The return of radioactive waste was initiated by Rosatom and the US Department of Energy. This is the eighth shipment of HEU from Uzbekistan since 2004 and marks the removal of all HEU from the country. In 2004, unirradiated HEU fuel of the VVR-SM reactor was returned to Russia from the Nuclear Physics Institute of the Uzbekistan Academy of Sciences. In 2006, Rosatom returned the first ever shipment of irradiated fuel from the same reactor. A few years later, in 2012, two more shipments of VVR-SM spent nuclear fuel were returned to Russia by air.
INN-3M reactor fuel was the first to be transported in liquid condition, preceded by long preparation. INN-3M is a solution-based research reactor with the aqueous solution of uranyl sulfate (enriched to 90% of U-235) in the core. A specific feature of this reactor is its ability to stop the chain reaction by increasing the solution temperature and emitting radiolytic gases. The reactor could operate in impulse and static modes. It was started in December 1975 and shut down on the 1st of June 2013.
The research and development company Sosny (Rosatom’s long-standing partner specializing in solving non-standard and challenging tasks in the field of spent nuclear fuel management) has developed technology and equipment to drain spent liquid fuel from the reactor into temporary flasks and re-load it into shipping casks. Sosny has also developed special equipment to load liquid SNF casks into the SKODA VPVR/M container with the help of a re-load container. In addition, they designed technology and special equipment to receive and handle irradiated liquid nuclear fuel at Rosatom’s subsidiary Mayak. Safety of the equipment for liquid SNF management and its compliance with current rules and regulations has been proved by calculations. After the audit, the national regulator Rostekhnadzor issued a license for the acceptance, temporary storage of shipping casks and liquid SNF reprocessing at Mayak.
Before the first shipment of liquid SNF was returned to Russia from Uzbekistan, the two countries signed a new agreement to set a legal framework for the return of INN-3M fuel. The agreement reads that irradiated nuclear fuel is returned to Russia in accordance with the regulatory procedure for import of irradiated fuel assemblies to the Russian Federation for the purpose of temporary storage, reprocessing and disposal of radioactive waste.
This September flasks with INN-3M liquid fuel were loaded in the SKODA VPVR/M container. The shipment of irradiated nuclear fuel (about 27 liters) was transported by An-124-100 aircraft (Volga-Dnepr air carrier) in the TUK-145/C container (Shell Type C, includes SKODA VPVR/M and an energy absorption container) to Mayak for reprocessing. The licensing process and transportation were organized under control of Rosatom’s Nuclear Safety and Licensing Department.
The RRRFR Program was launched in 2010. Since then, spent nuclear fuel has been returned from Uzbekistan, Latvia, Bulgaria, Hungary, Kazakhstan, Lybia, Romania, Ukraine, Poland, Belarus, Serbia and the Czech Republic.
