An alarmist view on nuclear safety: NPC speaks

Published : May 08, 1999 00:00 IST

India's National Magazine from the publishers of THE HINDU

It is clear from the article by Dr. A. Gopalakrishnan, titled "Issues of nuclear safety" (Frontline, March 26), that the author's main objective is to induce changes in the Atomic Energy Act, 1962 and the powers of the Atomic Energy Regulatory Board (AERB). However, in his attempt to do so, he has made several comments about safety issues at the nuclear power stations operated by the Nuclear Power Corporation (NPC) at Tarapur, Maharashtra; Rawatbhatta, Rajasthan; Narora, Uttar Pradesh; Kakrapar, Gujarat; Kalpakkam, Tamil Nadu; and Kaiga, Karnataka. The comments are not based solely on fact; in fact, they seek to create an alarmist view regarding a national programme as important as the nuclear power programme, which has a tremendous role to play in achieving self-reliance in the energy sector.

At the outset, the NPC wants to set the record straight by pointing out that safety is of the utmost concern to it. Its expertise in this regard is internationally acknowledged. In fact, NPC engineers have shared their expertise internationally by participating in safety reviews and inspection of reactors in other countries conducted by the World Association of Nuclear Operators (WANO) and the International Atomic Energy Agency (IAEA). We are continuously updating our safety systems and procedures even at the cost of short-term economic benefit. Besides, all our plants are designed, constructed, commissioned, operated and maintained under the strict supervision of the AERB. The regulatory agency has pointed out from time to time various safety-related improvements that the NPC should make with regard to systems and operating procedures as a matter of abundant caution. The NPC has been abiding by these directives in letter and spirit. Whenever the AERB's experts have made a suggestion for improvement to the NPC directly, it has taken steps to implement it. We do not consider the AERB, the NPC, various undertakings under the Department of Atomic Energy (DAE) and even the experts in the various Indian Institutes of Technology and other academic institutions in India as being adversaries. We are all part of a single scientific fraternity that has been mandated by the founding fathers of the nation to develop and deliver the numerous benefits of nuclear energy to the nation in an economical and safe manner.

It has been the practice of the AERB to bring to the notice of the Station Directors and other executives of the NPC any lapse or scope for improvement in safety procedures. Such directives have been immediately attended to. In fact, as the licensing authority the AERB has the power to shut down any reactor at any time if it deems it necessary. Dr. Gopalakrishnan deviated from all these practices just before his term ended as Chairman, AERB and came out with a list of 130 "safety issues" and submitted it to the Atomic Energy Commission. The Commission asked the NPC to reply to this report. The NPC found that 95 of the 130 "safety issues" concerned its area of operation and submitted a report to the AEC. Out of the 95 "safety issues", 78 have been implemented and the remaining 17 are under various stages of implementation. Some of them are of a medium- and long-term nature. The AERB has not come under any pressure from the DAE to suppress this report; instead, it has overseen the time-bound implementation of the report.

There are a number of vested interests internationally who are running down India's self-reliant achievements in nuclear energy and have been periodically using the international media to create fear psychosis. "Another Chernobyl in the making", "Sitting on a volcano" and so on have been the refrains, which are nothing but half-truths and motivated lies. It is clear that these international quarters are in no way interested in nuclear safety, but are bitten by the old colonial bug of "white man's burden". Unfortunately, the author's refrain of "130 safety issues" has added grist to the mill.

In order to clear some misplaced doubts raised in the article, the following information is presented:

