Pradeep Ramuhalli

Profile Information
Name
Dr. Pradeep Ramuhalli
Institution
Oak Ridge National Laboratory
h-Index
ORCID
0000-0001-6372-1743
Expertise
Cable Degradaiton, Data Analytics, Diagnostics, Prognostics
Publications:
"Irradiation Testing of Ultrasonic Transducers" Joshua Daw, Gordon Kohse, Joe Palmer, Pradeep Ramuhalli, Brian Reinhardt, Joy Rempe, Bernhard Tittmann, Robert Montgomery, Jean-Francois Villard, H. T. Chien, ANIMMA 2013 Special Edition, IEEE Transactions on Nuclear Science Vol. 61 2013 1-7 Link
Ultrasonic technologies offer the potential for high accuracy and resolution in-pile measurement of numerous parameters, including geometry changes, temperature, crack initiation and growth, gas pressure and composition, and microstructural changes. Many Department of Energy-Office of Nuclear Energy (DOE-NE) programs are exploring the use of ultrasonic technologies to provide enhanced sensors for in-pile instrumentation during irradiation testing. For example, the ability of single, small diameter ultrasonic thermometers (UTs) to provide a temperature profile in candidate metallic and oxide fuel would provide much needed data for validating new fuel performance models. Other efforts include an ultrasonic technique to detect morphology changes (such as crack initiation and growth) and acoustic techniques to evaluate fission gas composition and pressure. These efforts are limited by the lack of existing knowledge of ultrasonic transducer material survivability under irradiation conditions. To address this need, the Pennsylvania State University (PSU) was awarded an Advanced Test Reactor National Scientific User Facility (ATR NSUF) project to evaluate promising magnetostrictive and piezoelectric transducer performance in the Massachusetts Institute of Technology Research Reactor (MITR) up to a fast fluence of at least 1021 n/cm2 (E> 0.1 MeV). This test will be an instrumented lead test; and real-time transducer performance data will be collected along with temperature and neutron and gamma flux data. By characterizing magnetostrictive and piezoelectric transducer survivability during irradiation, test results will enable the development of novel radiation tolerant ultrasonic sensors for use in Material and Test Reactors (MTRs). The current work bridges the gap between proven out-of-pile ultrasonic techniques and in-pile deployment of ultrasonic sensors by acquiring the data necessary to demonstrate the performance of ultrasonic transducers.
"Progress towards developing neutron tolerant magnetostrictive and piezoelectric transducers" Brian Reinhardt, Bernhard Tittmann, Joy Rempe, Joshua Daw, Gordon Kohse, David Carpenter, Michael Ames, Yakov Ostrovsky, Pradeep Ramuhalli, Robert Montgomery, Hualte Chien, Bernard Wernsman, AIP Conference Proceedings Vol. 1650 2015 1512-1520 Link
Current generation light water reactors (LWRs), sodium cooled fast reactors (SFRs), small modular reactors (SMRs), and next generation nuclear plants (NGNPs) produce harsh environments in and near the reactor core that can severely tax material performance and limit component operational life. To address this issue, several Department of Energy Office of Nuclear Energy (DOE-NE) research programs are evaluating the long duration irradiation performance of fuel and structural materials used in existing and new reactors. In order to maximize the amount of information obtained from Material Testing Reactor (MTR) irradiations, DOE is also funding development of enhanced instrumentation that will be able to obtain in-situ, real-time data on key material characteristics and properties, with unprecedented accuracy and resolution. Such data are required to validate new multi-scale, multi-physics modeling tools under development as part of a science-based, engineering driven approach to reactor development. It is not feasible to obtain high resolution/microscale data with the current state of instrumentation technology. However, ultrasound-based sensors offer the ability to obtain such data if it is demonstrated that these sensors and their associated transducers are resistant to high neutron flux, high gamma radiation, and high temperature. To address this need, the Advanced Test Reactor National Scientific User Facility (ATRNSUF) is funding an irradiation, led by PSU, at the Massachusetts Institute of Technology Research Reactor to test the survivability of ultrasound transducers. As part of this effort, PSU and collaborators have designed, fabricated, and provided piezoelectric and magnetostrictive transducers that are optimized to perform in harsh, high flux, environments. Four piezoelectric transducers were fabricated with either aluminum nitride, zinc oxide, or bismuth titanate as the active element that were coupled to either Kovar or aluminum waveguides and two magnetostrictive transducers were fabricated with Remendur or Galfenol as the active elements. Pulse-echo ultrasonic measurements of these transducers are made insitu. This paper will present an overview of the test design including selection criteria for candidate materials and optimization of test assembly parameters, data obtained from both out-of-pile and in-pile testing at elevated temperatures, and an assessment based on initial data of the expected performance of ultrasonic devices in irradiation conditions.
"Updated Results of Ultrasonic Transducer Irradiation Test" Joshua Daw, Gordon Kohse, Joe Palmer, Brian Reinhardt, Joy Rempe, Pradeep Ramuhalli, Paul Keller, Robert Montgomery, Hual-Te Chien, Bernhard Tittmann, Jean-Francois Villard, ANIMMA - Institute of Electrical and Electronics Engineers Vol. 2015 Link
Ultrasonic technologies offer the potential for high accuracy and resolution in-pile measurement of a range of parameters, including geometry changes, temperature, crack initiation and growth, gas pressure and composition, and microstructural changes. Many Department of Energy-Office of Nuclear Energy (DOE-NE) programs are exploring the use of ultrasonic technologies to provide enhanced sensors for in-pile instrumentation during irradiation testing. For example, the ability of small diameter ultrasonic thermometers (UTs) to provide a temperature profile in candidate metallic and oxide fuel would provide much needed data for validating new fuel performance models. These efforts are limited by the lack of identified ultrasonic transducer materials capable of long term performance under irradiation test conditions. To address this need, the Pennsylvania State University (PSU) was awarded an Advanced Test Reactor National Scientific User Facility (ATR NSUF) project to evaluate the performance of promising magnetostrictive and piezoelectric transducers in the Massachusetts Institute of Technology Research Reactor (MITR) up to a fast fluence of at least 10{sup 21} n/cm{sup 2}. A multi-National Laboratory collaboration funded by the Nuclear Energy Enabling Technologies Advanced Sensors and Instrumentation (NEET-ASI) program also provided initial support for this effort. This irradiation, which started in February 2014, is an instrumented lead test and real-time transducer performance data are collected along with temperature and neutron and gamma flux data. The irradiation is ongoing and will continue to approximately mid-2015. To date, very encouraging results have been attained as several transducers continue to operate under irradiation.
Presentations:
"Irradiation Testing of Ultrasonic Transducers" Joshua Daw, Gordon Kohse, Joe Palmer, Pradeep Ramuhalli, Brian Reinhardt, Joy Rempe, Bernhard Tittmann, 2013 Conference on Advancements in Nuclear Instrumentation, Measurements Methods (ANIMMA 2013) June 23-27, (2013)
"Microstructural Characterization of Irradiated U0.17ZrH1.6 Using Ultrasonic Techniques" Pradeep Ramuhalli, 2017 ANS Annual Meeting June 11-15, (2017)
NSUF Articles:
DOE Awards 33 Rapid Turnaround Experiment Research Proposals - Projects total approximately $1.5 million These projects will continue to advance the understanding of irradiation effects in nuclear fuels and materials in support of the mission of the DOE Office of Nuclear Energy. Monday, May 14, 2018 - Calls and Awards
DOE Awards Eight CINR NSUF Projects - Projects include $3M in access grants and R&D funding Monday, July 6, 2020 - Calls and Awards