Radionuklidų savitojo aktyvumo statybinėse medžiagose Lietuvoje eksperimentinis tyrimas, jų sukeltos apšvitos modeliavimas ir vertinimas

Abstract

The study is devoted to problems of exposure caused by radionuclides in construction materials. Results received by gamma measurements and calculations (dose modeling) are used. Construction materials produced and/or used in Lithuania were investigated. The results of measurements (concentrations of natural radionuclides and activity indexes) are given for different types of construction materials. On the basis of these results and peculiarities of use of construction materials they have been classified according to their radiological significance. It helps to determine possible amounts of construction materials to be investigated and priorities of investigations. Relationship between activity indexes of different construction materials and dose rates in premises constructed of these construction materials has been determined. It might be used for increase of precision of personal dosimetric measurements performed in premises constructed of different materials. Possible relationship between absorbed dose rate indoors and concentration of indoor radon is discussed. Results of measurements of concentrations of natural radionuclides in archeological samples of construction materials are also presented and discussed. Dose modeling has been performed with the help of ALARA planning tool Visiplan 3D. Distributions of absorbed dose rate in standard living premises have been determined, relationship between dose rate and different parameters of constructions, such as thickness, density, evaluated, impact of different radionuclides and different construction elements on dose rate assessed. Peculiarities of use of activity index for evaluation of construction materials from the point of view of radiation protection discussed, importance of availability of tools for fast and reliable evaluation of doses due to radionuclides in construction materials shown. It is the complex study of peculiarities related with one of the most important sources of exposure – construction materials.