Kakrapar unit 1 was fully refurbished and upgraded in 2009-10, after 16 years of operation, as was Narora 2, with cooling channel (calandria tube) replacement. In March 2016 unit 1 was shut down due to a coolant leak, and repairs ran through to May 2019. Kakrapar 2 was shut down in July 2015 and restarted in September 2018. There was widespread corrosion in both Kakrapar units and coolant channels were replaced.
Russia is supplying all the enriched fuel through the life of the plant, though India will reprocess it and keep the plutonium for civil use*. The first unit was due to start supplying power in March 2008 and go into commercial operation late in 2008, but this schedule slipped by six years. In the latter part of 2011 and into 2012 completion and fuel loading was delayed by public protests, but in March 2012 the state government approved the plant's commissioning and said it would deal with any obstruction. Unit 1 started up in mid-July 2013, was connected to the grid in October 2013 and entered commercial operation at the end of December 2014. It had reached full power in mid-year but then required turbine repairs for nearly six months. It generated only 2.8 TWh in its first year, at a cost of under Rs 4.0 per kWh (6 c/kWh). Unit 2 construction was declared complete in July 2015, it was grid-connected in August 2016, and commenced commercial operation at the start of April 2017. Each unit is 917 MWe net.
In 2002 the regulatory authority issued approval to start construction of a 500 MWe prototype fast breeder reactor (PFBR) at Kalpakkam and this has been built by BHAVINI (Bharatiya Nabhikiya Vidyut Nigam Ltd), a government enterprise set up under the DAE to focus on FBRs. It was expected to start up in September 2014, fuelled with MOX (mixed uranium-plutonium oxide, the 30% of reactor-grade Pu being from its existing PHWRs) made at Tarapur by BARC, as hexagonal fuel asemblies. It has a blanket with uranium and thorium to breed fissile plutonium and U-233 respectively, taking the thorium programme to stage two, and setting the scene for eventual full utilisation of the country's abundant thorium to fuel reactors. It is a sodium-cooled pool-type reactor having two primary and two secondary loops, with four steam generators per loop. It is designed for a 40-year operating lifetime at 75% load factor. Two more such 500 MWe fast reactors have been announced for construction at Kalpakkam, but slightly redesigned by the Indira Gandhi Centre to reduce capital cost. Then four more are planned at another site.
In 2002 the regulatory authority issued approval to start construction of a 500 MWe prototype fast breeder reactor at Kalpakkam and this is now under construction by BHAVINI. It is expected to be operating in 2016, fuelled with uranium-plutonium oxide (MOX, the reactor-grade Pu being from its existing PHWRs). It will have a blanket with thorium and uranium to breed fissile U-233 and plutonium respectively. This will take India's ambitious thorium program to stage 2, and set the scene for eventual full utilization of the country's abundant thorium to fuel reactors. Six more such 500 MWe fast reactors have been announced for construction, four of them by 2020. This fleet of fast reactors will breed the required plutonium which is the key to unlocking the energy potential of thorium in AHWRs. This will take another 15-20 years, and so it will still be some time before India is using thorium energy to any extent.
Design of the first 300 MWe AHWR (920 MWt, 284 MWe net) was completed early in 2014 at BARC. It is mainly a thorium-fuelled reactor but is versatile regarding fuel. Construction of the first one is due to start in the 12th plan period to 2017, for operation about 2022. At the end of 2016 large-scale engineering studies were validating innovative features of the design. No site or construction schedule had been announced for the demonstration unit. The AHWR can be configured to accept a range of fuel types including U-Pu MOX, Th-Pu MOX, and Th-U-233 MOX in full core, the U-233 coming from reprocessing in closed fuel cycle. A co-located fuel cycle facility is planned, with remote handling for the highly-radioactive fresh fuel.*
The 300 MWe AHWR will have vertical pressure tubes in which the light water coolant under high pressure will boil at 285°C, circulation being by convection. Thermal efficiency is 30.9%. It is moderated by heavy water. There are 452 fuel assemblies, with burn-up of 38 GWd/t. A large heat sink or "gravity-driven water pool" with 7000 cubic metres of water is near the top of the reactor building and has a safety function. It has a slightly negative void coefficient of reactivity and several advanced passive safety features to enable meeting next-generation safety requirements such as 72-hour grace period for operator response, elimination of the need for exclusion zone beyond the plant boundary, 100-year design life, and high level of fault tolerance. The advanced safety characteristics have been verified in a series of experiments carried out in full-scale test facilities. It is claimed that per unit of energy produced, the amount of long-lived minor actinides generated is nearly half of that produced in current generation light water reactors. A high level of radioactivity in the fissile and fertile materials recovered from the used fuel of the AHWR, and their isotopic composition, preclude the use of these materials for nuclear weapons*.
