kairos power LLC

partnered with

Argonne National Laboratory and Idaho National Laboratory

NEams [nuclear energy advanced modeling and simulation] thermalfluids test stand for fluoride-salt-cooled, high-temperature reactor development, RFA-17-14580

YEAR AWARDED: FY-2017

TOTAL PROJECT VALUE: $500K ($400K DOE funds awarded, $100K awardee cost share)

STATUS: Completed

PRINCIPAL LAB INVESTIGATORS: Elia Merzari ([email protected]); Rich Martineau (INL retired)

DESCRIPTION: Argonne National Laboratory (ANL), Idaho National Laboratory (INL), and Kairos Power, LLC partnered to implement a multiscale thermal-fluids hierarchy analysis methodology for Kairos’ fluoride high-temperature reactor (FHR). The project demonstrated Kairos Power’s design optimization process for the heat exchanger, a vital component of the reactor’s design. ANL performed high-fidelity simulations of Kairos’ heat exchanger design at different spatial scales. Simulations using Nek5000, an open-source computational fluid dynamic code developed under the Nuclear Energy Advanced Modeling and Simulation program analyzed the heat and fluid flow in twisted tube heat exchangers. Software design improvements were implemented in the System Analysis Module (SAM) with the ultimate goal of providing a reliable thermal-fluid system simulator for FHRs. INL implemented additional efforts to improve the software compatibility between SAM and RELAP-7 and to bring SAM in line with the Multiphysics Object-Oriented Simulation Environment (MOOSE) Software Quality Assurance Plan. A prototype-coupled simulation was performed for a simplified tank loop. Based on the MOOSE multi-app framework, this prototype-coupled code will constitute the basis of future work in this area.

BENEFIT: Plant-scale physics (SAM) informed by the lower-length scale (Nek5000) can significantly improve solution accuracy and reduce uncertainty when using the software in a predictive sense where little to no empirical data is available.

IMPACT: This collaborative process between INL, ANL, and Kairos resulted in multiscale, multiphysics advances for FHR concepts and other advanced reactor concepts. Forming a team that worked cooperatively using the same simulation tools resulted in a shared ownership of the tools.

LESSONS LEARNED: Improved cooperation among DOE laboratories enhanced industry partners’ confidence in relying on DOE for developing advanced modeling and simulation tools.

NEXT STEPS: Incorporating the Griffin application environment’s use into reactor physics and radiation transport should be straightforward, as both INL and ANL are developing Griffin. Including Griffin will allow the state-of-the-art calculations to be performed on most advanced reactors incorporating single-phase coolants. Finally, the BISON nuclear fuel performance code can be coupled to the system to evaluate long-term fuel phenomena, such as irradiation damage and creep.