Predisposal Waste Management and Decommissioning of the Finnish FiR1 Research Reactor

In the last two years VTT has made great progress in the decommissioning steps of our pool-type TRIGA research reactor, FiR1 which was commissioned in 1962 and shut down in 2015. Along with the reactor, the historic adjacent laboratories and hot cells are also under decommissioning. The Radiation and Nuclear Safety Authority of Finland (STUK) gave their safety assessment on decommissioning in 2019, and VTT expects the decommissioning licence to be granted by the Finnish Government during 2021.
Because the reactor is a small, operationally safe nuclear facility designed for educational use, the amounts of spent fuel, decommissioning waste and the associated radioactivity are relatively minor. Recently VTT managed to recycle FiR1 spent nuclear fuel for further use abroad. The reactor at the U.S. Geological Survey (USGS), located in Denver, Colorado, USA received the used fuel in January 2021. Arranging spent fuel management abroad is an exception permitted by the Finnish Nuclear Energy Act. Before sending the fuel, Finland received a report of the US authorities on their commitment to the management of the fuel batch. When the USGS ceases to use its reactor, it will deliver the spent fuel to Idaho National Laboratory, where several countries have previously sent similar batches of nuclear fuel from research reactors.
The low- and intermediate level dismantling wastes (LILW) need another solution, and they will be managed in collaboration with a Finnish NPP. VTT has been active in characterisation of the FiR1 reactor and associated laboratory waste streams as part of our licensing and decommissioning plans. The waste management activities are also complemented by coordination and technical involvement in the Euratom PREDIS project on predisposal radioactive waste management. This 4-year project with a 24 M€ budget between 47 partners aims at improved technical solutions for characterisation and treatment of metallic and organic wastes, as well as improved handling and monitoring of concrete waste packages in interim storage. Fortum will ultimately handle the final disposal of the dismantling waste at their Loviisa final disposal LILW facility.
Safety will be an absolute priority during the planning and execution of the VTT plant's and laboratory’s decommissioning. All measures related to the decommissioning will be carried out under the supervision of STUK. This presentation will give an overview of the achievements to-date on decommissioning and pre-disposal waste management.