Fermi 1 was the United States' only demonstration-scale breeder reactor, built during the 1950s at the Enrico Fermi Nuclear Generating Station on the western shore of Lake Erie south of Detroit, Michigan. It used the sodium-cooled fast reactor cycle, in which liquid sodium metal is used as the primary coolant instead of more typical nuclear reactor designs which are cooled with water. Sodium cooling allows for a more compact core with surplus neutrons, which are used to produce more fission fuel by converting a surrounding "blanket" of 238U into 239Pu which can be fed back into a reactor. At full power, it would generate 430 MW of heat (MWt), or about 150 MW of electricity (MWe). The design and construction of Fermi 1 was led primarily through the efforts of Walker Lee Cisler, president of Detroit Edison. Cisler believed that the breeder cycle would dominate the future commercial market as it would guarantee an effectively limitless supply of fuel, and ceaselessly championed efforts to produce Fermi 1 based on the design of the small experimental EBR-I in Idaho. His efforts were supported by Lewis Strauss, chair of the U.S. Atomic Energy Commission (AEC), who was a strong advocate of private companies entering the nuclear field. On 29 November 1955, EBR-I suffered a partial meltdown for reasons that were not completely understood at the time. Construction licensing for Fermi 1 started in January 1956. The AEC's review panel suggested the design should not proceed until the issue with EPR and breeder design in general was better understood with further testing on new experimental systems like EBR-II. When the report was mentioned in congressional meetings, Strauss refused to discuss it and approved construction. This led to a firestorm of debate within Congress and the press, along with a series of lawsuits by the United Auto Workers that briefly led to its construction license being revoked. Construction was delayed by several years and its budget doubled during that time; originally planned to start operations in 1959 or early 1960, Fermi 1 achieved criticality on 23 August 1963. While slowly increasing its power rating over the next two years, on 5 October 1966 it suffered a partial meltdown when the flow of sodium was disrupted by blockage of the inlet holes at the bottom of the reactor. The problem was seen early enough to safely scram the reactor and there was no radioactive release