RESULTS OF CALCULATION OF THE EFFECTIVE DOSE FIELD OF IONIZING RADIATION IN THE CENTRAL ROOM OF THE IGR REACTOR

Abstract

The characteristics of the effective dose field and the dose rate of the ionizing radiation formed in the room of the IGR reactor during its operation at a constant power of 100 MW for 40 seconds have been estimated.The value of the effective dose and its power in the experimental device has been determined in order to assess the level of the potential radiation load on the small-sized neutron detectors (fission chambers), which are supposed to be used to measure the local values of the fast neutron flux density during the irradiation of the device in the IGR reactor.To carry out the calculations, the models of the IGR reactor with an upper ceiling, concrete biological protection and two options for loading the central experimental channel of the reactor have been developed. Photon transfer modeling has been performed using the MCNP5 code and the libraries of ENDF/B-5,6 constants, while the characteristics of fission products, 235U decay processes and the processes of formation of gamma-quantum fields were described using the IAEA and JAEA nuclear data libraries.The validation of the proposed method for calculating the effective dose has been performed based on the results of the direct measurements of the effective dose in the reactor room. The validation results confirm the correctness of the proposed calculation models and techniques, and, accordingly, the admissibility of their application for assessing the radiation situation in the IGR reactor room.The obtained results will be used in the selection of the locations of secondary equipment for measuring the parameters of the experimental devices.