The final 19 used fuel assemblies have been removed from Russia’s floating technical base (FTB) Lepse at the Nerpa shipyard in Kola Bay. On 11 June, the motor ship Serebryanka delivered the assemblies in TUK-18 containers to the special storage site at FSUE Atomflot in Murmansk. Unloading and transportation of the 19 assemblies was funded from the federal budget.
Atomflot specialists will now unload the containers and will send the used fuel for processing at PA Mayak in Ozersk. The bow and aft sections of the Lepse will be transported to the long-term storage facility for reactor compartments at Sayda-Guba in 2022. “To ensure the dismantling of FTB Lepse, it was necessary to specially develop technologies and equipment, and to make non-standard decisions,” said Mustafa Kashka, General Director of Atomflot.
Work to unload Lepse began in May 2019 and, by July 2020, 620 used fuel assemblies had been removed. The dry cargo ship Lepse was built in 1934, and converted into a FTB in 1961. Until 1981, it supported the refuelling of Russia's nuclear icebreakers, after which it was used for storing used nuclear fuel and radioactive waste. In 1988 Lepse was decommissioned.
The project to deal with Lepse was carried out with international technical assistance. In 1996, it was included in the European Union’s TACIS programme (the CIS technical assistance programme) with funding allocated for the inspection of the used fuel. In 2008, the initial executive grant agreement (GIS) was concluded for disposal of Lepse, the recipient of which was LC NFC, with the European Bank for Reconstruction and Development (EBRD) as administrator. The aim of the project was to improve the radiation situation and eliminate serious environmental hazards in the region by removing used fuel and radioactive waste from the Lepse and sending it for reprocessing or temporary storage.
After 2011 with funding from Russia’s federal target programme “Ensuring Nuclear and Radiation Safety for 2008 and for the Period Until 2015”), a comprehensive radiation survey of the vessel was undertaken and preparatory work began. This included docking with partial conversion of the ship’s hull removing some radioactive material, decontamination, and installation of additional equipment. Lepse was then towed to the Nerpa Shipyard in 2012.
In September 2018, EBRD announced it had built a shelter for refuelling the vessel intended to create safe conditions to cut out the used fuel from the onboard storage tanks, transfer the nuclear material into new canisters and transport these for further storage at Mayak.
The EBRD said the cost of €23m shelter was financed through the Nuclear Window of the Northern Dimension Environmental Partnership Support Fund, an international fund with contributions from Belgium, Canada, Denmark, the European Union, Finland, France, Germany, the Netherlands, Norway and the UK, and managed by the EBRD.
Image: Lepse floating technical base