Publications

Operation of a closed Brayton cycle using simulated reactivity feedback

Conboy, Thomas M.; Radel, R.F.; Carlson, Matthew D.; Wright, Steven A.

This paper describes the modeling and initial operations of a reactivity feedback control system for an electric heater operating within a low pressure closed Brayton cycle. Modeling was carried out using Simulink, converted to a dynamic-linked library in RealTime Workshop, and interfaces with the Brayton cycle hardware through an 800MHz CompactRIO controller and its custom LabView set-up. Experimentally measured temperatures of the operating Brayton loop are used by the model to calculate average fuel and coolant temperatures for a simulated reactor core, which in turn govern feedback to electrical heating elements within the loop. Coupled with the reactivity controller, this laboratory-scale Brayton system operates with a heat source that has the feedback characteristics of a nuclear reactor core. This capability is being developed for space reactor transient analysis in support of NASA's FSP (Fission Surface Power) technology.