Research
Wireless Sensors
Wireless sensors that can function in a nuclear reactor offer significant advantages over wired sensors by eliminating the need for feedthroughs penetrating pressure barriers. This work focuses on a novel approach to develop inductive coupling and active or passive sensors that can measure parameters of interest such as displacement, pressure, temperature, etc.
​
We are performing lab breadboard development, room temperature system experiments, high temperature furnace testing, and prototype testing in water, liquid metal and high temperature sodium. Computational modeling for system design, performance optimization, sensitivity and uncertainty assessment, and noise reduction measures are conducted using the ANSYS multiphysics software.
Photothermal Techniques for Material Thermomechanical Properties
Optical techniques are being developed and used in determining thermomechanical properties at different length scales. We have measurement systems that use optical reflectance, optical pyrometry and IR spectrometer detections. These techniques are applied to samples at different length scales to simultaneously determine the thermal conductivity and heat capacity, measure in-plane and cross-plane thermal conductivities, and quantify interfacial energy transfer.
​
Frequency domain thermoreflectance (FDTR) and spatial domain thermal reflectance (SDTR) are being developed for Focused Ion Beam (FIB) fabricated nano-scale samples of irradiated materials. We are also developing innovative thermal wave techniques for reactor experiments.
High Frequency Photothermal Radiometry for Interface Energy Transfer
Accurate measurement of thermal properties is essential in understanding how electronics will function in different environments. This becomes increasingly difficult as electronics grow ever smaller.
​
PhotoThermalRadiometry (PTR) is a technique for measuring thermal properties of the film and interface by using a modulated laser to heat a sample and detect the infrared response.
​
We have designed, build, and tuned an experimental system for performing and measuring transient heat transfer and are currently pursuing various functionalities to expand its use. This work is an ongoing collaboration with Universite de Reims Champagne-Ardenne, where students spend a year abroad for joint research.
Predictive Plant Maintenance using Machine Learning and AI
The ever-increasing digitization of nuclear power industry and the rapid development of data science and technology have made data-driven health management increasingly important for future plant operations. The predictive maintenance technology represented by the prognostic health management will enhance component/system service life and significantly reduce operational cost for plants.
This work is focused on the in-depth mining and analysis of nuclear power systems or equipment operation monitoring data by using advanced machine learning techniques, such as Bayesian networks and deep neural networks. This research is a collaboration with Westinghouse, the Idaho National Laboratory, and Dr. Dan Cole’s research group.
Electromagnetic Sensors
Electromagnetic sensors can be used to measure and monitor the change of physical parameters, such as liquid metal flow, liquid metal level, displacement, pressure and strain. These type of sensors can perform non-intrusive measurements in extreme environments, such as in a nuclear reactor.
​
We are developing various types of electromagnetic sensors for application in liquid metal coolants. The work involves computational simulation of sensor performance, optimization of sensor design, sensor fabrication, laboratory experiments in Galinstan flow, and eventual testing in test reactors. Research collaborators include the Oakridge National Laboratory, Los Alamos National Laboratory, DOE Idaho National Laboratory, Argonne National Laboratory, and University of New Mexico.
Transient Boiling Heat Transfer
Pressurized water reactors run at a pressure of 155 bar, where water boils around 345 °C. Boiling only becomes a concern during an accident. For reactor safety analysis, understanding the transient boiling behavior is critical for new types of fuels being developed.
​
We conduct transient boiling experiments under various design parameters (water temperature and pressure, heating pulse width, heating pulse magnitude, and water velocity) with an autoclave system that corresponds to pressured water reactor conditions. This work is a collaboration with the Transient Reactor Test Facility at the Idaho National Laboratory, University of New Mexico, University of South Carolina, Texas A&M University, and Idaho State University.
Measuring Fuel Thermal Properties Using a Transient Reactor
An understanding of the changes in nuclear fuel thermal properties as a function of fuel burnup is essential for the design, operation and safety of nuclear power plants. However, there is a critical data gap for irradiated metallic fuels for advanced reactors. This project uses an innovative technique to determine high burnup fuel thermal diffusivity while keeping irradiated fuel and cladding intact.
​
We are developing a thermal wave method for metal fuel testing in the Transient Reactor Test Facility at the Idaho National Laboratory. The irradiated fuels from the Experimental Breeder Reactor II program are to be used to determine the effect of burnup on fuel thermal performance. This work is a collaboration with DOE Idaho National Laboratory and the University of Florida.
Gap conductance between inert gases and solids by molecular dynamics simulation
Thermal energy accommodation between inert gas molecules, such as helium, and a solid surface, such as cladding material and fuel is essential for energy transport efficiency. The gap conductance is a controlling factor impacting the design and safety of nuclear fuels.
​
We study the mechanisms affecting the thermal energy accommodation coefficient between an inert gas and solid nuclear materials and provide an efficient way to evaluate the energy transport performance and understand how the scattering process affects the energy and momentum accommodation.
THERMAL AND THERMOELECTRIC TRANSPORT STUDIES OF CORRELATED ELECTRONIC PHASES IN Quantum Wires
Understanding the quantum nature of matter in 1D electronic systems will be helpful in understanding the fundamental nature of multi-component fermionic quantum matter, and for synthesizing new and exotic quantum phases that may help form the basis for new quantum simulation and/or computing platforms.
​
We are exploring the thermal and thermoelectric transport properties of quantum nanowires at ultralow temperatures <0.1 K and in strong magnetic fields up to 18 T in collaboration with Prof. Jeremy Levy's group in the Department of Physics, University of Pittsburgh.
Optical Fiber Bundle Technique for Imaging
The ability to obtain image and video data of sample behavior in reactor experiments offers a suite of parameter measurement possibilities. We are designing and testing an optical method to be used in the Transient Reactor Test Facility at the Idaho National Laboratory.
​
This research is to provide unique visual data under harsh temperature, pressure, and radiation environments within a test chamber located inside the core. By using a high-resolution fiberscope inside a 3D printed mockup, light can be directed out of the harsh environment and into the custom built high speed camera’s sensor. The work involves prototype development and demonstration, uncertainty quantification, and feedthrough innovation. The Idaho National Laboratory is a collaborator of this project.
