Вибір і обґрунтування способів термічної утилізації радіоактивно забрудненої деревини

• Дата: 2023
• Автор: Klius, V.
• Формат: Стаття
• Мова: Ukrainian
• Опубліковано: State Scientific and Technical Center for Nuclear and Radiation Safety 2023
• Онлайн доступ: https://nuclear-journal.com/index.php/journal/article/view/1037
• Назва журналу: Nuclear and Radiation Safety

Significant amounts of burnt and dead wood, which have formed in recent years as a result of large-scale forest fires in the territory of the Chornobyl exclusion zone, pose a potential threat of secondary contamination for clean areas. To eliminate this threat, it is necessary to solve the issue of disposal for large amounts of radioactively contaminated wood. The paper analyzes methods for thermal disposal of radioactively contaminated wood. The goal of disposal is the maximum concentration of radionuclides in the ash for its disposal and the reduction of radionuclide migration into the atmosphere with flue gases. The main methods of wood thermal disposal are considered: burning, pyrolysis and gasification. With traditional filter incineration, radionuclides are deposited on fly ash particles with a size of 0.3-0.5 microns and are carried into the atmosphere with flue gases, which requires highly efficient cleaning equipment. On the other hand, during dry pyrolysis of wood, the removal of 137Cs activity with pyrolysis gas is not more than 10%. A similar result was obtained during the gasification of wood. Since the volume of pyrolysis and generator gases are smaller than the volume of flue gases resulting from combustion, the load on the gas treatment system will be much smaller. It was concluded that modern gasification technologies should be used for the industrial disposal of large amounts of contaminated wood. Generator gas is suitable for power generation in gas turbines or gas piston units. Electricity can be supplied to the existing power system of the Chornobyl exclusion zone. It is proposed to process low-activity wood by the method of oxidative pyrolysis for the production of biochar. Biochar specific activity must comply with health and safety standard GN 6.61-120-2005. Taking into account the international experience of using biochar, it is planned to carry out comprehensive studies regarding the effectiveness of radionuclide sorption by biochar.