Russia Completes Hybrid Submarine
Russia’s Sevmash shipyard at the Arctic city of Severodvinsk has completed a hybrid submarine powered by a diesel-electric plant and a small nuclear reactor. Designated B-90 and named Sarov, the submarine was completed on 17 December. The submarine is known as Project 20120 in Russian design terminology. She apparently employs the small nuclear reactor — known to some engineers as a “teakettle” — to keep a charge on the battery, providing essentially unlimited underwater endurance on relatively quiet electric propulsion. In effect, this is an Air-Indpendent Propulsion (AIP) system. The “teakettle” concept is not new. The Soviet Navy deployed a Project 651 (NATO Juliett) cruise missile submarine (SSG) in 1986-1991 with a similar diesel-electric/nuclear plant. That craft had a pressurized-water reactor with a single-loop configuration coupled with a turbogenerator. The Soviet report stated that the sea trials “demonstrated the workability of the system, but revealed quite a few deficiencies. Those were later corrected.” However, no follow-on efforts were undertaken at that time. (The Soviets built 16 diesel-electric Juliett SSGs from 1963 to 1968.) The B-90 was designed by the Rubin design bureau in St. Petersburg. Construction was begun at the Krasnoe Sormovo shipyard in Nizhnii Novgorod (formerly Gor’kiy), and…