Practical solutions of biological protection for implementing the basic principles of protection against ionizing radiation

The nuclear activities, namely the activities that involve the use of ionizing radiation sources, are carried out under a basic principle of personnel protection and safety - this including the preservation of natural environment - with an as much as possible benefit from the proposed activity. Starting from this basic principle, more fundamental principles of protection and safety against ionizing radiation were development and, in turn, they are the basis for the recommended criteria, requirement and guidelines to be applied in any nuclear activity achievement. Protection and safety against radiation operates with specific units that express the effect of ionizing radiation on human body (dose or exposure) and the likelihood of producing this effect (risk). The primary objectives of this field are: to present the occurrence of immediate injurious effects on humans by keeping the doses below a relevant threshold and to ensure that all reasonable measures for reducing the cumulative effects on population at present and in the future were taken. To achieve the proposed objectives, we rely on the conceptual framework developed by ICRP that includes justification of practices, optimization of protection, dose limitation and safety of sources. This paper intends to present in a concise way the meaning of these principles and a practical solution for biological protection based on these principles in any case of nuclear activity