Russia’s Experimental-Demonstration Centre for the Decommissioning of Uranium-Graphite Nuclear Reactors (UDC UGR, part of state nuclear corporation Rosatom) has postponed from 2020 to 2021 the beginning of the decommissioning of previously shut down industrial production reactors at the Siberian Chemical Combine (SCC) in Seversk, the UDC press service said on 26 February. “Today, preparations for the decommissioning of the ADE-4 reactor are entering their final stage. From 2021, specialists of the UDC UGR plan to begin decommissioning the ADE-4 and ADE-5 reactors,” it said. The two reactors produced approximately one sixth of Russia’s weapons-grade plutonium.
A total of five industrial uranium-graphite reactors operated at the SCC: I-1, EI-2, ADE-3, ADE-4, ADE-5. The decommissioning of EI-2 was formally accepted as completed by a government commission in 2015 - the first ever decommissioning of a commercial uranium-graphite reactor. To guarantee safe storage of the reactor for tens of thousands of years, SCC in 2010 established UDC UGR, which, in co-operation with leading research centres of the Russian Academy of Sciences, developed a unique decommissioning technology whereby all reactor cavities were filled with a mix of natural clays.
EI-2 began operating in February 1958 at the Tomsk-7 closed city (now Seversk). It was SCC's second industrial uranium-graphite reactor. The first (I-1) was launched in 1955 and together they formed the first dual-purpose NPP producing both weapons-grade plutonium and 100MWe of electricity. In the 1960s SCC put three more dual-purpose reactors into operation - ADE-3 (1961), ADE-4 (1964) and ADE-5 (1965) boosting power production to 600MWe.
Under a Russian-US agreement to end production of military-grade plutonium and I-1 was closed in 1990, EI-2 in 1991 and ADE-3 in 1992. ADE 4 and ADE 5 continued operating until 2008 as they also provided power to the site.
After the decommissioning of EI-2 in 2015, it was expected that the withdrawal of the remaining four shutdown reactors of the SCC would take about five years, until 2020. This has now been extended by one year.
