GRNTI 76.03 Медико-биологические дисциплины
GRNTI 76.33 Гигиена и эпидемиология
OKSO 14.04.02 Ядерные физика и технологии
OKSO 31.06.2001 Клиническая медицина
OKSO 31.08.08 Радиология
OKSO 32.08.12 Эпидемиология
BBK 51 Социальная гигиена и организация здравоохранения. Гигиена. Эпидемиология
BBK 534 Общая диагностика
TBK 5708 Гигиена и санитария. Эпидемиология. Медицинская экология
TBK 5712 Медицинская биология. Гистология
TBK 5734 Медицинская радиология и рентгенология
TBK 6212 Радиоактивные элементы и изотопы. Радиохимия
Purpose: Development of comprehensive organizational and methodical approaches to decommissioning of shallow radwaste (RW) repositories. Material and methods: The following researches were conducted during assessment of radiation and hygiene situation: - assessing the state of physical barriers of repositories (tanks) of solid and liquid RW; - assessing radiation situation at the repository site before and after remediation; - measuring specific activity of 90Sr and 137Cs in ground and subsurface water, core sample, soils, building structures. Methods: on foot gamma survey; gamma-ray spectrometric measurement of radionuclides in environmental samples using a stationary spectrometer; radiochemical extraction of radionuclides and their radiometry. Results: The surveys were performed in 2014–2016. They delivered data on gamma dose rate at the RW repository site, specific activity of 90Sr and 137Cs in ground and subsurface water, core sample, soils, building structures. The surveys showed that content of 90Sr in subsurface water varied from 0.25 to 0.4 Bq/kg, while content of 137Cs was below the detection threshold (0.01 Bq per sample). It was founded that distribution of 90Sr and 137Cs in soil (core sample) forming the top layer of the area is highly uneven. In some cases specific activity of soil exceeded 1000 Bq/kg (C-23 well at the depth of 2.75 m and C-24 well at the depth of 5 m). In all other cases specific activity of the core sample did not exceed 10 Bq/kg, and specific activity of soil was up to 50 Bq/kg which is over background values. The ambient dose equivalent rate at the site varied from 0.1 to 0.3 µSv/h. After remediation activities content of radionuclides in soil and subsurface water was at the levels of background values. More than 6700 measurements were performed (more than 2400 measurements of the ambient dose equivalent rate, more than 4100 measurements of beta-contamination of work surfaces and equipment, and more than 200 measurements of specific and volumetric activity of environmental samples). Conclusions: This work allowed to substantiate technical solutions, procedure of RW accounting and control, using of shelters and mobile systems for radiation safety of the personnel and environmental protection. It was demonstrated that average external radiation doses for the workers involved in decommissioning activities did not exceed 0.7 mSv (variation from 0.16 to 1.7 mSv), while internal radiation doses varied from 0.35 to 3.3 µSv. Density of beta-contamination of the site did not exceed 38 beta-particles/(cm2∙min) which corresponds to background values. The ambient dose equivalent rate of the site was within 0.09-0.15 µSv/h after the work has been done.
liquid and solid radioactive waste, repositories, specific and volumetric activity, decontamination, remediation
1. Abramov AA. Final results of implementation of the NRB FTP and challenges for the future. The 15th anniversary Russian scientific conference. Moscow, IBRAE, 2015. P. 15–21. (Russian).
2. RF Government Regulation of the 15 December 2016 No. 1248 “Nuclear and radiation safety for 2016–2020 and till 2030”.
3. Engatov IA, Mashkovich VP, Orlov YuV, et al. Radiation safety at decommissioning of civil- and military-oriented nuclear facilities. Moscow, Atomizdat, 1997. 213 p. (Russian).
4. Agapov AM, Linge II, Melikhov EM, et al. Radiation and new safety issues. Problems related to nuclear legacy and their solutions. Moscow, Papers of the Conference in honor of the 15th anniversary of IBRAE, 2012. P. 13-7. (Russian).
5. Bylkin BK, Engatov IA. Decommissioning of nuclear reactor systems. Moscow, National Research Center “Kurchatov Institute”, 2018, 223 p. (Russian).
6. Volkov VG, Danilovich AS, Zverkov YuA, et al. The experience of decontamination of radioactive soil at the site of National Research Center “Kurchatov Institute”. Atomnaya Energia, 2011;110(2):106-112. (Russian).
7. Korenkov IP, Shandala NK, Laschenova TN, Sobolev AI. Environmental protection at operation and decommissioning of radiation-hazardous facilities. Moscow, GEOTAR-Media, 2014, 432 p. (Russian).
8. Best foreign practices of site decommissioning and remediation. Vol. 1. Eds.: Linge II, Abramov AA. IBRAE, 2017, 336 p. (Russian).
9. Best foreign practices of site decommissioning and remediation. Vol. 2. Eds.: Linge II, Abramov AA. IBRAE, 2017, 187 p. (Russian).
10. GOST R 8.563-2009. State system for ensuring the uniformity of measurements. Procedures of measurements. Moscow, Standartinform, 2010. (Russian).
11. Korenkov IP, Laschenova TN, Shandala NK, Kiselev MM. Guidance on radiation and hygienic monitoring of the environment. Eds.: Ilyin LA, Samoylov AS. Moscow, GEOTAR-Media, 2018. 459 p. (Russian).
12. Guidance manual on calculation of emissions from uncontrolled sources in the industry. ZAO NIMIOTSTROM. Novosibirsk, 2002. 30 p. (Russian).