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Dangerous encounters

Nuclear plants are intricate, high-risk technologies. Accidents at these centres, even if categorised as "small" or "minor" do not exhaust the possibilities for failure or error. The sheer complexity of the system can be a cause for mishaps. Compounding the problem is the secrecy and control maintained by the institutions. Therefore, argues M.V. RAMANA, it is imperative to make the nuclear complex more transparent, and ensure better design, safety and training.

IT was an accident that was never supposed to have happened. Just three years earlier, an article in the Bulletin of the International Atomic Energy Agency (Volume 25, June 1983) claimed: "The design feature of having more than 1000 individual primary circuits increases the safety of the reactor system - a serious loss of coolant accident is practically impossible. The safety of nuclear power plants in the Soviet Union is assured by a very wide spectrum of measures ...." But, on April 26, 1986, Unit 4 of the Chernobyl reactor went prompt critical and exploded, releasing an immense amount of radioactivity (estimated at somewhere between 50 and 200 million curies) into the atmosphere. Practically every country in the northern hemisphere received some radioactive fallout. Between 100,000 and 150,000 hectares of agricultural land had to be abandoned. Estimates of number of worldwide deaths resulting from the radioactive contamination vary from a few hundreds to tens of thousands.

Chernobyl is not the only case of a major nuclear reactor accident. Nor is the RBMK design that was employed in Chernobyl the only kind that has suffered an accident. Even the much-touted "inherently safe" reactors are not risk free. A 1990 study by the Union of Concerned Scientists concluded: "As a general proposition, there is nothing 'inherently' safe about a reactor. Regardless of the attention to design, construction, operation, and management of nuclear reactors, there is always something that could be done (or not done) to render the reactor dangerous. The degree to which this is true varies from design to design, but we believe that our general conclusion is correct."

The best known instance of a reactor that is not of the RBMK variety and which did undergo a major accident was in March 1979 at Three Mile Island, Pennsylvania, U.S.. Following a cooling system failure, this pressurised light water reactor underwent a partial meltdown. Fortunately only a small amount of radioactivity was released into the atmosphere. But even that small release does have consequences for the people exposed to it. A 1997 study by University of North Carolina epidemiologist Steven Wing suggested that the release might have caused an increase in the rates for lung cancer and leukemia among area residents.

Other countries have been prone to accidents, both in nuclear reactors and associated nuclear facilities, as well. For example, in Japan, the recent criticality accident in the Tokaimura uranium processing plant led to large radiation doses to at least 49 people. The accident comes at the end of a number of others in recent years in Japan, all of which have contributed to a large increase in public opposition to nuclear power in the country. Earlier in July of this year, 51 tonnes of coolant water leaked from the Tsuruga nuclear power station. In March 1997, the Tokai Bituminization facility suffered a major fire, releasing radioactivity that was detected even 60 km away. At least 37 workers were internally contaminated with radioactive cesium. Prior to that, in December 1995, was the massive leak of sodium, which is used to cool the reactor core, in the prototype fast- breeder reactor at Monju as the reactor was operating. A major fire followed since sodium reacts violently with water and burns on contact with air. The fire and chemical reactions attacked the metal lining of the floor to a depth of three cm.

The Monju accident was only the latest in a long series of accidents at fast breeder reactors. In March 1994, during the dismantling of the French fast breeder reactor, Rapsodie, an unexpected reaction involving about 100 kg of sodium led to a violent explosion. One technician died and four others were severely injured. Since Rapsodie was only a small experimental reactor, the magnitude of the accident was limited. Potentially much more severe was the one that occurred at the Enrico Fermi fast breeder reactor in Michigan, U.S.. In October 1966, while operating at about a sixth of full power, the reactor suffered a partial meltdown resulting in radioactive release into the reactor building. Despite these portents, a few countries, including India, have persisted in pursuing fast breeder reactor technology. The vast majority, including the U.S. and Germany, have thankfully stopped.

