@inproceedings{0e4510d9b640469599f1367bf85f54bd,

title = "Assessment of thermal-hydraulic feedback models",

abstract = "VERA-CS is an advanced core simulator currently being developed by the Consortium for the Advanced Simulation of Light Water Reactors (CASL) that is used to perform reactor depletion calculations. The neutronics calculations are performed by the transport code MPACT to determine 3D pin-resolved power distributions. MPACT is coupled to the sub-channel thermal-hydraulic (TH) code CTF, which provides feedback to MPACT by way of fuel and moderator temperature and moderator density. In addition to the CTF coupling, a Simplified TH solver was also implemented in MPACT. This solver can use assembly, node (quarter-assembly), or channel sized meshes for ID coolant flow calculations. Steady-state simulations of Watts Bar Unit 1 were then conducted with each of the three Simplified TH models and compared with the coupled MPACT-CTF calculations. The boron concentration for each Simplified TH model was less than 2 ppm different from the MPACT-CTF result. All three meshing approaches gave an RMS pin power difference of 0.7% or less and RMS fuel temperature difference of 2.35 °C or less, but the channel model performed the best with pin power and fuel temperature RMS differences of 0.13% and 0.67 °C, respectively. Additionally, use of the Simplified TH models reduced runtime by more than a factor of 2 compared with the coupled MPACT-CTF solution.",

keywords = "CASL, CTF, MPACT, Th feedback",

author = "Aaron Graham and Thomas Downar and Benjamin Collins and Robert Salko and Scott Palmtag",

year = "2016",

language = "English",

series = "Physics of Reactors 2016, PHYSOR 2016: Unifying Theory and Experiments in the 21st Century",

publisher = "American Nuclear Society",

pages = "3616--3626",

booktitle = "Physics of Reactors 2016, PHYSOR 2016",

note = "Physics of Reactors 2016: Unifying Theory and Experiments in the 21st Century, PHYSOR 2016 ; Conference date: 01-05-2016 Through 05-05-2016",

}