Monday 6 August 2007

Safety--Indian Nuclear Plants

Business India, March 14-27, 1994

Crying Wolf

Exaggerated fears about safety in the Indian nuclear power industry obscure the more pressing regulatory issues.

Shivanand Kanavi

A fortnight ago the American TV network, CBS, broadcast a film on India's nuclear power stations -Another Chernobyl? The film described the Indian nuclear programme as the most dangerous in the world and cited numerous 'instances' of unsafe operating practices at Indian nuclear power plants. Unfortunately, in its eagerness to titillate a jaded American TV audience, CBS overstated its case. Sensational they may be, but such exaggerated accounts, in fact, obscure and detract attention from the very real technical and safety problems that bedevil the nuclear industry everywhere.

Concern has, however, centred on what CBS correspondent Steve Kroft described as "the crack in the Rajasthan reactor.” Unit I of the Rajasthan Atomic Power Station, at Rawatbhatta, commissioned in 1972, has developed certain problems, which have worried nuclear engineers. It is important to understand the nature of these problems.

The crack in the 'endshield' was discovered in 1981. The endshield is an attachment to the main reactor vessel called the 'calandria’. The fuel bundles pass through the end shield and are defuelled or refuelled through it, on line. The endshield does not contain radioactive fuel or the heavy water coolant that is used both to draw the heat away from the nuclear reaction to the steam generator and as a moderator to control the chain reaction within the limits suitable for steady power production. Plain water is circulated through the endshield chamber. Unlike the heavy water, this water does not become radioactive. Due to a minute crack in the endshield some of this water was found to have trickled into the containment chamber. It did not cause any release of radioactivity inside the reactor or to the outside environment.

The reactor was immediately shut down, and investigations revealed that the crack had been caused by embrittlement due to neutron bombardment of the carbon steel plate. The reactor had been designed by Atomic Energy of Canada Limited. They too had faced a similar problem earlier at their plant at Douglas Point, in Ontario, Canada, and subsequently had changed over to another material for fabricating the endshield. But following the 1974 nuclear explosion at Pokhran, Canada had ceased all nuclear co-operation with India, and Indian nuclear engineers had to fall back on their own resources to deal with the problem.

The Atomic Energy Regulatory Board, the Indian watchdog body for safety in all installations handling radioactive materials, immediately stepped in. The AERB along with reactor engineers at BARC and the Nuclear Power Corporation decided that the crack would not increase nor would it lead to greater seepage if the reactor were operated at half its designed power level, of 220 MW. Since then RAPS-I has been operating at a power generating capacity of 100 MW and the crack is being continuously monitored.

The crack has caused more worry to the power engineers than to the safety personnel. Indium foil, which has the property of changing shape under pressure and seeping into cracks, thereby sealing them, has been pressed onto the endshield crack. The fuel channels near the crack have also been defuelled as abundant caution. Attempts are also on to design methods to reach the endshield and replace it with a new stainless steel one. These attempts will take some time to fructify but can then be used profitably at all reactors as they ‘age’.

Even in the worst case scenario of the end shield cracking open and all the water pouring out, there will be no radioactivity released, either inside or outside the station. The reactor will be immediately shut down and unless methods are developed to safely clean the leaked water and replace the endshield, the reactor will be permanently shutdown by the AERB.

The other problem that is being monitored in RAPS-I&II and MAPS-I is the sagging of the primary heat transfer tubes within the reactor. These are tubes containing pressurised heavy water which carries away the heat from the nuclear fission taking place inside the fuel bundles. These pressurised tubes are separated from the calandria tubes by a concentric gap of 8mm by garter springs placed at intervals. While the heavy water in the primary heat transfer tubes is at about 270 degrees Celsius, the calandria tubes are surrounded by cold heavy water, used as a moderator, at 70 degrees Celsius.

It has been observed that due to vibrations within the PHT tubes, the springs tend to shift from their positions leading to a lack of support at certain portions of the PHT tubes. The weight of the zircalloy PHT tube containing heavy fuel bundles makes it then sag. If the sag leads to contact with the colder calandria tube, a local cold spot which develops at the point of contact leads to the accumulation of deuterium in the zircalloy tube at that point, which can lead to blistering and even a possible rupture, leading to the coolant draining away from the PHT tube. Even in such an eventuality the heavy water is still not released outside the reactor. The reactor will have to be shut down and the particular tube isolated. The same loss of coolant in a boiling water reactor will lead to an extremely serious accident, as witnessed in the Three Mile Island, US. The Indian pressurised heavy water reactor is much safer in that respect.

