The Gallium Thermal Hydraulic Experiment (GaTE) facility was designed by Co-PI Bindra and his team as a scaled-down model of an Advanced Breeder Test Reactor and is equipped with high-fidelity flow (Ultrasonic Doppler Velocimetry) and temperature (ODiSI-B) measurement systems. Some components of this facility are designed based on the scaling analysis of thermal transients in liquid-metal-cooled reactors. There are four main components of this facility: an electrically heated core, a moving magnet pump to circulate gallium, two heat exchanger/cooling loops, and an upper plenum. This experimental facility has been used to generate benchmark data for validating computer models and has the capability of emulating expected transients within a liquid metal reactor. This facility is ideal for obtaining surface thermal signature data and validating models and machine learning algorithms.

Co-PI Bindra's team has modified the existing experimental facilities to develop a scaled setup for a pebble bed-type high-temperature gas-cooled reactor. The main components of the test setup are the pressure vessels, which can operate under the prototypic conditions of the Xe-100 (Advanced Reactor Demonstration Project) under the development pebble bed type HTGR. There are two pressure vessels with dimensions of 7 feet and 2 feet. Pebbles of two different sizes (approximately 6 cm and 3 cm) as well as two different materials (graphite G-348 and alumina) can be used as a fuel or moderator surrogate. Other than the reactor vessel, the main components include a helium compressor, secondary heat removal systems, and helium pre-heaters. The system is designed to study design-based events under different conditions that result in the loss of forced circulation. The main tests performed within this facility are pressurized and depressurized conduction cooling. Pebble beds can be heated by introducing pre-heated hot gas into the vessel and resistive cartridge heaters. The existing vessel can house approximately 19000 (3-cm graphite) pebbles.

The Luna ODiSI system senses temperatures and stress levels using fiber optics in conjunction with a tunable laser source. The technology consists of distributed optical fibers that utilize Rayleigh scattering to sense small defects in each fiber's construction. The defects cause a difference in the index of refraction, creating Rayleigh backscattering at the location of these defects. These backscattering profiles are produced using a Mach-Zehnder interferometer. Sensors are aligned along the fibers in an array pattern. Using interference frequencies found from the coherent optical frequency domain reflectometry (c-OFDR) technique, the changes in sensor length are then proportional to the frequency created. Sensors are identified based on a keyed profile, and when a match is found, the stored spectrum is used as a base for all other values to measure in the spectrum.

The Ultrasonic Doppler Velocimetery (UDV) system has been installed and commissioned at the GaTE facility at PU. The UDV system is based on the principles of acoustic backscattering and is performing its intended function to measure velocity fields in the scaled outlet plenum. The system has three main components:
a) a DOP4000 pulsed velocimeter;
b) high temperature transducer probes; and
c) 2D/3D UDV software.

Note that UDV is the only measurement technique. established thus far for obtaining velocity field data in liquid metals. UDV can be used for flow field measurements in other opaque flow systems, such as blood flow.

The Thermo Scientific Multi-Gas analyzer, Model 60i, utilizes non-dispersive infrared (NDIR) optical filter technology to measure five gases in addition to an oxygen measurement via either chemical cell or paramagnetic technology. CO CO2 NO NO2 SO2 O2. The Model 60i is the only gas analyzer with built-in safeguards to protect the instrument from moisture damage. The 60i utilizes a low sample flow rate that reduces the amount of maintenance required due to the high particulate and moisture loading on optical surfaces. The analyzer also continuously measures moisture and can shut off the sample pump by activating an alarm before high levels of moisture damage the sensitive components.