Sevmorput is a Russian nuclear-powered cargo ship. The 1988-built vessel is one of only four nuclear-powered merchant ships ever built and, after returning to service in 2016 following an extensive refit, the only such vessel to remain in service as of 2022.

The ship was launched on 20 February 1986. The nuclear-powered LASH carrier was named Sevmorput after the Russian abbreviation for the Northern Sea Route. The ship’s KLT-40 reactor plant reached criticality on 26 October 1986. Sevmorput was delivered to the state-owned Murmansk Shipping Company (MSCO) on 31 December 1988.

Sevmorput is 260.30 meters long overall and 236.60 meters between perpendiculars. The breadth and depth of her hull are 32.20 meters and 18.30 meters, respectively. When loaded to the summer waterline, the ship draws 11.80 meters of water. However, in ice-covered waters, she operates with a slightly smaller draught of 10.65 meters to improve the icebreaking characteristics of her raked stem. The gross tonnage of Sevmorput is 38,226 and the net tonnage is 11,468. The ship’s deadweight tonnage is 33,980 tons at a maximum draught and 26,480 tons while operating at a reduced draught in ice. Her maximum displacement is 61,880 tons.

Sevmorput is powered by a single KLT-40 nuclear fission reactor with a thermal output of 135 megawatts. The reactor core contains 150.7 kilograms (of 30–40- or 90-percent) enriched uranium in uranium-zirconium alloy and has reportedly required refueling only twice. The nuclear power plant on board the vessel produces 215 tons of steam per hour at a pressure level of 40 atm (4.1 MPa) and a temperature of 290 °C. In case of emergency, steam can also be produced by a diesel-powered boiler (50 t/h, 2.45 MPa, 360 °C).

Sevmorput can carry 74 lighters, each with a cargo capacity of 300 tons, in six holds and in two layers on the stern deck. The cargo hold hatches are designed for lighters with a total weight of 450 tons. The lighters are loaded and unloaded with a large gantry crane, manufactured by KONE, with a span of 21.3 meters and a lifting capacity of 500 tons. The gantry crane has two three-ton auxiliary cranes.

According to Wikipedia