Since the explosion of Unit 4 at the Chernobyl nuclear power plant 10 years ago, Soviet-designed reactors--especially the RBMK design used at Chernobyl--have been the subject of considerable scrutiny by experts in the West as well as the former Soviet Union and Eastern Europe. The Source Book on Soviet-Designed Reactors has tracked much of the activity surrounding these plants, from their operational performance to efforts aimed at improving their safety, since it was first issued in 1992. There has been forward movement on the issue of Soviet reactor safety. While neither smooth nor consistent, nor always enough to satisfy, it is progress all the same.
Five years ago, those in the West who had been pressing for the closure of the Chernobyl nuclear power plant appeared to get what they wanted. The Ukrainian Parliament voted in 1991 to shut the plant in two years. With such a short lease on life, safety improvements planned for Chernobyl were scrapped. Growing energy shortages, however, prompted a reversal of the Parliament's decision in October 1993. The plant kept running, but without the benefit of technical upgrades made to similar reactors in Russia and Lithuania--a fact that greatly concerned the International Atomic Energy Agency.
An IAEA team of experts visiting Chernobyl in March 1994 expressed concern about operational difficulties at the plant stemming from the 1991 shutdown decision, about the accelerating loss of highly qualified staff, and--in particular--about the unaddressed design deficiencies of Unit 1, the oldest generation of RBMK reactors. Its conclusion: the plant did not meet international levels of safety.
When the G-7 leaders met in Naples in July of that year, they called for the shutdown of Chernobyl. Ukraine thought about it and then, toward the end of the year, said no. One Ukrainian nuclear expert described the call as an ultimatum, and ultimatums, he said, seldom succeed.
It took more than a year of negotiations for the two sides to reach formal agreement on the plant's closure. And there are still some loose ends, such as the exact date for the shutdown and just where the money will come from to help pay for it. In the meantime, Chernobyl will get some badly needed help. It would be irresponsible not to make safety improvements, says a German nuclear safety expert.
The G-7-Ukraine agreement, signed in December 1995, calls for short-term upgrades to Chernobyl Unit 3. A new U.S. Department of Energy project seeks to improve maintenance practices at RBMK plants, including Chernobyl. Maintenance errors are estimated to account for about half of all safety-related incidents at these plants.
The initial years after the 1986 explosion of Unit 4 at the Chernobyl nuclear power plant were a time of discovery. As details of the accident emerged, experts in the West as well as the Soviet Union and Eastern Europe started analyzing the design and operation of Soviet-designed reactors. What they learned--and shared--convinced them that improvements had to be made. By the early 1990s, the countries with these reactors were making technical and operational changes at their plants, and Western assistance efforts had begun in earnest.
Many of those efforts have borne fruit. That's one reason the Source Book is more comprehensive now than it was in 1992. But it's also bigger because of the challenges. Ranged against the achievements--at least in Ukraine and Russia--are economies on the ropes. Stuck somewhere between a command economy and a free market, these countries face challenges that the West finds hard to grasp. Consumers--especially big enterprises--use electricity from nuclear plants, but they don't often pay for it. So the plants have little money to buy fuel and spare parts, carry out safety upgrades, or pay their employees.
Another challenge facing experts in the former Soviet Union and the West is determining the health consequences of the Chernobyl accident. Screening programs have revealed a sharp increase in the incidence of childhood thyroid cancer in areas of Ukraine, Belarus and Russia affected by the accident. Epidemiological studies to date have shown no increased incidence of other types of cancer or disease, although the latency period for solid cancers--other than leukemia and thyroid cancer--is usually at least 10 years. Researchers and medical personnel have observed an increase in psychological disorders since the accident, a likely result of the tremendous stress imposed on the population of the affected areas.
Epidemiological studies in Ukraine, Belarus and Russia are hampered by a lack of funds, an infrastructure with little or no experience in chronic disease epidemiology, poor communications facilities and an immediate public health problem with many dimensions. The ability to detect future increased cancer incidence depends on identifying and following those groups of people who received the highest radiation doses and those who received lower doses. Without good mortality and cancer registries and dose reconstruction exercises, it will be difficult to achieve a sound correlation between disease and radiation dose.
Many in the West understand the factors driving continued operation of Soviet-designed reactors: the fact that nuclear energy plays a significant role in electricity supply, the desperate state of fossil-fuel plants--many of them old, inefficient and short of fuel, the lack of money to build replacement plants and, in some cases, the need to sell fossil fuels or electricity abroad for hard currency. In Russia, there is also the intangible factor of national pride in a long-established nuclear industry. Finally, as their economies begin to improve, these countries will need safe and reliable sources of electricity as an engine of growth.
For these reasons, few countries with Soviet-designed reactors are likely to turn their backs on nuclear energy any time soon. The transition to safer nuclear technology--and a more stable economy--won't happen without Western help. And much remains to be done. The U.S. nuclear industry understands this, and is actively participating in projects--through the World Association of Nuclear Operators and bilateral efforts--to help these countries improve the safety of their plants.
The Source Book is produced by the Nuclear Energy Institute. NEI, the trade association of the nuclear energy industries, represents almost 300 companies and organizations worldwide.
This edition of the Source Book includes a new section on Armenia. In October 1995, that country restarted Unit 2 at its Medzamor nuclear power plant--shut down in 1989 after a devastating earthquake. The section on Armenia is neither as extensive nor as detailed as those of the other countries with operating Soviet-designed reactors, a shortcoming that will be put right in the next edition of the Source Book.
Finally, a brief word on terminology and transliteration. Most spellings of Ukrainian nuclear plants and place names are transliterations from the Russian, reflecting the legacy of Russian linguistic domination of the nuclear industry in the former Soviet Union. These spellings also tend to be the versions most recognizable to readers in the West. Where transliteration from the Ukrainian is used, it appears in parentheses after the Russian transliteration. Also, throughout the Source Book, the terms probabilistic safety analysis, probabilistic safety assessment and probabilistic risk analysis are used. They all mean the same thing; the terminology varies to reflect the usage of specific organizations and countries.
NEI gratefully acknowledges the work of the many individuals and organizations that served as resources for this Source Book by researching, compiling and reviewing information.
Every effort has been made to ensure the accuracy of the information presented here. However, the Source Book's information has been drawn from a wide variety of sources, with sometimes differing views on highly technical subjects, and from information available directly from newly independent countries with rapidly evolving governments and power-production systems.
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