The NPC's reactors have worked at plant load factors of 60 per cent (1995-96), 67 per cent (1996-97), 71 per cent (1997-98) and 75 per cent (1998-March 1999) and are yielding a handsome return on investment to the government, with net profits of Rs.152 crores, Rs.253 crores, Rs.265 crores and Rs.326 crores (till March 1999) during the respective periods. No doubt the NPC is the envy of any power utility company in India, whether in the private sector or the public sector. The article states: "TAPS-1 and 2 (reactors at Tarapur) should have been shut down long ago." Although these reactors are over 25 years old, their life has been extended; even the parts which the author claims are "uninspectable nor do Indian scientists have the tools or technology for doing this" have been inspected, using sophisticated robots developed by the DAE, and the reactors have been found to be safe. The two reactors are working at above 100 per cent capacity (160 MWe, derated from 210 MWe owing to the non-availability of secondary steam generators) and produced over 2.3 billion units of power in the last 12 months. This, incidentally, is sold to electricity boards at an attractive price of 82 paise a unit. It is a boon in power-starved India. Regarding the Rajasthan reactors, the coolant channels at RAPS-2 have been replaced under the strictest international norms of quality control and tested to the satisfaction of the AERB before restart-up. Now this unit is running well. It is an important feat achieved by NPC engineers. During the same operation, a high-pressure injection core cooling system was introduced. A similar operation of re-tubing and connecting the high pressure emergency core cooling system will be carried out at RAPS-1 as well during a planned shut-down. The MAPS reactors are being continuously monitored for any sagging in the coolant tubes and on the basis of the Rajasthan experience there is a plan to re-tube them as well. Currently they are being operated in a safe manner and in the past year they have supplied over 2.2 billion units of electricity to the grid. GEC, the designers of the turbines at Narora, found that owing to poor water chemistry, the turbine blades had developed small cracks in other installations worldwide. GEC recommended first inspection of blades after 20,000 hours of operation and thereafter every 5,000 hours until the blades were modified. The NPC was planning to carry out the work accordingly. However, the blades failed, leading to a fire after only 16,000 hours of operation. Later it was found that wide-ranging frequencies in the Northern Grid had led to the failure. Thus it was a situation beyond the control of the NPC. However, the fail-safe systems built into the reactor worked, the operators took timely action and there was no nuclear accident. Since then, not only at Narora but at Kaiga, Kakrapar, Madras and Rajasthan, the blades have been modified as a measure of abundant caution though they had thousands of hours more to go. It is not true, as was mentioned in the article, that Narora was on the brink of a core meltdown. Indian reactors are safe against such an eventuality of a fire incident and they will go into a safe subcritical mode in case of a station black-out. After the unfortunate delamination in the inner containment dome at Kaiga-1 during its construction, a stringent design review was carried out to the satisfaction of the AERB. Redesigned domes with high performance M-60 concrete (used for the first time in India) have been built in Kaiga and Rajasthan. These projects are nearing completion after a delay of three years caused by the redesign process. All pre-commissioning tests are being conducted at the sites under the supervision of the AERB. The NPC has not only considered safety to be a paramount requirement but has tried its best to inform and educate the public through its Department of Health, Safety, Environment and Public Awareness headed by an executive at the level of a director. An informed public will support this national endeavour and not panic owing to scare-mongering by misinformed Indians or motivated foreigners when anti-science and irrationalism are on the rise worldwide. The Directorate publishes a large amount of literature, conducts exhibitions, organises seminars and so on to raise the scientific temper in the country. Most of this information is available in the magazine NuPower which is produced by the NPC and distributed freely. Recently the NPC's Web site (https://www.npcil.org) was launched. Anyone who needs more detailed or technical information regarding health and safety at the NPC, its financial performance and so on may contact the NPC's offices. They can also be put on the mailing list for NuPower. We are extremely sad that Dr. Gopalakrishnan, an erudite and knowledgeable engineer himself with whom we have had a long association, is now tilting at windmills. If he wants to educate parliamentarians about the need for a new law or any other matter of public interest, he should use means other than misdirected scare-mongering. M.Das Chief Engineer, Health, Safety & Public Awareness NPC, Mumbai

Dr. A. Gopalakrishnan, former Chairman of the Atomic Energy Regulatory Board, responded to the NPC's comments on his article. Excerpts:

I stand by all the data and information given in my article. The article was written with the twin objectives of arousing public interest towards demanding a truly independent nuclear regulatory agency in India and exposing authoritatively the untruths and misconceptions spread by the NPC and the DAE on matters related to the safety and economics of nuclear power. Let me answer some of the specific comments made by the NPC.

The average capacity factors for Indian nuclear power stations which I have quoted in my article are as published in Nuclear Engineering International (December 1995), calculated by the publication on the basis of data taken from the annual reports of the DAE, the NPC and the Central Electricity Authority (CEA). To my knowledge, the NPC has never questioned these data. Without questioning any of the figures I have given in the article, the NPC has now cited new data relating to the period since 1996; I have no means to check the veracity of the data relating to this period. The international practice is to compute capacity factors on the basis of the initial installed power capacity of a reactor unit. If, as in the case of India, the operating power level of a reactor is lower than this initial capacity, one has to account for this inherent inability to raise power as a shortfall in the capacity factor, since the investment was intended for the initial installed capacity level. By not doing this and manipulating the data in many other ways, the DAE and the NPC are cooking up high capacity factors to mislead the public, Parliament and the Government. Let the DAE publish an open technical report with the complete raw data and an analysis of the economics and performance of nuclear power stations since their inception, including the details of all costs on mining and uranium metal production, fuel element fabrication, waste processing, waste disposal and so on, which are currently not accounted for

The reactors at the Tarapur Atomic Power Station (TAPS), by virtue of their 1960s design, have many highly-stressed crucial inside locations which are unreachable, even with the world's most sophisticated remote-handling tools. This, among other reasons such as the high cost of repairs and modifications, is why similar reactors all over the world have been shut down. Besides being costly, these repairs will require supplies of foreign components and skills that are far beyond the DAE's present capabilities. With all these deficiencies, the TAPS reactors are run at a great risk to the population. The inspections done by the NPC are at best in only 50 per cent of the locations that are inspectable. To carry out these inspections, India again sought assistance from the United States as late as in 1994; the request was turned down. The fact that such a request was made shows that the DAE lacked the technological confidence to tackle the problems in Tarapur. When the Indian request was turned down, I had warned both the U.S. Nuclear Regulatory Commission and State Department officials that the U.S. would be held morally responsible if a major accident happened in the American reactors at Tarapur owing to the denial of spare parts and assistance in inspection. The U.S. responded by saying that India had the option to shut down the reactors, instead of subjecting its people to this increased risk. But the DAE's position hardened following this: it decided not to shut down the reactors but to run them with whate

The low cost of nuclear power and the so-called revenues earned by the NPC are irrelevant. Of course, if the DAE does not spend any money to get qualified spare parts or inspection tools for a reactor, postpones repairs for more than 20 years after they have been identified as essential, and does not take into account the large associated costs in the rest of the nuclear fuel cycle, it is no surprise that it is able to show attractive revenues and profits. All these earnings and much more will evaporate in no time, along with the reactor core, if a devastating accident occurs.

