Radiation Survey of Reactor Hall Walls at NRC Kurchatov Institute

A radiation survey of the reactor hall was conducted at the National Research Center Kurchatov Institute. It was found that the main radionuclide determining the wall contamination in the reactor hall is 137Cs. Its specific activity is >10 times higher than that of 90Sr. The depth of penetration into the walls of the reactor hall is equal to 5–6 mm. In terms of height, the radioactive contamination of the walls of the reactor hall is localized mainly in the lower portion of the walls up to 1 m. No relation was found between the removed surface contamination and the activity of the corresponding thin surface layer of the wall. It is shown that the initial decontamination of the walls of the reactor hall can lessen their radioactive contamination by a factor of 1.5–2.