Neutronic Design of the AMPS Reactor Core

Abstract

The Autonomous Marine Power Source (AMPS) is a nuclear-electric power plant designed for submarine application. The necessarily compact AMPS reactor ( 1) is water-cooled and fuelled with uranium-zirconium-hydride (U-ZrH1.6) eutectic alloy, clad in stainless steel. Erbium burnable neutron poison is incorporated in the fuel matrix to meet the design fuel burnup lifetime requirement while avoiding the need for more than an operating margin of excess reactivity. The reactor heat source (HHS) of the prototype AMPS plant supplies 1500 kWt to a low-temperature organic Rankine cycle energy conversion unit (ECU) which in turn generates 100 kWe, net. This paper describes the reactor physics studies performed in the AMPS reactor core design process.