Use of a Real-Time RELAP5 Model to Dynamically Test a Digital Feedwater Control System for a Boiling Water Reactor

Abstract

A RELAP5/MOD3.1 model of a boiling water reactor and an interface are developed as a real-time test platform for a physical feedwater control system and turbine governors. The reactor plant modeled is Browns Ferry unit 2. The model is used to test and tune the new digital reactor feedwater control system (RFWCS) for units 2 and 3. The set of modeled components, trips, and controls is determined based on the testing requirements for the RFWCS.

The work is performed in two phases. In the first phase, the existing plant is modeled, including the previously existing analog feedwater control system and governor. The resulting RELAP5 model is benchmarked against existing plant data. Benchmarking results are presented along with data on initialization to steady state.

Once the benchmarking effort is completed, the control systems in the model are altered to allow testing of the digital RFWCS in real time. An interface is developed to allow communications with the digital RFWCS and operator interaction, which allows the test platform to be used to determine control system response to various transients. Descriptions of the RELAP5 model and hardware and software for the interface are provided.