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 (ATR-NSUF) 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 in-situ. 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