A secret shipment bound for North Korea may have sunk off the coast of Spain
Russia may have attempted to transfer components for submarine nuclear reactors to North Korea, but the ship carrying the cargo sank off the coast of Spain. Analysts suggest that this was a secret military-technical operation as part of cooperation between Moscow and Pyongyang. It is currently impossible to definitively confirm the cargo’s contents, writes Defence Express.
Information has emerged online suggesting that Russia may have attempted to transfer components for submarine nuclear reactors to North Korea, but experts say the operation ended in failure when the vessel sank off the coast of Spain.
The vessel in question is the Russian ship Ursa Major, which, according to available information, sank in late 2024 under unexplained circumstances near the Spanish coast. According to analysts, it was traveling under the escort of the large landing ships Ivan Gren and Alexander Otrakovsky, which in itself indicates the heightened military significance of the voyage.
After the incident, reports began to surface that the ship may have been carrying components and casings of VM-4SG-type nuclear reactors, which are used in submarines. One of the expert comments cited in the article reads as follows: “As it later became known, it sank after a possible torpedoing by one of the NATO countries, and on board, in particular, were two VM-4SG-type nuclear reactors intended for use on submarines.”
Additional attention was drawn to the story by flights of American WC-135R radiological surveillance aircraft, which, according to analysts, operated twice over the sinking site in 2025 and 2026. Such aircraft are used to detect possible radioactive traces in the air, which further fueled speculation about the dangerous cargo.
Experts note that the discussion likely did not concern full-scale reactors, but rather individual components and housing elements capable of withstanding extreme operating conditions underwater. At the same time, the report emphasizes that the production of such structures is complex and technologically costly, so North Korea may have relied on external assistance.
A separate theory suggests that Russia may have transferred these components as “payment” for military support from North Korea, specifically for weapons and participation in supplying ammunition for the war against Ukraine. According to analysts, these components could have been intended for the DPRK’s new nuclear submarine, which was unveiled in late 2025.
Experts also note that, based on their technical specifications, such reactor modules could have been transported overland, for example by rail, which would have been cheaper and simpler; however, Russia chose a sea route with a military escort, which raises additional questions.
One hypothesis is that the cargo may have been decommissioned or had a high level of background radiation, making its transport by land dangerous or impossible.
The article also mentions that VM-4SG-type reactors were installed on Soviet and Russian nuclear submarines of the Project 667BDRM “Delfin” class, and among the possible sources of the components, the article cites the K-84 “Ekaterinburg,” which was decommissioned in 2022 and was being scrapped after decades of service.
At the same time, there is no confirmation of this in open sources, and some experts suggest that the Ursa Major may have been carrying a completely different dangerous cargo, which was merely disguised as reactor components.
It is currently difficult to definitively determine what exactly the ship was carrying, and analysts do not rule out that some traces may have been deliberately concealed. In particular, they point to a series of explosions in the area of the sinking during the operations of the Russian research vessel “Yantar,” which could be linked to the possible destruction of evidence on the seabed.
The Russian ship Ursa Major was damaged by a torpedo strike; such torpedoes are in service only with the United States, certain NATO countries, Russia, and Iran. The dry cargo ship was transporting two nuclear reactors for nuclear submarines, which Moscow planned to transfer to Pyongyang as payment for the deployment of North Korean troops.
On the night of December 24, 2024, the Russian dry cargo ship Ursa Major sank in the Mediterranean Sea; it may have been involved in the evacuation of a Russian military base in Syria.
The company “Oboronlogistika” claims that its vessel, the Ursa Major, sank in the Mediterranean Sea as a result of a mine explosion.
