Hallam Nuclear Generating Station  The Hallam Nuclear Power Facility (HNPF) in Nebraska was a 75 MWe graphite-moderated sodium-cooled nuclear power plant built by Atomics International. Full power was achieved in July 1963. The facility shut down on September 27, 1964 to resolve reactor problems. In May 1966, Consumers Public Power District rejected their option to purchase the facility from the Atomic Energy Commission (AEC). In response, the AEC announced its plan to decommission the facility in June, 1966. The facility operated for 6,271 hours and generated 192,458,000 kW-hrs of electric power. It was located near Hallam, about 25 miles southwest of Lincoln. The graphite-moderated sodium-cooled reactor design was an attempt to achieve economical commercial nuclear electricity. The liquid metal coolant enabled high-temperature, low-pressure operation. The graphite moderator enabled operation with low-enriched nuclear fuel. The benefits of this combination were expected to overcome the added complication of a chemically reactive coolant. The reactor was initially fueled with 3.6% enriched uranium-10 molybdenum alloy with stainless steel fuel. The graphite moderator was also clad in stainless steel. Three sodium heat-transfer loops (each with a radioactive primary loop and a non-radioactive secondary) moved heat to three steam generators. Steam fed into a common header to a single turbine-generator. The primary hot leg temperature was 945 °F and the secondary hot leg temperature was 895 °F. Uranium carbide was selected for the second core, at 4.9% enrichment. Hallam was proposed in March 1955 in response to the first round of invitations by the Atomic Energy Commission's Power Demonstration Reactor Program. It used technology being developed in the smaller Sodium Reactor Experiment (SRE), also built by Atomics International. Lessons from SRE applied to HNPF include:   Because HNPF was more than ten times larger than SRE, a components development and test program was performed to provide final design data. All major components, including fuel, control rods, instrumentation, pumps, and valves were tested. The fuel handling machine was assembled and tested. Scale model of a steam generator was tested in a sodium loop along related equipment and instrumentation. A formal three-session training program for operators was conducted in 1960. 30 personnel attended the first session for six months. Each person received approximately 900 hours of training. Construction began on April 1, 1959.