Análise de riscos de radiação não-ionizante em sistema de transmissão de energia elétrica

Abstract

The electromagnetic radiation is the propagation of associated electric and magnetic fields, in time and in space traveling in the air with speed of light. The radiation is classified according to the value of the frequency. It is noticed that equipment as televisions, radios and cellular telephones, among other, produce radiation that is no-ionizing, meaning that emitted energy is not capable to produce free ions in its passage for the matter, in other words, it is unable to extract electrons of atoms and molecules. The break process of the chemical bounding of the molecules is known as ionization. It is what happens in the region of frequency of the x-rays, gamma radiation and UV-A. In this case, the radiation produces injury to the health, with genetic alterations and somatic effects, coming from the alterations produced by the molecular ionization, including DNA. The radiation that is no-ionizing doesn't cause effects as that. Its principal biological effect is thermal, and non-thermal or molecular excitation. The limits for exposition doses do to no-ionizing radiation produced by electromagnetic radiation are established by international and national organisms. In our case, the basic limits are established by the ANATEL and ANEL regulatory agencies. These norms are based on the results of the scientific research accomplished in the area, both national and international. They define which are the maximum safe levels to be exposed to the radiation. We investigated the effects of non-ionizing radiation emitted by the transmission of electric energy at low frequency, ELF with special interest with the risks related with the transmission lines and sub-stations for the example problem, Sub-Estação da Companhia Energia Elétrica Estadual em Santa Maria, RS. In this installation we have three lines, with 230kV, 130kV and 69 kV. The results are indicating acceptable levels for the electric and magnetic field, resulting from theoretical evaluation. With de possibility of experimental measurements, the company will be allowed to develop safety strategies both for workers and public in general, with the definition of domain areas and minimal distances and time for the work in live lines.