Feed systems and nozzles for Phoebus reactor experiments.

Abstract

In support of the Phoebus IB and Phoebus 2A reactor experiments, an advanced and unique liquid-hydrogen feed system was designed, developed, and placed in successful operation at Test Cell C, Nuclear Rocket Development Station (NRDS). The system's configuration features two axial-flow liquid-hydrogen pumps, each powered by a five-stage axial-flow turbine, which may be operated singly or in parallel depending upon the flow requirements of the reactor experiment. The turbodrive gases are obtained by diverting a small portion of the pump discharge flow through a hot-water heat exchanger. They are then metered to each turbine by a common turbine control valve in response to an integrated turbopump speed/facility flow demand control system. Liquid-hydrogen bypass valves for each pump discharge duct are integrated into automatically controlled, specific-speed-limit systems to provide control of system discharge impedance under conditions of rapidly changing reactor propellant flow. The system's discharge pressure and flow capabilities range to 2000 psig and 35,000 gal/min. The nozzle requirements of the Phoebus 1 series of reactor experiments were satisfied by modifying and uprating the nozzles employed in the Kiwi reactor experiments. By improving the coolant passage design and by strengthening the reactor shell mounting flange, the operating capabilities of the nozzle were increased to more than satisfy the thermal and radiationinduced heating loads associated with the Phoebus 1 reactor tests.