Nuclear arm

Published : Aug 28, 2009 00:00 IST

The Pressurised Water Reactor that has been operating at Kalpakkam for three years. An identical reactor will power INS Arihant.-BY SPECIAL ARRANGEMENT

The Pressurised Water Reactor that has been operating at Kalpakkam for three years. An identical reactor will power INS Arihant.-BY SPECIAL ARRANGEMENT

THE tall S. Basu is a man who shuns the limelight and the big talk. To the outside world, he is the Director of the Bhabha Atomic Research Centre (BARC) Facilities at Kalpakkam. What was kept a secret was that he was also the Project Director of the Plutonium Recyling Project (PRP) at Kalpakkam. The PRP was a facade behind which BARC, a facility of the Department of Atomic Energy (DAE), built Indias first indigenous Pressurised Water Reactor (PWR). BARC also built another identical PWR, which is at the heart of Indias first nuclear-powered submarine, INS Arihant.

Both the PWRs can generate 80 MWe. Enriched uranium is the fuel that powers them. Light water acts as coolant and moderator. The Rare Materials Project (RMP) at Ratnahalli near Mysore, another DAE facility, produced the enriched uranium required for operating the two PWRs.

With the launching of INS Arihant on July 26, Basu is a proud man. Working on the project and completing it has been a big achievement. As an engineer, this is the best possible thing I could have done in my life. The boat is an engineers dream which has become a reality, he said.

July 26 was a historic day not only for Basu but for hundreds of personnel of the DAE, the Navy and the Defence Research and Development Organisation (DRDO) when the sluice gates of the dry dock in the Ship Building Centre at Visakhapatnam harbour opened, sea water gushed in and INS Arihant started floating. The launch propelled India into an exclusive club of countries that possess their own nuclear-powered submarines, which already has five members Russia, the United States, France, the United Kingdom and China. As Prime Minister Manmohan Singh, who launched the submarine, said, the occasion marked the culmination of years of hard work, dedication and perseverance.

The story of the Advanced Technology Vessel (ATV) programme, as the project to build the submarine was codenamed, is a remarkable one of coordination among the Navy, the DAE and the DRDO and of public-private partnership. The Prime Minister specifically thanked our Russian friends for their consistent and invaluable cooperation, which symbolises the close strategic partnership that we enjoy with Russia.

The PWR on board the submarine will be started up after about a year. By that time, the boat will be fitted with all equipment. Subsequently, it will undergo harbour acceptance and sea acceptance trials, before it is declared operational within two years from now. The submarine is about 111 metres long, 11 m broad and about 15 m tall. It has a surface displacement of 6,000 tonnes.

What will make Arihant a lethal platform is that it will be armed with K-15 ballistic missiles, which will be fired from under water. A booster will erupt into life under water and this will drive the missile to surface, then it will climb 20 km into the air, cut a parabolic path and hit targets on land. The K-15 missiles, developed by the DRDO, are already under production. The DRDO has test-fired them several times from submerged pontoons off the coast of Visakhapatnam. They can carry both conventional and nuclear warheads. They are 10.4 metres tall and weigh 6.3 tonnes each. They have a range of 700 km. Their warheads weigh about a 1,000 kg.

The significance of the deployment of K-15 missiles on board the Arihant is that it will complete Indias nuclear triad. It already can fire missiles (surface-to-surface) with nuclear warheads from the ground; it can deliver nuclear weapons from aircraft; and now it can launch missiles with nuclear warheads from under water.

While the Navy designed and built the boat at Visakhapatnam and BARC provided the nuclear propulsion, the DRDO also made important contributions to the project.

M. Natarajan, Scientific Adviser to the Defence Minister and Director-General of the DRDO, said, While a number of DRDO laboratories made their own contribution [to the ATV programme], I must acknowledge the bigger role played by the naval scientists and engineers working with the ATV project and the submarine design group. The funding of the ATV programme was through the DRDO.

While the Naval Physical and Oceanographic Laboratory (NPOL), Kochi, contributed sensors to Arihant, special acoustics were done by the Naval Science and Technological Laboratory (NSTL), Visakhapatnam. Other DRDO laboratories developed the submarines control systems, not the entire systems, but certain modules, said Natarajan.

W. Selvamurthy, Chief Controller, R&D (Life Sciences and Human Resources), DRDO, called the launching of INS Arihant a major milestone in building Indias strategic defence and second strike capability. Building the boat was a demonstration of Indias scientific prowess, its technical skills and a dynamic programme of managing a huge team of hundreds of persons who worked in this massive project. It is a demonstration that we can undertake such major technological initiatives, Dr. Selvamurthy said.

Srikumar Banerjee, Director, BARC, called the boat of this type a major technology in itself. He added, The whole platform is a very complex combination of various technologies. That is why we are happy that it has reached fruition.

An important advantage of a nuclear-powered submarine is that it can lurk under water for long durations unlike its conventional diesel-electric counterparts, which have to come to the surface periodically to recharge their batteries. This makes the latter vulnerable to attacks by the enemy. Nuclear-powered submarines are faster than diesel-electric boats. Besides, their ability to promenade the sea far and wide provides blue-water capability to the navy that possesses them.

Rear Admiral Michael Moraes, Flag Officer Commanding (submarines), said, Any strong nation would like to have a submarine fleet because they can go anywhere in the world. A nuclear-powered submarine has unlimited endurance. It is fast. The only limiting factor is the crews endurance and psychology. Moraes was sure the design of Arihant was quite good. The crew needed to man Arihant had already been trained. For submarines to survive, It is a constant battle between stealth technology and detection technology, he said. Modern submarines had a lot of quieting features. India had 16 conventional submarines. More would be built. It would be ideal for India to have four SSBNs and nine SSNs. (Here SS denotes submersible ship; B, ballistic missile; and N, nuclear-powered.)

