Investigation of the radiation situation at the dumps of the mine No. 1 of the LPO "Almaz" five years after recultivation

Abstract

Introduction. The work was completed on the remediation of dumps located in the area of nine tunnels of mine No. 1 of the Lermontov production association “Almaz” over 2014-2015. The article presents the results of a study of the radiation situation on these dumps five years after the remediation. Materials and methods. During the survey, the methods of pedestrian gamma survey were used using a portable spectrometric complex MKS-01A “Multirad-M” and soil sampling with subsequent measurement of the specific activity of radionuclides using a stationary gamma spectrometer manufactured by CANBERRA. The activity of 210Po and 210Pb was measured using a UMF-2000 radiometric setup after their radiochemical isolation. Results. After the remediation of the dump areas, where gamma ambient dose equivalent rate exceeds 0.5 μSv/h, areas significantly decreased and do not exceed 10% of the total dump area, with the exception of the dumps of tunnel No. 42. On the territory of all surveyed dumps, except for dumps of tunnels No. 10 and No. 26, there are areas where gamma ambient dose equivalent rate exceeds 0.6 μSv/h, which is prohibited in accordance with the adopted remediation criteria. Not all tunnel mouths are isolated. Limitations. It is assumed that comparing the content of radionuclides in soil with the criteria for classifying them as solid radioactive waste 238U and 230Th are in secular equilibrium. Measurements of the total alpha-activity in the soil and comparison with the recultivation criteria for this parameter were not carried out. Conclusion. At present, the radiation situation in some areas of all surveyed reclaimed dumps, except for the dumps of tunnels No. 10 and No. 26, does not meet the requirements established in the remediation project.