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

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.

Contribution:
Belskikh Yu.S. — the concept and design of the study, writing a text;
Shandala N.K. — the concept and design of the study, writing a text, editing;
Titov A.V. — collection and processing of material, writing a text;
Isaev D.V. — collection of literature data, collection and processing of material;
Semenova М.P. — collection and processing of material, editing;
Oskina K.Yu., Gushchina Yu.V., Filonova A.A. — collection and processing of material.
All authors are responsible for the integrity of all parts of the manuscript and approval of the manuscript final version.

Acknowledgement. The authors express their gratitude to the staff of the Unit No. 101 of the Centre of Hygiene and Epidemiology of the FMBA of Russia. The study had no sponsorship.

Conflict of interest. The authors declare no conflict of interest.

Received: June 06, 2022 / Accepted: June 08, 2022 / Published: July 31, 2022