Comprehensive safety assessment of radioactive waste disposal in clayey formations (case study of St. Petersburg region)

According to the IAEA requirements, disposal of radioactive waste (RAW) in geological formations is one of the ways of RAW management. It is noted that an analysis of the safety of RAW disposal in lithified clay formations requires an assessment of the underground environment as a multicomponent system. Subsurface structures of RAW repositories are in complex interaction with other components of the subsurface medium. The Upper Vendian clay and the Lower Cambrian blue clay are considered promising formations for waste burial in the St. Petersburg region. The authors argue that these soils should be considered as fissured strata exposed to confined mineralized water with a low redox potential (-35 mV) and a rich anaerobic microbial community. Complex patterns of corrosion of tunnel lining materials are detected. It is concluded that similar processes will take place in the linings of RAW repositories. The impact of the radiolysis on the clays, engineering barrier materials and intensification of microbial activity are considered. Accordingly, the use of Vendian and Lower Cambrian clays as host formations does not guarantee reliable and safe isolation of these wastes, which requires further comprehensive theoretical and applied research.

Dashko R. E., Lokhmatikov G. A. Comprehensive safety assessment of radioactive waste disposal in clayey formations (case study of St. Petersburg region). MIAB. Mining Inf. Anal. Bull. 2022;(9−1):66—76. [In Russ]. DOI: 10.25018/0236_1493_2022_101_0_66.

Dashko R. E.¹ , Dr. Sci. (Geology and Mineralogy), Professor, e-mail: regda2002@mail.ru, ORCID ID: 0000-0002-2469-0910;
Lokhmatikov G. A.¹ , Postgraduate Student, e-mail: kriptoforan@gmail.com, ORCID ID: 0000-0001-9134-3022;
¹ Saint-Petersburg Mining University, 199106, Saint-Petersburg, Russia.

Dashko R. E., e-mail: regda2002@mail.ru.

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