PM-1 Microreactor • Sundance AFS, WY (1962)

This small plant produced 1.25 MW and was designed to maintain high power quality and capacity, operate within narrow regulation limits for frequency and voltage, handle shifts in power loads of plus or minus 30%, and operate under extreme climatic conditions (-45-degree F winters and 102-degree summers). At a 6,000-foot elevation, the reactor was situated atop Warren Peak in the Bearlodge Mountains six miles from Sundance, Wyoming. Because of the remote location, the reactor had to be modular and prefabricated prior to shipment. The Martin Company near Baltimore, Maryland, used highly skilled operators and factory equipment to manufacture the plant. The reactor design included flanged interconnections to allow quick disconnect for disassembly, packaging, transport and reassembly at the field site. The C130 aircraft airlifted 16 identical shipping containers to Rapid City, South Dakota. Large trucks then transported the parts 93 miles to the station. Reactor operations personnel reassembled the prefabricated components into a complete operating reactor, rather than requiring construction crews. The reactor operated using a unified control console rated with reliability at 99.45%. The plant needed only one person to monitor the plant and control auxiliary equipment. Another worker performed a roving tour of the equipment, continually inspecting the working parts. More advanced versions of PM-1 were considered, such as liquid-metal cooled reactors and gas cooled reactors that could operate at higher temperatures. Portable reactors also included the SM-1 in Virginia (1957), PM-2A in Greenland (start up in 1960), PM-3A in Antarctica (1962 )SM-1A in Alaska (1962), and the STURGIS floating power plant (MH-1A) in the Canal Zone in Panama (1967). The U.S. Air Force and Army Nuclear Power Program recognized that any increase in capital cost for PM-1 was justifiably overridden by its high reliability— especially, where a large amount of high-quality electric power is needed. PM-1 fuel supported operations for two years before the reactor needed refueling. The pre-existing diesel generator was used as a secondary power source. Today’s microreactors require further technical development and rigorous regulatory approvals before deployment. However, learning from successful applications like PM-1 shows the art of the possible. https://inl.gov/feature-story/hold-on... Credit: DOE, National Archives The appearance of U.S. Department of Defense (DoD) visual information does not imply or constitute DoD endorsement.