A. Scope of nuclear energy use.
We all are power consumers and the comfort of our modern homes is a complete dependence on what is now the electric power supply. The research for new sources of energy has been active throughout centuries. Some 100 years ago, the phenomenon of radioactivity was discovered and this discovery gave rise to dreams of unlimited power supplies. The average efficiency of uranium fuel is 2.5 million times greater than that of traditional sources of energy such as coal, oil, and natural gas. On a projection basis the natural resources of traditional fuel will be exhausted in 200 years, if the fuel production optimum remains at the same level as it is now. Similarly the natural resources of splitting materials will last 500 years and those of fuel for thermonuclear reactors will last for thousand years to come [4]. This is a very serious argument in favor of nuclear means as a global energy solution.
The functioning of the industrial fuel and energy complex entails destructive consequences for the environment at all the stages from geological prospecting and mining works to power production. The extraction, transportation, processing and burning of hydrocarbon fuel account for more than 80% of air pollution. Coal, as the primary fuel, produces, when burning, the largest amount of environmental pollution, including radioactive materials. Natural gas is dangerously combustible and explosive. There have been numerous accidents at gas pipelines. For example, 572 people died and some 1, 000 other people were badly injured as a result of the explosion of the gas pipeline in Bashkiria, Russia, on June 3, 1989 [1]. The hydrocarbon-based energy production from coal as a "natural" fuel source is to blame for the warming of the climate, acid rain, the destruction of architectural monuments, and large related expenditures on environmental protection and healthcare programs.
In its turn, nuclear power production is a comparatively young industry which has developed parallel to defense programs. At present, a total of 480 nuclear power plants (NPP) are operating or being built around the world, based on data reported to the International Atomic Energy Agency (IAEA) Power Reactor Information System [2]. During 1994, four nuclear power plants with altogether 3356 MW(e) were newly connected to electricity grids in China, Japan, Republic of Korea, and Mexico, bringing the world's total number of operating reactors to 432 in 29 countries and Taiwan. Additionally, a total of 48 reactors were reported as being constructed in 15 countries [5].
The total share of nuclear energy generation in the world is growing constantly and has already exceeded 17 percent (Chart 1). Worldwide in 1994, for instance, total nuclear power generation amounted to 2130.13 terawatt-hours of electricity [2]. This is more than the world's total electricity generation -- 1912 terawatt-hours from all sources in 1958 [6]. In many countries nuclear power's share of electricity production is very high (Chart 2). In seven countries - Lithuania, 76.4%; France, 75.3%; Belgium, 55.8%; Sweden, 51.1%; Slovak Republic, 49.1%; Bulgaria, 45.6%, and Hungary, 43.7% - it represents close to half or more of total electricity use. All in all, 18 countries (including Taiwan) rely upon nuclear power plants to supply at least a quarter of their total electricity needs.
At present, the total electric power of all nuclear power plants in the world amounts to some 400 gigawatts (GW). According to forecasts, by the year 2050 humankind will need electric power of more than 50, 000 GW [7]. This problem is likely to be solved by means of nuclear sources of energy. It is expected that the nuclear plants of future generations will be safer and more efficient than the existing nuclear power plants. The efficiency of such nuclear power plants is supposed to reach approximately 95% or more [12]. Yet, this level of efficiency can be reached only on the basis of thermonuclear plants.
Nuclear power has become a firm basis for the development of various branches of human activities. One can imagine many purposes for the use of nuclear energy and can be certain that nuclear power will be always useful to people. The development of this industry may be especially intensified if some of the present obstacles -- including financial constraints, low electricity demand in industrialized countries, and negative public attitudes in some countries -- evolve in a positive direction. Yet, safety issues must always be given a clear priority. The Chornobyl disaster dispelled the illusion of the complete safety of nuclear power production and brought about discussion of an effective regulatory mechanism capable of insuring this safety and promoting a policy of energy sustainability all over the world.
