California - class cruiser The " California " class cruisers were a set of two of nuclear - powered guided missile cruiser s operated by the United States Navy between 1974 and 1998 . Other than their nuclear power supply and lack of helicopter hangars , ships of the " California " class were comparable to other guided missile cruisers of their era , such as the " Belknap " class . The class was built as a follow - up to the nuclear - powered " Long Beach " , " Bainbridge " , and " Truxtun " classes . Like all of the nuclear cruisers , which could steam for years between refuelings , the " California " class was designed in part to provide high endurance escort for the navy ' s nuclear aircraft carrier s , which were often limited in range due to their conventionally powered escorts continuously needing to be refueled . Overview . The was the fourth nuclear - powered cruiser in the U . S . Navy ; the previous three were the , and . The second " California " class cruiser , , was the fifth nuclear - powered cruiser in the United States Navy . Other than the four ships of the Soviet Navy ' s " Kirov " class , which were actually built with a combination of nuclear and fossil - fuel propulsion , no other country has launched nuclear - powered cruisers . Only two ships of the class were built , the " California " and the " South Carolina " , and both were decommissioned in the autumn of 1999 . These ships were followed on by the four nuclear - powered cruisers of the " Virginia " class . These cruisers were named for states because they were seen as quite large , powerful , capable , and survivable ships . Also , in the meantime , the names of cities had been given to the nuclear submarines in the very large " Los Angeles " class , which eventually expanded to 62 boats , all ( but one ) named for American cities . The USS " California " and her sister ship the USS " South Carolina " were equipped with two Mk - 13 launchers , fore and aft , capable of firing the Standard SM - 1MR or SM - 2MR surface - to - air missiles , one Mk - 112 launcher for ASROC missiles , and eight Mk - 141 launch tubes for Harpoon missiles . They were equipped with two Mk - 45 5 " rapid - fire guns , fore and aft . Four 12 . 75 " torpedo launchers ( two on each side , protruding from their magazine space on the main deck ) were fitted for light weight anti - submarine torpedoes . Two Mk - 15 Phalanx 20 mm gun systems were fitted in the 1980s . The ships were originally designed to carry and launch the Mark 48 torpedo from a large space beneath the flight deck aft . Although a surface - launched version of the Mk 48 was never produced , the ships retained this large magazine space until their retirement . Both ships underwent a mid - life refueling overhaul in the early 1990s to give them a further 18 years active service . This modernization upgraded their two 150 MW D2G reactor plants with new 165 MW D2W reactor cores , installed the New Threat Upgrade ( NTU ) to improve their AAW capability , and removed their ASW capability , which involved disabling their SQS - 26 sonar and removing their " ASROC " anti - submarine weapons , though the 2 triple Mk - 32 ASW torpedo launchers were retained . External differences resulting from this modernization included the removal of the ASROC launcher and the large deckhouse forward of it that served as the ASROC magazine , replacement of the SPS - 40 radar antenna with the SPS - 49 antenna , and replacement of the SPS - 48C with the larger SPS - 48E antenna . Both ships retained the bulbous sonar domes at the forefoot ( beneath the waterline ) until retirement , even after their sonar systems were disabled . While the ships were as modernized as much as possible , and were capable of service until 2010 ; they still were only capable of firing SM - 2MR missiles from their Mk - 13 launchers , and their high cost of operation made them targets for early retirement , and were both decommissioned in 1999 .