Nuke, Line And Sinker: Last Voyage Of North Korea-Bound Russian Ship

CNN reported that a second WC-135R nuclear-sniffer flight over the site occurred on February 6, 2026.

In December 2025, North Korea published photographs of what it described as its first nuclear-powered submarine, showing Kim Jong Un beside the sealed hull, with no clear evidence of a functioning reactor.

A WC-135R aircraft, a specialized nuclear-sniffer plane, flew over the site for the first time on August 28, 2025.

A week after the sinking, the Russian vessel Yantar arrived at the wreck site and remained over the seabed for five days. Four more explosions were detected, possibly targeting what's left on the seabed.

Roughly 60 miles off the Spanish coast, 14 surviving crew members were brought ashore at Cartagena. Investigators debriefed Captain Igor Anisimov, who later testified that the 'manhole covers' were components of two nuclear reactors similar to those used by submarines, though they did not confirm whether fuel was present.

On the morning of December 23, 2024, the Ursa Major was struck by a sequence of explosions after being escorted along the European coast. One of the Russian escort ships fired red flares, and four explosions followed; by 11:10 pm, the vessel was gone.

A 50 cm by 50 cm hole was found in the vessel's hull, with the damaged metal facing inwards and the deck reportedly covered in shrapnel. Spain's maritime investigation suggested the hole was consistent with a Barracuda supercavitating torpedo, a weapon reportedly possessed by the United States, a small number of NATO allies, Russia and Iran.

Spain's maritime investigation concluded that the reactors aboard the Ursa Major were likely VM-4SG models, commonly used in Russia's Delta IV class ballistic missile submarines.

The Ursa Major left the Russian fuel port of Ust-Luga in the Gulf of Finland in early December 2024. Official paperwork listed its cargo as two large 'manhole covers', 129 empty containers and two Liebherr cranes, bound for Vladivostok on Russia's Pacific coast.

In October 2024, North Korea reportedly sent an estimated 10,000 troops to Russia to assist with Moscow's war in Ukraine.