Detectability prediction for a thermoacoustic sensor in the breazeale nuclear reactor pool

Open Access
Hrisko, Joshua Eric
Graduate Program:
Master of Science
Document Type:
Master Thesis
Date of Defense:
February 08, 2016
Committee Members:
  • Steven Lurie Garrett, Thesis Advisor
  • acoustics
  • thermoacoustics
  • sensors
  • breazeale
  • nuclear
  • reactor
  • signal processing
  • vibration
  • frequency
  • detection
  • radiation
Laboratory experiments have suggested that thermoacoustic engines can be incorporated within nuclear fuel rods. Such engines would radiate sounds that could be used to measure and acoustically-telemeter information about the operation of the nuclear reactor (e.g., coolant temperature or fluxes of neutrons or other energetic particles) or the physical condition of the nuclear fuel itself (e.g., changes in temperature, evolved gases) that are encoded as the frequency and/or amplitude of the radiated sound [IEEE Measurement and Instrumentation 16(3), 18-25 (2013)]. For such acoustic information to be detectable, it is important to characterize the vibroacoustical environments within reactors. Measurements will be presented of the background noise spectra (with and without coolant pumps) and reverberation times within the 70,000 gallon pool that cools and shields the fuel in the 1 MW research reactor on Penn State’s campus using two hydrophones, a piezoelectric projector, and an accelerometer. Several signal-processing techniques will be demonstrated to enhance the measured results. Background vibrational measurement were also taken at the 250 MW Advanced Test Reactor, located at the Idaho National Laboratory, using accelerometers mounted outside the reactor’s pressure vessel and on plumbing will also be presented. The detectability predictions made in the thesis were validated in September 2015 using a nuclear fission-heated thermoacoustic sensor that was placed in the core of the Breazeale Nuclear Reactor on Penn State’s campus. Some features of the thermoacoustic device used in that experiment will also be revealed. [Work supported by the U.S. Department of Energy.]