The fate of the ‘Ursa Major’: Mystery surrounds Russian ship sunk off the coast of Spain carrying nuclear material

The exploits of Ukrainian espionage, officially acknowledged or not, eventually reach the public eye. Around the second half of December 2024, Kyiv’s intelligence services reported that a Russian ship was damaged and stranded in the Mediterranean. It had suffered, they claimed, an engine problem. The GUR, the Ukrainian Ministry of Defense’s spy agency, identified the vessel as the Sparta. According to Kyiv’s version at the time, it was en route to Syria to transport military equipment. Ukraine never claimed responsibility for any sabotage that might have damaged the enemy vessel. On December 23, 2024, the cargo ship, renamed Ursa Major — although until 2021 it bore the name Sparta on its hull, a long-standing family of Russian ships — sunk to a depth of 2,500 meters off the coasts of Algeria and Spain.

According to information gathered by the Spanish government and reported by CNN on Tuesday, the ship was carrying, in addition to more than 100 empty containers, several components of two nuclear reactors — such as those used in nuclear submarines — including the reactor housings.

The sinking of the Ursa Major was never included on the list of victims of Ukrainian naval drones — capable of operating in the Mediterranean Sea — as were dozens of ships belonging to the so-called Russian “ghost fleet,” with which the Kremlin sails outside the law to trade, primarily, in hydrocarbons and military equipment. The mystery remained. A year after the Ursa Major turned off its tracking system, which it only activated to request a rescue operation — carried out by Spanish maritime authorities — the local newspaper La Verdad de Murcia published a remarkable investigation revealing that the ship was transporting materials for assembling nuclear reactors, destined for the port city of Rason in North Korea, a Russian ally.

Shortly afterward, on January 12, 2025, four members of the conservative opposition Popular Party submitted a question to the Spanish parliament regarding the rescue of the Ursa Major. On February 23, the government, based on information from the Cartagena Port Authority — the sinking occurred 70 miles from this city in Murcia — and the National Rescue Coordination Center, responded to the question and reconstructed a scene reminiscent of the Cold War: 10 hours of rescue operation in which Spanish rapid response teams were able to save the lives of 14 of the 16 crew members and deal with the presence of a Russian warship, which took over operations before the cargo ship sank.

That December, the Ursa Major traversed one of the routes most frequently used by the Russian ghost fleet. It departed on December 11 from Ust-Luga, a port near St. Petersburg, on the Gulf of Finland. Ukrainian attack aircraft frequently fly there, covering hundreds of miles, with the mission of striking one of Moscow’s most important strategic enclaves, which is also under pressure in the Black Sea. The 142-meter-long cargo ship sailed west, following the Danish coast toward the North Sea, before entering the Baltic Sea and heading south toward Europe, to the Iberian Peninsula.

This general cargo ship was part of a fleet of around 600 vessels that Moscow uses to circumvent international sanctions. According to the maritime news website Equasis, the vessel, which has changed flags up to six times since its construction in 2009 — although it was flying the Russian flag when it sank — belonged to the shipping company SC-SOUTH LLC, a subsidiary of the Russian company Oboronlogistika, which was sanctioned by the United States and the EU after the invasion of Ukraine for being a “provider of transport services for the Russian Ministry of Defense.”

The Ursa Major then used a route that its fellow maritime offenders have begun to avoid in recent months due to pressure from European countries, led by France (Norway, the United Kingdom, Germany, and Belgium also contribute), against the Russian ghost fleet. These ships have turned west, bypassing the Baltic Sea and the English Channel, to sail south around the Irish coast.

Sources at a Western foreign ministry indicated in a recent conversation that these Russian ships also have uniformed personnel on Moscow’s payroll on board. It is unknown whether this was the case with the Ursa Major. According to information gathered by Spanish authorities, the cargo ship was sailing with 16 crew. Fourteen were rescued, and two were reported missing. Neither the whereabouts of this pair of crew members nor the cargo could be verified after the sinking. As Secretary of State for Defense María Amparo Valcarce acknowledged before a parliamentary committee in February, accessing the wreck is “technically” possible, but the risks make it “unfeasible.”

Explosions

Both the information from La Verdad de Murcia and that gathered a few months later by CNN indicate that the ship’s captain, Igor Vladimirovich Anisimov, admitted to the Cartagena Port Authority that on December 23, after hearing three explosions, he found a 50-centimeter by 50-centimeter hole in one side of the hull, possibly caused by unidentified ammunition. This caused the ship to begin listing, as the Spanish rescue teams confirmed upon their arrival.

According to sailors’ testimonies, there was another explosion in the engine room. The helicopter supporting the rescue efforts witnessed water entering through the stern. This occurred as a Russian warship approached the area. After announcing that it was taking control of operations, since the ship was flying a Russian flag — in accordance with the United Nations Convention on the Law of the Sea — the vessel launched pyrotechnics with parachutes. Five minutes later, at around 10:00 p.m., the lights on the Ursa Major, perhaps affected by water entering the electrical system, went out. At 11:20 p.m., the cargo ship disappeared completely beneath the waves.

The captain maintained in his statement that the ship was not carrying nuclear fuel. With the wreck at a depth of 2,500 meters, it remains unknown whether this was the case, as well as what could have struck the cargo ship, what caused the disappearance of the two sailors, or the role played by the warship sent by the Russian military.

The information provided by the Spanish government came in response to a question from the opposition regarding “maritime surveillance, preventative analysis, and strategic control.” However, as Western diplomatic sources recently admitted, it is not possible to board every ship suspected of belonging to the Russian ghost fleet. First, because the law of the sea leaves little room for such actions beyond acts of piracy, false flag operations, slavery, etc. Second, because, in the case of Russia, there is evidence of the presence of members of its security forces on board.

The Ursa Major is not the first ship in this shadow fleet to sail off the southern coast of Europe. Nor will it be the last.

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