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Radionuclides behavior on strongly contaminated territories of 30-km Chernobyl zone was studied. Samples in two layers for determination of the possible impact of the works on construction of the “Shelter” object were collected. As a result, abnormal A(241Am)/A(137Cs) ratio was observed on a number of samples. The value varies between 0.004 to 0.30. Activity of 94Nb and 60Co was observed on the number of samples. Problems with spectrometer calibration appeared, when samples from Chernobyl zone with low activity were used. Calibration on efficiency of γ-rays registration become complicated in low energy interval because of different density of the investigated samples. To solve this problem methodological researches were performed, taking into account efficiency variation of γ-rays registration in samples with big volume. For this purpose, activities of 137Cs and γ-rays with 661 keV energy were compared. 137Cs activity was defined from appearance of Kx-emission of Ba (36 keV). [ABSTRACT FROM AUTHOR]

Corrective actions apply whenever activities are identifiable, non-conforming, or there are deviations in the policy of testing and procedures on the management system. Implementation of the corrective actions in laboratory for testing of milk and milk products supplied algorithm for identifying and assessing the calibration range of technical device densitometer for milk and milk products. Based on three main factors - load operation, stability of the technical means in the calibration interval and the factor of uncertainty of additional technical resources to the primary were calculated the calibration interval of the densitometer. The result obtained (1.6 years or 19 months) showed a reduction of projected maximum calibration period of five months, mainly related to the reporting of the response operation (30.96%) for the first year (ICI). Subsequent calibration period (NCI) will be determined after the calibration interval of 19 months (1.6 years). [ABSTRACT FROM AUTHOR]