The successful removal of over one hundred disused radioactive sources from two irradiation facilities located at the “FOTON” nuclear site in Tashkent, Uzbekistan was completed last month with IAEA support. The site includes the IIN-3M research reactor, which is undergoing decommissioning.
While the removal of disused sources is common during the decommissioning of research reactors, the sheer number of sources stored at the “FOTON” premises made this operation unique.
Disused radioactive sources, which continue to emit ionizing radiation following the end of their useful life in medicine, industry or research, can pose a threat to the public and the environment if not handled and stored properly. The sources of “FOTON” were used for the production of semiconductors.
“Some of the sources were difficult to remove from the irradiation facilities, requiring some extra effort, organizational flexibility and smart operations to resolve complicated technical issues,” said Christophe Xerri, Director of the IAEA Division of Nuclear Fuel Cycle and Waste Management. The complications that arose were to carefully and precisely remove the sources some of which had been placed in the facility for more than 20 years without any damage, leakage or contamination. The irradiator equipment and the premises had to remain non-contaminated.
Effective and proven technology was used to retrieve the disused radioactive sources from the two old irradiation facilities, said Umar Shalikhbaev, Director of the Institute of Nuclear Physics in Tashkent. The radioactive sources were removed from irradiators and placed in a shielding container, which was then used to transport the sources to disposal facilities.
In order to accomplish this project successfully, the IAEA provided support at various stages such as in assessing the inventories of the disused sealed radioactive sources before removal began.
In addition, prior to the extraction of the disused radioactive sources, the IAEA supported a training programme to enhance the skills of the staff involved in the removal, as well as of those engaged in the wider decommissioning activities.
The sources were transported to three facilitates: the Uzbekistan National Disposal Facility, the Central Isotope Laboratory and the Centre for State Sanitary and Epidemiological Inspection.
International collaboration
After the final shutdown of the “FOTON” research reactor IIN-3M in July 2015, IAEA provided assistance for the removal of the sources and the decommissioning of the site. The reactor’s fuel had been repatriated to the Mayak reprocessing facility in the Russian Federation.
The decommissioning of the IIN-3M research reactor in Tashkent is scheduled to be completed by the end of 2017. The IAEA has also provided assistance to the Uzbekistan regulatory authority to enhance the legal framework for decommissioning process for the research reactor.
