High-Temperature Gas-Cooled Pebble-Bed Reactors Running In And Transient Modeling Capabilities Demonstration
- Idaho National Laboratory (INL), Idaho Falls, ID (United States)
- Argonne National Laboratory (ANL), Argonne, IL (United States)
This study presents a comprehensive benchmarking and verification effort of several thermal-hydraulic and multiphysics capabilities for high-temperature gas-cooled reactor (HTGR) applications. The first part of this effort focuses on the running-in verification of Griffin's multiphysics capabilities, specifically for simulating the evolution of Pebble Bed reactor cores from startup to equilibrium. In the absence of validation data, code-to-code comparisons are conducted with Kugelpy, showing good agreement for key quantities like maximum power density and fresh core k-eigenvalue predictions. However, discrepancies in equilibrium core predictions suggest potential issues with cross sections, underscoring the need for further refinement and evaluation. The HTTF system analysis code benchmark involves RELAP5-3D, SAM, and GAMMA+ to assess their predictive capabilities for HTTF behavior under both normal operation and pressurized conduction cooldown (PCC) transient conditions. While there is good agreement in predicting major parameters such as coolant temperature, solid temperature, and flow distribution, discrepancies in transient behavior highlight differences in modeling approaches, nodalizations, and heat transfer models. The HTTF lower plenum CFD benchmark employs nekRS to simulate flow mixing phenomena, successfully capturing relevant flow physics and demonstrating mesh independence in complex geometries. Preliminary results suggest a relatively uniform temperature field but significant unsteadiness in the flow, requiring time-averaging analyses. The GPBR200 system analysis code benchmark uses SAM's core channel and porous media models, incorporating an RCCS loop for decay heat removal. During steady-state and transient conditions, including protected de-pressurized and pressurized loss of forced cooling (DLOFC and PLOFC), both models show good agreement in predicting temperature profiles and key parameters. Notably, while the core channel model underpredicts convective heat transfer effects, both models maintain temperatures well below the TRISO fuel safety limit. These benchmarking efforts collectively enhance the predictive capabilities of the tools used in HTGR design and safety analysis, guiding developments to improve their accuracy and applicability.
- Research Organization:
- Idaho National Laboratory (INL), Idaho Falls, ID (United States); Argonne National Laboratory (ANL), Argonne, IL (United States)
- Sponsoring Organization:
- USDOE Office of Nuclear Energy (NE), Nuclear Energy Advanced Modeling and Simulation (NEAMS)
- DOE Contract Number:
- AC07-05ID14517; AC02-06CH11357
- OSTI ID:
- 2474862
- Report Number(s):
- INL/RPT--24-80533-Rev000; ANL/NSE--24/63
- Country of Publication:
- United States
- Language:
- English
Similar Records
High-Temperature Gas-Cooled Reactors Multiphysics Simulation Demonstration and Code Validation
Code Benchmark of the HTTF Pressurized Conduction Cooldown Test Using SAM
Multi-Physics System-level Simulations of a Generic Pebble Bed High-Temperature Gas Cooled Reactor with Coupled SAM/Griffin Model
Technical Report
·
Mon Sep 01 00:00:00 EDT 2025
·
OSTI ID:2997226
Code Benchmark of the HTTF Pressurized Conduction Cooldown Test Using SAM
Journal Article
·
Sun Apr 16 20:00:00 EDT 2023
· Nuclear Science and Engineering
·
OSTI ID:2378034
Multi-Physics System-level Simulations of a Generic Pebble Bed High-Temperature Gas Cooled Reactor with Coupled SAM/Griffin Model
Technical Report
·
Sat Jul 01 00:00:00 EDT 2023
·
OSTI ID:1994383