An early AEC decision was to set up the Bhabha Atomic Research Centre (BARC) at Trombay near Mumbai. A series of 'research' reactors and critical facilities was built here: APSARA (pool-type, 1 MW, operating 1956-2010) was the first research reactor in Asia, CIRUS (40 MWt, 1960) built under the Colombo Plan, and Dhruva (100 MWt, 1985) followed it along with fuel cycle facilities. CIRUS used natural uranium fuel, was moderated by heavy water and cooled by light water. It was extensively refurbished and then recommissioned in 2002, and ran to 2010. Dhruva was fully designed and built indigenously, and uses metallic uranium fuel with heavy water as moderator and coolant. Dhruva is extensively used in neutron beam research studies involving material science and nuclear fission processes. As well as research uses, the CIRUS and Dhruva units are assumed to be largely for military purposes, as is the Trombay plutonium plant commissioned in 1965. In line with international agreement, the government shut down CIRUS at the end of 2010.
BARC is also responsible for the transition to thorium-based systems and in particular is developing the 300 MWe AHWR as a technology demonstration project. This will be a vertical pressure tube design with heavy water moderator, boiling light water cooling with passive safety design and thorium-plutonium based fuel (described more fully above). A large critical facility to validate the reactor physics of the AHWR core has been commissioned at BARC, and BARC's research laboratory at Tarapur tests various AHWR systems. An engineering-scale Power Reactor Thorium Reprocessing Facility (PRTRF) has been constructed at Trombay to reprocess thoria fuel bundles irradiated in PHWRs, was expected in operation in 2015.
The bill does not make any mention of India ratifying the CSC or any international treaty or framework governing nuclear liability under which the supplier cannot be sued in their home country. The CSC was not yet in force internationally, but Indian ratification would bring it closer to being so, and was part of the September 2008 agreement with the USA. In October 2010 India signed the CSC. In 2011 the US Secretary for State said she expected India to ratify the CSC by year end, "and we would encourage engagement with the International Atomic Energy Agency to ensure that the liability regime that India adopts by law fully conforms with the international requirements under the convention." Eventually, in February 2016, India deposited its instrument of ratification of the CSC with the IAEA. However, it is not clear how it relates to the nuclear liability law, though the Ministry of External Affairs said in a statement that ratification of the CSC marked a "conclusive step in the addressing of issues related to civil nuclear liability in India." The US Energy Secretary welcomed the ratification. The CSC entered into force for India in May 2016.
India's situation as a nuclear-armed country excluded it from the Nuclear Non-Proliferation Treaty (NPT)* so this and the related lack of full-scope IAEA safeguards meant that India was isolated from world trade by the Nuclear Suppliers' Group. A clean waiver to the trade embargo was agreed in September 2008 in recognition of the country's impeccable non-proliferation credentials. India has always been scrupulous in ensuring that its weapons material and technology are guarded against commercial or illicit export to other countries.
In December 2006 the US Congress passed legislation to enable nuclear trade with India. Then in July 2007 a nuclear cooperation agreement with India was finalized, opening the way for India's participation in international commerce in nuclear fuel and equipment and requiring India to put most of the country's nuclear power reactors under IAEA safeguards and close down the CIRUS research reactor at the end of 2010. It would allow India to reprocess US-origin and other foreign-sourced nuclear fuel at a new national plant under IAEA safeguards. This would be used for fuel arising from those 14 reactors designated as unambiguously civilian and under full IAEA safeguards.
Another, more recent approach, centres on the concept of containment, designed to 'cap' the production of fissile material for weapons purposes, which would hopefully be followed by 'roll back'. To this end India and the USA jointly sponsored a UN General Assembly resolution in 1993 calling for negotiations for a 'cut-off' convention, the Fissile Material Cut-off Treaty (FMCT). Should India and Pakistan join such a convention, they would have to agree to halt the production of fissile materials for weapons and to accept international verification on their relevant nuclear facilities (enrichment and reprocessing). In short, their weapons programs would be thus 'capped'. It appeared that India was prepared to join negotiations regarding such a FMCT under the 1995 UN Conference on Disarmament (UNCD). 2b1af7f3a8