When such blistering was observed in the Pickering reactor, in Canada, the Canadians switched over, in 1983, to a better material called niobium-stabilised zircalloy with a greater support of a larger number of more or less fixed garter springs. Again, due to the embargo on Indo-Canadian nuclear exchanges, the information reached India only in 1985. Since then all reactors are being periodically monitored for any sign of sagging using an ultrasonic probe developed by BARC. BARC and the NPC are also developing a complex retubing machine that can change the old tubes with the newly developed niobium-stabilised zircalloy tubes. The newer reactors at Kaiga and Kakrapar are fitted with these newer tubes.

Another worrisome problem is the corrosion of some valves that use cobalt alloys. Their corrosion, though very small, leads to cobalt being exposed inside the reactor to radiation which coverts into radioactive Cobalt-60. This isotope has a long half-life and poses an exposure risk to workers carrying out maintenance. However, a very positive development in this regard is the development of a chemical method using dilute organic acids to remove this CobaIt-60 from the system. It has been recently used successfully in MAPS-I; the results showing the reduction of radiation ranging from 50 to 97 per cent was reported in the last week of February at the International Conference on Operational Safety of Pressurised Heavy Water Reactors.

Conversion of small amounts of heavy water in the reactor to the deadly tritium is another problem that is monitored in all Pressurised Heavy Water Reactors, Recently BARC has also developed a method to remove tritium from the heavy water used in reactors. Its on-line application is still to be developed but has given a fillip to all those concerned with safety.

Dr A. Gopalkrishnan, a nuclear engineer from the University of California, at Berkeley, who worked on reactor designs and safety in various establishments in the US for 15 years, now heads the Atomic Energy Regulatory Board. While being proud of the achievements of our scientists and engineers regarding safety, he has a very clear agenda for higher safety standards in Indian nuclear power stations. Right now no individual worker is exposed to more than internationally accepted levels of radiation, but this is being achieved by using more manpower and rotating them so that the accumulated dosage per person is still at international levels.

But Gopalkrishnan is not satisfied with this arrangement. Most exposure happens not during the operation of the plant but while maintaining it or carrying out some repairs. He says, "More attention to local shielding, training repair crews using mockups prior to the job so that they spend the least amount of time in radiation zones, semi-automation of maintenance and inspection jobs, will definitely bring the total dosage of all workers in a plant to international levels.” Internationally acceptable radiation exposure levels are continuously being scaled down, leading to pressure on our own nuclear establishment to better safety practices.

Following the fire at the Narora Unit-l power station in March 1993, the AERB initiated a planned shut down of all nuclear power stations to check for faulty turbine blades. Cracks in a few blades in the General Electric-designed generator at Narora had led to the fire that caused damage worth over Rs.75 crore and considerable revenue loss due to plant shut down. Though over 50 such sets worldwide have shown cracks after prolonged usage, the sets used in India tend to break down earlier due to unstable conditions in the Indian power grid system. Due to wide load fluctuations, the frequency of the alternating current in the grid varies widely between 49 Hertz and 51.5 Hertz, leading to dangerous vibrations in the turbine.

The AERB' s insistence on checking all the turbines meant a loss of revenue for the NPC, but already the precaution has yielded results. Four blades with cracks were found in MAPS-l in Madras recently by the independent consulting group from the Central Mechanical Engineering Research Institute that carried out the tests. Though very new, the Kakrapar-I turbine is also being checked and, in fact, all blades are being replaced with design modifications made by BHEL. The Narora fire was not in the reactor but in the turbine and the safety systems of the reactor operated as designed. That is why although it was a financial disaster; the fire was classified on the Nuclear Events Scale - a sort of nuclear 'Richter scale' - as a level-3 incident and not an accident.

When asked why no official report has been published so far about Narora to allay public fears and permit informed debate, Gopalkrishnan says, "My aim is to make at least safety related information as publicly accessible as possible. Instead of leaving this to the individual initiative of the chairman of the AERB, it is better that it is statutorily recognised as well."

Regarding some of the questions raised by the critics about the radiation hazard at the thorium-rich, monazite sands in Kerala and the unusual number of deformities among people in villages around the Rawatbhatta power station, Gopalkrishnan says, "A highly rigorous epidemiological study is being conducted at Chavara, Kerala, by the regional cancer research institute. In another year the results will be available. Let us wait till then. Meanwhile, no such epidemiological work can be conducted in the villages around the Rawatbhatta plant since the sample size is too small to come to any conclusion. However, according to the suggestion of Dr Sanghamitra Ghadekar (an activist who has herself painstakingly collected the Rajasthan data and who is asking for a scientific investigation), I am going to constitute a panel of genetic and medical experts to analyse it from that angle and see. After all, as far as radiation from the Rajasthan power station is concerned, it has been continuously monitored and no dangerous level of radiation has been released outside."

