JSC PO Sevmash (Russian: ОАО «ПО „Севмаш“», Севмаш, СМП) is a shipbuilding company based in Severodvinsk, a port city on Russia's White Sea. The name Sevmash is an abbreviation of Severnoye Mashinostroitelnoye Predpriyatie (Северное Машиностроительное Предприятие), i.e. "Northern Machine-Building Enterprise". Sevmash is the largest shipbuilding enterprise in Russia and today the country's only nuclear submarine producer.