The significance of BARC developing the PWRs was, in the estimate of Anil Kakodkar, Chairman, Atomic Energy Commission, a demonstration that we have our own indigenous PWR technology. Kakodkar, who is also Secretary, DAE, was one of the original designers of the PWR. He said, This PWR technology is very complex. You have to make it extremely compact and pack it in the cramped space of the submarines hull. It was a big challenge.

Kakodkar said BARC developing this PWR was an important development because it marks the beginning of the indigenous PWR capability. The PWR technology was most popular worldwide for electricity generation. India building this PWR acquired significance in the context of it planning to import PWRs from France, Russia and the U.S. for electricity generation. Kakodkar said India already had a family of a variety of reactors. It had built 15 world-class Pressurised Heavy Water Reactors (PHWRs) that generated electricity. These PHWRs used natural uranium as fuel and heavy water as both coolant and moderator, he said. India was building the Prototype Fast Breeder Reactor (PFBR) at Kalpakkam, which was globally advanced, and its breeders would use plutonium-uranium oxide as fuel.

It would soon start building the Advanced Heavy Water Reactor (AHWR), which was globally unique, Kakodkar said. The AHWR would use thorium as fuel. BARC was also developing the Compact High Temperature Reactor (CHTR) to split hydrogen from water. Hydrogen would be the fuel of the future. On August 2, the DAE lifted the veil of secrecy that it had thrown over its PRP, which developed the PWR that powers INS Arihant. Reporters were shown the facility at Kalpakkam that houses the PWR. It is a nondescript building, situated on the shore of the Bay of Bengal. Except for the manicured lawns and a sculpture of a dolphin drenched by a fountain, no aesthetic sense is evident.

Inside a huge hall sits the PWR. There is a big pressure hull, a biological shielding tank with the reactor core inside surrounded by water, a reactor pressure vessel with fuel inside, steam generator, heat exchangers, a control room and an auxiliary control room. It is called pressure hull because it enables the boat to withstand the pressure exerted on it by sea water on all sides when it dives into the sea. The reactor was running when reporters went around the plant. The turbine was rotating at 120 revolutions per minute, enough to provide a speed of 12 knots an hour to Arihant.

The land-based PWR and the submarine version are on a 1:1 scale. This shore-based reactor has been running smoothly for the past three years, said A. Moorthi, Scientific Officer, BARC.

For Basu, the D-day was September 22, 2006, when the shore-based PWR started operating. All aspects of the project were done for the first time by us. We operate this reactor to generate data to be used for the sea-going version. We are doing a lot of research and development [R&D] that will go into future PWRs, he said.

Banerjee explained the several challenges the designers faced in developing a reactor for submarine application. It was a different ballgame altogether to build a nuclear-powered pack for a submarine than building one on the shore. The first and foremost was that it should be compact enough to be packed into the cramped space inside the boat. Its weight should be minimal. Another requirement was that the power in the reactor in a submarine should rise fast from 25 per cent to 100 per cent within a few minutes. It is this attribute that gives the submarine its capability of attaining full speed from its cruising speed within a short time, he said.

A submarine is a moving platform. It is submerged in water too. It undergoes pitching and rolling and other motions. The boat also faces the danger of being ripped apart from depth-charges. Against these odds, we have designed and developed this reactor. It is a major achievement, said Banerjee. The PWR in Arihant is designed for fast manoeuvres and a rapid speed pick-up.

There are novelties not only in its design but in its manufacturing. The steam generator, which produce super-heated steam to drive the turbine, is a novelty in itself. There are also novelties in the design and manufacture of heat exchangers, control rod mechanisms, pressurisers and so on.

Safety was the foremost consideration in building this PWR because a submarine operated in an isolated condition, without having any support from outside, said Banerjee. The vessel is designed in such a manner that it releases no radioactivity into the surroundings in the submerged condition.

Asked whether the Russians helped in designing and building the PWR, Kakodkar, Banerjee and Basu were emphatic that BARC developed it on its own. Banerjee said: The Russians were consultants. The consultancy was done for the whole submarine, not for the power part alone. Basu asserted, Everything is totally indigenous [in this PWR]. We developed it. It is our own reactor. We did not take it from anybody else.

M.R. Srinivasan, former AEC Chairman, was also emphatic that the DAE developed the reactor on its own. While building the reactor was always a part of the DAEs activity, the Navys role was to design and build the submarine, he said. So it was a joint DAE-Navy project. Srinivasan said, The naval personnel had some assistance from Russia in designing the submarine, but the reactor is a totally Indian effort. The reactor, its components including the pressure vessels, and its fuel were made in India by Indian industry.

The ATV programme has a chequered history. According to Srinivasan, the idea of building a nuclear-powered submarine took shape about 25 years ago. If Indias nuclear weapons had to survive a first strike, they should either be kept in silos or deployed in submarines. Since India had accepted the principle of no first use, that is, it will not use nuclear weapons first, it decided that its nuclear weapons should be made secure not only in land-bases but in submarines.

The decision that the DAE should build the propulsion for a nuclear-powered submarine was taken during Indira Gandhis time and it was followed up during Rajiv Gandhis prime ministership. While the earlier view was to use plutonium as fuel for the nuclear propulsion, it was later decided that India should use enriched uranium, produced at the Rare Materials Plant, to fuel the reactor.

Srinivasan called the launching of Arihant a creditable achievement. It took time, but a lot of technologies had to be developed in the country. The Bhabha Atomic Research Centre and the Indian industry have done a very good job, he said.

While Larsen & Toubro did the tough job of building the hull, there were contributions from Walchandnagar Industries Limited and others.

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