Given the pressure on PSUs to become profit centres and the temptation on part of managements to take short cuts, the question of safety in nuclear power stations assumes new significance. Due to increased openness shown by the AERB, more individual workers, as well as unions, are directly approaching the AERB, often anonymously, with safety related complaints. The AERB is examining the complaints. However, there is a need to develop a second opinion regarding safety and nuclear engineering. In this respect, it is inexplicable that the NPC is not utilising the safety audit services offered by the International Atomic Energy Agency. After all, the safety services are independent of signing the nuclear non-proliferation treaty and, in fact, Indian experts have participated in such multinational teams to check safety in others' plants.

There is, however, no excuse for not developing nuclear engineering faculties in some academic institutions, like the IITs and the Indian Institute of Science, which can then provide the expertise for a second opinion as well. Besides, without questioning the authenticity of the data provided by the health physics division of BARC, which checks the release of radiation to the environment at all power stations and monitors the individual doses absorbed by each worker, it is clear that constituting the division as a separate body will enhance the credibility of the nuclear programme.

Lastly, while the developments in indigenous nuclear R&D have been impressive, particularly in the light of the embargo both in the supply of equipment and technical information to India, the weaknesses are there for all to see. For example, while all the reactors are working at lower than their rated capacity, the natural focus should be on carrying out well-focused R&D. At this stage the hurry to also develop advanced reactor systems, fast breeder prototype reactors, etc, shows that, without solving the problems at hand, there is a tendency to go on to the next prestigious project. In fact, it is most puzzling that BARC wants to have its hand in every scientific pie, whether parallel processing, superconductivity, or lasers, which can very well be done by other academic and R&D institutions. It would do well to concentrate instead on making our nuclear programme both safer and economically successful.

The International Nuclear Event Scale

Level and Examples

Major accident, 7 ,Chernobyl, USSR, 1986

Serious accident, 6, None

Accident with off-site risks, 5, Windscale, UK, 1957 and Three Mile Islands, USA,1979

Accident mainly in installation, 4 , Saint- Laurent, France, 1980

Serious incident, 3, Narora, India, 1993, Vendellos, Spain, 1989

Incident, 2 , None

Anomaly, 1, None

Special Report--Bhabha Atomic Research Centre

Business India September 6-19, 1999

Thorium is the word

Often criticized for being covered in a shroud of security and secrecy, Bhabha Atomic Research Centre has been the incubator of many strategically important technologies. Today Anil Kakodkar is focusing BARC on developing thorium technology for power generation

Shivanand Kanavi

When you are finally able to get through the security shielded gates of BARC understandable after Pokhran-II - and enter its labs ensconced in verdant surroundings in Trombay, you are likely to hear only two words - Thorium and mum. Ask director Anil Kakodkar or any senior scientist about the future of BARC and they will say, "Thorium". But if you want to know anything about Pokhran-I1, thermonuclear bombs, nuclear submarines, and so on, be warned - mum's the word.

A band of highly motivated scientists and engineers went about building Apsara, the first nuclear reactor in Asia, more than 45 years ago at the Atomic Energy Establishment, Trombay. Today they have converted that marshland into a veritable storehouse of science and technology. "As far as scientific and engineering expertise goes, I think we have a goldmine here," says Anil Kakodkar. A 56-year-old nuclear engineer, Kakodkar threw away several offers from the private sector after his graduation from VJTI, and joined the atomic energy establishment against the wishes of his friends and relatives, but he has not looked back since then.

"Every day here, is a challenge for an engineer or a scientist. We have vastly grown since those early days and today have over 4,500 scientists and engineers on this campus and about 10,000 technicians and support staff. Naturally the informality that existed then is difficult to maintain, but as for scientific dissent, we thrive on it. In fact, if we had all the division heads here for this discussion on BARC we may not have a very peaceful session!" he says.

Is the money spent on BARC commensurate with its output? One observer who preferred to remain anonymous said: "Half of India's R&D budget has gone into atomic energy. Is that justified?" This is a question often asked both by the lay public and in scientific circles, though it has been muted after the five nuclear explosions in Pokharan in May 1998. For most people BARC has always meant the bomb, but why are scientific circles envious of BARC? The answer, naturally, is money. When research funding in India has been meagre the fight for a share of the pie becomes intense.

Indian universities are starved of research funds. Even leading universities do not have any. Many top-ranking universities have cut down the number of research journals they used to subscribe to for want of money. As for modernising labs and other infrastructure, the less said the better. Increasingly, they are being asked to raise funds from non-governmental sources, primarily industry and alumni. Even the blue-eyed boys of higher education and research in the IITS found it traumatic when they were told that government funds were no longer available.

