuclear power programme has not met its stated objectives. The three stages of the previously enunciated plan appear to be non-realisable even in a time-frame spanning five decades. The key to a reasonable growth of nuclear power will thus have to be the commissioning of a large number of pressurised heavy water and light water reactors. It is therefore necessary to restructure the nation's nuclear power strategy taking into account the present acute scarcity of power in the country and the relevance of nuclear power in India's portfolio of energy options."

BHOJE questioned the validity of Tongia and Arunachalam making projections for the future on the basis of the PLF recorded in the past by PHWRs in India. In recent years, the Nuclear Power Corporation (NPC) had taken steps to improve the performance of the nuclear power stations at Tarapur, Rawatbhatta, Kalpakkam, Narora and Kakrapar, he said.

According to NPC Chairman and Managing Director Y.S.R. Prasad, the PLF of nuclear power stations in India had gone up from 60 per cent in 1995-96 to 67 per cent in 1996-97 and 71 per cent in 1997-98. In the first six months of 1998-99, it further rose to 73 per cent.

Bhoje and Lee questioned the assumption that the rate of building PHWRs in India would be slow and that the amount of plutonium reprocessed from them would be inadequate to build FBRs at short doubling time. Bhoje said that the rate at which PHWRs would be built would depend on the ability to master the technology, the availability of finance and public acceptance. He said that NPC engineers had mastered the technology to build 220 MWe PHWRs and that the design for 500 MWe PHWRs had been standardised. Two units of 220 MWe capacity each at Kaiga in Karnataka and two more at Rawatbhatta (Units 3 and 4) were under construction and they would start generating power in 1999-2000. The construction of two reactors of 500 MWe capacity each at Tarapur had begun on October 10. The NPC, which was making profits, would allocate more money in the future to build PHWRs, and the number of construction teams would increase. Budgetary support for nuclear power projects in the Ninth Plan period (1997-2002) had gone up from Rs.3,500 crores to Rs.4,800 crores. (Comparatively, top NPC sources said, the fund allocation for nuclear power projects was "a disaster" between 1991 and 1996, and the projects suffered greatly.)

The Fast Breeder Test Reactor at the Indira Gandhi Centre for Atomic Research, Kalpakkam.-S. THANTHONI

Lee said that the development of indigenous technology was a key goal in building PHWRs and future breeders. Bhoje further said that the figures cited by Tongia and Arunachalam in respect of plutonium reprocessed from PHWRs were "low". Besides, he said, the DAE had "intentionally kept low" the inventory of the oxide fuel that had been designed as fuel for the PFBR; this was done considering the Indian reprocessing plants' supply of plutonium. Bhoje said, "We have not optimised it (oxide fuel) for breeding. We will optimise it when we reach the commercial stage, when a series of FBRs will be built... Plutonium production from PHWRs will double when the PLF goes up. This itself will make plutonium largely available for the growth of FBRs."

Russia and the United States had reported a doubling time of 12 to 15 years for oxide fuel. "This aspect has been neglected in the article," asserted Bhoje. "Only the initial, low value of breeding of the PFBR has been taken into account and extrapolated. The article is based on wrong assumptions."

Lee said that Tongia and Arunachalam had predicted a shortage of plutonium for the second core of the PFBR and had suggested that the construction of the PFBR be postponed. But the quantity of spent fuel reprocessed from the PHWRs would be so large as to require "another Kalpakkam Reprocessing Plant" , Lee added.

Other scientists at the IGCAR defended the choice of oxide fuel for the PFBR. (Tongia and Arunachalam have advocated metallic fuel.) France used oxide fuel for its Rapsodie, Phenix, Super Phenix I and the planned Super Phenix II breeder reactors, they pointed out. The EFR (European Fast Reactor of 1,000 MWe capacity) was to be fuelled by oxide fuel. BOR-60 in the former Soviet Union used oxide fuel. "Most countries have selected oxide fuel; the cost of production is low and it is easy to fabricate," one of the scientists said.

IGCAR scientists are particularly displeased with the statement that India should not go in for breeders. According to Bhoje, the world's largest energy resource today was in breeders. India started late on the breeder project, but, according to Bhoje, a 10-year delay in breeder projects did not matter much when one considers the country's energy needs over a long period. The scientists ridiculed the recommendation that India import uranium and LWRs. "Who will give us LWRs?" a scientist asked. Even before the Pokhran II series of nuclear tests in May, the U.S. and Canada were insisting that India accede to the Nuclear Non-Proliferation Treaty (NPT) and the Comprehensive Test Ban Treaty (CTBT) as conditions for the sale of LWRs.

The scientists argued that the choice of PHWRs for nuclear power stations in India was deliberate, keeping in view the uranium reserves. Since there would be a shortfall in meeting the target of 15 GWe from the indigenous PHWRs, the Union Government decided to import two reactors (VVER-1000) of 1,000 MWe each to be built at Koodankulam in Tamil Nadu. A team from France met DAE officials in October in order to sell reactors to India. "These will fill some of the gaps, but they will not be enough. India has to go in for FBRs," the scientists said.

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