Nuclear power plant special features

The high cost of constructing a modem nuclear power plant— three to four billion dollars, in the U.S.— reflects in part the wide range of safety features needed to protect against various possible mishaps, especially those which could release to the environment any of the plant s inventory of radioactive substances. (Small special-purpose reactors, such as those used to power nuclear submarines or aircraft carriers, have different costs and technical features from the large, land-based reactors used to supply electrical grids.) Some of those features are incorporated into the reactor core itself. Eor example, all of the fuel in a reactor is sealed in a protective coating... 

All these features of nuclear power plants make it very attractive for developing countries to introduce nuclear power and for industrialized countries to expand nuclear power usage. In addition, the need to improve the fuel cycle, waste management and nuclear proliferation resistance, requires special design characteristics and fuel management provisions. 

Nuclear reactor power plants are complex systems with three special features which have to be allowed for in design and plant operation. If operation or design, or both, are faulty or inadequate, serious damage to the fuel, the reactor core or, in extreme cases, the reactor circuit, can result. These special features of nuclear power plant can be summarised as follows ... 

Economically, cost-effective performance of valve maintenance means performing and bundling of all individual activities under the umbrella of an experienced service provider which act as a main contractor. The great advantage of such a contract for the customer is to order the complete maintenance service on a fixed price which is lower as the total cost obtained from a large number of individual services. Competent and reliable subcontractors which are familiar with special features of components are involved to ensure good quality of work. Under such conditions the mutual cooperation can preserve the maintenance competence and know-how to ensure the safety and availability as long as the nuclear power plant is in service. Effective improvements based on process analyses can also be implemented. 

Although the postshutdown concentration of samarium can be a serious consideration in some reactor situations, the control of the xenon concentration is a problem of more general importance in all thermal reactors. This problem is especially serious when the I concentration at shutdown is relatively large. Under these circumstances the Xe concentration increases rapidly after shutdown and can reach appreciable magnitudes before decaying away. This buildup is important from the standpoint of control, since a large positive reactivity change must be available if it is to be required that there be a restart of the reactor around the time the maximum occurs. Thus special xenon-override control rods would be required in a mobile nuclear power plant if short-time startups were to be an essential operational feature. 

The design objectives for accident conditions are to limit to acceptable levels (1) the risks to the pubhc from possible releases of radioactive material from the nuclear power plant and (2) the risks to site personnel from these releases and from direct radiation exposure. These design objectives should be achieved by means of high quality design and special features, such as safety systems and protection systems, that are incorporated into the design of the... 

Projects for nuclear power plants to be sited in tropical, polar, arid or volcanic areas shall be assessed with a view to identifying special design features which may be necessary as a result of the characteristics of the site. 

However, with reactor incidents, direct loss of life or casualties are extremely rare. In this respect the nuclear record compares well with other energy-related industries (see Appendix 10). There have been accidents at nuclear plants, leading to injury and in some cases deaths. In these, nuclear plant is similar to all other process and power plant. The special feature of nuclear plant is the awesome potential power in the plant and its highly radioactive contents. 

The individual sees that his private sphere is threatened by a radioactive intrusion of which he has no measure of control. In a case of this nature, it is the mobilization, by the authorities and public powers with the means and professional competencies, especially reserved for public domain, that are about to threaten and overcome his privacy. This radioactive intrusion is, consequently, difficult to control because the resources of the individual are not adequate, and he is not a professional. If he is an expert in radioactivity, it is at the plant, and not at his home, where he is socialized in a familial group, which stipulates certain social behaviors and bans others. If there is confusion between the two spaces, the hegemony of the public sphere will trump that of the private. This breeds distortion and will thus lose its special features. It is an intolerable situation because it signifies the loss of intimacy, autonomy and individual identity. The growth of the nuclear risk outside its rightful limits and outside of the dedicated industrial zones is where the eventuality of nuclear risk will penetrate changes in the private sphere and the relationship to the risk. The result is that the views of the individuals are confronted. 

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