FIELD: environmental control. SUBSTANCE: process includes taking samples of environment and of technological samples, preparation of samples for measurement on liquid scintillation counter, measurement and recording of sample spectrum and measurement parameters, convolution of sample spectrum into groups, formation of model spectrum of sample on basis of library of basic spectra, minimization of deviation of model spectrum from sample spectrum and identification of content of radionuclides in sample. In this case sample spectrum is convoluted into groups which boundary values Ni are quasi- arithmetic progression of type of Ni+1= Ni+[(i+1)/2] where I=1, 2,... n and minimization of deviation of model spectrum from sample spectrum is carried out by composition of model spectrum of definite type. Difference between model spectrum and sample spectrum is minimized to determine relative contributions of spectra of radionuclides into model spectrum of sample. Minimization is carried out in several stages selecting first of all bigger value δ and zero values cj and determining minimum of expression. After this δ is decreased and minimization process is repeated . In this case starting values of contributions cj for each next step of minimization are results of preceding step. Calculation is stopped when process of minimization of expression turns to be unstable and identification of radionuclides in examined sample is completed by recalculation of obtained values cj in terms of absolute activities of radionuclides in sample. Technical result of invention consists in possibility of isolation of radionuclides with low levels of activity against background of radionuclides having higher activities by selection of proper scale of convolution of spectra into groups and in determination of criterion of minimization of sample spectrum from model spectrum. EFFECT: improved efficiency of process. 4 dwg, 4 tbl