However, the IITS have been lucky. Criticised for their flight to North America, it is these very alumni that are coming to their aid. The IITS are increasingly tapping them for funds and are having some success. Kanwal Rekhi, a successful entrepreneur in the Silicon Valley, is in fact confident that nearly $500 million can be raised from IIT alumni worldwide if the idea is marketed properly. University Department of Chemical Technology at Mumbai has pioneered non-governmental fundraising through industrial consultancy and donations from alumni. Of course, it helps when UDCT'S alumni practically run India's chemical industry. But one swallow does not a summer make.

The 44 national laboratories of CSIR which form the largest chain of publicly-funded R&D labs in the world have an annual budget only twice that of BARC! However, CSIR saw the writing on the wall in the late 1980s and, in the past five years, under R.A. Mashelkar's leadership, has implemented a vigorous programme of innovation and technology marketing worldwide. This is making a positive impact on R&D in India in terms of a trend, though the large numbers have yet to come. In such a situation, would you grudge a scientist outside atomic energy and space a little bit of heartburn?

So what has been the outcome of R&D at BARC? Strategically it is clear that the single most important contribution to India's nuclearisation programme has come from BARC. Its founders were way ahead of their times and invested in a small way in many technologies that have proved strategically indispensable. For example, reprocessing spent fuel from power reactors and some research reactors leads to recovery of fissile material like plutonium, which can be used to either build fission bombs or fuel other power reactors. It is obviously a dual-use technology.

Research into reprocessing started way back in 1963-64, much before any fuel needed reprocessing. In fact, India is one of the very few countries today which has this complex chemical technology. This work has two aspects. One, obviously, was Pokharan-I in 1974. But it also led to reprocessing at an industrial level, so that today reprocessing plants at Trombay, Tarapur, and Kalpakkam are operating with BARC technology. The simultaneous work on fast breeder reactors with French help has led to important cumulative experience in this technology so that a new Indira Gandhi Centre for Atomic Research has been built at Kalpakkam near Chennai to develop this further towards building a 500 MW-prototype fast breeder reactor. Such a reactor will produce more fissile material than it consumes, roughly in a ration of 1:1.2, and hence the name 'breeder'.

Similarly, the unit in BARC which assembled instruments for controls at Apsara and later CIRUS (Canada-India Research Reactor) was spun off as Electronic Corporation of India (ECIL), which produces control instrumentation not only for all the reactors but also for several defence projects. The work done on heavy water production using a new hydrogen sulphide process has been industrialised under the Heavy Water Board, which runs several plants that produce heavy water for the power reactors.

A small group at BARC known as the Atomic Fuel Division took on the challenge of fabricating fuel for the Apsara, CIRUS, and Tarapur plants despite the fact that the original equipment suppliers from the UK, Canada, and the US were ready to supply it themselves. This work led to the large industrial Nuclear Fuel Complex at Hyderabad that fabricates all the fuel elements required for the power reactors. The isotope division, which used research reactors like CIRUS and, later, Dhruva to produce over a hundred radioactive isotopes for medical and other applications, has spun off another industrial unit, BRIT (Board for Radiation and Isotope Technology). Today over 150 hospitals practice nuclear medicine and about 500 laboratories use radio-immuno-assay techniques. Nearly a million patients a year in India are investigated using radio isotope techniques developed at BARC, with isotopes made industrially by BARC. Moreover, 350 commercial organisations have sprung up to service the need for isotope radiography used in non-destructive testing of industrial plants.

The nuclear power plants themselves require a lot of R&D work for operation and maintenance. Some of it involves advanced reverse engineering in adverse circumstance when you do not even possess the drawings of spares, as in the case of Tarapur Atomic Power plant, in other cases it involves innovative work to keep the power running. For example, Kakodkar is proud of the work done to get the reactors at Chennai on line when they were about to be shut down for good because of a moderator manifold collapse in the heart of the reactor. Similarly, when the coolant channels in the two Rajasthan reactors had to be replaced, BARC developed the expertise and the robotics required - a highly complex engineering challenge. Till then only Canada had the technology, but the BARC-NPC technology was much cheaper and accomplished the task in less time and well within the radiation exposure limits.

