Nuclear reactors create a harsh environment for fuel and structural components as they operate at high temperatures and high irradiation and have corrosive components. Precise monitoring of the reactor’s environment is an ever-present need for the long-term operation and stability of the reactor. The knowledge of the exact conditions is crucial for studying the degradation of fuel and components and improving their performance. There is a need to create novel sensing solutions to study and record the real-time conditions in and out of the pile in the reactor to study microstructure, chemistry, mechanical, and other property changes when subjected to irradiation. The temperature range of interest for the fuel and structural component community varies significantly, depending on the reactor technology evaluated. However, radiation hardness and survivability at high temperatures are two critical requirements of any technology proposed for monitoring temperature in such harsh environments. Optical sensors have the advantage of being immune to electromagnetic radiation and are ideally suited for the nuclear environment. Due to their small size, these sensors can easily be embedded within structures and components, providing crucial data regarding their performance and structural integrity. However, commercial silica-based optical sensors encounter radiation-induced attenuation, emission, and contraction and require novel engineering techniques to improve their signal reliability. This talk will present the advantages, challenges, and novel approaches of using optical fiber sensors inside a nuclear reactor.
Biography: Dr. Nirmala Kandadai is an Assistant Professor in the Department of Electrical and Computer Engineering at Oregon State State University. She completed her Ph.D. at The University of Texas at Austin in 2012, studying the interaction of high-intensity lasers with molecular gas clusters. After her Ph.D., she worked for a year as a postdoctoral fellow at The University of Texas at Austin, working on improving the contrast of a Petawatt laser system, and then 3 years as a Laser Scientist at the National energetics. At National Energetics, she led her team in designing and building high-power ultrafast laser systems, including the front end of a 10 PW laser system for the European Union’s Extreme Light Infrastructure Beamlines facility (ELI-Beamlines). She was in Boise as a Research Assistant Professor in 2016 and as a tenure track Assistant professor since 2019. She started the IEEE WIE Boise section in 2020 and was the chair of the IEEE WIE Boise section from 2020 -2022. She was awarded Idaho accomplished under 40 awards in 2022 for her work in promoting young girls and women in STEM. She moved to Oregon State in 2022 as an Assistant Professor. At Oregon State, she is the director of the fiber optics laser and integrated research lab (FLAIR). Her current research work includes laser-matter interactions, sensors for extreme environments, infrared thermography, thermal conductivity, laser sintering, and plasma modeling. She is currently an IEEE senior member.