Russian ship M/V Ursa Major sank in December 2024 carrying nuclear reactors

The M/V Ursa Major, a Russian-flagged heavy-lift ship, sank in December 2024 in the Western Mediterranean off the coast of Cartagena, Spain. Spanish authorities have reported that the vessel may have been sunk by a torpedo. At the time of its sinking, the ship was reportedly carrying two VM-4SG Nuclear Pressurized Water Reactors (PWR) destined for North Korea. These reactors are believed to be intended for use in a new class of nuclear-powered submarines.

The M/V Ursa Major is part of what has been referred to as Russia’s Shadow Fleet. Investigations into the incident are ongoing, with further details expected to emerge as authorities continue to analyze the circumstances surrounding the sinking.

For related coverage, see investigators believe Russian ship Ursa Major carried nuclear components for North Korea.