Russian state nuclear corporation Rosatom said on 22 July that it was completing unloading used nuclear fuel from floating base Lepse.
“In a short time, under unfavorable radiation conditions, Rosatomflot specialists carried out unique work to unload sub-standard used fuel assemblies,” said Mustafa Kashka, General Director of FSUE Atomflot. Rosatom organisations are carrying out final work to unload most of the used fuel from the Lepse floating technical base (FTB) at the branch of CS Zvezdochka JSC in the Nerpa shipyard.
The last of the six batches of used fuel assemblies was reloaded into TUK-18 transport packaging containers and delivered to the special storage site at Atomflot by the motor ship Serebryanka. The work started in May 2019, since when 620 used fuel assemblies have been cut out and unloaded from the FTB bow package using specially developed technologies and unique equipment.
“Dose loads on personnel did not exceed the control levels and average annual values. We have taken an important step towards improving the environmental safety of the Arctic region,” said Kashka.
“Disposal of Lepse is an internationally significant environmental project,” said Alexander Zhelnin, Director General of Nuclear Fuel Cycle Logistics Centre LC NFC. “The unloading of the last batch of used nuclear fuel marked the successful completion of the project which was carried out with international technical assistance. The remaining 19 assemblies in the caissons are planned to be unloaded in 2021 using federal budget funds."
As of today, 97% of the fuel from the FTB Lepse has been unloaded, and 24 control units have already been sent for reprocessing to PA Mayak.
“Since last year, the maximum rate of used fuel removal from the storage facilities at Andreeva Bay, Gremikha point and the Lepse vessel has been achieved. At the same time, the total activity of the exported nuclear materials is about half a million curies, making it possible to solve the problem of creating a zone in the north-west of Russia without nuclear hazardous facilities, which is especially important for the environment, " said Oleg Kryukov,Rosatom’s director for state policy in the field of radioactive waste, used fuel and decommissioning of nuclear and radiation hazardous.
The dry cargo ship Lepse was built in 1934, and converted into a floating technical base in 1961. Until 1981, it supported the refuelling of Russia's nuclear icebreakers. Since 1981, Lepse has been used for storing used nuclear fuel and radioactive waste. In 1988 Lepse was decommissioned.
In 1996, the project to deal with Lepse 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 the disposal of the Lepse, the recipient of which was LC NFC, with the EBRD as the administrator. The aim of the project was to improve the radiation situation and eliminate serious environmental hazards in the region by removing used nuclear 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.
Photo: Lepse fuel assemblies removal in northwest Russia completed (Photo credit: EBRD)