B. Problem of danger and the costs of clean up.
On the 26th of April, 1986, operational unit no. 4 of the Chornobyl nuclear power station (USSR, Ukraine) suffered a major accident. It is the world's most serious nuclear power accident so far. The direct costs include 1, 000 immediate injuries, 31 deaths, 135, 000 people evacuated from their homes in Ukraine, and at least $25 billion in financial losses [3]. The health of people and the environment in the Ukraine, Belarus, and Russia will be affected for decades. Estimates of resulting cancer deaths by researches in the field range from 1, 000 to almost 500, 000 [8, 9]. In all, the "bill for Chornobyl" may be presented as follows:
The economic impacts of the accident on the country as a whole and on adjacent regions are:
The accident was followed by a prolonged release into the atmosphere of large quantities of radioactive products. The specific features of release favored a widespread distribution of radioactivity throughout the northern hemisphere, mainly across Europe. Radioactivity, transported by the multiple plumes from Chornobyl was measured not only in northern and southern Europe, but also in Canada, Japan, and the United States [10].
This progressive spread of contamination at large distances from the accident site has caused considerable concern in many countries, and the reaction of national authorities has been extremely varied, driven by different socio-economic, political, and psychological factors in determining the countermeasures. Although the radiological consequences of the accident were very serious in the region surrounding the Chornobyl site, only in some countries did the levels of radioactive contamination resulting from the release warrant protective actions directly motivated by radiation protection considerations. But in this situation significant differences in national regulatory approaches between countries resulted in serious disruption of international commercial activity.
A particular problem raised by the transboundary character of the Chornobyl accident concerned its impact on the international trade of goods, particularly, foodstuffs. Shortly after the deposition of contaminates, concern was expressed regarding acceptable levels of activity in imported and exported foodstuffs. Derived intervention levels, which were expressed in terms of concentrations of radionuclides in the different environmental matrices and food, were provisionally established by the Commission of the European Communities (CEC) for the import and export of foodstuffs to and from EEC Member countries, as well as between them [10]. The repercussions of this question were not limited to the countries directly affected by the activity deposition. Many other countries were concerned with the possible risks to their populations from food imported from Europe, and established controls and limitations on these importations. Many of these countries adopted levels of activity for the screening of imported food which were similar to those recommended by the CEC, but other countries chose to use more restrictive limits, in some cases corresponding to inconsequential levels of activity in foodstuffs. This was another factor of disruption in the normal commercial activities and mutual relations between countries.
To overcome these difficulties, a significant effort is currently being made by several international organizations towards achieving a criteria harmonization for the establishment of intervention levels.
Chornobyl was not the first nuclear power plant to suffer core damage. The core at Three Mile Island (TMI) reprocessing plant Unit 2 was badly damaged during its accident in 1979 [3]. The release of radioactive material from TMI was, however, very small. The accident in Windscale was never fully documented publicly [10]. It is, therefore, difficult to say what similarities there might be between this accident and Chornobyl. There are, however, two important reasons for stating that Chornobyl is unique. First, large populations were for the first time not only frightened but also contaminated by radioactive fallout. Second, the biological impact through contamination spread over a whole continent, directly involving many countries and international organizations [11].
The Chornobyl nuclear accident has highlighted weaknesses in the world's existing mechanism of nuclear energy use. The most crucial of them are:
Thus, from this tragic accident several lessons should be learned, notwithstanding the fact that a considerable effort directed towards better international coordination of concepts and measures for the protection of the public in case of emergency and the relevant harmonization of respective scientific bases has been already initiated. These lessons suggest an overall and extensive process of improvement of radiation protection response to the risk of nuclear accidents. This is currently being sponsored by several international institutions, including the United Nations (UN), the International Atomic Energy Agency (IAEA), the World Health Organization (WHO), the Nuclear Energy agency of the Organization for Economic Cooperation and Development (OECD/NEA) and CEC.