CFD Model Development and validation for High Temperature Gas Cooled Reactor Cavity Cooling System (RCCS) Applications

Abstract

The Reactor Cavity Cooling System (RCCS) is a passive safety system that will be incorporated in the VTHR design. The system was designed to remove the heat from the reactor cavity and maintain the temperature of structures and concrete walls under desired limits during normal operation (steady-state) and accident scenarios. A small scale (1:23) water-cooled experimental facility was scaled, designed, and constructed in order to study the complex thermohydraulic phenomena taking place in the RCCS during steady-state and transient conditions. The facility represents a portion of the reactor vessel with nine stainless steel coolant risers and utilizes water as coolant. The facility was equipped with instrumentation to measure temperatures and flow rates and a general verification was completed during the shakedown. A model of the experimental facility was prepared using RELAP5-3D and simulations were performed to validate the scaling procedure. The experimental data produced during the steady-state run were compared with the simulation results obtained using RELAP5-3D. The overall behavior of the facility met the expectations. The facility capabilities were confirmed to be very promising in performing additional experimental tests, including flow visualization, and produce data for code validation.

High-Temperature Gas-Cooled Reactor Research Survey and Overview: Preliminary Data Platform Construction for the Nuclear Energy University Program

“…This showed that the RCCS performance via natural circulation is sufficient for heat loss in accident scenarios. Adapted from [30].…”

“…Figure 11. Facility shakedown experimental results compared to the RELAP5-3D simulations.Adapted from[30].…”

Status Report on the Water-Based NSTF RCCS Capability: Preparations and Design for the Transformation of the Natural Convection Shutdown Heat Removal Test Facility (NSTF) From Air to Water-based Cooling

“…The designs proposed stem from existing work at US Universities for water-cooled RCCS [1,2], and input from AREVA for their 625 MW t SC-HTGR [3]. The US Universities collaborated with the air-based program at ANL, and thus used a similar reactor reference of the GA-MHTGR.…”

“…With the estimated volume of water storage tank just having 10 times of networking piping, tank dimensions are obtained for given height to diameter ratio of 2, which was used in previous experimental facilities of similar kinds from Texas A&M University and University of Wisconsin-Madison[1,2]. The estimated dimensions for water storage tank are summarized in Table…”