Development, Verification, and Validation of an Advanced Systems Code KP-SAM for Kairos Power Fluoride Salt–Cooled High-Temperature Reactor (KP-FHR)

To meet the Kairos Power (KP) Fluoride Salt-Cooled High-Temperature Reactor (FHR) (KP-FHR) development and commercialization schedules, the System Analysis Module (SAM), which is an advanced systems code for Generation IV liquid-cooled reactors developed at Argonne National Laboratory (ANL), has been selected as the basis for the development of the KP-FHR systems code KP-SAM. This allows for an accelerated joint development effort between the KP and ANL teams. This paper presents a general overview of the KP-SAM development process, its current status, completed verification, and ongoing validation efforts. KP-SAM development follows the U.S. Nuclear Regulatory Commission Evaluation Model Development and Assessment Process framework. SAM is a high-order fully implicit transient systems code written in C++. The SAM software design, major physical models, and Jacobian Free Newton Krylov–based numerical methods are briefly discussed. KP-SAM has matured enough to be used for the unvalidated demonstration safety analysis for the low-power KP-FHR test reactor (Hermes) as part of Preliminary Safety Analysis Report work. By following the guidance of an internal KP-FHR thermal fluid Phenomena Identification and Ranking Table report, some of the most important separate-effects-test validations were completed for the first iteration. A scaled integral-effects test is under detailed design and will be built in 2022 to provide key data to validate KP-SAM for licensing safety analysis.