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We report on the development of a novel, continuous-flow, radially focused ultrasonic disruptor capable of lysing Bacillus spores in the absence of added chemical denaturants, enzymes, or microparticles. Greater than 99% disruption was achieved for Bacillus globigii spores and Escherichia coli and Bacillus subtilis vegetative cells with sample residence times of 62, 12, and 12 s, respectively. Microscopic and SEM images indicated that at equivalent power levels, the incidence of cell death or loss of viability typically exceeded the efficiency of (visible) cell lysis. However, semiquantitative PCR showed up to a 1,000-fold increase in intracellular DNA availability from ultrasonically disrupted spores, and liberated DNA was intact and available for subsequent detection.

Executive SummaryThis current report is a summary of information obtained in the "Information Capture" task of the U.S. DOE-funded "Under Sodium Viewing (USV) Project." The goal of the multi-year USV project is to design, build, and demonstrate a state-of-the-art prototype ultrasonic viewing system tailored for periodic reactor core in-service monitoring and maintenance inspections. The study seeks to optimize system parameters, improve performance, and re-establish this key technology area which will be required to support any new U.S. liquid-metal cooled fast reactors.The earliest information presented herein dates from the early 1970s when the DOE Hanford Site and Argonne National Laboratory were supporting instrumentation development for sodium-cooled fast reactors (SFRs). The most recent U.S. advanced liquid metal reactor (ALMR) design was the Power Reactor Innovative Small Module (PRISM). The U.S.-sponsored design effort was discontinued in 1995; however, General Electric (GE) continued development up to year 2000. A number of other countries (especially India, Japan, France, and Great Britain) have built and operated fast, metal-cooled reactors and supporting diagnostic instrumentation for in-service inspections. Piezoelectric transducers have been reported in systems used to: (i) acquire in-core images; (ii) perform ultrasonic NDE inspections; and (iii) measure liquid sodium levels, detect structural anomalies, and detect leaks.This study has served to identify important design parameters and options for an ultrasonic USV system. These include:1. The preferred piezoelectric material for liquid sodium temperatures up to 260°C is lead zirconate titanate (PZT). Higher Curie temperature (T c ) materials such as lithium niobate and lead metaniobate have also been used.2. Most demonstrated USV ultrasonic transducers are of the direct sodium immersion type. Only a few designs use an ultrasonic waveguide to isolate the transducer from the molten sodium.3. Poor sodium wetting of the transducer face has been an issue. Degraded wetting results in inefficient mechanical (acoustic) coupling between the transducer and the liquid sodium working fluid. Solutions have required either coating the transducer face (e.g., with evaporated or sputtered gold) or bonding a metal diaphragm to the transducer face (e.g., stainless steel or nickel).4. Thermal shock damage to the piezoelectric transducer is an important issue. Fracture of piezoelectric ceramics due to high thermal gradients/transients or thermal expansion mismatches at the transducer face or backing layer must be considered early in the design process.5. Cable length between the transducer and ultrasonic transceiver has a major impact on received signal amplitude. The minute electrical charges generated by the piezoelectric transducer dictate use of lowcapacitance, radiation-resistant, high-temperature cables, and cable length must be kept as short as possible. Impedance matching and signal conditioning must be considered.6. To date, most ultrasonic USV systems have ...

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