Nuclear & Arms Control — 2026-05-13

Investigation Reveals Sunken Russian Ship Was Carrying Submarine Nuclear Reactors Destined for North Korea

The Ursa Major sank December 23, 2024, roughly 60 miles off Spain after three engine-room explosions killed two crew members; 14 survived. Captain Igor Anisimov told Spanish investigators the manifest items listed as "manhole covers" were submarine nuclear reactor components and that the ship would divert to the North Korean port of Rason, testimony the Spanish government confirmed in a February statement to lawmakers. CNN, citing a source familiar with the inquiry, reports the Russian escort vessel Ivan Gren fired red flares before four further explosions sank the vessel, and that Russian spy ship Yantar spent five days over the wreck one week later. US nuclear-sampling aircraft flew over the site twice in the past year; a USAF spokesman confirmed the aircraft "supports nuclear debris collection and analysis."

Analysis
Per a single CNN investigation with no independent corroboration, Ivan Gren's four secondary explosions and Yantar's five days over the wreck with further detonations indicate Moscow assessed the physical record as a liability worth eliminating. The same pattern fits standard OPSEC around sensitive military hardware. December 2025 DPRK submarine imagery and South Korean reporting of at least one 2025 reactor transfer suggest the program continued regardless. Formal salvage or environmental assessment is unlikely by end of December 2026: Spanish institutional reluctance, 2,500-meter depth, and absent coastal contamination remove the primary pressure point, leaving coordinated sanctions dependent on intelligence attribution rather than physical evidence.

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