In 1994, the DAE and the NPC approached Canada for consultancy, technical assistance and tooling to carry out the replacement of coolant tubes in the second unit of the Rajasthan Atomic Power Station. If the DAE and the NPC were confident of their technological knowledge and capabilities to do this job for the first time ever in India on their own, why did they seek Canadian assistance? It is difficult to believe the NPC's claim that the retubing at RAPS-2 was done excellently. Neither the DAE nor the NPC nor the AERB has ever undertaken a similar job, and only time will tell whether or not it is indeed a high-quality repair job. The recent incident in which 14 tonnes of radioactive heavy water was spilled at the Madras Atomic Power Station also does not reflect the NPC's claim that it has learnt enough about the maintenance and repair of such reactors.

As regards the cracks in the turbine blades in the Narora Atomic Power Station, GEC recommended the first inspection of blades after 20,000 hours of operation for the company's customers world-wide who were operating their turbines within the stipulated low level of vibration. In India, given the frequency fluctuations in the Northern Grid and the frequent shutdowns and re-starts, the NPC has been operating the NAPS turbines at high levels of blade vibration. And yet, with all the expertise it claims it has, the DAE did not foresee that, given these operational conditions, fatigue failure of blades could occur much earlier than 20,000 hours. In fact, BHEL did realise this and recommended that the NPC replace the blade design before any accident occurred. But the DAE did not act on this advice until after the accident. The cause was an unquestioning belief in a guideline without examining its technical basis and the ground realities in India, which in most cases are much more adverse than those experienced abroad.

The delamination of the containment dome at Kaiga was an avoidable incident. Senior NPC civil engineers and the private firms which provide civil engineering designs and construction drawings to the DAE have had a close relationship. In this atmosphere of comradeship, the NPC engineers did not carry out the necessary quality checks on the designs they received before passing them on to the Kaiga project team. The AERB also did not check this, because it had almost no civil engineering staff with it. Serious design errors went undetected and these eventually led to the failure of the dome. It was negligence by the NPC civil engineering team that caused this. A distorted NPC report, which tried to cover up this reason, was rejected outright by the non-DAE members of the AEC, while the AERB report that spelt out in detail the actual reasons was approved.

Whenever the facts and evidence go against it, the DAE takes shelter behind the AERB, which it created and controls. The AERB's approval has, therefore, no sanctity in the present set-up where the Board is used as instrument of convenience by the DAE to mislead the public, the Government and Parliament. The entire structure and line of control of the AERB needs to be altered and the DAE's hold on it removed if the AERB is to do its job properly.

The NPC statement says that I "deviated from all these practices... and came out with a list of 130 safety issues and submitted it to the AEC." The AERB reports to the AEC; its charter is to carry out independent evaluations of safety. All that the AERB did in 1995 was to refer back to the earlier recommendations of the various safety committees of the DAE, the NPC and the AERB and consolidate the unfinished actions in a report. What was wrong with this? The AERB was fully within its rights, and the entire Board approved its action. It appears to have hurt the DAE because the DAE could not sweep those issues under the carpet with the collusion of the AERB, as it did in the past. Its game was fully exposed in the process. But the preparation of the 1995 Safety Issues Document and its submission to the full membership of the AEC was a bold and necessary step. It focussed attention on the callousness and the negligence of the DAE. One hopes that sincere corrective actions will be taken at least now.

The insinuation in the NPC's comments is that articles like mine are part of the attempt by "vested interests... who are running down India's self-reliant achievements in nuclear energy (with) half-truths and motivated lies." It has been a practice for the DAE to dismiss any criticism of its functioning as the work of anti-nationals. It is unfortunate that the DAE, which prides itself as a great scientific establishment, does not believe in the basic tenets of scientific temper, which should include an honest exercise in self-evaluation and introspection in the face of criticism.

India's nuclear programme was started with the promise of supplying abundant nuclear electricity to the nation. After 40 years of this programme, we have a total derated nuclear power capacity of 1,840 MWe of which on an average hardly 900 MWe had been available over these years - an output less than that of a single conventional power station of the NTPC. Add to this the near-meltdown of the core in Narora, the poor condition of the reactors at the TAPS and the RAPS, the dome collapse at Kaiga, the flooding at the KAPS, and the recent 14-tonne radioactive heavy water spill at the MAPS. The DAE seems to be effectively running itself down without any outside help.

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