India started its commercial nuclear power programme with the twin units (2x160 MW) of imported boiling water reactors (BWRs) at Tarapur (TAPS) from the General Electric Company, USA, in 1969.

Subsequently, India planned to have its main plank for nuclear power gene-ration based on the Canadian technology of using natural uranium and heavy water in pressurised heavy water reactors (PHWRs) since that route seemed easier to make India self-dependent on fuel resources. These BWRs and PWRs, which are more popular in the world, use low enriched uranium and natural water.

Between building up infrastructure for industrial production of heavy water, based on enrichment of the heavy hydrogen isotope present in water required for PHWRs and that of enrichment of uranium (natural U-235 isotope content of 0.71 per cent has to be increased to about 2-4 per cent) for the PWRs, the former was technologically capable of quicker realisation.
So two reactors (2 x 220 MW) of the PHWR type, specifically known as Canadian Deuterium Uranium (CANDU) was planned to be set up at Rajasthan Atomic Power Station (RAPS) under a collaboration with Canada. Construction of the first first RAPS reactor was started in 1973 while efforts to realise full indigenisation of this type of reactor were also initiated in parallel.

But the Canadian cooperation was terminated prematurely due to India carrying out the nuclear test explosion in 1974 which attracted embargos from nuclear nations of the world. Subsequently the second unit was constructed with indigenous efforts and completed in 1981. This led to the saga of India developing its own heavy water reactor technology indigenously.

Today the technology has matured and Nuclear Power Corporation (NPC) can make reactors of this type (sometimes known as INDU synonymous with CANDU). India has 15 of these out of the total 17 reactors currently operating in the country now with an installed capacity of 4120 MW. NPC is geared to turn out these reactors within a construction period of five years. The earlier reactors were of 220 MW and the more recent one is of 540 MW; the future one is being standardised at 700 MW.

The first two units of TAPS and two units of RAPS, which were imported from US and Canada respectively, were understandably under facility-specific safeguards agreements with IAEA, though India was a non-signatory to the NPT agreement. In spite of Canada and the US walking out of the agreements, India kept its commitment to the faci-lity-specific agreement with IAEA for these reactors.

Pressurised water reactors in India – delayed start

But the state-of-the-art nuclear power stations of 1000 MW today in the world are of the PWR type for which we need enriched uranium and in the foreseeable future we have to depend only on imported fuel for such reactors. The Russians have developed their own version of the pressurised natural water enriched uraniumreactors known as Vodo-Vodyanoi Energetichesky Reactor (VVERs). Since India needed to have a mix of reactors, an agreement with the then USSR (in 1988) was the only recourse, since the embargos were in place with all nuclear-supplying countries.

There was the limitation of uranium resources in the country and our own technology using fast reactors which use the more abundantly available thorium has taking time and is yet to mature. The promise by DAE for an early breakthrough was being hindered by technological problems and embargos on import of appropriate components including the enriched uranium required to kick-start this technology. India’s initial collaboration with France in this field was also interrupted in 1974 resulting in delays. (Refer to A Perspective on the Thorium Utilisation in Indian Atomic Energy Program, by K.S. Venkateswarlu and M.R. Iyer, PTI Science Service, 1-15 September, 2008, Vol.17, No.27).

In this context the agreement to set up twin pressurised water reactors of the Russian VVER-type was signed in 1988 between Indian prime minister Rajiv Gandhi and Russian president Mikhail Gorbachev and seemed to be a way out to accelerate the growth of nuclear power in India. Unfortunately before the agreement could mature, the Soviet Union split up (in 1991), resulting in political and economic uncertainty in Russia and to the agreement remaining dormant for more than 10 years. Due to these factors the project was in cold storage since then though India started preparing the site since early 1990s.

In 1992, the NSG directives came into operation and USA took strong objection to Russia supplying nuclear power plants to India contravening the directives as Russia was a party to these directives in spite the project being covered under facility specific safeguard agreement with IAEA. But since the original agreement with USSR of 1988 predates this freeze, Russians did not resile on the agreement but proceeded cautiously on the project. The original agreement was with an economic package. Evidently the Russians were neither a political nor economic force by then and they themselves were depending on international aid after the split up. Thus, though the project might appear on paper to be incubating since 1988, the construction as such started only in 2002. In anticipation of the realisation of the project, the site was selected much earlier and the mandatory pre-operational surveys and other preparatory work were being carried out. The actual construction work began only in 2002 with the original target date of commissioning the first unit in 2007 and the second in 2008.

Kudankulam incubation comparable to Tianwan

The average incubation period for construction of nuclear reactors around the world is around 5 to 6 years. In India, though the earlier PHWRs construction took substantially longer, recent ones have gone on stream in around five years. The incubation periods of some nuclear power stations around the world including the VVER-type being set up in China by Russia are shown in Fig. 1.

