Scientists from the National Research Centre, Kurchatov Institute, and the Shirshov Institute of Oceanology of the Russian Academy of Sciences annually conduct naval expeditions aimed at monitoring the condition of underwater radiation hazardous objects in the Arctic. The most recent expedition, completed in December 2025 aboard the research vessel Akademik Ioffe, inspected the sunken nuclear submarine K-27 in Stepovoy Bay near Novaya Zemlya.
Measurements show that protective barriers isolating the nuclear fuel from the marine environment still remain intact. Based on these findings, the specialists selected a coastal area for a future underwater station designed to provide continuous 24/7 radiation monitoring of the K-27 reactors. The Kurchatov Institute is completing work on the underwater station, which is an unattended device with a long service life and the ability to remotely configure equipment. Similar stations are expected to be used in the future at other sunken radiation hazardous facilities.
The soviet nuclear submarine K-27 was built in 1962. In 1968, a radiation accident occurred on the gusset, after which it was taken out of service. In 1981, the submarine was sunk in the Kara Sea near the Novaya Zemlya archipelago at the entrance to Stepovoy Bay.
K-27-Soviet nuclear submarine, the only ship built under the project 645 ZHMT with lead-bismuth-cooled RM-1 fast reactors entered service in 1962. From April to June 1964, she made a record-breaking autonomous voyage to the waters of the Central Atlantic, winning several awards. However, in May 1968, a radiation accident occurred and the entire crew of 105 people suffered acute radiation sickness, nine of whom died. In February 1979, the boat was excluded from the Soviet Navy and disbanded in October 1980. In September 1982, it was scuttled in the Kara Sea off the northeast coast of the Novaya Zemlya Archipelago at the entrance to Stepovoi Bay at a depth of 31 metres.
In September 2024, during the fifth expedition conducted by the Emergencies Ministry, divers undertook a detailed survey of the vessel despite severe weather conditions, including snowstorms and low air and water temperatures. The work was carried out using underwater drones Rovbuilder-600 and Falcon with a gamma-ray spectrometer from the Kurchatov Institute.
Institute experts say the K-27 nuclear submarine requires regular monitoring to check the protective barriers that prevent radioactivity from entering the marine environment. During the December expedition, the scientists conducted a series of geological and geomorphological studies of the coast of Stepovoy Bay to identify the best site for the underwater radiation monitor. A test version of the monitor is currently operating at the Institute.
The expedition also used underwater spectrometers, which the Kurchatov Institute has been developing since the mid-1990s. Currently, the fifth generation of these devices is being created. Spectrometers of the REM-4x series have proved excellent when conducting surveys of underwater radiation-hazardous objects, including nuclear submarines.
