ML-1 was an experimental nuclear reactor built as part of the US Army Nuclear Power Program between 1961 and 1965. It was intended to provide truck-mounted nuclear power that could accompany troops from place to place and provide power to command and communication centers, evacuation hospitals, depots, and radar and weapons systems.[1]: 99
Unlike the other seven reactors of this program, it did not use a steam turbine, but instead used a nitrogen coolant at 315 pounds per square inch (2,170 kPa) to drive a closed-cycle gas turbine. It was designed to produce 3.3 MWthermal of heat and 400 kW of shaft horsepower with an outlet temperature of 1,200 °F (649 °C).[2]
Though the concept of a nitrogen closed cycle gas turbine was strong, the design failed to live up to expectations, and was abandoned with the closure of ML-1 in 1965 after several major refits and with only a few hundred hours of testing completed in all. Similar concepts have been more recently proposed as part of the PBMR program as derivatives thereof.
A 1964 economic analysis concluded that the overall cost of purchasing and operating the ML-1 for a period of 10 years would be about ten times that of a comparable diesel plant at normal fuel costs.[3]