More comprehensive statistics of the construction time for nuclear reactors around the world given by IAEA recently is shown in Fig. 2. Russia recently commissioned two nuclear reactors in China at the Tianwan Nuclear Power Plant site and two more reactors are now at the contracting stage. Ultimately, this site may hold eight such reactors.

Thus Kudankulam complex is similar to the status and plans for erection of VVERs in Tianwan, the construction of which commenced in October 1999 for the first unit, and in October 2000 for the second reactor unit.

In Kudankulam, construction for the first reactor started in 2006, and the second one in mid-2007. It has taken nearly eight years for the first unit to start from the time ground was broken. Thus, the construction time planned for the Kudankulam reactors was shorter than the time taken for the Chinese units and is realistic.

But a number of other factors have delayed its start up. One was that the infrastructure around Kudankulam site was very primitive. Before the project initiation, the primitive road leading up to the site often used to sink, making it incapable of supporting movement of heavy machinery (such as the pressure vessel weighing up to 300 tonnes) from Russia via the Turticorin port. So a minor port had to be constructed to enable heavy machinery received by ship to be landed at the site through barges. While this port became operational in Kudankulam in January 2004, the road infrastructure took time to be developed.

Problems with water resources

Another factor was that the Tamil Nadu government was unable to assure continuous, uninterrupted water supply essential for the plants though at the time of site selection the water requirements were known to the state. In fact the original plans for using the Pechiparai dam water for the station was subsequently objected to in public hearings.

As a result of this, the DAE was forced to install four huge desalination plants imported from Israel for process water with a capacity of 7680 cubic meters per day, installed at a cost of Rs.116 crore. This further delayed the project. Another desalination plant installed by the Tatas caters to the water supply for the project township.

There were also some objections initially about locating the reactors at the site due to apprehensions in the public mind about its safety and possible confusion with the world war vintage unsafe Chernobyl-type of graphite reactors. The International Atomic Energy Agency (IAEA) recently described the VVER plant of the Kudankulam type as the world's safest. The modification in Russian reactor design incorporates some very novel concepts of safety and some of these have been evolved and incorporated after the original agreement was signed in 1988.

Coastal nuclear power stations in India generally use sea water for final cooling of condenser steam. This involved the erection of a submarine dyke in the sea of more than one kilometre length to prevent marine organisms from being pumped into the coolant circuit and installation of a massive caisson. The alternative used in western countries or even in our inland sites such as Narora is the use of ordinary water and cooling towers. This again demanded larger quantity of process water. The erection of the marine cooling pond at Kudankulam in itself is a technological feat adopting new features than the ones used in our other PHWR coastal power stations. But all this infrastructure erected will be sufficient to cater to the needs for a multi- units site. So the installation of additional reactors under the agreement reached very recently with the Russians, thanks to the removal of embargos as a result of the agreement with NSG and IAEA, should be smooth.

Flow of components and safeguard requirements

The Russians were not very much geared to production and supply of this modified type of VVERs to another country and this also might have delayed meeting the target dates. Till now, Russia has sold and erected a few reactors mostly in nearby East European countries, with the only similar case being an agreement with China, whose status is explained earlier. The design also required minor changes to meet the strict regulatory norms of the Atomic Energy Regulatory Board of India.

In spite of the escape clause in the original agreement, which was pre-dated to the NSG directives, the Americans might have been restraining the Russians to exercise caution in going ahead with the shipment of the enriched fuel for the reactors.

A facility-specific safeguards agreement for KKNP is in place similar to the ones we have for TAPS 1&2 and RAPS 1&2. Since the store for irradiated fuel has also to be under safeguards, the IAEA has its own stipulations for making the facility safe.
These are some of the factors which would have contributed to delays. The future rectors of this type to be installed at the site are expected to take less time.

The revised date of commissioning is understood to be August 2009 for the first unit and May 2010 for the second unit. The enriched uranium fuel for the first charge is reported to have been received at the site. The agreements for the next two units have already been signed. The year 2009 should see the prospect of substantial electric power flowing into the southern grid, promising to reduce the power deficit in the whole region.

The Kudankulam project gives a headstart to the Russians for installing nuclear power projects in India compared to new entrants like USA and France in the post-NSG waiver era. Tamil Nadu government should also develop the coastal belt in that region into an industrial complex by chipping in financial and infrastructure support to gear up realisation of power independence for the region.

The Kudankulam site as of now is geared to have six units of 1000 MW each, with a total capacity of 6000 MW. Addition of further units at Kudankulam would make the site the biggest hub of nuclear power in India and free Tamil Nadu and Kerala from the perennial power shortage they are suffering.