Simulation of the High Temperature Test Facility (HTTF) Core Using the 2D Ring Model with SAM

Abstract

A two–dimensional ring model is developed with SAM to model the core of the High Temperature Test Facility (HTTF) at the system level. The ring model simplifies the complex structure of the HTTF core by converting the hexagonal rows of heaters and flow channels into layers of concentric annular rings. The ring model is first compared against a three–dimensional (3D)–one–dimensional (1D) model where the solid structures are fully resolved in three dimensions while the fluid structures are modeled as 1D flows. Comparison between the 3D–1D and the ring models shows that the latter can predict major parameters reasonably well under steady–state normal operating conditions, but the heater temperatures are under predicted. Adjustment is made to the effective thermal conductivity of the ceramic core of the ring model to improve the heater temperature predictions. The ring model is also used to simulate a transient pressurized conduction cooldown condition and is benchmarked with the experimental data from the HTTF Test PG–27. Good agreement is obtained between the experimental data and the predictions by the ring model.

Keywords:

• High–temperature gas–cooled reactor
• system–level modeling
• ring model, SAM

Acknowledgments

This work is supported by the DOE NE’s NEAMS program. The submitted manuscript has been created by UChicago Argonne, LLC, operator of Argonne National Laboratory (Argonne). Argonne, a DOE Office of Science laboratory, is operated under contract no. DEAC02-06CH11357.

Disclosure Statement

No potential conflict of interest was reported by the author(s).

Notes

^a The GIF uses the very-high-temperature reactor (VHTR) for such reactor types. However, the original targeted core outlet temperature has been reduced from ~1000°C to 700°C to 950°C, and thus in this paper we will use the HTGR to represent the general concept.