SNAP 8 Reactor Test Program

The SNAP 8 reactor is a heat source suitable for long endurance 10 to 50 kw space electric power supplies. The major milestones in the development of this reactor are three ground tests: the SNAP 8 Experimental Reactor (S8ER), the SNAP 8 Developmental Reactor Mockup (S8DRM), and the SNAP 8 Developmental System (S8DS). The S8ER test was completed in April 1965 after 500 days of nuclear operation. S8ER demonstrated long-term operation of the SNAP 8 reactor by operating for 1 year at thermal power levels in the range 400 to 600 kwt with a 1300° F coolant NaK outlet temperature. This test included a continuous run of 5000 hours. The continuous operation of S8ER was due in part to a facility reliability upgrading undertaken to minimize unnecessary test interruptions caused by instrumentation malfunctions or electrical disturbances at the test site. The second SNAP 8 reactor, S8DRM, has undergone a series of nonnuclear tests to verify the performance of the automatic startup and control drive system, and to determine the reactor´s environmental capabilities (e.g., shock, vibration, vacuum, and temperature). The third SNAP 8 reactor test, S8DS, will start nuclear operation late in 1966. The objective of this test is to verify the SNAP 8 flight reactor design, and to operate the reactor coupled to a power conversion system.