Besides Sredniy, five island bases are being built by 1,500 workers - at Alexandra Land, Rogachevo, Cape Schmidt, Wrangel and Kotelny, as an icebreaker has carved a channel through the ice for the Northern Fleet flotilla, the report says.
Russia sees the Arctic as a strategic priority in its new naval doctrine.
The fleet's vice-admiral, Viktor Sokolov, inspected the construction site on Sredniy, flying there by military helicopter when the flotilla reached the Kara Sea. During the Cold War the USSR tested nuclear weapons in the area.
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