cruisers were nuclear-powered but these have all been retired. United States naval reactors are given three-character designations consisting of a letter representing the ship type the reactor is designed for, a consecutive generation number, and a letter indicating the reactor's designer. The ship types are "A" for aircraft carrier, "C" for cruiser, "D" for destroyer, and "S" for submarine. The designers are "W" for Westinghouse, "G" for General Electric, "C" for Combustion Engineering, and "B" for Bechtel. Examples are S5W, D1G, A4W, and D2W. Most information concerning United States naval reactors is not secret—see Naval Nuclear Propulsion Information. Accidents involving naval nuclear-powered vessels United States (1963; Thresher/Permit-class; sank, 129 killed) (1968; Skipjack-class; sank, 99 killed) Both sank for reasons unrelated to their reactor plants and still lie on the Atlantic sea floor. Russian or Soviet K-8 (1960; November-class submarine; loss of coolant) K-19 (1961; Hotel-class submarine; two loss of coolant accidents, 27 killed due to one accident) K-11 (1965; November-class submarine; two refueling criticalities) K-159 (1965; November-class submarine; radioactive discharge) Lenin (1965; Lenin-class icebreaker; loss of coolant) Lenin (1967; Lenin-class icebreaker; loss of coolant) K-140 (1968; Yankee-class submarine; power excursion) K-8 (loss of coolant) (1970; November-class submarine; sank after fire, 52 killed) K-320 (1970; Charlie I-class submarine; uncontrolled startup) K-116 (1979; Echo II-class submarine; reactor accident) K-122 (1980; Echo I-class submarine; fire, 14 killed) K-222 (1980; Papa-class submarine; uncontrolled startup) K-27 (1982; Modified November-class submarine; scuttled) K-123 (1982; Alfa-class submarine; loss of coolant) K-429 (1983; Charlie I-class submarine; sank due to improper work at shipyard, 16 killed) K-431 (1985; Echo II-class submarine; refueling criticality, 10 killed) K-429 (1985; Charlie I-class submarine; sank at moorings) K-219 (1986; Yankee I-class submarine; sank, 6 killed) K-278 Komsomolets (1989; Mike-class submarine; sank, 42 killed) K-192 (1989; Echo II-class submarine; loss of coolant) K-141 ''Kursk (2000; Oscar II-class submarine; sank, 118 killed) K-159 (2003; November-class submarine; sank under tow, 9 killed) While not all of these were reactor accidents, they have a major impact on nuclear marine propulsion and the global politics because they happened to nuclear vessels. Only four Soviet nuclear submarines accidentally sank with nuclear weapons on board and remain on the sea floor to this day. Operator Timeline See also JASON reactor List of United States Naval reactors Naval Reactors Decommissioning of Russian nuclear-powered vessels References External links http://www.nukestrat.com/pubs/nep7.pdf - 1994 paper highlighting limited, public-relations only value of all-nuclear task groups given