"If you want to discuss the commercial or industrial applications of R&D carried out at BARC then these are some major ones. Our mandate has been to develop the technology of applying nuclear energy for power and other purposes. It is clear that BARC has been the mother institution for the entire nuclear industry in India," says Kakodkar. "The monies earned through transferring some of the spinoff technologies like the enzyme-based process to manufacture invert sugar, used heavily in biscuits and the confectionery industry, or particle size analysers are used in the pharmaceutical industry, etc, are incidental. Unlike CSIR laboratories, which were set up to develop processes and technologies for existing industry and earn money through royalties and licensing, were set up to give birth to many industries which did not even exist," says A.K. Anand, director of the Reactor Projects Group, who is in charge of technology transfer and international relations.

"For example, the expertise in robotics developed at BARC under M.S. Ramkumar's leadership is of a very high standard. We had to develop it to build an online fuelling machine for the power reactors and then a coolant channel inspection system for the same.Just then Indian Oil Corporation, which owns over 6,000 km of overland cross-country pipelines, tapped this expertise. Thus came into being the Instrumented Pipeline Inspections Gauge (IPIG), which will soon be tested on the Patna-Barauni pipeline. Since IOC pays over a Rs11akh per kilometre for such an inspection to foreign companies who hold proprietary technologies, the development of IPIG is very welcome," says Kakodkar. "Similarly, several groups started working on parallel processing in the early 1990s in India when the Cray XMP computer was denied to us and even the purchase of the Cray XMP by the meteorological department had several humiliating conditions attached. Our supercomputer group produced Anupam, which has reached 1.3 gigaflop speed and is the only Indian supercomputer that is successfully running the weather modelling programme," he adds.

Being such a hi-tech centre, isn't BARC concerned about intellectual property rights (IPR)? "We are slowly becoming aware of IPR in the case of non-nuclear technologies and are preparing to protect some of our innovations. As far as strategic technologies are concerned the issue does not arise. If somebody is ready to licence these technologies for a fee there is no problem. We can then say there is a free market for technology. But if such technologies are brought under sanctions and embargoes, where is the issue of patents?" asks Kakodkar, warming up to the subject of IPR.

"In the 1950sand 1960s, when there was hardly any high-technology infrastructure in the country. But now that there are the IITS, the CSIR labs, etc, is it necessary to do everything under one roof and that too such diverse things as biotechnology, lasers, and parallel processing?" ask some critics. Kakodkar says things are changing. He believes in networking and that is why there is an increasing emphasis on partnering with universities, the IITS, and the CSIR labs. At the same time he claims that only four engineers worked on Anupam and that, some of the biotechnology was a by-product of work being done with nuclear applications in mind. "We have a simple guideline to approve projects - they have to be relevant or excellent. That gives a general focus to the work. The specific focus, of course, is thorium, while work on isotope technology will continue," he says.

What is thorium technology and what is its relevance to India? "India has a limited supply of uranium (estimated reserves are only 78,000 tonnes) as against 518,000 tonnes of thorium. Therefore, to achieve long-term energy security, it is imperative to develop technology for large scale electricity generation using thorium," says R.K. Sinha, head of the reactor engineering group. (see box)

While the reactor engineering group is busy setting up critical facilities for advanced heavy water reactors that will use large amounts of thorium as fuel, K. Balu and his group at the nuclear recycle group are already studying reprocessing and waste treatment for thorium. Balu's group is credited with having developed the vitrification technology that will immobilise highly radioactive nuclear waste in a glasslike structure so that the waste will not leach out. This glass will be further covered by two stainless steel jackets and then lowered into a thick concrete vault built into basaltic rock. The site is chosen so that there is very little seismicity in the area and no fissures that carry groundwater. "The technology is there, though it will be used several decades later," says Balu.
Thus the whole cycle of making fuel bundles, designing reactors that will burn thorium, reprocessing the spent fuel, and disposing of waste are being worked on today with thorium as the centre. "Just as the technology that we are now using in power reactors was developed about 30 years ago, we need to start developing technologies that will be used 30 years hence," says Kakodkar.

Pokhran fallout

"A major management technique that Kakodkar is associated with at BARC is the formation of multi-disciplinary task forces," says A.P. Jayaraman, a senior scientist who now heads the public awareness division. "We have at least 20 major task forces operating today," says Kakodkar. "The composition is purely need-based and not hierarchical. These groups also work in a very transparent way - nobody can hide behind technical jargon to explain why he did not fulfill his task"
Like all hi-tech organisations in the country, BARC is losing up to 30 per cent of its young scientists working in computers and electronics within five years of their joining. But Kakodkar points out that this is happening in the IT industry itself. Pokhran-II, of course, has helped attract young people to BARC. Recently, when he went to deliver the convocation address at IIT Madras, the generally self-effacing Kakodkar was faced with hordes of IIT graduates asking for his autograph. "For the first time in my life," he says.

