processes Article IAEA-Assisted Treatment of Liquid Radioactive Waste at the Saakadze Site in Georgia Giorgi Nabakhtiani 1 , Irma Giorgadze 2 and Michael I. Ojovan 3, *   Citation: Nabakhtiani, G.; Giorgadze, I.; Ojovan, M.I. IAEA- Assisted Treatment of Liquid Radioactive Waste at the Saakadze Site in Georgia. Processes 2021, 9, 1679. https://doi.org/10.3390/pr9091679 Academic Editor: Victor Ioannovich Malkovsky Received: 7 August 2021 Accepted: 16 September 2021 Published: 18 September 2021 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2021 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). 1 Department for Radioactive Waste, Nuclear and Radiation Safety Agency, 200 Mikheili Tsinamdzghvrishvili St, Tbilisi 0112, Georgia; giorgi.nabakhtiani@gmail.com 2 Department of Engineering Physics, Georgian Technical University, 68, Merab Kostava St, Tbilisi 0160, Georgia; irmagiorg@gmail.com 3 Department of Materials Science and Engineering, Faculty of Engineering, University of Sheffield, Sheffield S1 3JD, UK * Correspondence: m.ojovan@sheffield.ac.uk Abstract: 50 m 3 of legacy liquid radioactive waste at the Saakadze site in Georgia was treated using a modular type facility with apparatuses encased in three metallic 200 L drums using as purification method the sorption/ion exchange technology. The main contaminant of water in the underground tank was the long-lived radionuclide 226 Ra. The casing of processing equipment enabled an effective conditioning of all secondary waste at the end of treatment campaign which resulted in the fully purified water stored on site for further reuse or discharge, and three 200 L metallic drums with cemented radioactive waste which are currently safely stored. Keywords: treatment; liquid radioactive waste; sorption; ion exchange; purification; conditioning 1. Introduction Nuclear waste management has received considerable attention due to the important link between the safe management of radioactive waste and public acceptance of nuclear facilities and peaceful applications of nuclear energy. Radioactive waste management is typically divided into predisposal and disposal steps, where predisposal comprises all the steps in the management of radioactive waste from its generation up to disposal. The predisposal includes processing technologies that are primarily intended to produce a wasteform that is compatible with the selected or anticipated disposal option and complies with established waste acceptance criteria [1]. Liquid radioactive waste is highly mobile, and its storage is associated with hazards from potential leakages and contamination, so it cannot be considered passively safe. International disposal standards prescribe only solids as being acceptable forms for disposal facilities [2]. Consequently, liquid radioactive waste is typically processed to decrease the waste volume, solidifying the treated waste (typically a sludge) using durable wasteforms such as cements [3]. Treatment of aqueous waste separates it into two streams: a small volume fraction of concentrate containing the bulk of radionuclides and a large volume of water which has a sufficiently low level of contamination to permit discharge to the environment or recycling. Effective liquid treatment separates as much as of the radioactive contaminants as possible from the primary waste in the concentrated fraction, which typically requires conditioning prior to storage and disposal. A flow chart for managing aqueous radioactive waste is given in Figure 1. The radioactive waste packages produced after treatment and conditioning contain the solidified waste and are then stored in a passively safe condition pending a disposal route becoming available. Processes 2021, 9, 1679. https://doi.org/10.3390/pr9091679 https://www.mdpi.com/journal/processes