A Method for Mean Energy Estimation of Gamma Radiation Spectrum in the Conditions of Radiation Accidents in the Nuclear Power Plant Premises

Abstract

In this work the values of the mean γ-radiation energies of radionuclides are calculated using BDRG-47R OBD detectors with a high dose rate registration range and a wide range of gamma-ray energies, for example, in the case of emergency emission in a severe radiation accident in the nuclear power plant. Under these conditions, spectrometric equipment, as shown in Chernobyl and Fukusem-1 accidents, can’t provide qualitative measurements. Therefore, to estimate the average energy of the γ-radiation spectrum, only four BDRG-47P DB detectors are used, three of which were used filters made of tungsten, lead, and bismuth. The fourth one remains without filter. The estimation of the average energy of the γ-radiation spectrum is based on the idea of using half value layer of the filter material. The calculations show that the error in estimating the average γ-radiation spectrum energy depends on the spectrum and varies from 5% (0.25 MeV) to 36% (MeV 1.25 MeV), which allows to obtain a lower and upper estimate of the dose rate for personnel who must carry out repairs in premises. The proposed methodology makes it possible to assess the maximum safety time of personnel in the zone of radioactive contamination, the minimum number of workers for repair work, and also to draw up a working plan for repair work, i.e. minimize the material losses that may arise in such situations.