Inactivation of radioactive waste from S2 facilities

The safe inactivation of waste in genetic engineering facilities of containment levels 2 to 4, which contains genetically modified organisms (GMOs) of risk groups 2 to 4 and simultaneously radioactive substances, is the subject of a statement issued by the Central Committee of the Federal Office for Nuclear Safety (ZKBS) in July 2020. It first states that both genetic engineering law and radiation protection law must be observed during waste treatment and disposal. The GenTSV stipulates that wastewater and waste from facilities in which genetic engineering work of containment levels 2, 3, or 4 is carried out must be inactivated or sterilized in the building (containment level 2) or in the facility (containment levels 3 and 4) by autoclaving at a temperature of 121°C for 20 minutes or by equivalent processes. The Nuclear Waste Disposal Ordinance (AtEV) regulates the delivery obligation for radioactive waste. The competent authority may then specify the type of treatment of radioactive waste prior to delivery.

The ZKBS statement recommends that radioactive waste containing GMOs be safely stored until it has sufficiently decayed and can be disposed of in accordance with the GenTSV (Genetic Waste Ordinance). This prevents radioactive contamination of the autoclave and the possible release of radioactive water vapor from the autoclave into the genetic engineering facility. If safe storage of the radioactive waste until decay is not possible (e.g., due to the long half-life of the radionuclides used) and the type of waste permits, the ZKBS recommends inactivating the waste using chemical processes (at containment level 2) or sterilizing it using such processes (at containment levels 3 or 4) as an alternative to autoclaving. The suitability of the chemical processes to be used should be decided on a case-by-case basis, since in addition to the range of action of the disinfectant used, its reaction with the radioactively labeled substances and environmental compatibility must also be taken into account.