The decline in countries investing in fast breeder reactors also stems from the general disenchantment with nuclear power. The most recent forecast by the International Atomic Energy Agency, one of whose functions is to promote atomic energy, showed the share of nuclear power to total electricity generated decreasing from the current 16 per cent to somewhere between 10 to 14 per cent in 2020. Safety related concerns and the costs associated with the technology employed to reduce the risk of accidents have played an important part in this decline. For example, in August 1997, over a third of all nuclear power reactors in Ontario, Canada were closed down following an official report that revealed safety problems in them. Safety levels at reactors were said to be only "minimally acceptable" and their performance was said to be "well below the level of performance ... allowed by the world's best facilities."

The performance of Canada's nuclear reactors should be of particular interest to the Indian nuclear programme since the bulk of Indian reactors are based on Canadian designs. However, the Department of Atomic Energy (DAE) seems not to have even taken notice of the Ontario report and examined its own reactors in light of their findings. Nor did the recent Tokaimura accident prompt examination.

Instead, we have the Atomic Energy Commission (AEC) Chairman saying: "There is no possibility of any nuclear accident in the near or distant future in India. We have 150 reactor years of safe operation." This statement goes much further in its conviction than the one about the state of Soviet reactors in 1983. What makes the assurance even more absurd is that at the time of the Chernobyl accident, the Soviet Union had over a thousand reactor years of experience. The confidence is also misplaced because there have been several accidents over the course of the India's nuclear history - these include the fire at Narora, multiple heavy water leaks in Kalpakkam, the collapse of the containment at Kaiga and flooding of the pumps in Kakrapar. It was lucky that some of these did not result in major catastrophes.

Compounding the problem of over-confidence is the secrecy and control maintained by the institutions that construct and operate these reactors. This is not limited to India. But, with secrecy written into its mandate through the 1962 Atomic Energy Act - described as draconian even by a former AEC chairman - the DAE has been able to get away with it in a manner that has not been possible in many other countries. In part, the secrecy reflects the close connection between nuclear power production and nuclear weapons development. But, it also serves to cover accidents, safety violations and poor performance. Therefore, one important step that needs to be taken to reduce the risk of accidents is to make the nuclear complex much more transparent. Making the Atomic Energy Regulatory Board, currently answerable to the AEC, independent and giving it clout to enforce safety standards would also help.

A complete list of accidents at nuclear facilities around the world would be impossible to compile. But, a list like that, even if it is compiled and catalogued according to the kinds of accidents, would not exhaust all the possibilities for failure or error. Nuclear power plants and the associated facilities are intricate, high-risk technologies. As sociologist Charles Perrow has argued, the sheer complexity of the system can be a cause of mishaps, mishaps that he terms "normal accidents" because of the inevitability of systemic failures associated with the technology. In such systems, small beginnings can cause major disasters. The fact that there have been few major accidents so far is no guarantee that they will not occur in the future. What starts as a minor "incident" could quickly spin out of control leading to a huge calamity. At Chernobyl, less than 90 seconds elapsed between a computer warning to shut down the reactor and the total destruction of the reactor. Thus, each and every accident, small or large, should be treated as a close encounter with disaster.

Often, accidents in the nuclear industry are attributed to "human error." But tracing accidents to this cause does not help because operators of such complex systems are frequently confronted by unexpected events and it is only in hindsight that one can say what they "ought" to have done. Alternatively, it is human error at every level - starting from the design and construction of the system, to training operators, to preparing emergency plans to even societal reliance on such systems in the first place - that should be considered as the cause of accidents when they occur. But what human error does cause, humans can also ameliorate if not eliminate. Possibilities for doing so range from some of the obvious - better design, construction, training, etc. - to actively pursuing safer and more sustainable forms of energy production and use.

The writer is a research associate at the Center for Energy and Environmental Studies, Princeton University.

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