Did Pokhran-II create butterflies in his belly? "Surprisingly, no. In fact the only time I remember spending a sleepless night was when, as a young engineer at BARC 30 years ago, I went ahead with designing and putting together a high-pressure, high¬ temperature loop beg, borrow, or steal. The day before it was to be tested I could not sleep as I had not listened to the traditional wisdom of some of my senior colleagues and had done what I thought was right. But the next day it worked." Kakodkar still carries the courage of his convictions, but has grown wise enough to carry his junior and senior colleagues with him. At BARC undoubtedly there is a spring in everybody's step. Pokhran has contributed to it in no small measure and Kakodkar's leadership no less.

BARC budget
Rs crore
1996-97 1997-98 1998-99 1999-2000
(salaries, Consumables) 220 290 330 340
Capital ex (new assets) 42 57 103 200

Unlocking thorium secrets

India would be a leader in nuclear technology if it develops the thorium cycle for power.

Thorium has several advantages over uranium.
• Worldwide thorium deposits are three times more than that of uranium. In India’s case it is nearly seven times.
• Thorium is a more fertile material than natural uranium, i.e. there will be a larger percentage of thorium 232 converted to fissile uranium 233 than uranium 238 converted to plutonium 239 in the existing pressurised heavy water reactors.
• Thorium is a better conductor of heat and that makes the fuel bundles last longer in the reactor without significant deterioration.
• Long-lived radioactive by-products (actinides) which create waste disposal problems are produced in much less quantity in the thorium fuel cycle than with uranium.
BARC today is concentrating on all elements of a thorium fuel cycle, from fuel fabrication to reprocessing and extraction of uranium 233 while avoiding the complications posed by the highly radioactive U232, and then disposing of the waste produced during the thorium cycle. For experimental purposes thorium is already being loaded into existing power reactors. This has not only helped in power-flattening in the core of the reactor but also provided some quantity of U233. Exposing thorium to neutrons in the Dhruva research reactor has also generated small quantities of U233. A new research reactor Kamini has been built using U233 and thorium.

The whole three-stage nuclear programme might take considerable time for both technological and financial reasons. For example, according to the original plan, 10,000 MW was supposed to be produced by 2000. However, after the Nuclear Power Corporation placed orders with equipment suppliers for advanced procurement and so on, funding was withdrawn by the Central government. That left both NPC and Indian industry involved in hi-tech nuclear fabrication high and dry.

Business India is witness to the fact that two 500MW reactors, which will now be erected in Tarapur around 2004, were already fabricated and lying ready in 1993 at BHEL, Walchandnagar, and L&T! Thus the biggest brakes on India’s nuclear power programme have been the planners in Delhi rather than the Department of Atomic Energy.

In such a situation Kakodkar and his team at BARC have come up with an innovative intermediate solution called the advanced heavy water reactor (AHWR). This technology is highly competitive compared to the existing technologies in several ways:

• Instead of heavy water, ordinary water is used as a coolant.
• The complexity of steam generation is greatly reduced, thereby reducing delivery time.
• Natural convection used in safety systems reduces the capital costs considerably.
• It is thermally more efficient due to the use of moderator heat in preheating feed water.
• Coolant channels can be constructed on an assembly line, thereby reducing construction cost and time.
• It is safer than existing reactor technologies.
The additional advantage of AHWRs will be the use of a large amount of thorium in the fuel. However, since nobody in the world yet possesses thorium technology, BARC’s efforts today will start having positive economic effect in 2020. Considering that the technologies being used industrially today for power production were actually worked on 30 years back that is really investing in the future.

Radiation with a heart

The word 'radiation' conjures up images of the deformed bodies after Hiroshima. However, radiation can be lifesaving as well. Besides the well-known gamma irradiation of tumours using Cobalt-60 units that are supplied all over India by BARC, the centre's scientists have also come to the rescue of cardiac surgeons. One of the techniques used to save cardiovascular patients suffering from choked arteries is angioplasty.

Simply put, the surgeon sends a tiny balloon into a choked artery and inflates it at the right place. The additional internal pressure thus expands the blood vessel, facilitating the flow. To make sure that the arterial walls do not collapse, surgeons insert tiny metallic coils called stents within the blood vessel. However, these stents can cause tiny injuries to the walls and when these injuries heal the scar tissue can choke up the vessel again.

BARC scientists led by S.M. Rao and his team at the isotope division came up with a solution for this fatal problem. They coated these stents with tiny amounts of radioactive phosphorus so that wounds caused by stents are cauterised in a short time, preventing scar formation and saving the patient's life. Already 30-40 such implants have been carried out by surgeons on Mumbai with a very good success rate. Currently multicentric trials of this technique are being carried out and, if successful, will give patients undergoing angioplasty a new lease of life.

