Russian Shipwreck Off Spain Could Be Carrying Technology For DPRK Nuclear Submarine
- 12.05.2026, 10:20
New details of the shipwreck have emerged.
The Russian cargo ship Ursa Major ("Big Bear"), believed to be carrying components of two submarine nuclear reactors to North Korea, sank in the Mediterranean Sea after a series of mysterious explosions. According to one version, it could be an attempt to disrupt the transfer of sensitive Russian nuclear technology to Pyongyang. This is stated in the investigation CNN, citing Spanish investigators, sources and analysis of the vessel's movement.
The vessel sank on December 23, 2024, about 100 kilometers off the coast of Spain. The circumstances of the accident have remained classified since then, but CNN says there was unusual military activity around the ship.
The channel says US WC-135R aircraft known as "nuclear sniffers" - designed to search for traces of radioactive materials and commonly used in monitoring nuclear activity by Russia, Iran and North Korea - flew over the wreck at least twice.
In addition, the Russian ship Yantar, which has been repeatedly accused by Western countries of spying and sabotage in NATO waters, arrived at the wreckage a week after it sank. According to CNN's source, four more explosions were recorded after its arrival.
Spanish authorities have officially made little comment on the incident. It wasn't until February 2026 that the Spanish government acknowledged that the ship's captain told investigators the vessel was carrying "components of two nuclear reactors similar to those used on submarines."
The captain, according to the investigation, could not confirm whether the reactors contained nuclear fuel.
The Ursa Major, also known as the Sparta III, was owned by Russian-affiliated Oboronlogistica. It was previously used in Russia's Syrian campaign to transport military equipment.
The ship left St. Petersburg on December 11, 2024. Official documents indicated Vladivostok as the final point of the route. The cargo declaration included two large "hatches", 129 empty containers and two large Liebherr harbor cranes.
But, as CNN notes, Spanish investigators questioned the logic of such a route: the ship was actually sent from one Russian port to another, despite the presence of a developed railroad network.
According to the investigation, the ship's captain Igor Anisimov later admitted to Spanish investigators that the final delivery point could have been the North Korean port of Rason. Presumably, that is where the two reactors were to be delivered.
CNN journalists link the possible transfer of technology to the strengthening of cooperation between Moscow and Pyongyang after the North Korean military was sent to Russia in the fall of 2024 to participate in battles in the Kursk region.
The investigation also draws attention to the photos of the first North Korean nuclear submarine published by the DPRK in December 2025. The images show the country's leader Kim Jong-un inspecting the submarine's hull, but no signs of a working reactor can be seen in the images.
The Spanish investigators believe the first alarming signal was the Ursa Major's sudden slowdown on Dec. 22. At the time, the crew told rescuers there were no problems. However, the very next day, three explosions occurred on the starboard side of the ship in the engine room area. Two crew members died.
14 sailors evacuated by lifeboat and were picked up by Spanish rescuers. Later, the Russian warship Ivan Gren, which had earlier escorted the Ursa Major, arrived at the site.
A short time after the Ivan Gren arrived, flares were fired over the area, after which seismologists recorded four more explosions, according to CNN. An hour and a half later, the ship finally sank.
The investigation was also looking into the nature of the damage to the hull. The owner company later said a hole measuring about 50 by 50 centimeters was found in the side, and metal was bent inward.
One version of the Spanish investigation suggests the use of a Barracuda-type supercavitating torpedo, a high-speed weapon that experts estimate only a few countries, including the United States, Russia and Iran, possess.
At the same time, some experts interviewed by CNN considered this version unlikely. Some experts suggested that the damage is more likely to be the result of a magnetic mine.
Officially, neither Russia, Spain nor the United States have presented final conclusions about the causes of the disaster. The Pentagon declined to comment. Several Western security officials acknowledged the story looked "strange" but called some of the conclusions of the Spanish investigation too bold.
The wreckage of the ship now lies at a depth of about 2.5 kilometers. Spanish authorities have said that lifting the flight recorder from such a depth is too difficult and dangerous. Some experts, however, doubt this explanation and suggest that the "black box" could already be in the possession of one of the parties.