A Rapid Procedure Development Approach for Multi-stage Validation of Novel Nuclear Power Plant Systems

The integration of renewable energy sources into the modern grid introduces variability in generation, challenging nuclear reactors to remain economically viable amid low wholesale electricity prices. To address this, Idaho National Laboratory's Flexible Plant Operation and Generation program explores alternative revenue streams, including commoditizing excess thermal energy. A Thermal Power Dispatch (TPD) system enables steam extraction from the secondary loop for industrial uses like hydrogen production via high-temperature steam electrolysis. This study utilized two full-scope simulators based on a standard Westinghouse three-loop pressurized water reactor: GSE Solutions' Generic Pressurized Water Reactor (GPWR), developed on the SimExec and JADE platforms, and another using a European development platform through collaboration with a nuclear vendor. Both simulators implemented similar TPD designs and supported operational requirements evaluation through multistage validation. Rapid iterative design cycles refined operations, human-machine interfaces (HMI), and procedures via operator scenario testing. A flexible procedure development process accommodated rapid HMI prototype changes across both simulators, maintaining realism for operator immersion. Unlike traditional methods, procedures were developed in parallel with the concept of operations and HMI design. This approach supports advanced reactor designs, where drastically different operations require rapid, iterative procedure development. The study demonstrates the feasibility of this process for emerging nuclear technologies, enhancing operational flexibility and competitiveness in a renewable-dominated energy landscape. Additionally, standardized two-column procedure guidelines, modeled after Westinghouse practices and DOE/NUREG-0899 standards, were developed to support this approach.