A Russian cargo ship, which apparently was carrying two nuclear reactors for submarines, possibly intended for North Korea, suffered a series of explosions and sank in unexplained circumstances about 60 miles off the coast of Spain in 2024, according to an investigation published by CNN.
The unusual fate of the Ursa Major has been shrouded in secrecy since it sank on Dec. 23, 2024. But it may have been a rare and high-risk intervention by a Western military to prevent Russia from sending a nuclear technology upgrade to a key ally, North Korea, according to the CNN report. The ship sailed just two months after Kim Jong Un sent troops to assist Moscow's invasion of Ukraine.
A wave of recent military activity around the wreckage has deepened the mystery surrounding its cargo and destination. US nuclear "sniffer" aircraft flew over the sunken ship twice over the past year, according to public flight data. The wreckage was also visited a week after the sinking by a suspected Russian spy ship, which caused four further explosions, according to a source familiar with the Spanish investigation into the incident.
The Spanish government has said little, issuing a statement only on Feb. 23 after pressure from opposition lawmakers. The statement confirmed that the Russian captain of the ship told Spanish investigators that the Ursa Major was carrying "components for two nuclear reactors similar to those used in submarines," and that he was unsure whether they were loaded with nuclear fuel.
The sequence of events that led the Ursa Major to sink to the bottom of the Mediterranean Sea remains unclear. Spain's investigation points to the possibility that a rare type of torpedo was used to breach the ship's hull, as a source familiar with the details of the investigation told the US news network. The incident took place in the final days of Joe Biden's presidency, as the war in Ukraine was reaching a peak in Moscow's favor and the US administration sought to avoid direct escalation with the Russians.
The Ursa Major, also known as Sparta III, was used by Russia's shadow fleet in its military campaign in Syria, where it helped evacuate Russian equipment. It docked at the fuel port of Ust-Luga in the Gulf of Finland on Dec. 2, before moving to a container facility at the docks of St. Petersburg. The ship's official cargo documents said it was bound for Vladivostok, in Russia's Far East, when it sailed on Dec. 11 carrying two large "manhole covers," 129 empty shipping containers and two large cranes.
In October of that year, its owner, the state-linked company Oboronlogistics, said in a statement that its ships had been licensed to carry nuclear material. Time-lapse video footage of the Ursa Major being loaded at Ust-Luga, analyzed by CNN, shows containers being placed inside the ship's hull, with a gap left below where the "manhole covers" would later be positioned.
