Izvestiya vuzov. Yadernaya Energetika

The peer-reviewed scientific and technology journal. ISSN: 0204-3327

Dynamics of the Concentration of Gaseous Radionuclides 14CO2 and 14CH4 Released above the Burial Site of Operational Radioactive Waste at Nuclear Power Plants

3/18/2024 2024 - #01 Environmental aspects of nuclear power

Garelina S.A. Grigoryan G.B. Zaharyan R.A. Sedrakyan A.M.

DOI: https://doi.org/10.26583/npe.2024.1.09

UDC: 504.054

Near-surface storage facilities for operational radioactive waste at Nuclear Power Plants (NPP) contain waste of low and intermediate level radioactivity, which consist mainly of organic materials, including a sufficiently large amount of cellulose. In such storage facilities, significant amounts of gases, such as 14CO2 and 14CH4, can be formed as a result of microbial decomposition of cellulose and metal corrosion. The released radioactive gases can be released from the storage by gas diffusion through the air-filled pore space of the waste, the filling material and the shutter cover, leading to radiation exposure of residents living near the storage.

The article presents a discussion of microbial and chemical degradation of cellulose. For gas release, it is assumed that the complete transformation of cellulose waste into gases under the action of microbes is in principle permissible. Taking into account the two main mechanisms of gas formation (iron corrosion and microbial degradation of cellulose), analytical expressions were obtained for calculating the atmospheric concentration of gaseous radionuclide in the area above the waste disposal site and the total dose from inhalation of the released gases 14CO2 and 14CH4.

Based on the developed mathematical model of the burial system and its implementation with the help of the AMBER program, calculations of the annual individual dose from inhalation of 14CO2 and 14CH4, which will be released from the near-surface storage of the Armenian NPP after its closure, and an assessment of the safety of this storage by inhalation dose per person exposed to maximum exposure above ground, were performed.

It is shown that operational undivided pre-compacted solid radioactive waste of NPP containing cellulose, iron and other decomposing and gas-forming materials can be disposed of in safe conditions.

Thus, the paper assessed the potential impact of the formation, accumulation and migration of gas containing radionuclides as a result of microbial and chemical degradation of cellulose, which is part of radioactive waste in near-surface storage facilities at NPP on their long-term storage.

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radiation safety of nuclear power plant storage facilities nuclear power plant safety nuclear power plant radiation safety assessment safety

Link for citing the article: Garelina S.A., Grigoryan G.B., Zaharyan R.A., Sedrakyan A.M. Dynamics of the Concentration of Gaseous Radionuclides 14CO2 and 14CH4 Released above the Burial Site of Operational Radioactive Waste at Nuclear Power Plants. Izvestiya vuzov. Yadernaya Energetika. 2024, no. 1, pp. 107-118; DOI: https://doi.org/10.26583/npe.2024.1.09 (in Russian).

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