Russia’s ADE-2 industrial uranium-graphite reactor at the Mining and Chemical Combine (MCC) in Zheleznogorsk, is to become become a nuclear industry museum, joining the world's first nuclear icebreaker Lenin and the Obninsk NPP, the world's first civil nuclear power plant. The ceremony, marking the event on 27 February was held mostly online because of pandemic restrictions. A live broadcast connected representatives of almost all MCC divisions located in different halls, while direct participants had passed testing for COVID-19 the day before.

ADE-2 was the last of Russia’s dual purpose plutonium production reactors to be closed. It was shut down in 2010, after producing weapons-grade plutonium for nearly 52 years, in line with the 1997 Plutonium Production Reactor Agreement with the US. It also provided heat and electricity to Zheleznogorsk and nearby areas, which was its main function after1993. It continued to produce weapons-grade plutonium as a by-product, but under the terms of the US agreement, this could not be used for weapons purposes and was stockpiled.

The first AD reactor was launched in 1958 at MCC, solely for plutonium production. The second, ADE-1, launched in 1961, was intended also to produce electricity (hence the “E” for energy in its name) but never did so as the combined heat and power plant (CHPP) had not been completed. ADE-2 began operation in December 1963 after the CHPP was in place. All three reactors were built underground and used cooling water from the Yenisei river.

It was a huge undertaking. Some 27,000 prisoners worked on the construction of underground reactors. The volume of rock removed was several million cubic metres. More than 1 million cubic metres of concrete were laid, and tens of thousands of tons of metal structures, pipelines, cables were put in place. In the underground rooms, giant fans were installed with a capacity of about 1 million m3 of air per hour.

The AD series reactors, designed by OKBM, are water-cooled uranium-graphite thermal neutron reactors. Three more were subsequently built at the Siberian Chemical Combine in Seversk – 

ADE-3, which began operation in 1961, ADE-4 (1964) and ADE-5 (1965). Seversk already had two older dual purpose production reactors in operation – I-1 and EI-2, which began operation in 1955 and 1958. These were designed by the NN Dollezhal Research & Development Institute of Power Engineering (Nikiet).

In 1992, the AD and ADE-1 reactors at MCC were shut down but ADE-2 continued operating until replacement power generating capacity could be built at the plant. At SCC, in line with the Russian-US agreement to end production of military-grade plutonium, 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. 

EI-2 in 2015 became the first uranium-graphite reactor to be successfully decommissioned. In 2019, Russia’s Experimental-Demonstration Centre for the Decommissioning of Uranium-Graphite Nuclear Reactors (UDC UGR, part of Rosatom) postponed from 2020 to 2021 the beginning of the decommissioning of the other closed reactors at SCC. MCC is investigating possible methods for decommissioning AD and ADE-1, Following public hearings in 2013 MCC said it favoured burying them on site as the mountain under which they were built forms a natural safety barrier.