In December 1945, Rickover was appointed
Inspector General of the
19th Fleet on the west coast, and was assigned to work with
General Electric at
Schenectady,
New York, to develop a nuclear propulsion plant for destroyers. In 1946, an initiative was begun at the
Manhattan Project's Clinton Laboratory (now the
Oak Ridge National Laboratory) to develop a nuclear electric generating plant. Realizing the potential that nuclear energy held for the Navy, Rickover applied. Rickover was sent to Oak Ridge through the efforts of his wartime boss, Rear Admiral Earle Mills, who became the head of the Navy's
Bureau of Ships that same year. Rickover became an early convert to the idea of
nuclear marine propulsion, and was the driving force for shifting the Navy's initial focus from applications on destroyers to submarines. Rickover's vision was not initially shared by his immediate superiors: he was recalled from Oak Ridge and assigned "advisory duties" with an office in an abandoned ladies' room in the Navy Building. He subsequently went around several layers of superior officers, and in 1947 went directly to the Chief of Naval Operations,
Fleet Admiral Chester Nimitz, also a former submariner. Nimitz immediately understood the potential of nuclear propulsion in submarines and recommended the project to the Secretary of the Navy,
John L. Sullivan. Sullivan's endorsement to build the world's first nuclear-powered vessel, , later caused Rickover to state that Sullivan was "the true father of the Nuclear Navy." Subsequently, Rickover became chief of a new section in the
Bureau of Ships, the Nuclear Power Division reporting to Mills. He began work with
Alvin M. Weinberg, the Oak Ridge director of research, to initiate and develop the
Oak Ridge School of Reactor Technology and to begin the design of the
pressurized water reactor for submarine propulsion. In February 1949 he was assigned to the
Atomic Energy Commission's Division of Reactor Development, and then assumed control of the Navy's effort within the as Director of the
Naval Reactors Branch. This twin role enabled him to lead the effort to develop
Nautilus. The original selection of Rickover as head of development of the nation's nuclear submarine program ultimately rested with Admiral Mills. According to Lieutenant General
Leslie Groves, director of the Manhattan Project, Mills was anxious to have a very determined man involved. He knew that Rickover was "not too easy to get along with" and "not too popular," but in his judgement Rickover was the man on whom the Navy could depend "no matter what opposition he might encounter". While his team and industry were completing construction of
Nautilus, Rickover was promoted to the rank of
rear admiral in 1953. However, this was anything but routine, and occurred only after an extraordinary chain of events: Regardless of the challenges faced in developing and operating brand-new technology, Rickover and the team did not disappoint: the result was a highly reliable nuclear reactor in a form-factor that would fit into a submarine hull with no more than a
beam. This became known as the
S1W reactor.
Nautilus was launched and commissioned with this reactor in 1954. Later Rickover oversaw the development of the
Shippingport Atomic Power Station, the first commercial pressurized water reactor nuclear power plant.
Kenneth Nichols of the AEC decided that the Rickover-Westinghouse pressurized-water reactor was "the best choice for a reactor to demonstrate the production of electricity" with Rickover "having a going organization and a reactor project under way that now had no specific use to justify it." This was a reference to the first core used at Shippingport originating from a cancelled
nuclear-powered aircraft carrier. This was accepted by
Lewis Strauss and the Commission in January 1954. Rickover was promoted to
vice admiral in 1958, the same year that he was awarded the first of two
Congressional Gold Medals. He exercised tight control for the next three decades over the ships, technology, and personnel of the nuclear Navy, interviewing and approving or denying every prospective officer being considered for a nuclear ship. Over the course of Rickover's career, these personal interviews numbered in the tens of thousands; over 14,000 interviews were with recent college-graduates alone. The interviewees ranged from midshipmen and newly commissioned
ensigns destined for nuclear-powered submarines and surface combatants, to very senior combat-experienced naval aviator
captains who sought command of nuclear-powered aircraft carriers. The content of most of these interviews has been lost to history, though some were later chronicled in several books on Rickover's career, as well as in a rare personal interview with
Diane Sawyer in 1984. In 1973, though his role and responsibilities remained unchanged, Rickover was promoted to the rank of four-star
admiral. This was the second time (after
Samuel Murray Robinson) in the history of the U.S. Navy that an officer with a career path other than an operational line officer achieved that rank. Because his responsibilities did not include direct command and control of combatant naval units, technically Rickover was appointed to the grade of admiral on the retired list so as to provide some clarity on this issue. This was also done to avoid affecting the maximum-authorized number of admirals (O-10) on the "active list." As head of Naval Reactors, Rickover's focus and responsibilities were dedicated to reactor safety rather than tactical or strategic submarine warfare training. However, this extreme focus was well known during Rickover's era as a potential hindrance to balancing operational priorities. One way that this was addressed after Rickover retired was that only the very strongest, former at-sea submarine commanders have held Rickover's now unique eight-year position as
NAVSEA-08, the longest chartered tenure in the U.S. military. From Rickover's first replacement,
Kinnaird R. McKee, to today's head of Naval Reactors,
William J. Houston, all have held command of nuclear submarines, their squadrons and ocean fleets, but none have been a long-term
Engineering Duty Officer such as Rickover. In keeping with Rickover's promotion to four-star admiral, those who were subsequently selected for assignment to Director, Naval Reactors are promoted to this same rank, but also on active duty status. Historian Francis Duncan, who for over eight years was granted generous access to diverse numbers and levels of witnesses—including U.S. presidents—as well as Rickover himself, came to the conclusion that the man was best understood with respect to a guiding principle that Rickover invoked foremost for both himself and those who served in the U.S. Navy's nuclear propulsion program: "exercise of the concept of responsibility." This is further evidenced by Rickover listing
responsibility as his first
principle in his final-years paper and speech, ''Thoughts on Man's Purpose in Life''.
Safety record Rickover's stringent standards are largely credited with being responsible for the U.S. Navy's continuing record of zero reactor accidents (defined as the uncontrolled release of fission products to the environment resulting from damage to a reactor core). He made a point of being aboard during the initial sea trial of almost every nuclear submarine completing its new-construction period. Following the
Three Mile Island accident on March 28, 1979, Admiral Rickover was asked to testify before Congress in the general context of answering the question as to why naval nuclear propulsion had succeeded in achieving a record of zero reactor-accidents, as opposed to the dramatic one that had just taken place. The accident-free record of United States Navy reactor operations stands in some very stark contrast to those of the Soviet Union, which had
fourteen known reactor accidents. As stated in a retrospective analysis in October 2007:
Views on nuclear power Given Rickover's single-minded focus on naval nuclear propulsion, design, and operations, it came as a surprise to many in 1982, near the end of his career, when he testified before the U.S. Congress that, were it up to him what to do with nuclear powered ships, he "would sink them all." At a congressional hearing Rickover testified that: A few months later, following his retirement, Rickover spoke more specifically regarding the questions "Could you comment on your own responsibility in helping to create a nuclear navy? Do you have any regrets?": ==Focus on education==