Russian Cargo Ship Sunk Off Spain Carried Nuclear Reactors Bound for North Korea

A Russian cargo ship secretly carrying components for two submarine nuclear reactors—likely destined for North Korea—sank in the Mediterranean Sea in December 2024 after a series of unexplained explosions, a Spanish-led investigation has revealed. The discovery raises concerns about a potential covert transfer of advanced nuclear technology between Moscow and Pyongyang, and suggests a rare military intervention to prevent the shipment from reaching its final destination.

The vessel, the Ursa Major—previously known as Sparta III—was en route from Russia when it sank on December 23, 2024, approximately 60 miles off the coast of Spain, between Spain, and Algeria. Of the 16 crew members on board, 14 were rescued, while two—second engineer Nikitin and engineer Yakovlev—remain missing and are presumed dead. The ship’s Russian captain later disclosed to Spanish investigators that two large hatch covers, declared on the manifest as &quot. non-dangerous merchandise," were in fact components for nuclear reactors similar to those used in submarines. He also indicated that the ship was likely headed to the North Korean port of Rason, though he declined further details due to safety concerns.

Spanish authorities have not publicly confirmed the ship’s final destination, but the investigation suggests a deliberate effort to intercept the cargo. A source familiar with the probe told CNN that Western military officials may have used a rare supercavitating torpedo—a weapon capable of traveling at extreme speeds underwater—to sink the vessel and prevent the transfer. The Russian Foreign Ministry initially attributed the sinking to an "explosion in the engine room" but provided no further explanation.

The wreckage of the Ursa Major has since become a focal point of international intrigue. US nuclear "sniffer" aircraft were reported to have flown over the site twice in the past year, while a suspected Russian spy ship visited the wreckage a week after the sinking, triggering four additional explosions, according to the same source. The Spanish government released a statement on February 23, 2026, confirming the captain’s disclosure about the reactor components but offering no further details on the explosions or the ship’s intended route.

The timing of the incident is particularly significant. The Ursa Major set sail just two months after North Korean leader Kim Jong Un sent troops to assist Russia in its invasion of Ukraine, a move that deepened military cooperation between the two nations. The potential transfer of nuclear submarine reactor technology would represent a major escalation in North Korea’s nuclear capabilities, raising alarms about proliferation risks and regional security.

While the Spanish investigation remains classified, the findings align with broader concerns about illicit nuclear trade routes. The ship’s construction date—2009—and its previous name, Sparta III, have also fueled speculation about its origins and intended use. The discovery underscores the challenges of monitoring covert nuclear shipments, particularly in high-traffic maritime zones like the Mediterranean.

No official confirmation has been issued by Russia or North Korea regarding the cargo or the ship’s fate. The Spanish government has declined to comment beyond its February statement, leaving key questions unanswered: Who authorized the interception? What was the exact nature of the reactor components? And why did the ship’s crew and Russian authorities initially downplay the cargo’s true purpose?

As geopolitical tensions remain high, the Ursa Major incident serves as a stark reminder of the risks posed by unchecked nuclear proliferation and the lengths to which nations may go to prevent sensitive technology from falling into the wrong hands.