A novel ultrasonic waveguide transducer (UWT) has been developed for undersodium inspection of sodium-cooled fast reactor (SFR). Its performance was evaluated and compared with other four types of waveguide designs. The signal transmission efficiency and detection sensitivity has been greatly improved. The preliminary results in molten sodium demonstrate that our novel ultrasonic waveguide transducer is able to achieve 1 mm lateral resolution and 0.5 mm vertical resolution in molten sodium with temperature ranged from 300°F to 650°F.

In this report, we first present the basic design of a low--noise waveguide and its performance followed by a review of the array transducer technology. The report then presents the concept and basic designs of arrayed waveguide transducers that can apply to under--sodium viewing for in--service inspection of fast reactors. Depending on applications, the basic waveguide arrays consist of designs for sideway and downward viewing. For each viewing application, two array geometries, linear and circular, are included in design analysis. Methods to scan a 2--D target using a linear array waveguide transducer are discussed. Future plan to develop a laboratory array waveguide prototype is also presented.

This report summarizes the first year research and development effort leading to development of high--temperature sensors for enhanced geothermal systems. It covers evaluation of ultrasonic and electromagnetic (EM) techniques applied to temperature measurement and flow characterization. On temperature measurement, we have evaluated both microwave radiometry and ultrasonic techniques for temperature gradient and profile measurements. Different antenna designs are evaluated and array loop antenna design is selected for further development. We have also evaluated ultrasonic techniques for total flow characterization, which includes using speed of sound to determine flow temperature, measuring acoustic impedance to estimate fluid density, and using cross--correlation technique to determine the mass flow rate. Method to estimate the flow enthalpy is briefly discussed. At end, the need and proposed techniques to characterize the porosity and permeability of a hot dry rock resource are presented.Waveguide--based ultrasonic and far--field electromagnetic sensors for downhole reservoir characterization ANL--10/34 ii Waveguide--based ultrasonic and far--field electromagnetic sensors for downhole reservoir characterization ANL--10/34 iii