PNNL

Abstract

This paper summarizes the design process for high temperature ultrasonic phased array transducers for imaging in liquid sodium at temperatures up to 260C. The project is funded by the USDOE Generation IV Reactor Program and includes collaboration with the Japanese Atomic Energy Agency. The transducer system is being designed to be able to provide images inside a sodium cooled fast reactor, to support operation and maintenance activities including potentially location of looseor damaged parts during service outages. The prototype transducer array is being designed for 8 to 16, 3MHz rectangular lead niobate (K-81) or bismuth titanate (K-15) piezoelectric elements spaced at ?/2 (wavelength in sodium). A nickel or nickel alloy faceplate serves as the sodium wetting surface. Scan angle of the focused ultrasonic beam is ±30 degrees. Imaging spatial resolution is = 1mm. The array is designed to be operated using a commercial phased array control system and it is planned that array testing will be performed in room temperature water, hot oil (260C), and molten sodium (260C).