Method for calculating the characteristics of the damaging dose for VVÉR vessel steel

An approach to calculating the characteristics of the damaging dose to VVÉR structural materials is presented. The results of calculations of the spectra of primary knock-out atoms and the damaging dose are presented in terms of the number of displacements per atom and the effective displacements per atom on the inner and outer surfaces of VVÉR-440 and-1000 vessels and at the position of the control samples in VVÉR-440. The results of calculations of the neutron and gamma-ray spectra are used as initial data. The production rate of the displacements is calculated with the known differential cross section and with a cascade function recommended in the IAEA NRT model. It is shown that this rate is more than 10 times higher in the control samples than on the inner surface of a VVÉR-440 vessel. The influence of the neutron spectrum on the damaging dose is investigated. Calculations of the number of effective displacements per atom are performed using known data on the cascade efficiency obtained by the molecular dynamics method. Computational results are presented for the contribution of gamma rays to the production rate of displacements.[PUBLICATION ABSTRACT]