Nuclear medu wada

Hardly any body outside of BARC or its nuclear agriculture division and a few agriculture universities might know that 95 per cent of urad dal (black gram) grown in Maharashtra is a BARC product. Urad, a pulse whose flour is the main ingredient of medu wada, a popular south Indian snack, is produced with varieties developed by genetically altering conventional breeds through irradiation. The variety TAU-1 has led to an increase of yield per hectare by 29 percent.

Similarly, a popular mustard variety grown in Assam is another BARC product. The widely exported large-sized groundnut is another BARC product Trombay Groundnut (TG-1). Today more and more varieties of ground nuts, soya beans, moong dal, and tur dal, are produced with higher yields, pest-resistance, and other desirable qualities.

Plant breeders and farmers depend on the genetic variability available in nature for cross-breeding and developing new breeds. The former is the result of .spontaneous mutations. However mutations can be induced artificially to enhance variability manifold. One of the most efficient methods of changing plant genes (mutagenesis) is exposing the seeds to neutrons or gamma radiation. The irradiated seeds are deeply studied to understand the effect brought about by irradiation and it has been found that best results are obtained when these modified seeds are further used in cross-breeding. BARC has been working in this field since the early 1970s and the result is a little-known but significant contribution to increased food production.

Indian Nuclear Industry

Business India, December 6-19, 1993

The Nuclear Fallout

With the nuclear power programme facing a serious resource crunch, industries will have to explore new options for using their nuclear-related skills.

Shivanand Kanavi

When we talk of nuclear power we talk about its economic viability, envi­ronmental hazards, fears of radiation leak­age, waste disposal, or even problems regarding closing down the reactor after its useful life. But the other spin-offs to our economy - in terms of scientific-technical manpower, engineering skills and capaci­ties, not to talk about the bottom lines and business turnovers - have not been studied in any detail.

These spin-offs have been varied. Since the 1960s, when India start­ed generating electricity us­ing nuclear power, a host of industries have sprung up in heavy engineering, fabrica­tion, and construction. All these owe their entire devel­opment of skills, quality consciousness, confidence to tackle bigger and bigger problems (in size as well as in technological levels), to their participation in the in­digenous nuclear power programme.

Anyone who does not know the abysmal condition of our laboratories and uni­versities in the 1940s, and even our engineering indus­try in the 1960s and early 1970s, cannot easily appreciate the spin ­offs that have occurred due to the nuclear programme. M.S. Krishnamurthy, joint general manager, of the engineering giant, Larsen and Toubro, who has been associat­ed with the nuclear program for over 25 years, says, "Without the push given by the nuclear power programme we would not be able to do what we are capable of doing today. In the pre-nuclear era, we used to make some equipment for dairies and small cement plants, that weighed a couple of tones. Today, we have moved into the third generation of heavier precision engineer­ing at Hazira that can fabricate components weighing up to 450 tonnes."

This technological advantage works out in other areas as well. For P.J. Bhounsule, sales development manager, L&T (an IIT graduate who has worked on nuclear projects for nearly two decades), the engi­neering challenges they encountered while catering to their nuclear commitment were of the toughest variety. "One of the toughest assignments we faced was the welding of the two halves of the half-a-metre thick steel disk, that was the deck plate of the Dhruva reactor," says Bhounsule. "The weld had to be so perfect that even the tiny atoms of helium couldn't leak through. Simple heating of the two lips in the joint, led to unequal expansion along the diame­ter and circumference of the half disks, leading to gaps between the lips of the joint. We had not calculated the different heat sink characteristics. This led us to use com­puter simulation for the first time."

An analysis of the results revealed that the problem could be solved if the disks were thermally insulated and heat provided at twenty-five distributed points all over. "Finally, we machined channels into the lips so that they could lock into each other and after careful deep welding from both sides of the disk, we got the defect-free weld," claims Bhounsule proudly.

This precision and problem-solving ca­pacity that they have acquired is what all the industries associated with nuclear technol­ogy praise. T.S. Sakethan, general manager, special products division, Walchandnagar Industries (WIL), proudly shows his hi-­tech dust-free shop floor, ingeniously as­sembled right in the midst of the cranes and fork lifts. He points out a welder meticu­lously welding the tubes to a tube sheet in a heavy water heat exchanger. The Welds have to be totally defect free," he says. "Normal methods of non-destructive test­ing (NDT) like sonography, radiography, dye penetration, and magnetic particle pat­terns cannot be used here, so we do statisti­cal quality analysis. The welder has to be trained in the technique for months together and pass all sorts of tests."

But even this is not enough. The welder's skill is constantly checked out, since there is little or no room for error. "Every day before he starts work, he has to weld a few sam­ples, which are then phys­ically sawed off and tested for defects," says Sa­kethan. "Only when the samples show zero defect is he allowed to touch the job that day." This may sound unnecessarily time­consuming but with the risks of nuclear leaks tak­ing precedence over all else, it's a necessary precaution.

One corollary to this kind of nit-pickety precision is that cus­tomers of nuclear manufacturers are posi­tive that they will get quality that's of the best kind. P.J. Bhounsule of L&T says, "The philosophy of quality control had to be changed from post manufacture checks to planned quality assurance, systematic definition of manufacturing procedures and documentation. All these have helped us obtain authorisation to use various quality stamps of the American Society of Mechanical Engineers and the ISO 9001 certification. "

M.L. Mitra, director, environment and public awareness, Nuclear Power Corpora­tion, who was deeply involved in the hand­holding operations in the early years, recalls, "We had to convince many in the industry that quality does not mean higher cost but lower project cost."

As the confidence in their technical abilities and quality grew, the industries were able to take on more challenging tasks. Currently, nuclear man­ufacture involves the stan­dardised design of the 235 MW reactor, the consolidation of infrastructure and manufac­ture using the convoy system, cutting project time, the design and manufacture of 500 MW reactors for Tarapur III and IV and Rajasthan III and IV. The industries have also built components for the heavy water projects and the Fast Breeder Test Reactor. Now, the pool-type Prototype Fast Breeder Reactor to generate 500 MW, using liquid sodium, has been designed and the industry will participate in its fabrication as well.

But perhaps the best spin-offs to these nuclear-affiliated industries have been in terms of turnover. L&T alone has done Rs.312 crore of nuclear work. Bharat Heavy Electricals, which has gained the maximum benefit, has made over Rs.800 crore. Most of the business is pure profit in ­the industry only has to pay for labour costs, as the raw materials are provided by the DAE and the NPC.

Besides its contribution to corporate bottom-lines, what have been the spin-offs in terms of new business? "With our expertise, if not on a turnkey basis, at least as critical component manufacturers, we can get con­tracts from multinationals who want to set up industries in India," says T.V. Rudrappa, general manager, quality assurance, WIL.

R.D. Hariani, technical director, GR En­gineering. concurs, "Association with the Nuclear Power Corporation has helped us indirectly in getting jobs in other sectors as the quality has been upgraded in an overall sense." Krishan Kumar, general manager of the public sector giant, Bharat Heavy Electricals, is equally upbeat regarding spin-offs, "BHEL has gained considerably technologically through its association with nuclear power. Now, we are in a position to execute the conventional side of the nuclear power plant on a turnkey basis." After the recent fire in the generator in Narora I the turbine generator that was based on GE design is also being redesigned for Indian conditions by BHEL and NPC.

With these design modifications Indian Nuclear-related industries have finally come into their own. They have moved from their total dependence on foreign designs, to making design changes, to finally conceptualising and manu­facturing their own designs. K.R. Balakrishnan, general manager, control panels, GEC Alsthom India. Ltd, who have supplied' over Rs.15 crore worth of control protection equipment and switch gear to all the reac­tors, says unequivocally that association with NPC projects has helped them acquire experience in designing and manufacturing equipment suitable for an earthquake-prone environment.

K.K. Sinha, chairman and managing director, Mishra Dhatu Nigam (Midhani), a PSU set up to develop super alloys, is proud that hundreds of tonnes of very special steel called grade 403 (which is a medium car­bon steel but whose composition is con­trolled within a very narrow range) were produced by Midhani. Similarly, another copper niobium special steel, called 17-4 PH grade, was also developed and pro­duced by Midhani for the nuclear reactor components using electro slag refining and vacuum arc furnaces. Not many countries in the world have these capabilities, says Sinha proudly.

Where to, from here? With the resource crunch threatening India's own nuclear programme options, the logical next step would have been to export the technology. But the government has given very little thought to going into the global nuclear business, although Japan and South Korea are feverishly building nuclear power sta­tions. Besides this, there may be a number of developing countries that will go in for the smaller 235 MW PHWR if the fuel supply can be arranged. Indian expertise in building research reactors had been sought world wide, but India did not pursue it.

The real test of our nuclear industry will come in delivering systems and compo­nents on schedule for international clients. And in the ultimate analysis, the industry will be able to use the skills it has acquired in other fields. For although the nuclear industry is facing a serious resource crunch, the resourceful among them will turn this adversity into opportunity.